Mo-Zhen Wang

Three-dimensionally ordered macroporous (3DOM) polytetrafluoroethylene (PTFE) has hardly been prepared due to the poor solubility in most of solvents and high melting temperature of PTFE raw material. In this work, monodispersed polystyrene (PS) microspheres and PTFE latex particles were controlled to simultaneously deposit from water. After the deposits were calcinated at 400 °C, a self-supported superhydrophobic 3DOM PTFE film with a static water contact angle of 154° was successfully fabricated. The pore size can be tunable from 1.5 to 3 μm, depending on the size of PS microspheres. The prepared 3DOM PTFE film were used as micromolds and microreactors to prepare poly(methyl methacrylate) (PMMA) particles and TiO2 macroporous material, respectively. This work provides a facile method to fabricate 3DOM PTFE materials.

Formation of Cagelike Sulfonated Polystyrene Microspheres via Swelling-Osmosis Process and Loading of CdS Nanoparticles

Co-reporter:Hanqin Weng, Xuefeng Huang, Mozhen Wang, Xiang Ji, and Xuewu Ge

Langmuir December 10, 2013 Volume 29(Issue 49) pp:15367-15374

Publication Date(Web):November 22, 2013

DOI:10.1021/la403045c

In this report, we studied the formation mechanism of cagelike polymer microspheres fabricated conveniently and efficiently through a swelling-osmosis process of sulfonated polystyrene (SPS) microspheres in a ternary mixed solvent (water/ethanol/heptane). The scanning electron microscopy and transmission electron microscopy observations indicated that the morphology of the final cagelike SPS microspheres is mainly controlled by the composition of the mixed solvent and the swelling temperature. Considering the solubility parameters of related reagents and the low interface tension of heptane and the aqueous solution of ethanol (only 6.9 mN/m), we confirm that the porogen procedure starts from the swelling of SPS microspheres by heptane, followed by the osmosis process of water molecules into the swollen SPS microspheres forced by the strong hydrophilicity of −SO3H group. The water molecules permeated into SPS microspheres will aggregate into water pools, which form the pores after the microspheres are dried. These prepared cagelike SPS microspheres are further served as the scaffold for the in situ generated CdS nanoparticles under γ-ray radiation. The CdS/SPS composite microspheres show good fluorescence performance. This work shows that the cagelike SPS microspheres have a wide industrial application prospect due to their economical and efficient preparation and loading nanoparticles.

Chitosan modified by γ-ray-induced grafting of poly(tributyl-(4-vinylbenzyl)phosphonium) as a biosafe and high-efficiency gene carrier

Co-reporter:Kun Zeng;Fu-xing Lin;Juan Xie;Jie-lin Rong;Yu Zhao;Ye-zi You;Anila Asif;Xue-wu Ge

New Journal of Chemistry (1998-Present) 2017 vol. 41(Issue 10) pp:4182-4189

Publication Date(Web):2017/05/15

DOI:10.1039/C7NJ00008A

The development of gene carriers with high delivery efficiency and enough biosafety to replace the current viral vectors and cationic liposomes has long been a key project to achieve the practical application of gene therapy. As an abundant natural polymer, chitosan (CS) possesses incomparably high biocompatibility. However, when it is used as a gene carrier, the gene transfection efficiency is rather disappointing. Herein, we prepared a novel chitosan derivative, poly(tributyl-(4-vinylbenzyl)phosphonium)-grafted CS (CS-P), via γ-ray radiation-induced grafting copolymerization of tributyl-(4-vinylbenzyl)phosphonium in an acidic solution of CS. The CS-P could combine with pEGFP through a complex coacervation method to form pEGFP-loaded CS-P complex particles with a size of about 150 nm and a high positive zeta potential of 41.7 ± 6.1 mV. Agarose gel electrophoresis and an MTT assay show that the pEGFP-loaded CS-P particles have excellent biosafety, superior to pEGFP-loaded unmodified CS particles. In vitro and in vivo gene transfection experiments based on HeLa cells confirmed that pEGFP loaded into CS-P particles exhibits much higher gene transfection efficiency than that loaded into unmodified CS. This work provides not only a new way to modify CS with quaternary phosphonium, but also a useful and feasible way to obtain new CS-based gene vectors with high gene transfection efficiency and biosafety for potentially practical clinic applications.

One-step synthesis of self-healable hydrogels by the spontaneous phase separation of linear multi-block copolymers during the emulsion copolymerization

Co-reporter:Lan-Lan Li, Ru-Yi Jiang, Jin-Xing Chen, Mo-Zhen Wang, Xue-Wu Ge

Chinese Chemical Letters 2017 Volume 28, Issue 4(Volume 28, Issue 4) pp:

Publication Date(Web):1 April 2017

DOI:10.1016/j.cclet.2016.12.025

Self-healable polyacrylamide-based hydrogels were prepared at room temperature via a one-step emulsion copolymerization of acrylamide (AM), dodecyl 2-methacrylate (DM), and 5-acetylaminopentyl acrylate (AAPA) using sodium dodecyl sulfonate (SDS) as the emulsifier and ammonium persulfate (APS) as the initiator. The produced linear multi-block copolymer chains are composed of randomly-linked hydrophilic polyacrylamide segments (PAM) and hydrophobic segments constituted by DM and AAPA units (P(DM-co-AAPA)). The P(DM-co-AAPA) segments will self-aggregate into hydrophobic microdomains during the polymerization process driven by the hydrophobic interactions, and finally separate from water phase, acting as the crosslinks and leading to the formation of strong hydrogels with a storage modulus as high as 400 Pa. These hydrophobic microdomains will be dissolved in water when the temperature increases to 70 °C, resulting in a temperature-responsive reversible sol-gel transition of the prepared hydrogels. Furthermore, the prepared hydrogels have excellent self-healing ability. The broken hydrogels can be automatically healed into a body with a same strength within 2-min’s contact. This work provides a new simple way to prepare reversible physical crosslinked hydrogel with high strength and self-healing efficiency.Download high-res image (89KB)Download full-size imageThe temperature-responsive hydrogel with excellent self-healing ability was one-step synthesized by the emulsion copolymerization of acrylamide, dodecyl 2-methacrylate, and 5-acetylaminopentyl acrylate.

Fibrous N-doped hierarchical porous carbon microspheres: Synthesis and adsorption performance

Co-reporter:Yunyun Xie, Wenxiu Yang, Mozhen Wang, Xuewu Ge

Chemical Engineering Journal 2017 Volume 323(Volume 323) pp:

Publication Date(Web):1 September 2017

DOI:10.1016/j.cej.2017.04.035

•N-doped hierarchical porous carbon (FNC) microspheres were fabricated.•The FNC microspheres with a surface area of 554.5 m2/g have micro- and macro-pores.•The FNC microspheres can be stably dispersed in water due to the N-doping.•The FNC microspheres have an excellent adsorption ability for RhB and can be reused.The creation of high surface area and effective active sites is the key problem for the synthesis of high-performance porous carbon materials. In this work, polyacrylonitrile-coated fibrous silica (F-SiO2@PAN) microspheres were prepared by in situ polymerization of acrylonitrile on fibrous mesoporous silica microspheres induced by γ-ray radiation. After F-SiO2@PAN microspheres were carbonized and etched with hydrofluoric acid, uniform fibrous N-doped porous carbon (FNC) microspheres with an average size of 286 nm and a molar ratio of C/N of 5.2 were successfully prepared. As revealed by TEM, SEM, and N2 adsorption-desorption isotherms analysis, FNC microspheres have a hierarchal micro-macroporous structure with a particular high surface area of 554.5 m2/g. The FNC microspheres also exhibit a good water dispersibility and an excellent adsorption ability to rhodamine B in water. The equilibrium adsorption capacity of FNC microspheres could reach 95.4 mg/g, which is 1.6 times as that of the primary silica template microspheres. The adsorption kinetics and thermodynamics of FNC microspheres are in accord with the pseudo-second-order kinetic equation and Freundlich isotherm model, respectively. This work provides a facile synthesis method for novel N-doped hierarchical micro-macroporous carbon microsphere as a potential high-performance adsorbent material.Download high-res image (103KB)Download full-size image

Chitosan-based core–shell structured particles for in vivo sustainable gene transfection

Co-reporter:Fu-xing Lin, Jie-lin Rong, Mo-zhen Wang, Dan-dan Bao, Yun Wang, Zhen-xing Gong, Yu-fang Gu, Yu Zhao and Xue-wu Ge

Journal of Materials Chemistry A 2016 vol. 4(Issue 5) pp:893-901

Publication Date(Web):21 Dec 2015

DOI:10.1039/C5TB02074C

A core–shell structured chitosan (CS)-based gene vector with a sustainable gene transfection effect was designed and successfully prepared in this study. The pEGFP was first combined with the thiolated and N-alkylated chitosan (TACS). Then, hydroxybutyl chitosan grafted with poly(ethylene glycol) (EG–HBC) was coated on the pEGFP-loaded TACS particles. The prepared pEGFP-loaded TACS@EG–HBC particles have a size of about 200 nm and little cytotoxicity. The in vitro and in vivo gene transfection experiments indicate that the pEGFP-loaded TACS@EG–HBC particles possess a better sustainable gene transfection capacity and a high transfection efficiency, which should be attributed to the biodegradation of the CS-based shell, the thiolation and N-alkylation modification on CS cores, and the grafted PEG chains with better biocompatibility. The in vivo gene expression of the loaded pEGFP can persist up to 60 days. This novel gene vector has a theoretical and practical significance for gene therapy with sustained transfection effect.

Hierarchical porous SnO2/reduced graphene oxide composites for high-performance lithium-ion battery anodes

Co-reporter:Lechen Chen, Xiaohang Ma, Mozhen Wang, Chunhua Chen, Xuewu Ge

Electrochimica Acta 2016 Volume 215() pp:42-49

Publication Date(Web):10 October 2016

DOI:10.1016/j.electacta.2016.08.079

•Reduced graphene oxide (rGO) was obtained by γ-ray radiation on GO dispersion.•Hierarchical porous SnO2 incorporated with rGO (HP-SnO2/rGO) was fabricated.•LIB using HP-SnO2/rGO as the anode exhibits superior cycle and rate performance.The structure design of SnO2-based anode material is crucial for the development of high-performance lithium-ion batteries (LIB). Here, a solvent-evaporation induced codeposition of monodispersed polystyrene (PS) microspheres (241 nm) and γ-radiation reduced graphene oxide (rGO) at the presence of the surfactant, cetyltrimethylammonium bromide (CTAB), has been firstly conducted to prepare a self-stand PS/rGO composite template film, which can transform into a porous SnO2/rGO composite material after being infiltrated with the precursor of SnO2 and further calcinated at 420 °C. TGA, SEM, TEM, and nitrogen adsorption-desorption isotherms analyses indicate that the prepared SnO2/rGO composite material has 52.1 wt% of rGO, and a hierarchical pore structure, i.e., mesopores (3.312 nm) and macropores (∼200 nm) coexist. The half-cell using the hierarchical porous structured SnO2/rGO composite as the electrode exhibits an excellent cycle performance (850 mAh g−1 in 100 cycles at a current density of 0.3C) and rate property of 436 mAh g−1 at a current density of 4.5C. This work indicates that the incorporation of graphene-based materials into hierarchical porous SnO2 matrix will be a potential way to obtain high-performance LIB anode material.

Macroporous Polytetrafluoroethylene Film with a Reusable Matrix and Its Application as the Microreactors

Co-reporter:Yunlong Wang;Chi Zhao;Mozhen Wang;Qichao Wu;Xiao Zhou;Xuewu Ge

Macromolecular Materials and Engineering 2016 Volume 301( Issue 6) pp:674-681

Publication Date(Web):

DOI:10.1002/mame.201500393

Effect of γ-Ray-Radiation-Modified Graphene Oxide on the Integrated Mechanical Properties of PET Blends

Co-reporter:Lizhao Xie, Guowei Duan, Weikang Wang, Mozhen Wang, Qichao Wu, Xiao Zhou, and Xuewu Ge

Industrial & Engineering Chemistry Research 2016 Volume 55(Issue 29) pp:8123-8132

Publication Date(Web):July 7, 2016

DOI:10.1021/acs.iecr.6b01935

The surface modification of graphene oxide (GO) determines the interactions between GO and polymers, which possibly produces a significant impact on the mechanical properties of polymer. Here, GO was first modified with poly(glycidyl methacrylate) (PGMA) and triethylenetetramine (TTA) through γ-ray radiation. Then, a tiny small amount (0.04%) of the prepared modified GO was filled with a PET/ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (PET/ST2000) blend. The morphological analyses on these filled PET blends confirmed that the surface chemical structure of GO had a crucial impact on the mechanical property of the blend. The chemical bonding between GO and ST2000 was more efficient in improving the dispersibility of GO and the compatibility between PET and ST2000, leading to a 2.5-fold increase in the impact strength, along with a slight increase in tensile strength. However, the addition of reduced GO lacking polar groups caused fatal damage in the mechanical property of the blend.

Synthesis and morphology control of raspberry-like poly(ethylene terephthalate)/polyacrylonitrile microspheres

Co-reporter:Yong-Fei Xu, Mo-Zhen Wang, Qi-Chao Wu, Xiao Zhou, Xue-Wu Ge

Chinese Chemical Letters 2016 Volume 27(Issue 2) pp:195-199

Publication Date(Web):February 2016

DOI:10.1016/j.cclet.2015.12.004

The fabrication of raspberry-like poly(ethylene terephthalate)/polyacrylonitrile (PET/PAN) microspheres by γ-ray radiation-induced polymerization of acrylonitrile on micron-sized PET microspheres were first reported in this work. A PET emulsion was firstly prepared by dispersing a PET solution with 1,1,2,2-tetrachloroethane/phenol mixture as the solvent into an aqueous solution of sodium dodecyl sulfate. Then, PET microspheres were formed by precipitating the PET emulsion droplets from ethanol. The influence of the PET solvent and the weight ratio of ethanol to PET emulsion on the morphology of the PET microspheres had been investigated. After the surface of the prepared PET microspheres was grafted with poly(acrylic acid), the grafting polymerization of AN also had been successfully initiated by γ-ray radiation to form PAN microspheres with a size of about 100 nm on the PET microspheres. This work provides a new method to fabricate micron-sized PET microspheres, and further expands the functionalization of PET and its application fields.PET microspheres are fabricated by precipitating the PET emulsion droplets from the precipitant. The grafting polymerization of AN can be further initiated by γ-ray radiation on the PET microspheres to form raspberry-like PET/PAN microspheres.

Fabrication of macroporous polystyrene/graphene oxide composite monolith and its adsorption property for tetracycline

Co-reporter:Le-Chen Chen, Shan Lei, Mo-Zhen Wang, Jun Yang, Xue-Wu Ge

Chinese Chemical Letters 2016 Volume 27(Issue 4) pp:511-517

Publication Date(Web):April 2016

DOI:10.1016/j.cclet.2016.01.057

Macroporous polystyrene microsphere/graphene oxide (PS/GO) composite monolith was first prepared using Pickering emulsion droplets as the soft template. The Pickering emulsion was stabilized by PS/GO composite particles in-situ formed in an acidic water phase. With the evaporation of water and the oil phase (octane), the Pickering emulsion droplets agglomerated and combined with each other, forming a three-dimensional macroporous PS/GO composite matrix with excellent mechanical strength. The size of the macrospores ranged from 4 μm to 20 μm. The macroporous PS/GO composite monolith exhibited high adsorption capacity for tetracycline (TC) in an aqueous solution at pH 4–6. The maximum adsorption capacity reached 197.9 mg g−1 at pH 6. The adsorption behaviour of TC fitted well with the Langmuir model and pseudo-second-order kinetic model. This work offers a simple and efficient approach to fabricate macroporous GO-based monolith with high strength and adsorption ability for organic pollutants.A macroporous polystyrene/graphene oxide composite monolith with high adsorption capability for tetracycline was fabricated via the aggregation of Pickering emulsion droplets stabilized by the PS/GO composite particles.

Highly crosslinked poly(ethyleneglycol dimethacrylate)-based microspheres via solvothermal precipitation polymerization in alcohol–water system

Co-reporter:Jinxing Chen, Chi Zhao, Hanhong Huang, Mozhen Wang, Xuewu Ge

Polymer 2016 Volume 83() pp:214-222

Publication Date(Web):28 January 2016

DOI:10.1016/j.polymer.2015.12.028

•The solvothermal precipitation polymerization of EGDMA was firstly reported.•Highly-crosslinked PEGDMA microsphere can be prepared in an alcohol–water solution.•The formation of highly-crosslinked PEGDMA microsphere needs no extra stabilizer.•The comonomer 4-vinyl pyridine can stable and functionalize the PEGDMA microsphere.The preparation of highly crosslinked polymer microspheres through the polymerization reaction in an alcohol–water solution without any stabilizer is still a difficult task. Here, we first reported a facile preparation of monodispersed highly-crosslinked microspheres through the polymerization of ethyleneglycol dimethacrylate (EGDMA) in an alcohol–water solution in the presence of a small amount of hydrophilic comonomer with a high reactivity ratio in a sealed autoclave at above the boiling point of the solvent, which can be considered as a solvothermal precipitation polymerization process. The formation mechanism of the poly(ethyleneglycol dimethacrylate) (PEGDMA)-based microspheres involving an initial nucleation process and the grow process of the microspheres was proposed and confirmed by the composition and distribution of the hydrophilic comonomer in the oligomers and microspheres, which were analyzed by 1H and 13C CP-MAS solid NMR spectra, elemental mapping, and XPS. This work opens a new economic and environmental-friendly way to prepare highly-crosslinked functional PEGDMA-based microspheres.Highly-crosslinked PEGDMA microsphere can be prepared by the solvothermal precipitation polymerization of EGDMA in an alcohol–water solution in the presence of a small amount of hydrophilic comonomer with a high reactivity ratio.

Preparation of three-dimensional inverse opal SnO2/graphene composite microspheres and their enhanced photocatalytic activities

Co-reporter:Lechen Chen, Lizhao Xie, Mozhen Wang and Xuewu Ge

Journal of Materials Chemistry A 2015 vol. 3(Issue 6) pp:2991-2998

Publication Date(Web):08 Dec 2014

DOI:10.1039/C4TA05898D

Three-dimensional inverse opal SnO2/graphene (IO-SnO2/graphene) microspheres with a size of several tens of microns are first prepared by a well-designed two-step calcination of polystyrene (PS) colloidal crystal template balls infiltrated with the sol precursors of SnO2 and graphene oxide. The polystyrene colloidal crystal template balls are formed by the self-assembly of monodispersed PS microspheres confined in water droplets of an inverse emulsion induced by the slow evaporation of water. Characterization with scanning electronic microscopy, Raman spectra, X-ray diffraction and X-ray photoelectron spectroscopy proved the ordered macroporous inverse opal composed of crystalline SnO2 and in situ reduced GO during the calcination. The pore size depends on the PS microspheres. The UV-vis diffusive reflectance spectra show that the light absorption edge of the prepared IO-SnO2/graphene microspheres can shift more than 400 nm. The photoluminescence spectra indicates that the IO structure and the introduction of rGO make the charge carriers transfer fast and retard the hole/electron recombination in the IO-SnO2/graphene microspheres so that their photocatalytic performance on the UV photolysis of methyl orange is considerably better than that of commercial SnO2 nanoparticles. However, the photocatalytic performance also depends on the content of GO. The addition of 0.06 wt% of GO achieves the best photocatalytic effect. Excessive GO will result in a diminished catalytic activity. This work provides a way to fabricate a new morphological SnO2 based materials with enhanced photocatalytic activity, which helps in the exploration of new photocatalysts with high performance.

Fabrication of High-Performance Magnetic Lysozyme-Imprinted Microsphere and Its NIR-Responsive Controlled Release Property

Co-reporter:Jinxing Chen, Shan Lei, Yunyun Xie, Mozhen Wang, Jun Yang, and Xuewu Ge

ACS Applied Materials & Interfaces 2015 Volume 7(Issue 51) pp:28606

Publication Date(Web):December 7, 2015

DOI:10.1021/acsami.5b10126

The preparation of efficient and practical biomacromolecules imprinted polymer materials is still a challenging task because of the spatial hindrance caused by the large size of template and target molecules in the imprinting and recognition process. Herein, we provided a novel pathway to coat a NIR-light responsive lysozyme-imprinted polydopamine (PDA) layer on a fibrous SiO2 (F-SiO2) microsphere grown up from a magnetic Fe3O4 core nanoparticle. The magnetic core–shell structured lysozyme-imprinted Fe3O4@F-SiO2@PDA microspheres (MIP-lysozyme) can be easily separated by a magnet and have a high saturation adsorption capacity of lysozyme of 700 mg/g within 30 min because of the high surface area of 570 m2/g and the mesopore size of 12 nm of the Fe3O4@F-SiO2 support. The MIP-lysozyme microspheres also show an excellent selective adsorption of lysozyme (IF > 4). The binding thermodynamic parameters studied by ITC proves that the lysozyme should be restricted by the well-defined 3D structure of MIP-lysozyme microspheres. The MIP-lysozyme can extract lysozyme efficiently from real egg white. Owing to the efficient NIR light photothermal effect of PDA layer, the MIP-lysozyme microspheres show the controlled release property triggered by NIR laser. The released lysozyme molecules still maintain good bioactivity, which can efficiently decompose E. coli. Therefore, this work provides a novel strategy to build practical NIR-light-responsive MIPs for the extraction and application of biomacromolecules.Keywords: controlled release; Fe3O4 nanoparticles; fibrous SiO2; lysozyme; NIR-light; polydopamine; protein imprinting

pH-Responsive cagelike porous polymer microspheres prepared via consecutive RAFT polymerization induced by γ-ray radiation

Co-reporter:Hanqin Weng, Hanhong Huang, Yusong Wang, Mozhen Wang and Xuewu Ge

Polymer Chemistry 2015 vol. 6(Issue 44) pp:7717-7725

Publication Date(Web):10 Sep 2015

DOI:10.1039/C5PY01257K

Although RAFT polymerization in a homogeneous system has been widely studied, RAFT mediated polymerization on a solid–liquid surface has rarely been mentioned. In this work, a two-step consecutive RAFT polymerization of methyl methacrylate (MMA) and acrylic acid (AA) on the sulfonated polystyrene (SPS) microspheres dispersed in water was achieved under γ-ray radiation. As a result, poly(acrylic acid) (PAA)-grafted cagelike porous SPS/PMMA microspheres with distinct pH-responsive release properties have been fabricated. The RAFT mediated polymerization on the surface of porous microspheres has been discussed in detail based on the 1H NMR spectra combined with the 2D 1H–13C heteronuclear singular quantum correlation (HSQC) spectra. This work not only enriches the mechanism of heterogeneous surficial RAFT polymerization, but also indicates that γ-ray radiation induced RAFT mediated polymerization on a solid–liquid surface should be a practical technique for the fabrication of porous materials with subtle controllable surface properties.

The unfolding of G-quadruplexes and its adverse effect on DNA—gold nanoparticles-based sensing system

Co-reporter:Sheng Cheng, Bin Zheng, Mozhen Wang, Xuewu Ge, Qing Zhao, Wei Liu, Michael Hon-Wah Lam

Biosensors and Bioelectronics 2014 Volume 53() pp:479-485

Publication Date(Web):15 March 2014

DOI:10.1016/j.bios.2013.10.016

•The adsorption of DNAs in G-quadruplex solutions onto gold nanoparticles was observed.•The adsorption behavior was investigated in three widely used guanine-rich sequences.•ICP-AES was used to discover the occurrence of the unfolding of G-quadruplexes.•The potential unfolding by gold nanoparticles has adverse effect on the biosensing system.The adsorption of DNAs in G-quadruplex solution onto 13 nm gold nanoparticles (AuNPs) was studied through monitoring of the localized surface plasmon resonance (LSPR) absorbance of 13 nm AuNPs at 520 and 650 nm (A650/A520) in the solutions of three widely studied guanine-rich sequences, TBA(5′-GGTTGGTGTGGTTGG-3′), PW17(5′-GGGTAGGGCGGGTTGGG-3′), and PSO (5′-GGGTTAGGGTTAGGGTTAGGG-3′). It was found that the degree of adsorption of DNAs in Pb2+ stabilized G-quadruplex (G-Pb2+) solutions is up to 93% after more than 5 h of incubation. Furthermore, the lead concentrations in the solutions containing G-quadruplex and AuNP were analyzed by an inductively coupled plasma atomic emission spectrometer. The results showed that Pb2+ had been released from the G-quadruplexes, which means the G-quadruplexes may be unfolded in the presence of AuNP. This interaction between G-quadruplexes and AuNP demonstrated that long time incubation between DNAs and AuNPs would possibly make it unable to distinguish G-quadruplex from ssDNA. Thus, a biosensing system consisting of PW17 and AuNPs was developed to detect Pb2+. It was found that the LSPR responses at A650/A520 were sensitive to [Pb2+]. However, the sensitivity of the system was interfered by the potential unfolding of PW17-Pb2+ in the presence of AuNPs. This unexpected adverse effect of AuNPs on DNA-based biosensors should be taken into consideration in the future development of biosensing systems that are based on ssDNA aptamers and unmodified AuNPs.

The fabrication and corrosion resistance of benzotriazole-loaded raspberry-like hollow polymeric microspheres

Co-reporter:Dong Zhao, Mozhen Wang, Yongfei Xu, Zhicheng Zhang, Xuewu Ge

Surface and Coatings Technology 2014 Volume 238() pp:15-26

Publication Date(Web):15 January 2014

DOI:10.1016/j.surfcoat.2013.10.031

•BTA can be encapsulated in raspberry-like hollow polymeric microspheres.•The release of BTA can be triggered by the change of pH.•The BTA-encapsulated raspberry-like hollow microspheres can be embedded into WPU film.•The composite WPU film exhibits good anti-corrosive property.This work presents a synthesis of submicron-sized raspberry-like hollow microspheres loaded with corrosion inhibitor (1H-benzotriazole (BTA)) through a multi-stage emulsion polymerization. The combination of hierarchical raspberry-like surface structure and loading of BTA makes the prepared microspheres have good corrosion resistance. When BTA-loaded raspberry-like hollow microspheres are embedded in a water-borne polyurethane film, the obtained composite film can protect the copper from corrosion both in acidic and alkaline corrosive solutions.

Fabrication of Superhydrophobic Three-Dimensionally Ordered Macroporous Polytetrafluoroethylene Films and Its Application

Co-reporter:Yunlong Wang, Mozhen Wang, and Xuewu Ge

Langmuir 2014 Volume 30(Issue 36) pp:10804-10808

Publication Date(Web):September 1, 2014

DOI:10.1021/la502866h

Synthesis of Anisotropic Polymer/Inorganic Particles via Asymmetric Swelling–Dissolving Process

Co-reporter:Xiang Ji, Mozhen Wang, Xuewu Ge, and Huarong Liu

Langmuir 2013 Volume 29(Issue 4) pp:1010-1016

Publication Date(Web):January 2, 2013

DOI:10.1021/la304806d

In this work, an asymmetric swelling–dissolving process of original submicrometer-sized decentered sulfonated polystyrene/silica (SPS/silica) particles in a ternary mixed solvent (water/ethanol/heptane) was first reported. Actinia-like and porous snowman-like SPS/silica composite particles are fabricated through tuning the composition of the ternary mixed solvent. Actinia-like particles, with a silica core embedded in a “blooming” SPS matrix, are obtained when the composition of the mixed solvent is 5 g/5 g/0.1 g (water/ethanol/heptane). If the amount of heptane in the mixed solvent is doubled, then porous snowman-like particles are produced. The TEM and SEM images show that silica particles are exposed in these two anisotropic SPS/silica composite particles compared with the original decentered SPS/silica particles. Considering the particles morphology and the swelling and dissolving performance of SPS in different solvents, the formation of the new-shaped anisotropic SPS/silica composite particles should be attributed to an asymmetric swelling-dissolving process; that is, the swelling–dissolving rate of SPS coating around the protruding silica part is faster than the other part of the composite particles. The anisotropic swelling–dissolving property of polymer/inorganic composite particles inspires a facile way to the fabrication of new composite particles.

Morphological Control of Multihollow Polymer Latex Particles through a Controlled Phase Separation in the Seeded Emulsion Polymerization

Co-reporter:Bingxin Li, Yongfei Xu, Mozhen Wang, and Xuewu Ge

Langmuir 2013 Volume 29(Issue 48) pp:14787-14794

Publication Date(Web):2017-2-22

DOI:10.1021/la403166q

In this work, we first reported that the phase separation can take place both inside and outside of a multihollow-structured cross-linked seed microspheres swollen by styrene monomers in water during the radiation-induced seeded emulsion polymerization. The phase separation process in these two opposite directions will determine the morphology of final latex particles. First, sulfonated cross-linked polystyrene (SCPS) seed microspheres were swollen by styrene in water. Water will permeate into the SCPS seed microspheres during the swelling process, forced by the osmotic pressure produced by the strong hydrophilicity of the sulfonic acid groups. New aqueous phases are created and stabilized by the hydrophilic −SO3H groups, resulting in a multihollow structure of swollen SCPS seed microspheres. When the polymerization of styrene is induced by 60Co γ-ray radiation, the phase separation of newly formed polystyrene phase will occur at the seed microsphere-water interface inside and/or outside of the SCPS seed microspheres through adjusting the diameter of seed microsphere, the content of cross-link agent, and the sulfonation degree of SCPS seed microspheres. As a result, SCPS latex particles with a variety of special morphologies, such as spherical multihollow, plum-like, and walnut-like latex particles were obtained. The results of this study provide not only a simple and interesting way to design and synthesize multihollow polymer latex particles with controllable surface morphologies but also a better understanding on phase separation mechanism during the swelling and polymerization of monomers in cross-linked amphiphilic polymer networks.

Formation of Cagelike Sulfonated Polystyrene Microspheres via Swelling-Osmosis Process and Loading of CdS Nanoparticles

Co-reporter:Hanqin Weng, Xuefeng Huang, Mozhen Wang, Xiang Ji, and Xuewu Ge

Langmuir 2013 Volume 29(Issue 49) pp:15367-15374

Publication Date(Web):November 22, 2013

DOI:10.1021/la403045c

Fabrication of raspberry SiO2/polystyrene particles and superhydrophobic particulate film with high adhesive force

Co-reporter:Dezhi Xu, Mozhen Wang, Xuewu Ge, Michael Hon-Wah Lam and Xueping Ge

Journal of Materials Chemistry A 2012 vol. 22(Issue 12) pp:5784-5791

Publication Date(Web):14 Feb 2012

DOI:10.1039/C2JM15364E

We report a facile and novel strategy on the fabrication of well-defined raspberry SiO2/polystyrene (SiO2/PS) particles via radiation miniemulsion polymerization. Starting from methacryloxypropyltrimethoxysilane (MPS)-functionalized SiO2 particles (176 nm), raspberry SiO2/PS particles (257 nm) with a submicron SiO2 core decorated by nano-sized PS latex particles (58 nm) are obtained after γ-ray induced miniemulsion polymerization of styrene (St). It is found that MPS grafted density on the surface of submicron SiO2 particles, the weight ratio of St to SiO2 particles (WSt/o-SiO2), as well as the surfactant concentration will affect the morphology and wettability of the resultant SiO2/PS hybrid particles. When the well-defined raspberry SiO2/PS particles are deposited on a blank glass substrate, a dual-size roughness surface topology was observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). This film has a static water contact angle as high as 151°. However, this film exhibits a large contact angle hysteresis (∼116°) and strong adhesion to water. Furthermore, this kind of superhydrophobic particulate film can be used as a “mechanical hand” for transportation of small water droplets without loss, thus it may have potential applications in industrial fields.

Facile fabrication of flower-like nanocomposite microparticles via seeded miniemulsion polymerization

Co-reporter:Jianan Zhang, Xuewu Ge, Mozhen Wang, Mingyuan Wu, Jianjun Yang and Qingyun Wu

Polymer Chemistry 2012 vol. 3(Issue 8) pp:2011-2017

Publication Date(Web):24 Apr 2012

DOI:10.1039/C2PY20193C

Seed polymer/silica particles are synthesized by double in situ miniemulsion polymerization of methyl methacrylate (MMA) and hydrolysis–condensation of tetraethoxysilane (TEOS) under basic conditions simultaneously. Nanocomposite microparticles with a controlled morphology are fabricated from seed polymer/silica particles by the further miniemulsion polymerization of styrene. We have demonstrated that the seed PMMA/silica particles are cross-linked by nanosilica particles, which are dispersed homogeneously in the polymer matrix. The in situ formed silica nanoparticles acting as the cross-linking agent favor the formation of nonspherical nanocomposite microparticles with a flower-like structure. Furthermore composite microparticles of spherical morphology are obtained without γ-(trimethoxysilyl)propyl methacrylate (MPS). The addition of divinylbenzene (DVB) leads to a higher degree of cross-linking of the seed polymer particles, which favors the formation of peanut-like microparticles.

Synthesis and Characterization of -CD-Coated Polystyrene Microspheres by -Ray Radiation Emulsion Polymerization

Co-reporter:Dezhi Xu;Mozhen Wang;Xuewu Ge;Michael Hon-Wah Lam

Macromolecular Rapid Communications 2012 Volume 33( Issue 22) pp:1945-1951

Publication Date(Web):

DOI:10.1002/marc.201200437

Abstract

Polystyrene (PS) microspheres coated with β-cyclodextrin (β-CD) were fabricated via γ-ray-induced emulsion polymerization in a ternary system of styrene/β-CD/water (St/β-CD/water). The solid inclusion complex of St and β-CD particles formed at the St droplets–water interface can stabilize the emulsion as the surfactant. TEM and XPS results showed that β-CD remains on the surface of PS particles. The average size of the PS particles increases from 186 to 294 nm as the weight ratio of β-CD to St rises from 5% to 12.5%. The water contact angle (CA) of PS latex film is lower than 90°, and reduces with the β-CD content even to 36°. Thus, this work provides a new and one-pot strategy to surface hydrophilic modification on hydrophobic polymer particles with cyclodextrins through radiation emulsion polymerization.

A novel approach for preparation of “cage-like” multihollow polymer microspheres through sulfonated polystyrene particles

Co-reporter:Xueping Ge;Xuewu Ge;Mozhen Wang;Huarong Liu;Bin Fang

Colloid and Polymer Science 2012 Volume 290( Issue 17) pp:1749-1757

Publication Date(Web):2012 November

DOI:10.1007/s00396-012-2709-8

A new and effective process has been developed for fabrication of novel cage-like multihollow polymer particles by using sulfonated polystyrene (SP) particles as the templates, with heptane as the phase separation agent, in an ethanol/water medium. The ratio of water/ethanol and the heating temperature play important roles in the formation of these multihollow particles. It was found that the cage-like polymer particles could be obtained when the ratio of ethanol/water is 5:5 (w/w), with a temperature above 50 °C. After a detailed study, the formation mechanism was proposed based on an SP swollen (ethanol and heptane penetrating process) and phase separation process. This new method for fabricating the cage-like multihollow polymer particles has a great meaning not only on confirming the formation mechanism, but also on providing an effective way to prepare the special hollow core/porous shell polymer particles, which could have wide range of potential applications, such as catalysts, sensors, and drug release.

Colloidal silver deposition onto functionalized polystyrene microspheres

Co-reporter:Jianan Zhang, Xuewu Ge, Mozhen Wang, Jianjun Yang, Qingyun Wu, Mingyuan Wu and Dandan Xu

Polymer Chemistry 2011 vol. 2(Issue 4) pp:970-974

Publication Date(Web):03 Feb 2011

DOI:10.1039/C0PY00320D

This paper presents a facile method for the preparation of silver/polystyrene (Ag/PS) composite microspheres. PS microspheres with carboxyl and nitrile groups on the surfaces were synthesized via a two-step dispersion copolymerization of styrene, itaconic acid, and acrylonitrile in ethanol–water media. Ag/PS composite microspheres were prepared successively by addition of AgNO3 aqueous solution to the dispersion, absorbing to the surfaces of functional PS microspheres, and then reduction of Ag+ ions to silver nanoparticles by aqueous hydrazine hydrate. The results showed that Ag nanoparticles with size of about 50 nm were located on the shell of PS microspheres due to the combined interactions between the carboxyl and nitrile groups of PS microspheres and the in situ formed silver nanoparticles. The as-prepared Ag/PS microspheres showed good catalytic properties.

One-Pot Synthesis of Colloidal Nanobowls and Hybrid Multipod-like Nanoparticles by Radiation Miniemulsion Polymerization

Co-reporter:Xueping Ge;Xuewu Ge;Mozhen Wang;Huarong Liu;Bin Fang;Zhi Li;Xiaojun Shi;Cunzhong Yang;Guang Li

Macromolecular Rapid Communications 2011 Volume 32( Issue 20) pp:1615-1619

Publication Date(Web):

DOI:10.1002/marc.201100337

Facile fabrication of free-standing colloidal-crystal films by interfacial self-assembly

Co-reporter:Jianan Zhang, Mozhen Wang, Xuewu Ge, Mingyuan Wu, Qingyun Wu, Jianjun Yang, Manyi Wang, Zhilai Jin, Nannan Liu

Journal of Colloid and Interface Science 2011 Volume 353(Issue 1) pp:16-21

Publication Date(Web):1 January 2011

DOI:10.1016/j.jcis.2010.09.007

This paper reports a rapid and facile method of preparing free-standing colloidal crystals from monodisperse charged polystyrene (PS) microspheres. Mixed solvents (ethanol/water) were used as the dispersion medium in the self-assembly process of colloidal crystals. By a simple “floating self-assembly” method, PS microspheres floated on the surface of liquid and self-assembled into large area of three-dimensional (3D) ordered colloidal crystals within 15 min. Then epichlorohydrin was added in as a cross-linking agent to strengthen the colloidal-crystal film. After cross-linking reactions between the microspheres, the obtained colloidal-crystal film was free-standing and could be easily transferred to other substrates. Using tetrabutyl titanate as a titania precursor, 3D porous TiO2 materials with rodlike skeletal structure were fabricated from the prepared free-standing colloidal crystal. This work provides a facile method to fabricate free-standing colloidal-crystal film, which can be used as an ideal template for the preparation of porous materials.Graphical abstractOptical photographs of colloidal multi-layers from PS microspheres of different size: (a) 140 nm, (b) 216 nm, and (c) 282 nm. (d and e) show the free-standing colloidal films prepared from 158 nm microspheres.Research highlights► Colloidal crystals are fabricated via “floating self-assembly” method within 15 min. ► Free-standing colloidal-crystal film is obtained using epichlorohydrin as cross-linking agent. ► Free-standing colloidal crystals could be used as ideal templates for 3DOM materials.

Preparation and characterization of polymer/silica nanocomposites via double in situ miniemulsion polymerization

Co-reporter:Jianan Zhang;Nannan Liu;Mozhen Wang;Xuewu Ge;Mingyuan Wu;Jianjun Yang;Qingyun Wu;Zhilai Jin

Journal of Polymer Science Part A: Polymer Chemistry 2010 Volume 48( Issue 14) pp:3128-3134

Publication Date(Web):

DOI:10.1002/pola.24094

Abstract

Polymer/SiO₂ nanocomposite microspheres were prepared by double in situ miniemulsion polymerization in the presence of methyl methacrylate, butyl acrylate, γ-methacryloxy(propyl) trimethoxysilane, and tetraethoxysilane (TEOS). By taking full advantage of phase separation between the growing polymer particles and TEOS, inorganic/polymer microspheres were fabricated successfully in a one-step process with the formation of SiO₂ particles and the polymerization of organic monomers taking place simultaneously. The morphology of nanocomposite microspheres and the microstructure, mechanical properties, thermal properties, and optical properties of the nanocomposite films were characterized and discussed. The results showed that hybrid microspheres had a raspberry-like structure with silica nanoparticles on the shells of polymer. The silica particles of about 20 nm were highly dispersed within the nanocomposite films without aggregations. The transmittance of nanocomposite film was comparable to that of the copolymer film at around 70–80% from 400 to 800 nm. The mechanical properties and the fire-retardant behavior of the polymer matrix were improved by the incorporation of silica nanoparticles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3128–3134, 2010

Novel Walnut-like Multihollow Polymer Particles: Synthesis and Morphology Control

Co-reporter:Xueping Ge, Mozhen Wang, Hua Wang, Qiang Yuan, Xuewu Ge, Huarong Liu and Tao Tang

Langmuir 2010 Volume 26(Issue 3) pp:1635-1641

Publication Date(Web):September 24, 2009

DOI:10.1021/la902493r

Novel walnut-like multihollow polymer particles were first prepared by γ-ray radiation emulsion polymerization using cross-linked and sulfonated polystyrene spheres (CSPs) as the template. The formation process was studied in detail, and the morphology of walnut-like multihollow polystyrene particles could be controlled by the content of cross-linking agent, sulfonation time of CSP particles, and the weight ratio of monomer/CSP. In addition, an application of walnut multihollow polymer particles on bonding Ag nanoparticles onto the surface was achieved, which could be extended to other noble metal nanoparticles and could have a wide range of potential applications, such as catalysts, sensors, solar cells, and photonic crystals.

The morphological control of anisotropic polystyrene/silica hybrid particles prepared by radiation miniemulsion polymerization

Co-reporter:Xueping Ge, Mozhen Wang, Qiang Yuan, Hua Wang and Xuewu Ge

Chemical Communications 2009 (Issue 19) pp:2765-2767

Publication Date(Web):27 Mar 2009

DOI:10.1039/B901094G

Novel anisotropic hybrid particles with various morphologies have been synthesized by radiation miniemulsion polymerization for the first time.

Polymer/metal interpenetrating phase composites prepared via -ray initiated in-situ emulsion polymerization

Co-reporter:Mozhen Wang;Hongwei Geng;Xuewu Ge;Jianrong Li;Dongpeng Kou

Polymer Composites 2009 Volume 30( Issue 9) pp:1258-1264

Publication Date(Web):

DOI:10.1002/pc.20687

Abstract

The poly(methylmethacrylate)/metal and poly(butylacrylate-co-styrene)/metal interpenetrating phase composites (IPCs) were prepared via γ-ray irradiation in-situ bulk and emulsion polymerization, respectively. The monomers were first introduced into open-cell aluminum foam and aluminum alloy foam and were in-situ polymerized by γ-ray irradiation at room temperature. The characterization and compressive test results showed that this method expands the variety of the polymer component resulting in a useful range of physical properties of the IPCs, such as density and porosity. The PMMA/metal IPC has a high polymer filling ratio, modulus and exhibits a similar compressive behavior to that of PMMA. On the other hand, the P(BA-co-St)/metal IPC has a relatively low polymer filling ratio and its compressive behavior is similar to that of metal foam matrix, but it has wider plastic plateau than the component metal foams, like the case of metal foam filled with rubber. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

Effects of concentration of nonionic surfactant and molecular weight of polymers on the morphology of anisotropic polystyrene/poly(methyl methacrylate) composite particles prepared by solvent evaporation method

Co-reporter:Xueping Ge;Mozhen Wang;Xiang Ji;Xuewu Ge;Huarong Liu

Colloid and Polymer Science 2009 Volume 287( Issue 7) pp:819-827

Publication Date(Web):2009 July

DOI:10.1007/s00396-009-2036-x

The effects of the concentration of polyoxyethylene octylphenyl ether (OP-10) as a nonionic surfactant and the molecular weight of polymers (polystyrene (PS) and poly(methyl methacrylate) (PMMA)) on the morphology of anisotropic PS/PMMA composite particles were investigated. In the case of polymers with lower molecular weight (Mw ≈ 6.0 × 104 g/mol), the PS/PMMA composite particles have dimple, via acorn, to hemispherical shapes along with the increase of the OP-10 concentration. On the other hand, when the polymers have higher molecular weight (Mw ≈ 3.3 × 105 g/mol), the morphology of PS/PMMA composite particles changed from dimple, via hemispherical, to snowman-like structure while the concentration of OP-10 was increased. Furthermore, thermodynamic analysis was first simply made by spreading coefficients, and the results indicated that both the concentration of OP-10 aqueous solution and the molecular weight of polymers were very important to the final morphology of anisotropic composite particles.

The Mechanism of the Formation of Multihollow Polymer Spheres through Sulfonated Polystyrene Particles

Co-reporter:Qiang Yuan, Libin Yang, Mozhen Wang, Hua Wang, Xueping Ge and Xuewu Ge

Langmuir 2009 Volume 25(Issue 5) pp:2729-2735

Publication Date(Web):February 6, 2009

DOI:10.1021/la803724r

Multihollow poly(methyl methacrylate) (PMMA) particles were successfully fabricated simply by γ-ray radiating emulsions consisting of MMA monomers, sulfonated polystyrene (SP) particles, and water. The mechanism on the formation of the holes was studied in detail. It was found that there were two routes to achieve two different multihollow structures dependent on the initial location of SP particles before emulsification. If SP particles first located in the water phase, cage-like hollow PMMA particles were obtained through the formation of a Pickering emulsion. Otherwise, if SP particles first located in the oil (MMA) phase, a different multihollow structure would be produced via the formation of a multiple emulsion. This work provides a simple method to fabricate two different structured multihollow particles using the same conditions.

Grafting of polymers from clay nanoparticles via high-dose gamma-ray irradiation

Co-reporter:Tao Wang, Mozhen Wang, Zhicheng Zhang, Xuewu Ge, Yue'e Fang

Materials Letters 2007 Volume 61(Issue 17) pp:3723-3727

Publication Date(Web):July 2007

DOI:10.1016/j.matlet.2006.12.023

In this work, the prepared mixture of low concentration of ethyl acrylate (EA) monomers and organophilic montmorillonite (OMMT) particles in methanol solution was exposed to gamma-ray (γ-ray) irradiation. It was found that EA monomers first polymerized at relatively low radiation dose (< 10 kGy), then the polymerized PEA chains can graft onto the OMMT particles when the radiation dose increases above 185 kGy. Electron spin resonance (ESR) tests verified that a large amount of radicals could be created on PEA chains and the OMMT particles at high radiation dose. When the radicals on the PEA chains combined with the radicals on the surface of silicate layers of OMMT particles, the grafting reaction took place. Furthermore, Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) results all confirmed the presence of PEA grafting on the surface of the stacking silicate layers of OMMT particles.

Preparation of core (PBA/layered silicate)–shell (PS) structured complex via γ-ray radiation seeded emulsion polymerization

Co-reporter:Tao Wang, Mozhen Wang, Zhicheng Zhang, Xuewu Ge, Yue'e Fang

Materials Letters 2006 Volume 60(Issue 20) pp:2544-2548

Publication Date(Web):September 2006

DOI:10.1016/j.matlet.2006.01.045

In order to improve the impact strength of PS matrix dramatically and keep its high tensile strength at the same time, a novel core–shell structured complex was prepared by γ-ray radiation seeded emulsion polymerization. The core is made of poly (butyl acrylate) (PBA) and the intercalated or exfoliated organophilic montmorillonite (OMMT), while the shell is PS. The prepared core (PBA/OMMT)–shell (PS) structured complex combines the advantage of the strengthening of silicate layers and the toughening of elastomer in plastic matrix. When the core (PBA/OMMT)–shell (PS) structured complex was blended in pure PS matrix, the impact strength of blend was dramatically improved and the tensile strength of PS remains high as well.

Surface treatment of poly(ethylene terephthalate) by gamma-ray induced graft copolymerization of methyl acrylate and its toughening effect on poly(ethylene terephthalate)/elastomer blend

Co-reporter:Liang Ma, Mozhen Wang, Xuewu Ge

Radiation Physics and Chemistry (September 2013) Volume 90() pp:92-97

Publication Date(Web):1 September 2013

DOI:10.1016/j.radphyschem.2013.04.004

•PMA was grafted onto PET resins by γ-ray radiation-induced copolymerization.•The obtained PET-g-PMA can improve the compatibility between PET and E-MA-GMA.•A small amount of PET-g-PMA can enhance the impact strength of PET/E-MA-GMA blend.To improve the compatibility between ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (E-MA-GMA) elastomer and poly(ethylene terephthalate) (PET), thereby enhance the toughening effect of E-MA-GMA on PET, γ-radiation-induced graft copolymerization technique was used to graft methyl acrylate (MA) monomer onto PET. The produced PET-g-PMA copolymer can be used as a self-compatibilizer in PET/E-MA-GMA blend since the copolymer contains the same segments, respectively, with PET and E-MA-GMA. The impact strength of PET/E-MA-GMA blend increased nearly by 30% in the presence of less than 0.1 wt% PET-g-PMA compared with that of the neat PET/elastomer blend, without loss of the tensile strength of the blends. This work proposed a potential application of radiation-induced grafting copolymerization technique on the in-situ compatibilization of PET/elastomer blends so as to improve the integral mechanical properties of PET based engineering plastic.

The characterization of latex particles prepared by pulsed electron beam induced emulsion polymerization

Co-reporter:Yongfei Xu, Mozhen Wang, Xuewu Ge

Radiation Physics and Chemistry (October 2012) Volume 81(Issue 10) pp:1634-1638

Publication Date(Web):1 October 2012

DOI:10.1016/j.radphyschem.2012.05.001

The emulsion polymerization of styrene (St) and methyl methacrylate (MMA) induced by 10 MeV pulsed electron beams (PEB) was investigated. The monomer conversion of MMA and St was found to be very low so that the final prepared poly(methyl methacrylate) (P(MMA)) and polystyrene (PS) latex particles exhibit porous structures, as verified by TEM and SEM observations. The results of dynamic light scattering (DLS) and gel permeation chromatography (GPC) showed that both the particle size and the molecular weight of PS and PMMA latexes decrease with the increase of the absorbed dose. However, the molecular weights and the particle sizes of the PS and PMMA latexes change differently with the irradiation time. This work indicated that emulsion polymerization induced by high energy electron beam has an advantage over that induced by γ-ray or chemical initiators in the preparation of latex with a low molecular weight and porous structure.Highlights► A 10 MeV 400 kGy/min LINAC was used to induce emulsion polymerization. ► Influences of monomer and emulsifier concentration on conversion were studied. ► Molecular weight and particle size of latex on the absorbed dose were studied. ► Resulting latex particles are porous. ► Various nucleation mechanisms co-exist during polymerization.

The morphological control of anisotropic polystyrene/silica hybrid particles prepared by radiation miniemulsion polymerization

Co-reporter:Xueping Ge, Mozhen Wang, Qiang Yuan, Hua Wang and Xuewu Ge

Chemical Communications 2009(Issue 19) pp:

Publication Date(Web):

DOI:10.1039/B901094G

Preparation of three-dimensional inverse opal SnO2/graphene composite microspheres and their enhanced photocatalytic activities

Co-reporter:Lechen Chen, Lizhao Xie, Mozhen Wang and Xuewu Ge

Journal of Materials Chemistry A 2015 - vol. 3(Issue 6) pp:NaN2998-2998

Publication Date(Web):2014/12/08

DOI:10.1039/C4TA05898D

Chitosan-based core–shell structured particles for in vivo sustainable gene transfection

Co-reporter:Fu-xing Lin, Jie-lin Rong, Mo-zhen Wang, Dan-dan Bao, Yun Wang, Zhen-xing Gong, Yu-fang Gu, Yu Zhao and Xue-wu Ge