Xinlin Yang

Tumor targeted hollow double-layered polymer nanoparticles (HDPNs) with S-nitrosothiols for nitric oxide (NO)-release as chemotherapy were described. Via a two-stage distillation precipitation co-polymerization, simple post-treatment and S-nitrosothiol modification, the S-nitroso HDPNs showed pH and glucose dual responsiveness. This would benefit accurate binding with the sialic acid over-expressed cancer cells, providing prerequisites for the disulfide polymer assisted cell uptake, intracellular GSH induced decomposition and rapid NO release. Confocal microscopy and cytotoxicity assay with normal versus tumor cells demonstrated in vitro recognition, intracellular delivery ability and tumor cell targeting cytotoxicity. Especially worth mentioning, the inevitable small amount of NO leakage in the transmission would take part in normal physiological activities and not cause serious side effects, providing a possible solution to avoid the intolerable side effects of traditional chemotherapy treatments for cancer.

Functional polymer microspheres as “turn-off” chemosensors for detection of copper cations

Co-reporter:Mengmeng Zhang;Xiaowei Si;Dehao Jiang;Yan Lu

Colloid and Polymer Science 2017 Volume 295( Issue 12) pp:2383-2393

Publication Date(Web):25 October 2017

DOI:10.1007/s00396-017-4209-3

Functional polymer microspheres with fluorescent carbazole unit and various functional groups, such as amide, pyridyl, and imidazole, were prepared by distillation precipitation copolymerization of divinylbenzene (DVB) as a crosslinker, N-vinylcarbazole (NVCz), together with acrylamide (AAm), 4-vinylpyridine (VPy), and 1-vinylimidazole ((VIM) as functional monomers in acetonitrile in the absence of any stabilizer. The resultant polymer microspheres were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, photoluminescent spectroscopy, inductively coupled plasma (ICP), and X-ray photoelectron microscopy (XPS). The functional polymer microspheres acted as a “turn-off” chemical sensor with excellent stability for determination of copper cation (Cu2+) in methanol via the quenching effect of fluorescence after adsorption of Cu2+ from the solution through the capture ability of functional groups, such as pyridyl, imidazole, and amide on the surface of polymer microspheres. A good linear relationship was set up between the photoluminescence intensity at the emission peak of 352 nm and the Cu2+ concentrations ranging from 0 to 1.0 μM with the presence of pyridyl group as a ligand. The effects of the functional groups were investigated on the fluorescent response for the microspheres as chemical sensors.

Double shelled hollow SnO2/polymer microsphere as a high-capacity anode material for superior reversible lithium ion storage

Co-reporter:Meijun Zhou, Yongchang Liu, Jun Chen and Xinlin Yang

Journal of Materials Chemistry A 2015 vol. 3(Issue 3) pp:1068-1076

Publication Date(Web):10 Nov 2014

DOI:10.1039/C4TA05235H

Double shelled hollow tin dioxide/poly(ethyleneglycol dimethacrylate-co-methacrylic acid) (SnO2/P(EGDMA-co-MAA)) microspheres were prepared by selective removal of the silica inner core via etching with hydrofluoric acid from the corresponding SiO2/SnO2/P(EGDMA-co-MAA) tri-layer microspheres. These tri-layer microspheres were synthesized using a combination of the modified Stöber method for the silica inner core, a hydrothermal technique for the sandwiched SnO2 layer and distillation precipitation polymerization for the coated P(EGDMA-co-MAA) shell-layer. The double shelled hollow microspheres were utilized as anode materials for lithium ion batteries, which had a significantly enhanced cycling performance compared to when neat SnO2 hollow spheres were used.

Hollow double-layered polymer microspheres with pH and thermo-responsive properties as nitric oxide-releasing reservoirs

Co-reporter:Tuanwei Liu, Wei Zhang, Tao Song, Xinlin Yang and Chenxi Li

Polymer Chemistry 2015 vol. 6(Issue 17) pp:3305-3314

Publication Date(Web):18 Mar 2015

DOI:10.1039/C5PY00001G

Nitric oxide (NO)-releasing hollow double-layered polymer microspheres (HDPMs) with both pH- and thermo-responsive properties in aqueous media are designed and prepared by a multi-step process. Hollow double-shelled polymer microspheres with secondary amino groups are prepared by distillation precipitation copolymerization of N-isopropylacrylamide (NIPAAm) with 2-(dimethylamino)ethyl methacrylate (DMAEMA) and EGDMA in the presence of SiO2/P(2-(ethyl(boc)amino)ethyl methacrylate (bocAmEMA)-co-EGDMA) core–shell microspheres as seeds to obtain SiO2/P(bocAmEMA-co-EGDMA)/P(EGDMA-co-DMAEMA-co-NIPAAm) tri-layered microspheres with subsequent removal of the silica core by hydrogen fluoride aqueous solution and deprotection of secondary amino groups with CF3CO2H. Hollow polymer microspheres with N-diazeniumdiolated NO donors are prepared by the reaction between secondary amino groups of hollow P(AmEMA-co-EGDMA)/P(EGDMA-co-DMAEMA-co-NIPAAm) microspheres and high pressure of NO (5.0 atm) under basic conditions (CH3ONa). The resulting microspheres are systematically characterized by TEM, FT-IR, TGA, elemental analysis and dynamic laser scattering (DLS). The final N-diazeniumdiolated hollow double-shelled microspheres show a controlled NO release behavior dependent on pH and temperature in the environments.

Silica/polymer microspheres and hollow polymer microspheres as scaffolds for nitric oxide release in PBS buffer and bovine serum

Co-reporter:Tuanwei Liu, Dongwei Zhang, Xinlin Yang and Chenxi Li

Polymer Chemistry 2015 vol. 6(Issue 9) pp:1512-1520

Publication Date(Web):02 Dec 2014

DOI:10.1039/C4PY01326C

This work reports the design, preparation and characterization of functional polymer microspheres as a reservoir for nitric oxide (NO)-release. Silica/polymer core–shell microspheres and the corresponding hollow functional polymer microspheres with secondary amino groups were converted to N-diazeniumdiolate as scaffolds for nitrogen oxide (NO) release. The silica/polymer core–shell microspheres were prepared by a multi-step procedure, which involves the synthesis of functional 2-(ethyl(boc)amino)ethyl methacrylate (bocAmEMA) monomers with boc-protected secondary amine sites, distillation precipitation polymerization of ethyleneglycol dimethacrylate and boc-protected co-monomers with the presence of 3-(methacryloxy)propyltrimethoxysilane (MPS)-modified silica nanoparticles as seeds, de-protection of the amino sites, and subsequent reaction between the secondary amino and NO under high pressure (5.0 atm) in the presence of sodium methoxide. The corresponding hollow polymer microspheres were prepared via the selective removal of the silica core from the silica/polymer core–shell microspheres with a hydrofluoride (HF) aqueous solution and the subsequent conversion to N-diazeniumdiolate NO donors via exposure to a high pressure of NO (5.0 atm) under basic conditions. The hollow microspheres with secondary amino groups exhibited a high storage capacity for NO (up to 5.5 μmol NO/mg), greatly increasing that of NO from the corresponding silica/polymer core–shell donors (3.6 μmol NO/mg). Both the silica/polymer and hollow polymer scaffolds are shown to release NO for extended periods of time with an ‘apparent’ t1/2 value of 35 min (silica/polymer scaffolds; PBS buffer), 10 min (hollow polymer scaffolds; PBS buffer), 19 min (hollow polymer scaffolds; bovine serum), and release durations of 24 h via the proton initiated diazeniumdiolate decomposition to give off NO spontaneously under physiological conditions.

Hollow polymer nanoparticles with S-nitrosothiols as scaffolds for nitric oxide release

Co-reporter:Tuanwei Liu, Wei Zhang, Xinlin Yang, Chenxi Li

Journal of Colloid and Interface Science 2015 Volume 459() pp:115-122

Publication Date(Web):1 December 2015

DOI:10.1016/j.jcis.2015.08.011

This work reported the design, preparation and characterization of functional hollow polymer nanoparticles with S-nitrosothiol (SNO) as scaffolds for nitric oxide (NO) release in PBS buffer and bovine serum. The thiolated hollow polymer nanoparticles were prepared by distillation precipitation polymerization of ethyleneglycol dimethacrylate (EGDMA) and 2-hydroxyethyl methacrylate (HEMA) in presence of 3-(methacryloxy)propyltrimethoxysilane (MPS)-modified silica as seeds and the selective removal of silica core in hydrofluoric acid (HF) aqueous solution together with the subsequent surface esterification of hydroxyl groups with acryloyl chloride to introduce high density of vinyl groups and further Michael addition of carbon–carbon double bonds with hydrosulfide (HS−) anions. S-Nitrosothiol (SNO) functionalized hollow polymer nanoparticles were prepared via nitrosation of the surface thiol groups with acidified nitrite. The releasing characters of SNO-functionalized hollow polymer nanoparticles as NO scaffolds with capacity of 1.55 μmol/mg were investigated in different media, including PBS buffer exposure to trace copper cations and in real bovine serum.Functional hollow polymer nanoparticles with S-nitrosothiol (SNO) were synthesized as scaffolds for nitric oxide (NO) release in PBS buffer and bovine serum.

Synthesis of 1D Fe3O4/P(MBAAm-co-MAA) nanochains as stabilizers for Ag nanoparticles and templates for hollow mesoporous structure, and their applications in catalytic reaction and drug delivery

Co-reporter:Wei Zhang, Xiaowei Si, Bin Liu, Guomin Bian, Yonglin Qi, Xinlin Yang, Chenxi Li

Journal of Colloid and Interface Science 2015 Volume 456() pp:145-154

Publication Date(Web):15 October 2015

DOI:10.1016/j.jcis.2015.06.028

One-dimensional (1D) magnetic Fe3O4/P(MBAAm-co-MAA) nanochains were prepared by distillation–precipitation polymerization of MBAAm and MAA in the presence of Fe3O4 nanoparticles as building blocks under a magnetic heating stirrer, which played two critical roles: serving as magnetic field to induce the self-assembly of Fe3O4 nanoparticles into 1D nanochains and providing thermal energy to induce the polymerization of MAA and MBAAm on the surface of the Fe3O4 nanoparticles. The thickness of the P(MBAAm-co-MAA) layer can be easily tuned by adjusting the successive polymerization steps. The polymer layer that contained carboxyl groups was used as stabilizers for loading Ag nanoparticles and the reaction locus for deposition of outer silica layer via a sol–gel method in presence of C18TMS as the pore directing agent for tri-layer nanochains. The corresponding hollow mesoporous silica nanochains with movable maghemite cores (γ-Fe2O3@mSiO2) were produced after removal of the polymer mid-layer and the alkyl groups of the pore directing agent via calcination of the tri-layer nanochains at high temperature. The Fe3O4/P(MBAAm-co-MAA)/Ag nanochains exhibited a highly catalytic efficiency and well reusable property toward the reduction of nitrophenol. Furthermore, the γ-Fe2O3@mSiO2 nanochains possessed hollow mesoporous structure and high specific surface area (197.2 m2 g−1) were used as a drug carrier, which displayed a controlled release property.

Synthesis of poly(methacrylic acid)–manganese oxide dihydroxide/silica core–shell and the corresponding hollow microspheres

Co-reporter:Shuxuan Sun, Bin Liu, Xiaomeng Fu, Meijun Zhou, Wei Liu, Guomin Bian, Yonglin Qi, Xinlin Yang

Journal of Colloid and Interface Science 2015 Volume 438() pp:269-276

Publication Date(Web):15 January 2015

DOI:10.1016/j.jcis.2014.09.051

•Synthesis of poly(methacrylic acid)–MnO(OH)2/SiO2 microspheres.•Synthesis of Mn2O3/mesoporous silica double-shelled hollow microspheres.•Transferring the morphology of Mn2O3/m-SiO2 into Braunite-1Q via calcination.Poly(methacrylic acid)–MnO(OH)2/SiO2 core–shell microspheres were prepared by sol–gel hydrolysis of tetraethylorthosilicate (TEOS) in the presence of poly(methacrylic acid)–Mn(II) (PMAA–Mn2+) as template with ammonium hydroxide anion as catalyst and n-octadecyltrimethoxysilane (C18TMS) as pore-directing reagent. The PMAA–Mn2+ core was prepared by incubation of Mn2+ cations with PMAA microspheres via the coordination between carboxylate anion group on PMAA microsphere and Mn2+ cations. During this process, the Mn(II) species were formed as white Mn(OH)2 precipitates at first, which were subsequently oxidized into brown MnO(OH)2 in air. The Mn2O3/mesoporous silica (Mn2O3/m-SiO2) double-shelled hollow microspheres (DSHMs) were prepared through calcination of the PMAA–MnO(OH)2/SiO2 core–shell microspheres at 600 °C for the selective removal of PMAA template and pore-directing organic component from C18TMS, during which the crystalline structure of DSHM was developed into Braunite-1Q via the reaction between Mn2O3 inner-shell and silica outer-shell by annealing the DSHMs under higher temperatures of 800 and 900 °C. The Mn2O3 hollow microspheres (HMs) were prepared through the selective removal of the silica layer from the DSHMs by sodium hydroxide aqueous solution, which exhibited structure integrity and good ethanol dispersity due to the presence of mesoporous structure.

Preparation of magnetic molecularly imprinted polymer beads and their recognition for baicalein

Co-reporter:Song Wang, Bing Wang, Huitong Si, Juanjuan Shan and Xinlin Yang

RSC Advances 2015 vol. 5(Issue 11) pp:8028-8036

Publication Date(Web):17 Dec 2014

DOI:10.1039/C4RA13418D

Magnetite–β-cyclodextrin@poly(ethyleneglycol dimethacrylate-co-methacrylic acid) core–shell microspheres imprinted with baicalein (Fe3O4–β-CD@MIPs) were synthesized by ultrasonic assisted precipitation polymerization (UAPP) using methacrylic acid (MAA) as a functional monomer and EGDMA as a crosslinker in the presence of Fe3O4–β-CD nanoparticles as the template and baicalein (BAI) as the imprinting molecule. The structure, morphology and magnetic properties of the resultant Fe3O4–β-CD@MIPs have been systematically characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM), and thermogravimetric analysis (TGA). The unique recognition ability of Fe3O4–β-CD@MIPs for BAI was evaluated by the adsorption experiments via comparing those of Fe3O4@MIPs and Fe3O4–β-CD@NIPs non-imprinted nanoparticles.

Enhanced water retention and proton conductivity of proton exchange membranes by incorporating hollow polymer microspheres grafted with sulfonated polystyrene brushes

Co-reporter:Wei Zhang, Bei Zhang, Guangwei He, Bin Liu, Zhongyi Jiang, Xinlin Yang and Chenxi Li

RSC Advances 2015 vol. 5(Issue 7) pp:5343-5356

Publication Date(Web):04 Dec 2014

DOI:10.1039/C4RA13582B

Hollow polymer microspheres grafted with sulfonated polystyrene brushes (HPSS) were synthesized via a combination of surface-initiated atom transfer radical polymerization (SI-ATRP) of styrene from SiO2@P(MAA-co-DVB-co-CMSt) core–shell microspheres, sulfonation of the polystyrene brushes, and final removal of the silica core. These HPSSs were then incorporated into a sulfonated poly(ether ether ketone) (SPEEK) matrix to fabricate hybrid membranes. As a comparison, SPEEK/HPS hybrid membranes were prepared by incorporation of sulfonated hollow polymer microspheres (HPS) into a SPEEK matrix. Water retention, methanol resistance and proton conductivity were increased by doping with both kinds of hollow polymer microspheres. The SPEEK/HPSS hybrid membranes exhibited much higher proton conductivity than did the SPEEK/HPS hybrid membranes with the same filler contents ranging from 2.5 to 15 wt%. The highest conductivity was obtained at 0.33 S cm−1 for SPEEK/HPSS under 75 °C and 100% relative humidity (RH), which was 83.3% higher than that (0.18 S cm−1) for a SPEEK control membrane under the same conditions. The increment in proton conductivity was mainly attributed to the large cavities of HPSS acting as water reservoirs, and the excellent flexibility and high accessibility of the sulfate groups (–SO3H) on the surface grafted polymer brushes, which provide proton hopping sites for proton-conducting pathways. Moreover, the hybrid membranes exhibited good thermal and mechanical stability.

Raspberry-like particles via the heterocoagulated reaction between reactive epoxy and amino groups

Co-reporter:Tao Song, Tuanwei Liu, Xinlin Yang, Feng Bai

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2015 Volume 469() pp:60-65

Publication Date(Web):20 March 2015

DOI:10.1016/j.colsurfa.2015.01.016

•Synthesis of P(DVB-co-GMA)-NH2@SiO2/P(DVB-co-GMA) particles.•Raspberry-like particles via heterocoagulated reaction.•Heterocoagulated reaction between epoxy and amino groups.•Superhydrophilicity of polycarbonate film coated with raspberry-like particles.The core–corona polymer hybrid particle with a raspberry-like structure was prepared by a heterocoagulation through the chemical reaction between the epoxy groups of silica/poly(divinylbenzene-co-glycidyl methacrylate) (SiO2/P(DVB-co-GMA)) core–shell small microspheres and the amino groups of amino-modified poly(divinylbenzene-co-glycidyl methacrylate) (P(DVB-co-GMA)-NH2) microspheres, in which SiO2/P(DVB-co-GMA) acted as the corona and P(DVB-co-GMA)-NH2 behaved as the core. The film of resultant raspberry-like hybrid particles with dual-size structure had an average contact angle (CA) of 141.8°, indicating great prospects in the super-hydrophobic applications. The resultant polymer microspheres and raspberry like particles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform spectra (FT-IR), elemental analysis (EA) and contact angle system (CA).

Synthesis of monodisperse magnetic sandwiched gold nanoparticle as an easily recyclable catalyst with a protective polymer shell

Co-reporter:Wei Zhang, Bin Liu, Bei Zhang, Guomin Bian, Yonglin Qi, Xinlin Yang, Chenxi Li

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2015 Volume 466() pp:210-218

Publication Date(Web):5 February 2015

DOI:10.1016/j.colsurfa.2014.11.055

•Magnetic sandwiched gold nanoparticles have been synthesized.•The amino group on Fe3O4–NH2 played dual functions during the synthesis.•Fe3O4@Au/polyethyleneglycol dimethacrylate was recycled under magnetic field.•Magnetic sandwiched gold nanoparticles had a stable catalytic activity.Monodisperse magnetic sandwiched magnetite@gold/poly(ethyleneglycol methacrylate) (Fe3O4@Au/PEGDMA) core–shell microspheres were designed and prepared. The whole synthetic procedure mainly involved hydrothermal method for preparation of magnetite core with subsequent modification of (3-aminopropyl)trimethoxysilane (APS) for introduction of the surface amino groups, distillation precipitation polymerization for preparation of the P(EGDMA) shell and in situ reduction of gold precursor HAuCl4 for formation of the sandwiched Au nanoparticles. The thicknesses of the outer polymeric shells were well-controlled via altering the weight ratios of EGDMA monomers to magnetite core during polymerization. The catalytic activity of the sandwiched Fe3O4-Au@P(EGDMA) magnetic microsphere was studied by the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AnP) as a model reaction. These magnetic microspheres were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared spectra (FT-IR), thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM).A magnetic Fe3O4@Au/PEGDMA microsphere with a magnetite core, a permeable polymer shell and the sandwiched gold nanoparticles exhibited a stable and readily recoverable catalytic activity.

Preparation of polymer microspheres with reactive epoxy group and amino groups as stabilizers for gold nanocolloids with recoverable catalysis

Co-reporter:Tao Song;Meijun Zhou;Wei Liu;Guomin Bian;Yonglin Qi

Colloid and Polymer Science 2015 Volume 293( Issue 1) pp:187-197

Publication Date(Web):2015 January

DOI:10.1007/s00396-014-3408-4

Narrow disperse poly(divinylbenzene-co-glycidyl methacrylate) (P(DVB-co-GMA)) microspheres with reactive epoxy group were prepared by distillation precipitation copolymerization of divinylbenzene (DVB) and glycidyl methacrylate (GMA) with benzoyl peroxide (BPO) as initiator in neat acetonitrile. The epoxy group was modified with ethylenediamine (EDA) for transferring to amino group, which was used as a stabilizer for the gold metallic nanocolloids during the in situ reduction of gold chloride trihydrate (HAuCl4) with sodium borohydride (NaBH4) as a reductant. The catalytic properties of the microsphere-stabilized gold nanocolloids (P(DVB-co-GMA)-NH2@Au) were investigated by the reduction of aqueous 4-nitrophenol (4-NP) to 4-aminophenol (4-AnP) with NaBH4 as reductant. The resultant microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectra (FT-IR), elemental analysis (EA), Zeta potential, X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP) mission spectrum, and ultraviolet–visible spectroscopy.

Synthesis of multifunctional microspheres having polymer brush with magnetism, fluorescence, and pH-responsiveness

Co-reporter:Tuanwei Liu;Bin Liu;Xiaomeng Fu;Shuxuan Sun;Wei Liu

Colloid and Polymer Science 2015 Volume 293( Issue 3) pp:809-816

Publication Date(Web):2015 March

DOI:10.1007/s00396-014-3469-4

Multifunctional magnetite@silica-fluorescein isothioxylate-g-poly(dimethyl amino ethyl methacrylate) (Fe3O4@SiO2-FITC-g-PDMAEMA) tri-layer microspheres with magnetism, fluorescence, and pH-responsive PDMAEMA shell were designed and prepared. The functional PDMAEMA brush was grafted from Fe3O4@SiO2-FITC nanoparticles by the surface-induced atom transfer radical polymerization (SI-ATRP) onto the alkylbromide-modified Fe3O4@SiO2-FITC fluorescent templates, which were synthesized by the co-precipitation of Fe(II) and Fe(III) under basic condition together with the subsequently modified Stöber sol–gel technique. These nanoparticles were characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), fluorescence spectrum, dynamic light scattering (DLS), and zeta potentials.

Folic acid-conjugated pH/temperature/redox multi-stimuli responsive polymer microspheres for delivery of anti-cancer drug

Co-reporter:Rongrong Li, Fuli Feng, Yinsong Wang, Xiaoying Yang, Xinlin Yang, Victor C. Yang

Journal of Colloid and Interface Science 2014 Volume 429() pp:34-44

Publication Date(Web):1 September 2014

DOI:10.1016/j.jcis.2014.05.008

•Synthesis of P(MAA-co-BAC)/P(NIPAAm-co-BAC)-FA microspheres.•Characterization of the functional core–shell microspheres.•pH/temperature/redox multi-stimuli responsive controlled drug release character.The folic acid (FA)-conjugated pH/temperature/redox multi-stimuli responsive poly(methacrylic acid-co-N,N-bis(acryloyl)cystamine/poly(N-isopropylacrylamide-co-glycidyl methacrylate-co-N,N-bis(acryloyl)cystamine) microspheres were prepared by a two-stage distillation–precipitation polymerization with subsequent surface modification with FA. The microspheres were characterized by transmission electron microscopy, dynamical light scattering, Fourier-transform infrared spectra, UV–vis spectra and elemental analysis. The degradation of the functional microspheres could be triggered by a reductive reagent, such as glutathione, due to presence of BAC crosslinker. The drug-loaded microspheres exhibited a pH/temperature/redox multi-stimuli responsive drug release character for doxorubicin hydrochloride as a model anti-cancer drug, which was efficiently loaded into the microspheres with a high loading capacity of 208.0% and an encapsulation efficiency of 85.4%. In vitro drug delivery study indicated that the FA-conjugated microspheres could deliver Dox into MCF-7 cells more efficiently than the microspheres without functionalization of FA. Furthermore, WST-1 assay showed that the microspheres had no obvious toxicity to MCF-7 cells even at a high concentration of 2000 μg mL−1. The resultant microsphere may be a promising vector for delivery of anti-cancer drugs as it exhibits a low cytotoxicity and degradability, precise molecular targeting property and multi-stimuli responsively controlled drug release.Graphical abstract

Preparation of P(MBA-co-MAA)/Zr(OH)4/P(EGDMA-co-MAA)/TiO2 Tetra-layer Hybrid Microspheres and the Corresponding ZrO2/TiO2 Double-shelled Hollow Microspheres

Co-reporter:Dianbin Qin;Jinhui Yu;Guomin Bian;Yonglin Qi;Dongwei Zhang

Chinese Journal of Chemistry 2014 Volume 32( Issue 2) pp:163-171

Publication Date(Web):

DOI:10.1002/cjoc.201300676

Abstract

Double-shelled zirconia/titania (ZrO₂/TiO₂) hollow microspheres were prepared by the selective removal of the polymer components via the calcination of the corresponding tetra-layer poly(N,N′-methylenebisacryl amide-co-methacrylic acid) (P(MBA-co-MAA))/Zr(OH)₄/poly(ethyleneglycol dimethacrylate-co-methacrylic acid) (P(EGDMA-co-MAA))/TiO₂ hybrid microspheres. These tetra-layer microspheres were synthesized by the combination of the distillation copolymerization of N,N(-methylenebisacryl amide-co-methacrylic acid (MBA) or ethyleneglycol dimethacrylate (EGDMA) crosslinker and methacrylic acid (MAA) for the preparation of polymer core and third-layer as well as the controlled sol-gel hydrolysis of inorganic precursors for the construction of zirconium hydroxide (Zr(OH)₄) and titania (TiO₂) layers. The thicknesses of zirconia and titania shell-layers were conveniently controlled via varying the feed of zirconium n-butoxide (Zr(OBu)₄) and titanium tetrabutoxide (TBOT) during the sol-gel hydrolysis, while the sizes of polymer layers were tuned through a multi-stage distillation precipitation copolymerization. The structure and morphology of the resultant microspheres were characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), X-ray photoelectronic spectroscopy (XPS), and thermogrametric analysis (TGA).

Silica-g-poly[2-(N,N-dimethyl amino) ethyl methacrylate] hybrid nanospheres with polymer brushes as stabilizer for metallic nanocolloids

Co-reporter:Bin Liu, Shuxuan Sun, Zhenbo Gao, Dongwei Zhang, Guomin Bian, Yonglin Qi, Xinlin Yang, Chenxi Li

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 456() pp:195-202

Publication Date(Web):20 August 2014

DOI:10.1016/j.colsurfa.2014.05.037

•Preparation of SiO2-g-PDMAEMA nanospheres with polymer brushes.•Preparation of SiO2-g-PDMAEMA stabilized metallic nanocolloids.•Catalytic property of the supported catalyst in aqueous system.The silica-g-poly[2-(N,N-dimethyl amino)ethyl methacrylate] (SiO2-g-PDMAEMA) hybrid microspheres with polymer brushes were synthesized by the surface-grafted atom transfer radical polymerization (ATRP) from the surface alkyl bromide functionalized silica nanospheres. The inorganic nanosphere as surface-initiating polymerization site was prepared by the amide reaction of 2-bromoisobutyryl bromide with the surface amino group of silica via modification with (3-aminopropyl) trimethoxysilane (APS). The grafted PDMEMA brushes stabilized metallic nanocolloids (silver and palladium) were prepared by the in situ reduction of the inorganic salt precursors (AgNO3 and PdCl2) through the coordination effect of the amino groups to the metallic atom (Au, Ag). The catalytic properties of PDMAEMA brush-stabilized silver and palladium metallic nanocolloids were investigated via the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AnP) by sodium borohydride (NaBH4) as a model reaction with a facilely recoverable and stable catalytic property. The resultant hybrid microspheres were characterized by transmission electron microscopy (TEM), thermal gravimetric analyzer (TGA), Fourier infrared (FT-IR) spectra, and inductive coupled plasma emission spectrum (ICP).Preparation of SiO2-g-PDMAEMA nanospheres as stabilizer for metallic nanocolloids (M = Ag, Pd).

Preparation of reduction-triggered degradable microcapsules for intracellular delivery of anti-cancer drug and gene

Co-reporter:Fuli Feng, Rongrong Li, Qingyun Zhang, Yinsong Wang, Xiaoying Yang, Hongquan Duan, Xinlin Yang

Polymer 2014 Volume 55(Issue 1) pp:110-118

Publication Date(Web):14 January 2014

DOI:10.1016/j.polymer.2013.11.035

The reduction-triggered degradable poly(methacrylic acid-co-N,N-bis(acryloyl)cystamine)/polyethyleneimine (P(MAA-co-BAC)/PEI) microcapsules were prepared by distillation–precipitation polymerization for delivery of anti-cancer drug and gene. N,N-bis(acryloyl)cystamine (BAC) as a crosslinker containing a disulfide bond can be triggered by reductive agents, such as glutathione (GSH) and dithiothreitol (DTT), to endow the functional microcapsules with reduction-triggered drug release. The P(MAA-co-BAC)/PEI microcapsules were characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectra (FT-IR), laser particle size analyzer and elemental analysis. The degradable behavior of microcapsules was investigated by analysis of UV-vis spectroscopy. The controlled drug release behavior for P(MAA-co-BAC)/PEI microcapsules was strongly dependent on the absence/presence of GSH and the pH values with doxorubicin hydrochloride (DOX) as a model drug molecule. The in vitro gene transfection ability was evaluated by Hela cells with the transfection of plasmid DNA (pDNA) encoded with green fluorescent protein (GFP) and the transfection efficiency was determined by confocal fluorescence microscopy. Furthermore, the cytotoxicities of (P(MAA-co-BAC)/PEI) microcapsules before and after loading of DOX were assessed via WST-1 assay. The P(MAA-co-BAC)/PEI microcapsules provide the potential novel vectors for delivery of drugs and genes, promising for future applications in anticancer drug and gene combined therapy.

Enhanced water retention and stable dynamic water behavior of sulfonated poly(ether ether ketone) membranes under low humidity by incorporating humidity responsive double-shelled hollow spheres

Co-reporter:Enwei Yan, Jingtao Wang, Zhongyi Jiang, Hailiang Feng, Lingli Nie, Tao Xu, Xinlin Yang and Xu Zhang

Journal of Materials Chemistry A 2013 vol. 1(Issue 38) pp:11762-11777

Publication Date(Web):16 Jul 2013

DOI:10.1039/C3TA11620D

Many efforts have been devoted to maintaining the water content at a constant level in water retention proton exchange membranes, especially under a low humidity. It is necessary to develop a method for enhancing the water retention with a stable dynamic water behavior. Herein, humidity responsive double-shelled hollow spheres (DSHSs) were incorporated into a sulfonated poly(ether ether ketone) (SPEEK) matrix membrane to simultaneously enhance its water retention and improve its dynamic water behavior. The water retention of the DSHS incorporated SPEEK membrane was considerably increased compared to that of the SPEEK membrane due to the presence of a central cavity and gap between the inner and outer shell of the DSHSs. The humidity responsive DSHSs could rapidly adjust the water distribution within the SPEEK matrix and compensate the water evaporated under a low humidity, which is similar to the function of a vacuole in plant cells. As a result, the dynamic water behavior of the SPEEK/DSHS hybrid membranes was significantly improved. As a benefit from this, a continuous water network in the hybrid membranes could be maintained for a long time to enhance the proton conductivity of the hybrid membranes under a low humidity. A mechanism was proposed for the interpretation of these phenomena. The nanostructure of the hybrid membranes was studied by small-angle X-ray scattering (SAXS) and field emission scanning electron microscopy (FESEM).

Polymer shell as a protective layer for the sandwiched gold nanoparticles and their recyclable catalytic property

Co-reporter:Bin Liu, Xiaoman Wang, Yanwei Zhao, Jianchao Wang, Xinlin Yang

Journal of Colloid and Interface Science 2013 Volume 395() pp:91-98

Publication Date(Web):1 April 2013

DOI:10.1016/j.jcis.2012.12.010

Poly(ethyleneglycol methacrylate) (PEGDMA) shell was used as a protective layer for the sandwiched gold nanoparticles, which were prepared through the in situ reduction in the HAuCl4 precursor in the presence of (aminopropyl)trimethoxysilane (APS) modified silica/PEGDMA core–shell microspheres. In this process, the silica/PEGDMA core–shell microspheres were afforded by the distillation-precipitation polymerization of the EGDMA monomer on the APS-modified silica particles with the aid of hydrogen-bonding interaction. The gold nanoparticles were formed at the interface between the silica core and the PEGDMA outer layer through the strong coordinate interaction between the gold nanoparticles and the amino groups on the surface of the silica during the reduction in HAuCl4. The sandwiched gold nanoparticles exhibited highly catalytic efficiency and facile recovery with good stability.Graphical abstractHighlights► Synthesis of the sandwiched nanoparticles between the silica core and the PEGDMA shell. ► The dual functions of amino groups for the resultant sandwiched gold nanoparticles. ► Stable catalytic activity of the sandwiched gold nanoparticles during the recovery.

A general method for the synthesis of various rattle-type microspheres and their diverse applications

Co-reporter:Bin Liu, Jianchao Wang, Shuxuan Sun, Xiaoman Wang, Meng Zhao, Wei Zhang, Han Zhang and Xinlin Yang

RSC Advances 2013 vol. 3(Issue 40) pp:18506-18518

Publication Date(Web):30 Jul 2013

DOI:10.1039/C3RA42997K

A general method was developed for the preparation of various functional rattle-type microspheres possessing a movable inner core with different components and morphologies and a mesoporous silica shell. In this process, the cross-linked poly(methyl acrylic acid) (PMAA) sandwiched layer was used as a sacrificial layer for coating the functional cores as well as the reaction locus for the deposition of the outer silica layer via a sol–gel method in the presence of n-octadecyltrimethoxysilane (C18TMS) as the pore-directing agent for tri-layer microspheres. The mesoporous rattle-type microspheres were produced through calcination of the corresponding tri-layer microspheres at high temperature, during which the rattle-structure microspheres were formed through decomposition of the sandwiched PMAA layer and the meso-pores in the silica shell-layer (mSiO2) were simultaneously afforded by pyrolysis of the pore directing agent. The structure of the rattle-type microspheres can be facilely tuned by adjusting the size of the corresponding layers in the complex multilayer architecture with the silica inner core as an example. Further, these rattle-type microspheres with functional inner cores exhibited unique and novel properties with potential applications. As a result, the Au/mSiO2 rattle-type microspheres revealed a good catalytic performance towards the reduction of nitrophenol. The surface engineering of magnetic iron oxide/mSiO2 (MIO@mSiO2) rattle type microspheres was performed for grafting functional biocompatible poly(ethylene glycol) (PEG) and tumor targeting agent folic acid (FA) through a silica coupling reaction. The multifunctional rattle-type microspheres were used as a drug carrier with a controlled release property.

Preparation of a superparamagnetic MRI contrast agent with a tumor targeting function

Co-reporter:Junheng Gu, Wei Zhang, Xinlin Yang

Materials Letters 2013 Volume 94() pp:8-10

Publication Date(Web):1 March 2013

DOI:10.1016/j.matlet.2012.12.030

The folic acid (FA) conjugated superparamagnetic Fe3O4–SiO2 composite particles were prepared and their properties including saturate magnetization and relaxivity value were investigated. The Fe3O4–SiO2–FA conjugate biomaterials were prepared by the amide reaction between the carboxyl of FA molecule and the surface amino of 3-aminopropyltriethoxysilane (APS)-modified Fe3O4–SiO2 composite, which was synthesized via direct silica coating using Tween-80 modified Fe3O4 nano-aggregates. The morphology and structure of Fe3O4–SiO2–FA conjugate were characterized. The saturation magnetic intensity was measured by a magnetometer and contrast effect in solution of the Fe3O4–SiO2–FA composites as magnetic contrast biomaterial was determined by a clinical MRI instrument.graphical abstractSynthesis of a superparamagnetic MRI contrast agent with tumor targeting. Highlights► Synthesis of Fe3O4–SiO2–FA composite nanoparticles. ► Characterization of superparamagnetic Fe3O4–SiO2–FA composites. ► Tumor targeting superparamagnetic MRI contrast agents.

A controlled morphology of polymeric nanocapsules via the density of surface vinyl group for the precipitation polymerization

Co-reporter:Hailiang Feng, Enwei Yan, Jing Zhang, Xinlin Yang, Chenxi Li

Polymer 2013 Volume 54(Issue 17) pp:4511-4520

Publication Date(Web):2 August 2013

DOI:10.1016/j.polymer.2013.06.035

The morphology of the resultant poly(ethyleneglycol dimethacrylate-co-methacrylic acid)/polydivinylbenzene (P(EGDMA-co-MAA)/PDVB) nanocapsules for in situ precipitation polymerization of divinylbenzene in presence of P(EGDMA-co-MAA) nanocapsules as templates was controlled by the density of the residual surface vinyl group of the P(EGDMA-co-MAA) nanocapsules, which was dependent on the cross-linking degree (EGDMA) for the distillation precipitation copolymerization of EGDMA and MAA. The morphology of P(EGDMA-co-MAA)/PDVB hybrid nanocapsules can be regulated from the separated domains, raspberry-like to a double-layer structure by adjusting the EGDMA cross-linking degree from 20% to 100% for P(EGDMA-co-MAA) nanocapsule templates with various densities of the surface vinyl group. As a result, the well defined raspberry-like P(EGDMA-co-MAA)/PDVB nanocapsules were obtained in presence of P(EGDMA-co-MAA) templates with the intermediate density of surface vinyl group during the precipitation polymerization. The morphology and structure of the P(EGDMA-co-MAA)/PDVB nanocapsules were characterized by Fourier transform infrared analyses (FT-IR), Zeta potential, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and elemental analysis by ion chromatography.

Synthesis of P(MBA-co-MAA) microsphere-grafted PAMAM dendrimers and their application as supporters for gold nanoparticles

Co-reporter:Hailiang Feng;Runnan Zhang

Colloid and Polymer Science 2013 Volume 291( Issue 6) pp:1329-1339

Publication Date(Web):2013 June

DOI:10.1007/s00396-012-2863-z

Poly(N,N′-methylenebisacrylamide-co-acrylic acid) microsphere-supported polyamidoamine (PAMAM) dendrimers up to third generation (G) were grown onto the surface as well as the gel-layer of P(MBA-co-MAA) microspheres by a divergent method. The P(MBA-co-MAA) supported PAMAM dendrimers were used as heterogeneous stabilizers for the gold nanoparticles by an in situ reduction of HAuCl4 via the efficient coordination interaction between the amino groups of the supported PAMAM dendrimers and the gold atoms. The effects of the generations of the P(MBA-co-MAA) supported PAMAM dendrimer on the loadings and the catalytic activity of the heterogeneous Au nanoparticles were systematically investigated with the reduction of 4-nitrophenol to 4-aminophenol as a model reaction.

Multilayer Magnetic Composite Particles with Functional Polymer Brushes as Stabilizers for Gold Nanocolloids and Their Recyclable Catalysis

Co-reporter:Bin Liu, Dongwei Zhang, Jianchao Wang, Cheng Chen, Xinlin Yang, and Chenxi Li

The Journal of Physical Chemistry C 2013 Volume 117(Issue 12) pp:6363-6372

Publication Date(Web):March 4, 2013

DOI:10.1021/jp311467b

The functional poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) brush was grafted onto the alkyl-bromide-modified magnetite/silica/poly(N,N′-methylenebisacrylamide-co-2-hydroxyethylmethacrylate) (Fe3O4@SiO2@PHEMA) trilayer microspheres via the surface-induced atom transfer radical polymerization. Fe3O4@SiO2@PHEMA trilayer microspheres with surface alkyl bromide groups were prepared by the combination of sol–gel process for the synthesis of Fe3O4@SiO2 core–shell inorganic component and distillation–precipitation polymerization for the formation of PHEMA shell together with the subsequent esterification of the surface hydroxyl group and 2-bromoisobutyryl bromide. Furthermore, the gold nanoparticles were facilely loaded into the functional PDMAEMA brushes through the in situ reduction due to their strong coordinate interaction. These PDMAEMA brush-stabilized gold nanocolloids were used as a catalyst with the reduction of 4-nitophenol to 4-aminophenol as a model reaction, which revealed a highly catalytic efficiency and good reusable property.

Polyethyleneimine functionalized polymer microsphere: a novel delivery vector for cells

Co-reporter:Chunying Gao, Han Zhang, Ming Wu, Yang Liu, Yipan Wu, Xinlin Yang and Xizeng Feng

Polymer Chemistry 2012 vol. 3(Issue 5) pp:1168-1173

Publication Date(Web):23 Feb 2012

DOI:10.1039/C2PY20012K

Monodisperse poly(ethylene glycol dimethacrylate-co-methacrylic acid) (P(EGDMA-co-MAA)) microspheres with two different diameters (69 and 160 nm) were facilely synthesized via distillation precipitation polymerization in neat acetonitrile, and these microspheres interacted with the amino groups of polyethyleneimine (PEI) chains though hydrogen-bonding as well as electrostatic interactions to form PEI-functionalized (P(EGDMA-co-MAA)). The successful modification of P(EGDMA-co-MAA) microspheres with PEI was confirmed by dynamic light scattering (DLS) and agarose gel electrophoresis. The in vitro gene transfection was evaluated by co-culturing human embryonic kidney (HEK) 293T cells and P(EGDMA-co-MAA) microsphere/plasmid DNA (pDNA) complexes, and the results were determined by fluorescence microscopy. Furthermore, the cytotoxicity of PEI-functionalized P(EGDMA-co-MAA) microspheres was assessed via MTT assay and FDA–PI staining. The PEI-functionalized (P(EGDMA-co-MAA) provides a potential novel delivery vector for cells.

Facile method for synthesis of hollow porous magnetic microspheres with controllable structure

Co-reporter:Bin Liu, Wei Zhang, Qingyun Zhang, Han Zhang, Jing Yu, Xinlin Yang

Journal of Colloid and Interface Science 2012 Volume 375(Issue 1) pp:70-77

Publication Date(Web):1 June 2012

DOI:10.1016/j.jcis.2012.02.023

Hollow porous magnetic microspheres with strong magnetization and controllable structure were prepared via a facile electrostatic self-assembly of the positively charged Fe3O4 nanoparticles onto the surface of the negatively charged poly(N,N′-methylenebisacrylamide-co-methacrylic acid) (P(MBAAm-co-MAA)) microspheres with subsequent removal of the polymer core through calcination at high temperature. The shell thickness was facilely tuned through the ratio between Fe3O4 and polymer, and the void space was conveniently changed through the size of polymer microspheres. The hollow magnetic microspheres possessed high saturation magnetization value (51.38 emu/g) and porous structure with high specific surface area (108.04 m2/g). Based on these properties, the drug loading and release behaviors were investigated, which indicated that the hollow magnetic microspheres exhibited a controlled release process.Graphical abstractHighlights► Hollow porous microspheres with strong magnetization and controllable structure. ► Electrostatic self-assembly between Fe3O4 nanoparticles and polymer microsphere. ► Facilely controlled drug release from hollow magnetic microspheres.

A general method for the synthesis of monodisperse hollow inorganic–organic hybrid microspheres with interior functionalized poly(methacrylic acid) shells

Co-reporter:Bin Liu, Enwei Yan, Xu Zhang, Xinlin Yang, Feng Bai

Journal of Colloid and Interface Science 2012 Volume 369(Issue 1) pp:144-153

Publication Date(Web):1 March 2012

DOI:10.1016/j.jcis.2011.12.029

Hollow inorganic–organic hybrid microspheres, such as silica, titania, and zirconia, with interior poly(methacrylic acid) (PMAA) functionalized shell were synthesized by a general method containing a two-stage reaction. The hollow inorganic shell-layer with interior polymeric component was formed over the PMAA template during the second-stage controlled hydrolysis of inorganic precursors together with disintegration of PMAA cores and adhering to the interior wall of the silica during the drying process due to the capillary force as well as the competitive hydrogen bond interaction. In this process, PMAA microspheres were prepared by distillation precipitation polymerization of methacrylic acid (MAA) in acetonitrile as the first-stage reaction. The present work elaborately investigated the effects of the reaction conditions, including the amount of the tetraethyl orthosilicate (TEOS) precursors and the amount of ammonium hydroxide catalyst on the morphology and structure of the resultant hollow composite microspheres, which were characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectra (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption.Graphical abstractHighlights► Synthesis of hollow inorganic/PMAA hybrid microspheres via a two-step reaction. ► The hollow structure formed via a capillary force and the competitive H-bond interaction. ► Facile control the spherical shape and the thickness of the shell-layer.

Synthesis of polymer/zirconium hydroxide core–shell microspheres and the hollow porous zirconium oxide microspheres

Co-reporter:Dianbin Qin, Enwei Yan, Jinhui Yu, Wei Zhang, Bin Liu, Xinlin Yang

Materials Chemistry and Physics 2012 Volume 136(2–3) pp:688-697

Publication Date(Web):15 October 2012

DOI:10.1016/j.matchemphys.2012.07.043

Narrow-disperse poly(N,N′-methylenebisacryamide-co-methacrylic acid)/zirconium hydroxide (P(MBA-co-MAA)/Zr(OH)4) core–shell composite microspheres were synthesized by the controlled sol–gel hydrolysis of inorganic zirconium n-butoxide (Zr(OBu)4) precursor in ethanol and acetonitrile mixed solvent with P(MBA-co-MAA) microspheres as templates. The thickness of the outer inorganic Zr(OH)4 shell-layer was well-controlled via altering the mass ratio of Zr(OBu)4 to P(MBA-co-MAA) core particles as well as the water used for the hydrolysis. The corresponding hollow porous zirconium oxide (ZrO2) microspheres were obtained after the selective removal of P(MBA-co-MAA) core via the calcination of P(MBA-co-MAA)/Zr(OH)4 core–shell microspheres under 550 °C for 4 h in air. The structure and morphology of the resultant core–shell microspheres and the hollow porous ZrO2 microspheres were characterized by transmission electron microscopy (TEM), STEM together with EDX spectrum, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectra, micromeritic analyzer, and thermogravimetric (TGA) analysis.Graphical abstractMonodisperse P(MBA-co-MAA)/(ZrOH)4 core–shell microspheres with amorphous zirconium hydroxide shell-layer were prepared by the controlled hydrolysis of Zr(OBu)4 in acetonitrile/ethanol (4/1, V/V) mixed solvent. The mechanism of the encapsulation of zirconium hydroxide shell-layer over P(MBA-co-MAA) templates were performed via the efficient hydrogen-bonding interaction between the carboxylic acid groups as well as the amide groups on the surface of P(MBA-co-MAA) templates and the hydroxyl groups of the zirconium hydroxide molecules during the controlled hydrolysis.Highlights► Synthesis of P(MBA-co-MAA)/Zr(OH)4 core-shell composite microspheres. ► Controlled thickness of Zr(OH)4 shell-layer via altering loadings of Zr(OBu)4. ► Preparation of hollow ZrO2 microspheres with body-centered tetragonal phase.

Preparation of polymer@titania raspberry-like core–corona composite via heterocoagulated self-assembly based on hydrogen-bonding interaction

Co-reporter:Hongli Liu, Dan Wang, Xinlin Yang

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2012 Volume 397() pp:48-58

Publication Date(Web):5 March 2012

DOI:10.1016/j.colsurfa.2012.01.028

The polymer@titania core–corona composites were prepared by a heterocoagluated self-assembly of poly(4-vinylpyridine) (PVPy) core and poly(ethyleneglycol dimethacrylate-co-methacrylic acid)/titania (P(EGDMA-co-MAA)/TiO2) corona, during which the hydrogen-bonding interaction between the hydroxyl of titania corona and the pyridyl groups of the core particles played an essential role for the formation of the raspberry-like structure. The coverage of the titania (TiO2) nanoparticles on the polymeric cores were facilely controlled via adjusting the mass ratio between the core and corona particles. The effects of the pH and solvent on the stability of the resultant raspberry-like composites were investigated in detail. The structure and morphology of the polymeric core, titania corona particles and the resultant polymer@titania core–corona composites were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The nature of the interaction between the core and corona particles for the construction of the raspberry-like composite was identified with Fourier transform infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS).Graphical abstractThe polymer@titania core–corona composites were prepared by a heterocoagluated self-assembly of poly(4-vinylpyridine) (PVPy) core and poly(ethyleneglycol dimethacrylate-co-methacrylic acid)/titania (P(EGDMA-co-MAA)/TiO2) corona, during which the hydrogen-bonding interaction between the hydroxyl of titania corona and the pyridyl groups of the core particles played an essential role for the formation of the raspberry-like structure.Highlights► Synthesis of polymer@titania composite with a raspberry-like structure. ► Hydrogen-bonding interaction as a driving force for the heterocoagulated self-assembly. ► Effects of pH and solvent on the morphology of the core–corona composites.

Synthesis of CdS/SiO2/polymer tri-layer fluorescent nanospheres with functional polymer shells

Co-reporter:Bin Liu;Feng-kai Yang;Guang-yu Liu

Chinese Journal of Polymer Science 2012 Volume 30( Issue 3) pp:359-369

Publication Date(Web):2012 May

DOI:10.1007/s10118-012-1134-2

Tri-layer CdS/SiO2/polymer hybrid nanospheres were synthesized by distillation precipitation polymerization of either ethyleneglycol dimethacrylate (EGDMA) or EGDMA together with comonomers having different functional groups, such as methacrylic acid, 4-vinylpyridine and 2-hydroxyethylmethacrylate, in the presence of 3-(methacryloxy)propyl trimethoxysilane (MPS)-modified CdS/SiO2 nanoparticles as seeds in acetonitrile with 2,2′-azobisisobutyronitrile (AIBN) as initiator. In this approach, MPS-modified inorganic seeds were prepared by the modification of CdS/SiO2 nanoparticles via the self-condensation reaction between the hydroxyl groups of sinaols, in which the CdS/SiO2 nanoparticles were afforded by a reverse microemulsion technique for the synthesis of CdS core nanoparticles with the subsequent coating of silica layer. The polymer shell-layers encapsulated over the MPS-modified CdS/SiO2 inorganic seeds via the efficient capture of the monomers and oligomers from the solution with the aid of the vinyl groups incorporated by the MPS modification, in which the polymer shell-thickness and functional groups including carboxyl, pyridyl and hydroxyl, were facilely controlled by the feed of EGDMA as well as the types of comonomers used for the polymerization. These nanospheres were characterized by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), fluorescence spectroscopy and zeta potential.

Rattle-type microspheres as a support of tiny gold nanoparticles for highly efficient catalysis

Co-reporter:Bin Liu, Wei Zhang, Hailiang Feng and Xinlin Yang

Chemical Communications 2011 vol. 47(Issue 42) pp:11727-11729

Publication Date(Web):27 Sep 2011

DOI:10.1039/C1CC13717D

SiO2/poly(ethyleneglycol dimethacrylate) (PEGDMA) rattle-type microspheres loaded with tiny sized gold nanoparticles (∼2 nm) were prepared through a facile and novel method. Catalyzed reduction of 4-nitrophenol with NaBH4 demonstrated that this rattle-type microsphere possessed high catalytic efficiency.

Magnetic polymer microsphere stabilized gold nanocolloids as a facilely recoverable catalyst

Co-reporter:Han Zhang;Xin-lin Yang 杨新林

Chinese Journal of Polymer Science 2011 Volume 29( Issue 3) pp:342-351

Publication Date(Web):2011 May

DOI:10.1007/s10118-011-1036-8

Magnetically responsive hierarchical magnetite/silica/poly(ethyleneglycol dimethacrylate-co-4-vinylpyridine) (Fe3O4/SiO2/P(EGDMA-co-VPy)) tri-layer microspheres were used as stabilizers for gold metallic nanocolloids as a facilely recoverable catalyst with the reduction of 4-nitrophenol to 4-aminophenol as a model reaction. The magnetic microsphere stabilized gold metallic nanocolloids were prepared by in situ reduction of gold chloride trihydrate with borohydride as reductant via the stabilization effect of the pyridyl groups to gold nanoparticles on the surface of the outer shell-layer of the inorganic/polymer tri-layer microspheres.

Alternating Silica/Polymer Multilayer Hybrid Microspheres Templates for Double-shelled Polymer and Inorganic Hollow Microstructures

Co-reporter:Guoliang Li, Qin Shi, S. J. Yuan, K. G. Neoh, E. T. Kang and Xinlin Yang

Chemistry of Materials 2010 Volume 22(Issue 4) pp:1309

Publication Date(Web):January 11, 2010

DOI:10.1021/cm903501e

Alternating silica/polymer tetra- and penta-layer hybrid microspheres were first prepared via combined inorganic sol−gel reaction and distillation-precipitation polymerization. pH-responsive poly(methacrylic acid) (PMAA) hollow microspheres with asymmetric double-shells were produced after HF etching of the silica layers in the SiO2/PMAA tetra-layer microspheres with different degrees of cross-linking in the two PMAA layers. On the other hand, silica “core−double shell” hollow microspheres were obtained by calcination of the alternating silica/PMAA penta-layer microspheres. The resulting hollow polymer and silica microspheres with hierarchical structures were characterized by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) analysis, dynamic laser scattering (DLS), and confocal laser scanning microscopy (CLSM) measurements.

Synthesis of ellipsoidal hematite/polymer/titania hybrid materials and the corresponding hollow ellipsoidal particles

Co-reporter:Longyu Li, Dianbin Qin, Xinlin Yang and Guangyu Liu

Polymer Chemistry 2010 vol. 1(Issue 3) pp:289-295

Publication Date(Web):16 Dec 2009

DOI:10.1039/B9PY00230H

Ellipsoidal tri-layer hematite/poly(N,N′-methylenebisacrylamide-co-methacrylic acid)/titania (Fe2O3/P(MBA-co-MAA)/TiO2) hybrid materials were prepared by a three-stage reaction process, which included the combination of the controlled hydrolysis of inorganic salt to afford ellipsoidal hematite core and titania shell layer and distillation precipitation copolymerization of N,N′-methylenebisacrylamide (MBA) and methacrylic acid (MAA) in acetonitrile for the formation of a P(MBA-co-MAA) sandwiched mid-layer. The corresponding hollow ellipsoidal hematite-sphere-in-titania-spheres were afforded by selective removal of the sandwiched P(MBA-co-MAA) mid-layer viacalcination. Hollow titania ellipsoids were further obtained by selectively etching the hematite core in aqueous hydrofluoric acid (HF) solution from the ellipsoidal hematite-sphere-in-titania-sphere. The resultant ellipsoidal tri-layer Fe2O3/P(MBA-co-MAA)/TiO2 and the corresponding hollow ellipsoidal particles were confirmed by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy, X-ray diffraction (XRD), thermogravimetric (TGA) analysis and vibrating sample magnetometery (VSM).

Synthesis of P(EGDMA-co-MAA)/P(EGDMA-co-VPy)/titania/polymer tetra-layer microspheres

Co-reporter:Longyu Li, Guangyu Liu, Dianbin Qin and Xinlin Yang

Polymer Chemistry 2010 vol. 1(Issue 5) pp:650-657

Publication Date(Web):18 Feb 2010

DOI:10.1039/B9PY00302A

Poly(ethyleneglycol dimethacrylate-co-methacrylic acid)@poly(ethyleneglycol-co-vinylpyridine)/titania/poly(N,N′-methylene bisacrylamide) (P(EGDMA-co-MAA)@P(EGDMA-co-VPy)/TiO2/PMBAAm) and P(EGDMA-co-MAAP)@P(EGDMA-co-VPy)/TiO2/poly(ethyleneglycol dimethacrylate) tetra-layer microspheres were synthesized by distillation precipitation polymerization of N,N′-methylene bisacrylamide (MBAAm) and ethyleneglycol dimethacrylate (EGDMA) in the presence of P(EGDMA-co-MAAP)@P(EGDMA-co-VPy)/TiO2 core-shell particles as the seeds in acetonitrile. The P(EGDMA-co-MAAP)@P(EGDMA-co-VPy)/TiO2 seeds were prepared by a combination of a two-stage distillation precipitation polymerization and the subsequently controlled hydrolysis of titanium tetrabutaoxide (TBOT) in ethanol–acetonitrile mixed solvents. The structures of the resultant polymer and polymer/titania, polymer/titania/polymer multi-layer composite microspheres were confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR) and zeta-potential (ξ) analysis.

Synthesis of tetra-layer polymer composite microspheres and the corresponding hollow polymer microspheres with Au nanoparticles functionalized movable cores

Co-reporter:Han Zhang and Xinlin Yang

Polymer Chemistry 2010 vol. 1(Issue 5) pp:670-677

Publication Date(Web):17 Feb 2010

DOI:10.1039/B9PY00372J

Hollow poly(ethyleneglycol dimethacrylate) (PEGDMA) microspheres with Au nanoparticle functionalized movable cores were prepared by selective removal of the sandwiched silica mid-layer from the corresponding poly(ethyleneglycol dimethacrylate-co-methacrylic acid)/poly(ethyleneglycol dimethacrylate-co-vinylpyridine)@gold/silica/PEGDMA (P(EGDMA-co-MAA)/P(EGDMA-co-VPy)@Au/SiO2/PEGDMA) tetra-layer composite microspheres, in which the Au nanoparticles were stabilized by the pyridyl groups on the surface and gel-layer of P(EGDMA-co-MAA)/P(EGDMA-co-VPy) particles during the reduction of HAuCl4 with sodium borohydride. The tetra-layer polymer composite microspheres were synthesized via the combination of distillation precipitation polymerization for the preparation of the polymer core and outer shell layer together with the modified Stöber sol–gel process for the formation of the sandwiched silica mid-layer. The primary results indicated that the Au nanoparticle functionalized movable cores enabled the hollow polymer microspheres to act as efficient catalysts for the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride as the reductant.

Facile synthesis of monodisperse polymer/SiO2/polymer/TiO2 tetra-layer microspheres and the corresponding double-walled hollow SiO2/TiO2 microspheres

Co-reporter:Han Zhang, Xu Zhang, Xinlin Yang

Journal of Colloid and Interface Science 2010 Volume 348(Issue 2) pp:431-440

Publication Date(Web):15 August 2010

DOI:10.1016/j.jcis.2010.04.059

Monodisperse tetra-layer poly(ethyleneglycol dimethacrylate-co-methacrylic acid) (P(EGDMA-co-MAA))/SiO2/P(EGDMA-co-MAA)/TiO2 tetra-layer microspheres were facilely synthesized by the combination of the distillation precipitation polymerization for the preparation of P(EGDMA-co-MAA) layers and the controlled sol–gel hydrolysis of inorganic precursors for the formation of silica (SiO2) and titania (TiO2) layers. The thickness of the outer titania shell-layer was well-controlled via altering the feed of titanium tetrabutoxide (TBOT) during the sol–gel hydrolysis, while the size of polymeric layers were facilely controlled via a multi-step addition of ethyleneglycol dimethacrylate (EGDMA) crosslinker and methacrylic acid (MAA) monomer during the polymerization. The corresponding double-walled hollow inorganic microspheres containing SiO2 inner shell and TiO2 outer shell with various thickness were obtained after the selective removal of P(EGDMA-co-MAA) components via the calcination of the tetra-layer polymer/SiO2/polymer/TiO2 microspheres under 550 °C for 4 h in air. The structure and morphology of the resultant microspheres were characterized by transmission electron microscopy (TEM), X-ray diffractometer (XRD), X-ray photoelectron microscopy (XPS), and thermogravimetric analysis (TGA). Further, the photocatalytic properties of the resultant double-walled hollow SiO2/TiO2 microspheres were studied by photocatalytic degradation of methyl orange (MO) with ultraviolet (UV) irradiation of a 500 W high-pressure mercury lamp.Monodisperse P(EGDMA-co-MAA)/SiO2/P(EGDMA-co-MAA)/TiO2 tetra-layer microspheres and the corresponding hollow SiO2/TiO2 double-walled microspheres were synthesized by the combination of distillation precipitation polymerization and controlled sol–gel process and further calcination in air.

Synthesis of hollow fluorescent polymeric microspheres with movable magnetic cores

Co-reporter:Bin Liu;Hongfen Ji

Polymer International 2010 Volume 59( Issue 7) pp:961-966

Publication Date(Web):

DOI:10.1002/pi.2813

Abstract

Low-dispersity hollow poly[(ethyleneglycol dimethacrylate)-co-(N-vinylcarbazole)] (P(EGDMA-co-NVCz)) fluorescent microspheres with movable magnetic cores were prepared by quantitative removal of the silica component in hydrofluoric acid aqueous solution from the corresponding magnetite/silica/P(EGDMA-co-NVCz) tri-layer hybrid microspheres. The tri-layer microspheres with magnetic cores and fluorescent polymer shells were synthesized by distillation precipitation copolymerization of ethyleneglycol dimethacrylate crosslinker and N-vinylcarbazole fluorescent monomer in acetonitrile in the presence of 3-(methacryloxy)propyltrimethoxysilane-modified magnetite/silica particles as seeds, which were afforded by a modified Stöber sol–gel process, to coat the magnetite cores. The corresponding hollow fluorescent polymer microspheres with movable magnetic cores were studied using transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry, UV-visible spectroscopy and fluorescence spectroscopy. Copyright © 2010 Society of Chemical Industry

Preparation of magnetite and tumor dual-targeting hollow polymer microspheres with pH-sensitivity for anticancer drug-carriers

Co-reporter:Xiaoying Yang, Lei Chen, Bin Han, Xinlin Yang, Hongquan Duan

Polymer 2010 Volume 51(Issue 12) pp:2533-2539

Publication Date(Web):28 May 2010

DOI:10.1016/j.polymer.2010.04.032

The hollow poly(N,N′-methylenebisacrylamide-co-methacrylic acid) (P(MBAAm-co-MAA)) microspheres were prepared by the selective removal of poly(methacrylic acid) (PMAA) core from the corresponding PMAA/P(MBAAm-co-MAA) core-shell microspheres, which were synthesized via a two-stage distillation precipitation polymerization. The magnetic Fe3O4 nanoparticles onto the surface of hollow P(MBAAm-co-MAA) microspheres via partial oxidation of ferrous salt during the chemical deposition in the presence of potassium nitrate as oxidant with the aid of hexamethylene tetramine and the magnetic hollow microspheres were further functionalized with folic acid (FA) via the chemical linkage with amino groups of 3-aminopropyl triethoxysilane (APS)-modified P(MBAAm-co-MAA)@Fe3O4 microspheres to afford the magnetite and tumor dual-targeting hollow microspheres. The resultant dual-targeting hollow polymer microspheres with pH-sensitivity were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared-spectrometer (FT-IR), UV–vis absorption spectroscopy, and vibrating sample magnetometer (VSM). Finally, the drug loading capacities of the magnetite and tumor dual-targeting hollow P(MBAAm-co-MAA) microspheres and their releasing dependence on pH values were investigated with doxorubicin hydrochloride (DXR) as an anticancer drug model.

Synthesis of titania/polymer core-shell hybrid microspheres

Co-reporter:Longyu Li;Dianbin Qin;Guangyu Liu

Colloid and Polymer Science 2010 Volume 288( Issue 2) pp:199-206

Publication Date(Web):2010 January

DOI:10.1007/s00396-009-2172-3

Monodisperse titania/polymer core-shell microspheres were prepared by a two-stage reaction with titania as core and poly(ethyleneglycol dimethacrylate) (PEGDMA) as shell, in which the titania cores were synthesized by a sol-gel method and subsequently grafted with 3-trimethoxysilyl methacrylate as the first-stage reaction to incorporate the vinyl groups on the surface of inorganic core. The PEGDMA shell was then encapsulated over the MPS-modified titania core by distillation precipitation polymerization of ethyleneglycol dimethacrylate in neat acetonitrile during the second-stage polymerization via capture of the radicals of EGDMA with the aid of the reactive vinyl groups on the surface of inorganic core without any stabilizer or surfactant. The shell thickness of the core-shell hybrid microspheres was controlled by the feed of EGDMA monomer during the polymerization. The resultant titania particles and core-shell microspheres were studied by transmission electron microscopy, Fourier-transform infrared spectra, X-ray photoelectron spectroscopy, and thermogravimetric analysis.

Synthesis of monodisperse hollow polymer microspheres with functional groups by distillation precipitation polymerization

Co-reporter:Bo Huang;Feng Bai;Xin-lin Yang 杨新林;Wen-qiang Huang

Chinese Journal of Polymer Science 2010 Volume 28( Issue 2) pp:277-285

Publication Date(Web):2010 March

DOI:10.1007/s10118-010-9089-7

Monodisperse hollow polymer microspheres having various functional groups on the shell-layer, such as carboxylic acid, pyridyl and amide, were prepared by two-stage distillation precipitation polymerization in neat acetonitrile in the absence of any stabilizer or additive, during which monodisperse poly(methacrylic acid) (PMAA) afforded from the first-stage polymerization was utilized as the seeds for the second-stage polymerization. The shell layer with different functional groups was formed during the second-stage copolymerization of either divinylbenzene (DVB) or ethyleneglycol dimethacrylate (EGDMA) as crosslinker and the functional comonomers, in which the hydrogen-bonding interaction between the carboxylic acid group of PMAA core and the functional groups of the corresponding comonomers, including carboxylic acid, amide and pyridyl, played an essential role for the formation of monodisperse core-shell functional microspheres. The hollow polymer microspheres were then developed after the subsequent removal of PMAA cores by dissolution in ethanol under basic condition. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to determine the morphology of the resultant PMAA core, functional core-shell microspheres and the corresponding hollow polymer microspheres with different functional groups. FT-IR spectra confirmed the successful incorporation of the various functional groups on the shell layer of the hollow polymer microspheres.

Reparation of silica/poly(methacrylic acid)/poly(divinylbenzene-co-methacrylic acid) tri-layer microspheres and the corresponding hollow polymer microspheres with movable silica core

Co-reporter:Hong-fen Ji;Xiao-xu Wang;Xu Zhang;Xin-lin Yang 杨新林

Chinese Journal of Polymer Science 2010 Volume 28( Issue 5) pp:807-817

Publication Date(Web):2010 September

DOI:10.1007/s10118-010-9164-0

Hollow poly(divinylbenzene-co-methacrylic acid) (P(DVB-co-MAA)) microspheres were prepared by the selective dissolution of the non-crosslinked poly(methacrylic acid) (PMAA) mid-layer in ethanol from the corresponding silica/PMAA/P(DVB-co-MAA) tri-layer hybrid microspheres, which were afforded by a three-stage reaction. Silica/PMAA core-shell hybrid microspheres were prepared by the second-stage distillation polymerization of methacrylic acid (MAA) via the capture of the oligomers and monomers with the aid of the vinyl groups on the surface of 3-(methacryloxy)propyl trimethoxysilane (MPS)-modified silica core, which was prepared by the Stöber hydrolysis as the first stage reaction. The tri-layer hybrid microspheres were synthesized by the third-stage distillation precipitation copolymerization of functional MAA monomer and divinylbenzene (DVB) crosslinker in presence of silica/PMAA particles as seeds, in which the efficient hydrogen-bonding interaction between the carboxylic acid groups played as a driving force for the construction of monodisperse hybrid microspheres with tri-layer structure. The morphology and the structure of silica core, silica/PMAA core-shell particles, the tri-layer hybrid microspheres and the corresponding hollow polymer microspheres with movable silica cores were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy (XPS).

Hollow polymer microspheres containing a gold nanocolloid core adsorbed on the inner surface as a catalytic microreactor

Co-reporter:Xiaoxu Wang;Hongfen Ji;Xu Zhang;Han Zhang

Journal of Materials Science 2010 Volume 45( Issue 15) pp:3981-3989

Publication Date(Web):2010 August

DOI:10.1007/s10853-010-4470-z

Hollow polymer microspheres with different polarity and functional group for the shell layer containing gold nanocolloid cores adsorbed on the inner surface were prepared by selective removal of sandwiched silica layer from the corresponding gold/silica/polydivinylbenzene (Au/SiO2/PDVB), Au/SiO2/poly(ethyleneglycol dimethacrylate) (Au/SiO2/PEGDMA), and Au/SiO2/poly(ethyleneglycol dimethacrylate-co-methacrylic acid) (Au/SiO2/P(EGDMA-co-MAA) tri-layer microspheres, respectively. The tri-layer microspheres were synthesized by distillation precipitation polymerizations of divinylbenzene (DVB), ethyleneglycol dimethacrylate (EGDMA), EGDMA together with methacrylic acid (MAA) in presence of 3-(methacryloxy)propyltrimethoxysilane (MPS)-modified gold/silica (Au/SiO2) core–shell particles as seeds, which were prepared by coating of a layer of silica onto the surface of Au nanocolloids with the aid of polyvinylpyrrolidone (PVP) via a modified Stöber method. The catalytic property and stability as a microreactor of the hollow polymer microspheres with Au nanocolloid cores adsorbed on the inner surface were studied by the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AnP) with sodium borohydride (NaBH4) as reductant. Transmission electron microscopy (TEM) and Fourier transform infrared spectra (FT-IR) were used for characterizing the morphology and structure of the resultant microspheres.

Tuning the performance of direct methanol fuel cell membranes by embedding multifunctional inorganic submicrospheres into polymer matrix

Co-reporter:Jingtao Wang, Han Zhang, Zhongyi Jiang, Xinlin Yang, Lulu Xiao

Journal of Power Sources 2009 Volume 188(Issue 1) pp:64-74

Publication Date(Web):1 March 2009

DOI:10.1016/j.jpowsour.2008.11.109

A series of surface functionalized silica submicrospheres by distillation–precipitation polymerization were embedded into chitosan (CS) matrix to fabricate the hybrid membranes for direct methanol fuel cell (DMFC). SEM characterization indicated that the submicrospheres could disperse homogenously within the CS matrix via tuning the polymer/particle and particle/particle interfacial interactions. The incorporation of sulfonated silica and carboxylated silica led to the reduced fractional free volume (FFV), whereas the incorporation of quaternary aminated silica resulted in increased FFV in the hybrid membranes, which was confirmed by the free volume characteristics analysis using positron annihilation lifetime spectroscopy (PALS). The correlation between methanol crossover and FFV was established: the hybrid membranes with lower FFV displayed higher methanol resistance. Meanwhile, the correlation between the proton acceptor/donor capability and proton conductivity in the hybrid membranes was established. Compared with sulfonated silica and quaternary aminated silica, carboxylated silica possessed the optimum matching in proton acceptor and donor capabilities. Therefore, the membrane embedded with carboxylated silica displayed the highest proton conductivity. In particular, embedding carboxylated silica simultaneously reduced the methanol permeability by 63% and increased the proton conductivity by 40% in comparison with pure CS membrane.

Synthesis of tri-layer hybrid microspheres with magnetic core and functional polymer shell

Co-reporter:Guangyu Liu, Hui Wang, Xinlin Yang, Longyu Li

European Polymer Journal 2009 Volume 45(Issue 7) pp:2023-2032

Publication Date(Web):July 2009

DOI:10.1016/j.eurpolymj.2009.04.002

Tri-layer magnetite/silica/poly(divinylbenzene) (Fe3O4/SiO2/PDVB) core-shell hybrid microspheres were prepared by distillation precipitation polymerization of divinylbenzene (DVB) in the presence of magnetite/3-(methacryloxyl)propyl trimethoxysilane (MPS) modified silica core-shell particles as seeds. The polymerization of DVB was performed in neat acetonitrile with 2,2′-azobisisobutyronitrile (AIBN) as initiator to coat magnetite/MPS-modified silica particles through the capture of DVB oligomers with the aid of vinyl groups on the surface of inorganic seeds in absence of any stabilizer or surfactant. Other magnetite/silica/polymer tri-layer hybrid particles, such as magnetite/silica/poly(ethyleneglycol dimethacrylate) (Fe3O4/SiO2/PEGDMA) and magnetite/silica/poly(ethyleneglycol dimethacrylate-co-methacrylic acid) (Fe3O4/SiO2/P(EGDMA-co-MAA)) with various polarity and functionality, were also prepared by this procedure. Magnetite/silica/poly(N,N′-methylenebisacrylamide-co-methacrylic acid) (Fe3O4/SiO2/P(MBAAm-co-MAA)) were synthesized with unmodified magnetite/silica particles as seeds. The resultant tri-layer hybrid particles were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR), dynamic light scattering, and vibrating sample magnetometer (VSM).

Preparation of hollow composite spheres with raspberry-like structure based on hydrogen-bonding interaction

Co-reporter:Junyou Wang;Hao Li

Polymers for Advanced Technologies 2009 Volume 20( Issue 12) pp:965-971

Publication Date(Web):

DOI:10.1002/pat.1349

Abstract

The hollow composite spheres with a raspberry-like structure were prepared by a self-assemble heterocoagulation based on the inter-particle hydrogen-bonding interaction between the amide groups of hollow poly (N,N′-methylenebisacrylamide-co-N-isopropyl acrylamide) (P(MBA-co-NIPAAm)) microspheres and the carboxylic acid groups of poly(ethyleneglycol dimethacrylate-co-methacrylic acid) (P(EGDMA-co-MAA)) nanoparticles, in which P(EGDMA-co-MAA) nanoparticle acted as the corona and the hollow P(MBA-co-NIPAAm) microsphere behaved as the core. The control coverage of the corona particles on the surface of hollow core microspheres of P(MBA-co-NIPAAm)/P(EGDMA-co-MAA) hollow composite sphere was studied in detail through adjustment of the mass ratio between the core and corona particles. The effect of the pH on the stability of the raspberry-like hollow spheres was investigated. The polymer particles and the resultant heterocoagulated raspberry-like hollow spheres were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Copyright © 2008 John Wiley & Sons, Ltd.

Facile synthesis of functional silica/polymer composite materials and hydrophilic hollow polymer microspheres

Co-reporter:Guangyu Liu;Han Zhang;Yongmei Wang

Journal of Applied Polymer Science 2009 Volume 111( Issue 4) pp:1964-1975

Publication Date(Web):

DOI:10.1002/app.29255

Abstract

Monodisperse functional silica/polymer core-shell composite materials with silica as core and hydrophilic polymer with various functional groups, such as amide, carboxylic acid, hydroxyl, and pyridyl group, as shell were facilely prepared by a two-stage reaction, in which the silica core with diameter of 179 nm was synthesized in the first-stage reaction according to the Stöber method. The functional polymer shell was then encapsulated onto the silica core by distillation–precipitation copolymerization of N,N′-methylenebisacrylamide (MBAAm) as crosslinker and hydrophilic comonomers with different functional groups, including N-isopropylacrylamide, methacrylic acid, 2-hydroxyethyl methacrylate, and 4-vinylpyridine, in neat acetonitrile with 2,2′-azobisisobutyronitrile as initiator. The encapsulation of the functional polymer shell onto the silica core particles was driven by the hydrogen-bonding interaction between the hydroxyl group on the surface of silica core and the amide unit of MBAAm crosslinker as well as the functional groups of the comonomers during the distillation–precipitation polymerization without modification of the silica surface in absence of any stabilizer or surfactant. The shell thickness of the composite can be controlled by MBAAm fraction in the monomer feed during the polymerization. Hydrophilic hollow polymer microspheres with various functional groups, including amide, carboxylic acid, hydroxyl, and pyridyl, were further developed after selective removal of silica core with hydrofluoric acid. The functional core-shell silica/polymer composites and the corresponding functional hollow microspheres were characterized with transmission electron microscopy, Fourier transform infrared spectra, and dynamic light scattering. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Synthesis of pH-sensitive hollow polymer microspheres with movable magnetic core

Co-reporter:Guangyu Liu, Hui Wang, Xinlin Yang

Polymer 2009 50(12) pp: 2578-2586

Publication Date(Web):

DOI:10.1016/j.polymer.2009.04.002

Preparation of polymer/silica/polymer tri-layer hybrid materials and the corresponding hollow polymer microspheres with movable cores

Co-reporter:Hongfen Ji, Siping Wang, Xinlin Yang

Polymer 2009 50(1) pp: 133-140

Publication Date(Web):

DOI:10.1016/j.polymer.2008.10.043

Synthesis of hollow polymer microspheres with movable polyelectrolyte core and functional groups on the shell-layer

Co-reporter:Min Ji, Bin Liu, Xinlin Yang, Junyou Wang

Polymer 2009 50(25) pp: 5970-5979

Publication Date(Web):

DOI:10.1016/j.polymer.2009.10.063

Concentric Hollow Nanospheres of Mesoporous Silica Shell-Titania Core from Combined Inorganic and Polymer Syntheses

Co-reporter:Guoliang Li, E. T. Kang, K. G. Neoh and Xinlin Yang

Langmuir 2009 Volume 25(Issue 8) pp:4361-4364

Publication Date(Web):March 23, 2009

DOI:10.1021/la900756u

Nearly monodispersed concentric hollow nanospheres with a mesoporous silica shell and anatase titania inner core were synthesized by the combination of sol−gel reaction and distillation−precipitation polymerization. The well-defined mesoporous concentric hollow nanospheres, comprising two nanostructured functional inorganics, can be used for confined catalytic reactions. The direct synthesis procedures can be readily extended to preparation of the concentric hollow nanospheres with multiple cores, or other functional concentric hollow nanospheres having different core−shell compositions.

Preparation of silica/polymer hybrid microspheres and the corresponding hollow polymer microspheres with functional groups

Co-reporter:Guangyu Liu;Longyu Li;Zhao Dai

Polymers for Advanced Technologies 2008 Volume 19( Issue 12) pp:1922-1930

Publication Date(Web):

DOI:10.1002/pat.1233

Abstract

Monodisperse functional silica/polymer core–shell hybrid microspheres were prepared by a two-stage reaction with silica grafting of 3-(methacryloxy)propyl trimethoxysiliane (MPS) as core and polymer as shell having various functional groups such as chloromethyl, pyridyl, carboxylic acid, hydroxyl, and ester. MPS-modified silica core was synthesized by the Stöber method and subsequently grafted with MPS as the first-stage reaction. The functional polymer shell was then encapsulated over the MPS-modified silica by distillation precipitation copolymerization of divinylbenzene (DVB) as a crosslinker and comonomers with different functional groups, including chloromethylstyrene (CMSt), vinyl pyridine (VPy), methacrylic acid (MAA), 2-hydroxyethylmethacrylate (HEMA), ethyl methacrylate (EMA), ethyleneglycol dimethacrylate (EGDMA), and trimethylol propanetrimethacrylate (Trim), in neat acetonitrile with 2,2′-azobisisobutyronitrile (AIBN) as an initiator. The encapsulation of the functional polymer shell onto the MPS-modified silica core particles was driven by the capture of oligomer radicals the vinyl groups on the surface of the MPS-modified silica cores during the second-stage distillation precipitation copolymerization in the absence of any stabilizer or surfactant. The functionality and the shell thickness of the inorganic/polymer core–shell hybrid particles were controlled by the amount of DVB crosslinker and the functional comonomers during the copolymerization. The corresponding hollow polymer microspheres with various functional groups, including chloromethyl, pyridyl, carboxylic acid, and ester groups were further developed after the selective removal of silica core with hydrofluoric acid. The functional core–shell silica/polymer hybrid microspheres and the corresponding functional hollow polymer microspheres were characterized with transmission electron microscopy (TEM) and Fourier transform infrared spectra (FT-IR). Copyright © 2008 John Wiley & Sons, Ltd.

Synthesis of Ellipsoidal Hematite/Silica/Polymer Hybrid Materials and the Corresponding Hollow Polymer Ellipsoids

Co-reporter:Guangyu Liu, Xinlin Yang and Yongmei Wang

Langmuir 2008 Volume 24(Issue 10) pp:5485-5491

Publication Date(Web):April 16, 2008

DOI:10.1021/la8002004

Ellipsoidal trilayer hematite/silica/poly(divinylbenzene) hybrid particles were prepared by distillation precipitation polymerization of divinyl benzene (DVB) in the presence of hematite/3-(methacryloxy)propyl trimethoxysilane (MPS)-modified silica (SiO2) core−shell particles as the seeds. The polymerization of DVB was performed in neat acetonitrile with 2,2′-azobisisobtyronitrile (AIBN) as initiator to coat the hematite/MPS-modified SiO2 seeds through the capture of DVB oligomer radicals with the aid of a vinyl group on the surface of the hematite/MPS-modified silica core−shell particles in the absence of any stabilizer or surfactant. The other hematite/silica/polymer trilayer hybrid particles with different polarity and various functionality, such as hematite/silica/poly(ethylene glycol dimethacrylate) and hematite/silica/poly(divinyl benzene-co-methacrylic acid) could also be prepared by this procedure. Hematite/silica/poly(N,N′-methylenebisacrylamide) composite particles could be prepared with unmodified hematite/silica particles as seeds. Hollow poly(divinyl benzene) (PDVB) and poly(N,N′-methylenebisacrylamide) (PMBAAm) ellipsoids with movable hematite cores were subsequently developed after the selective etching of the silica midlayer in diluted hydrofluoric acid from hematite/silica/PDVB and hematite/silica/PMBAAm trilayer hybrids. Hollow PDVB ellipsoids were obtained by removal of the silica midlayer and hematite core of the trilayer hybrids with concentrated HF solution. The resultant trilayer hybrid particles and hollow polymer ellipsoids were characterized by transmission electron microscopy and vibrating sample magnetometer.

Raspberry-like polymer/silica core-corona composite by self-assemble heterocoagulation based on a hydrogen-bonding interaction

Co-reporter:Junyou Wang

Colloid and Polymer Science 2008 Volume 286( Issue 3) pp:283-291

Publication Date(Web):2008 March

DOI:10.1007/s00396-007-1767-9

Raspberry-like poly(ethyleneglycol dimethacrylate-co-4-vinylpyridine)/silica (poly(EGDMA-co-VPy)/SiO2) core-corona composite was prepared by a self-assemble heterocoagulation based on a hydrogen-bonding interaction between the pyridyl group of poly(EGDMA-co-VPy) core and the active hydroxyl group of silica corona. The raspberry-like composite was stable near the neutral environment with pH ranging from 5.0 to 8.0. The effects of the solvent and the mass ratio of silica to polymer microsphere on the coverage of the silica corona on poly(EGDMA-co-VPy) core were investigated in detail. The resultant core-corona heterocoagulates were characterized with scanning electron microscope and the nature of the interaction between the polymer core particle and silica corona particle was identified as hydrogen bonding with Fourier Transform Infrared spectroscopy.

Size-controlled gold nanocolloids on polymer microsphere-stabilizer via interaction between functional groups and gold nanocolloids

Co-reporter:Wei Liu, Xinlin Yang, Lei Xie

Journal of Colloid and Interface Science 2007 Volume 313(Issue 2) pp:494-502

Publication Date(Web):15 September 2007

DOI:10.1016/j.jcis.2007.04.055

Gold nanocolloids with the controlled diameter ranging from 5.2 to 10.7 nm were in situ prepared by reduction of gold chloride trihydrate with sodium borohydride as reductant via the interaction between the gold naocolloids and the functional groups on the surface of polymer microsphere-stabilizer. The nature of such interaction was studied in detail by X-ray photoelectron spectroscopy (XPS). The effect of the functional groups on the catalytic activity of the gold nanocolloids was preliminarily investigated with the reduction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride as reductant.Gold nanocolloids with the controlled diameter ranging from 5.2 to 10.7 nm were in situ prepared by reduction of gold chloride trihydrate with sodium borohydride as reductant via the interaction between the gold atoms and the functional groups on the surface of polymer microsphere-stabilizer.

Preparation of monodisperse hydrophilic polymer microspheres with N,N′-methylenediacrylamide as crosslinker by distillation precipitation polymerization

Co-reporter:Guangyu Liu;Yongmei Wang

Polymer International 2007 Volume 56(Issue 7) pp:

Publication Date(Web):12 JAN 2007

DOI:10.1002/pi.2223

Highly crosslinked cauliflower-like poly(N,N′-methylenebisacrylamide) particles were prepared by distillation precipitation polymerization in neat acetonitrile with 2,2′-azobisisobutyronitrile as initiator. Monodisperse hydrophilic polymer microspheres with various functional groups, such as amide, pyrrolidone and carboxylic acid, with a spherical shape and smooth surface in the size range 120–600 nm were prepared by distillation precipitation copolymerizations of functional comonomers including N-isopropylacrylamide, N-vinylpyrrolidone, methacrylic acid with N,N′-methylenebisacrylamide as crosslinker. The polymer particles were formed and precipitated out from the reaction medium during the distillation of the solvent from the reaction system through an entropic precipitation manner. The effects of the solvent and the degree of crosslinking on the morphology and the loading capacity of the functional groups of the resultant polymer particles were investigated. The resulting polymer particles were characterized with scanning electron microscopy, transmission electron microscopy, dynamic light scattering and Fourier transform infrared spectroscopy. Copyright © 2007 Society of Chemical Industry

Preparation of monodisperse fluorescent core–shell polymer microspheres with functional groups in the shell layer by two-stage distillation–precipitation polymerization

Co-reporter:Donglai Qi;Wenqiang Huang

Polymer International 2007 Volume 56(Issue 2) pp:

Publication Date(Web):31 OCT 2006

DOI:10.1002/pi.2130

Monodisperse crosslinked core–shell micrometer-sized microspheres bearing a brightly blue fluorescent dye, carbazole, and containing various functional groups in the shell layers were prepared by a two-stage distillation–precipitation polymerization in acetonitrile in the absence of any stabilizer. Commercial divinylbenzene (DVB), containing 80 vol.% of DVB, was polymerized by distillation–precipitation in acetonitrile without any stabilizer using 2,2′-azobisisobutyronitrile (AIBN) as the initiator for the first stage of polymerization which resulted in monodisperse polyDVB microspheres used as the core. Several functional monomers, including 2-hydroxyethyl methacrylate and acrylonitrile together with N-vinylcarbazole blue fluorescent comonomer, were incorporated into the shell layers with AIBN as initiator during the second stage of polymerization. The resultant core–shell polymer microspheres were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, UV-visible spectroscopy and fluorescence spectroscopy. Copyright © 2006 Society of Chemical Industry

Preparation of narrow-disperse or monodisperse poly{[poly(ethylene glycol) methyl ether acrylate]-co-(acrylic acid)} microspheres with ethyleneglycol dimethacrylate as crosslinker by distillation precipitation polymerization

Co-reporter:Zhao Dai;Wenqiang Huang

Polymer International 2007 Volume 56(Issue 2) pp:

Publication Date(Web):20 OCT 2006

DOI:10.1002/pi.2136

Narrow-disperse or monodisperse poly{[poly(ethylene glycol) methyl ether acrylate]-co-(acrylic acid)} (poly(PEGMA-co-AA)) microspheres were prepared by distillation precipitation polymerization with ethyleneglycol dimethacrylate (EGDMA) as crosslinker with 2,2′-azobisisobutyronitrile as initiator in neat acetonitrile in the absence of any stabilizer, without stirring. The diameters of the resultant poly(PEGMA-co-AA-co-EGDMA) microspheres were in the range 200–700 nm with a polydispersity index of 1.01–1.14, which depended on the comonomer feed of the polymerization. The addition of the hydrogen bonding monomer acrylic acid played an essential role in the formation of narrow-disperse or monodisperse polymer microspheres during the polymerization. Copyright © 2006 Society of Chemical Industry

Preparation of poly(divinylbenzene-co-N-isopropylacrylamide) microspheres and their hydrogen-bonding assembly behavior for raspberry-like core-corona polymer composite

Co-reporter:Guoliang Li;Yanyan Song;Wenqiang Huang

Journal of Applied Polymer Science 2007 Volume 104(Issue 2) pp:

Publication Date(Web):26 JAN 2007

DOI:10.1002/app.25875

Narrowdisperse poly(divinylbenzene-co-N-isopropylacrylamide) (poly(DVB-co-NIPAM)) functional microspheres with the diameter in the range of 630 nm and 2.58 μm were prepared by distillation–precipitation polymerization in neat acetonitrile in the absence of any stabilizer. The effect of N-isopropylacrylamide (NIPAM) ratio in the comonomer feed on the morphology of the resultant polymer particles was investigated in detail with divinylbenzene (DVB) as crosslinker and 2,2′-azobisisobutyronitrile (AIBN) as initiator. The monodisperse poly(DVB-co-NIPAM) microspheres with NIPAM fraction of 20 wt % were selected for the preparation of raspberry-like core-corona polymer composite by the hydrogen-bonding self-assembly heterocoagulation with poly(ethyleneglycol dimethacrylate-co-acrylic acid) [poly(EGDMA-co-AA)] nanospheres. Both of the functional poly(DVB-co-NIPAM) microspheres and the core-corona particles were characterized with scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), and elemental analysis (EA). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1350–1357, 2007

Preparation of narrow-dispersion or monodisperse polymer microspheres with active hydroxyl group by distillation–precipitation polymerization

Co-reporter:Feng Bai;Rui Li;Shuning Li;Wenqiang Huang

Polymer International 2006 Volume 55(Issue 3) pp:

Publication Date(Web):19 DEC 2005

DOI:10.1002/pi.1963

Narrow-dispersion or monodisperse polymer microspheres with active hydroxyl groups were prepared by distillation–precipitation polymerization in the absence of any stabilizer. The monomer hydroxyethyl methacrylate (HEMA) was copolymerized with either commercial divinylbenzene (DVB) (containing 80 % of DVB isomers) or ethyleneglycol dimethacrylate (EGDMA) as crosslinker by distillation–precipitation polymerization technique with 2,2′-azobisisobutyronitrile (AIBN) as initiator in neat acetonitrile. The effects of the crosslinker and the crosslinking degree on the morphology and the loading of the active hydroxyl group of the resultant microspheres were investigated. The agitation caused by distilling off a portion of the polymerization solvent during the polymerization avoided coagulation and resulted in the narrow-dispersion or monodisperse polymer microspheres for the distillation precipitation technique. Copyright © 2005 Society of Chemical Industry

Narrow-disperse or monodisperse crosslinked and functional core–shell polymer particles prepared by two-stage precipitation polymerization

Co-reporter:Feng Bai;Wenqiang Huang

Journal of Applied Polymer Science 2006 Volume 100(Issue 3) pp:1776-1784

Publication Date(Web):24 JAN 2006

DOI:10.1002/app.23059

Narrow-disperse and monodisperse cross-linked core–shell polymer particles containing different functional groups, such as esters, hydroxyls, chloromethyls, carboxylic acids, amides, cyanos, and glycidyls, in the shell layers in the micrometer size range were prepared by a two-stage precipitation polymerization in the absence of any stabilizer. Commercial divinylbenzene (DVB), containing 80% DVB, was precipitation polymerized in acetonitrile without any stabilizer as the first-stage polymerization and was used as the core. Several functional monomers, including methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, t-butyl acrylate, i-octyl acrylate, acrylic acid, acrylamide, acrylonitrile, styrene, and p-chloromethyl styrene, were incorporated into the shells during the second-stage polymerization. The resulting core–shell polymer particles were characterized with scanning electron microscopy and Fourier transform infrared spectroscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1776–1784, 2006

Enhanced water retention and stable dynamic water behavior of sulfonated poly(ether ether ketone) membranes under low humidity by incorporating humidity responsive double-shelled hollow spheres

Co-reporter:Enwei Yan, Jingtao Wang, Zhongyi Jiang, Hailiang Feng, Lingli Nie, Tao Xu, Xinlin Yang and Xu Zhang

Journal of Materials Chemistry A 2013 - vol. 1(Issue 38) pp:NaN11777-11777

Publication Date(Web):2013/07/16

DOI:10.1039/C3TA11620D

Double shelled hollow SnO2/polymer microsphere as a high-capacity anode material for superior reversible lithium ion storage

Co-reporter:Meijun Zhou, Yongchang Liu, Jun Chen and Xinlin Yang

Journal of Materials Chemistry A 2015 - vol. 3(Issue 3) pp:NaN1076-1076

Publication Date(Web):2014/11/10

DOI:10.1039/C4TA05235H

Rattle-type microspheres as a support of tiny gold nanoparticles for highly efficient catalysis

Co-reporter:Bin Liu, Wei Zhang, Hailiang Feng and Xinlin Yang