Hua-rong Liu

Herein we report a one-step method to prepare high internal water-phase double emulsions (W/O/W) via catastrophic phase inversion of water-in-oil high internal phase emulsions (W/O HIPEs) stabilized solely by 12-acryloxy-9-octadecenoic acid (AOA) through increasing the content of water phase. This is the first time for double emulsions to be stabilized solely by a single small molecular surfactant, which are usually costabilized by both hydrophilic and hydrophobic surfactants. After neutralized with ammonia, AOA is confirmed to be capable of stabilizing both W/O emulsions and O/W emulsions, which may account for its unique ability to stabilize double emulsions. The effects of different conditions (including changing the concentrations of AOA and salt (NaCl), pH value, the polarity of oils, the addition interval of water and stirring rate, etc.) on the formation and the stability of double emulsions as well as the inversion point have been investigated by using optical microscopy and conductivity monitoring. Finally, porous polymer microspheres with high interconnection (polyHIPE microspheres) were fabricated by γ-ray initiated polymerization of the as-prepared double emulsions composed of different monomers (styrene, or n-butyl acrylate, or methyl methacrylate), which have been confirmed by scanning electron microscopy. Our method is facile and effective for preparing high interconnecting porous polymer microspheres without tedious post-treatment of the products in common emulsion polymerization due to the use of polymerizable surfactant.

Nitrogen-Doped Hollow Carbon Nanospheres for High-Performance Li-Ion Batteries

Co-reporter:Yufen Yang, Song Jin, Zhen Zhang, Zhenzhen Du, Huarong Liu, Jia Yang, Hangxun Xu, and Hengxing Ji

ACS Applied Materials & Interfaces April 26, 2017 Volume 9(Issue 16) pp:14180-14180

Publication Date(Web):April 7, 2017

DOI:10.1021/acsami.6b14840

N-doped carbon materials is of particular attraction for anodes of lithium-ion batteries (LIBs) because of their high surface areas, superior electrical conductivity, and excellent mechanical strength, which can store energy by adsorption/desorption of Li+ at the interfaces between the electrolyte and electrode. By directly carbonization of zeolitic imidazolate framework-8 nanospheres synthesized by an emulsion-based interfacial reaction, we obtained N-doped hollow carbon nanospheres with tunable shell thickness (20 nm to solid sphere) and different N dopant concentrations (3.9 to 21.7 at %). The optimized anode material possessed a shell thickness of 20 nm and contained 16.6 at % N dopants that were predominately pyridinic and pyrrolic. The anode delivered a specific capacity of 2053 mA h g–1 at 100 mA g–1 and 879 mA h g–1 at 5 A g–1 for 1000 cycles, implying a superior cycling stability. The improved electrochemical performance can be ascribed to (1) the Li+ adsorption dominated energy storage mechanism prevents the volume change of the electrode materials, (2) the hollow nanostructure assembled by the nanometer-sized primary particles prevents the agglomeration of the nanoparticles and favors for Li+ diffusion, (3) the optimized N dopant concentration and configuration facilitate the adsorption of Li+; and (4) the graphitic carbon nanostructure ensures a good electrical conductivity.Keywords: carbon nanospheres; hollow structures; lithium-ion batteries; nitrogen-doping; porous materials;

Controllable synthesis of anisotropic silica/polymer composite particles via seeded dispersion polymerization

Co-reporter:Zhen Zhang, Hong Shao, Xiangtian Zhou, Linling Zhao, Huarong Liu, Xiang Ji, Hewen Liu

Materials Chemistry and Physics 2017 Volume 195(Volume 195) pp:

Publication Date(Web):1 July 2017

DOI:10.1016/j.matchemphys.2017.04.024

•Anisotropic SiO2/PS particles were controlled synthesized in large scale.•Snowman-like, raspberry-like and core-shell structure could be easily fabricated.•Snowman-like SiO2/PS particles could be formed directly at the very beginning.•The unilateral growth process of PS on silica surface is scarcely reported.In this work, seeded dispersion polymerization was adopted to prepare anisotropic silica/polymer composite particles with controllable sizes and morphologies using the surface-modified silica particles as the seeds. Through this approach, submicron-sized silica/polymer particles with snowman-like, dumbbell-like, raspberry-like and core-shell structures could be easily fabricated in large scale. Many factors that might affect the morphologies of composite particles including the weight ratio of monomer/silica seeds, the polarity of reaction medium, reaction temperature, reaction time, the amount of crosslinking agent or the polarity of monomers were investigated. The results indicate that the interfacial tension between PS phases and SiO2 particles and the coalescence between growing polymer nodules over silica particles are responsible for the formation of different particle morphologies. It is interesting that snowman-like SiO2/PS particles could be afforded by two different processes: one was normally transformed from raspberry-like particles via the coalescence between growing polymer nodules; the other was formed directly at a high content of monomer. These different morphological particles may have important applications in biological/medical materials, optical materials, sensors, catalyst support, colloidal stabilizer, etc.Download high-res image (183KB)Download full-size image

The facile synthesis of PMMA polyHIPEs with highly interconnected porous microstructures

Co-reporter:Zichao Li;Huarong Liu;Lai Zeng;Hewen Liu;Yanmei Wang

Journal of Materials Science 2016 Volume 51( Issue 19) pp:9005-9018

Publication Date(Web):2016 October

DOI:10.1007/s10853-016-0154-7

It is difficult to prepare stable high internal phase emulsions (HIPEs) of methyl methacrylate (MMA) due to the considerable high solubility of MMA in water phase. Here, we present a facile method to prepare the stable HIPEs of MMA (MMA HIPEs) with the widely used sorbitan monooleate (Span 80) as surfactant just by adding hexadecane (HD) or hydroxyl-terminated polybutadiene (HTPB) as a costabilizer. The different roles of the two long-chain costabilizers (HD and HTPB) to improve the stability of the MMA HIPEs were studied. Poly(methyl methacrylate) porous monoliths were prepared based on the MMA HIPE templates and characterized by field emission scanning electron microscopy, transmission electron microscopy, and N2 sorption analysis, which showed the formation of highly interconnected pores. Factors that affected the stability of MMA HIPEs and the morphology of polyHIPEs were also investigated.

A novel approach to preparing polystyrene/Fe3O4 multihollow microspheres with porous walls

Co-reporter:Jinde Zhang;Huarong Liu

Colloid and Polymer Science 2016 Volume 294( Issue 11) pp:1755-1763

Publication Date(Web):2016 November

DOI:10.1007/s00396-016-3938-z

A novel approach is presented here to prepare polystyrene/Fe3O4 multihollow microspheres with porous walls. Water-in-oil-in water (W/O/W) double emulsion was developed in mini-emulsion system with the help of amphipathic Fe3O4 nanoparticles dispersed in oil phase. A γ-ray irradiation from 60Co source initiated the radical polymerization and controlled the reaction degree. Most of polymerization took place in mini-droplets of monomer developed during mini-emulsification process. Therefore, every mini-droplet of monomer with water inside can act like soft template, and polymerization helps to solidify such soft template and successfully reserve and transfer the morphology of these water-in-oil mini-droplets to solid microspheres. Multihollow structure was developed after drying since water inside of microspheres evaporated. Superparamagnetic property was also confirmed by VSM characterization on nanocomposites. Finally, the mechanism of forming such structure was preliminarily elucidated.

Design of yolk–shell Fe3O4@PMAA composite microspheres for adsorption of metal ions and pH-controlled drug delivery

Co-reporter:Linling Zhao, Huarong Liu, Fengwei Wang and Lai Zeng

Journal of Materials Chemistry A 2014 vol. 2(Issue 19) pp:7065-7074

Publication Date(Web):17 Mar 2014

DOI:10.1039/C4TA00976B

Core–shell–shell structured Fe3O4@SiO2@PMMA composite microspheres were synthesized on a large scale by combining sol–gel reaction and seeded emulsion polymerization. The yolk–shell structured Fe3O4@PMAA microspheres with pH-responsive shells were then produced by the hydrolysis reaction of the PMMA shells in NaOH aqueous solution during etching of the silica interlayers. The resulting microspheres, with tunable void space and shell thickness, were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and dynamic laser scattering (DLS). The effect of shell thickness and void space of the yolk–shell Fe3O4@PMAA microspheres on the adsorption of metal ions and drug delivery was investigated. The results demonstrated the excellent adsorption capacity of Cu2+ and Pb2+ and reusability for Cu2+ using the optimum Fe3O4@PMAA microspheres as adsorbents under weakly acidic conditions, as well as the high loading capacity and pH-controlled release ability of yolk–shell Fe3O4@PMAA microspheres by loading ceftriaxone sodium and performing a controlled release study.

Hollow Metal–Organic Framework Nanospheres via Emulsion-Based Interfacial Synthesis and Their Application in Size-Selective Catalysis

Co-reporter:Yufen Yang, Fengwei Wang, Qihao Yang, Yingli Hu, Huan Yan, Yu-Zhen Chen, Huarong Liu, Guoqing Zhang, Junling Lu, Hai-Long Jiang, and Hangxun Xu

ACS Applied Materials & Interfaces 2014 Volume 6(Issue 20) pp:18163

Publication Date(Web):September 23, 2014

DOI:10.1021/am505145d

Metal–organic frameworks (MOFs) represent an emerging class of crystalline materials with well-defined pore structures and hold great potentials in a wide range of important applications. The functionality of MOFs can be further extended by integration with other functional materials, e.g., encapsulating metal nanoparticles, to form hybrid materials with novel properties. In spite of various synthetic approaches that have been developed recently, a facile method to prepare hierarchical hollow MOF nanostructures still remains a challenge. Here we describe a facile emulsion-based interfacial reaction method for the large-scale synthesis of hollow zeolitic imidazolate framework 8 (ZIF-8) nanospheres with controllable shell thickness. We further demonstrate that functional metal nanoparticles such as Pd nanocubes can be encapsulated during the emulsification process and used for heterogeneous catalysis. The inherently porous structure of ZIF-8 shells enables encapsulated catalysts to show size-selective hydrogenation reactions.Keywords: catalysis; emulsion; hollow nanostructures; interfacial reactions; metal−organic frameworks

Synthesis of snowman-like polymer-silica asymmetric particles by combination of hydrolytic condensation process with -ray radiation initiated seeded emulsion polymerization

Co-reporter:Feng-Wei Wang;Yang Zhang;He-Wen Liu;Xue-Wu Ge ;Xing-Yuan Zhang

Journal of Polymer Science Part A: Polymer Chemistry 2014 Volume 52( Issue 3) pp:339-348

Publication Date(Web):

DOI:10.1002/pola.27006

ABSTRACT

We report on a facile route to synthesize snowman-like asymmetric composite particles via γ-ray initiated seeded emulsion polymerization after a hydrolytic condensation process on the surface of second monomer swollen poly(styrene-divinylbenzene-acrylic acid) seeds. Effects of the amounts and kinds of second monomer and inorganic precursor, different radiation polymerization conditions including dose rates and absorbed doses on the morphology of the obtained particles were investigated. The obtained asymmetric particles can serve as ideal solid surfactants to stabilize the water-in-oil emulsions, and soap-free hierarchical materials were obtained by polymerization of monomers in water or oil phase. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 339–348

Synthesis of worm-like superparamagnetic P(St-AA)@Fe3O4/SiO2 Janus composite particles

Co-reporter:Feng-wei Wang;Xing-yuan Zhang

Colloid and Polymer Science 2014 Volume 292( Issue 6) pp:1395-1403

Publication Date(Web):2014 June

DOI:10.1007/s00396-014-3191-2

Novel Janus nanocomposite particles with superparamagnetic P(St-AA)@Fe3O4 seed microspheres as head and worm-like SiO2 as body were successfully prepared. The effects of different variables such as the amount of cetyltrimethyl ammonium bromide (CTAB), tetraethyl orthosilicate (TEOS), and ammonia and the composition of inorganic precursors and surfactants on the morphologies of final particles were studied by transmission electron microscopy (TEM) and field-emission scanning electron microscopy (SEM). Due to the amphiphilic difference between the two parts as well as their special morphologies, the fabricated worm-like particles could be applied to stabilize oil/water mixtures even if owing relative hydrophilic properties that might provide a new category of functional solid surfactants in Pickering emulsions and the fabrication of hierarchical materials.

Preparation of High Internal Water-Phase Double Emulsions Stabilized by a Single Anionic Surfactant for Fabricating Interconnecting Porous Polymer Microspheres

Co-reporter:Zichao Li, Huarong Liu, Lai Zeng, Hewen Liu, Song Yang, and Yanmei Wang

Langmuir 2014 Volume 30(Issue 41) pp:12154-12163

Publication Date(Web):2017-2-22

DOI:10.1021/la502564r

Facile approach to glycidyl methacrylate-based polyHIPE monoliths with high epoxy-group content

Co-reporter:Song Yang;Lai Zeng;Yipeng Wang;Xuehui Sun;Peijian Sun

Colloid and Polymer Science 2014 Volume 292( Issue 10) pp:2563-2570

Publication Date(Web):2014 October

DOI:10.1007/s00396-014-3295-8

This paper reports a facile approach to glycidyl methacrylate (GMA)-based polyHIPE monoliths with high epoxy-group content, which are fabricated using a high internal phase emulsion (HIPE) template via radiation-induced polymerization at room temperature. The effects of the polymerization temperature and the pore sizes of polyHIPE monoliths on the content of epoxy groups are investigated. Results show that the polymerization temperature is the most important factor in influencing the content of epoxy groups in GMA-based polyHIPE monoliths. To prove their superiority over monoliths with low epoxy-group contents, the as-prepared polyHIPE monoliths are applied in phenol removal from cigarette smoke through a reaction between the epoxy group and phenol. The results show that the higher the content of epoxy groups in the polyHIPE monoliths, the higher the rate of phenol removal, indicating their high performance in these specific applications for the polyHIPE monoliths with high epoxy-group contents.

Facile fabrication of polymer-inorganic hybrid particles with various morphologies by combination of hydrolytic condensation process with radiation seeded emulsion polymerization

Co-reporter:Feng-wei Wang;Lin-ling Zhao;Xing-yuan Zhang

Colloid and Polymer Science 2014 Volume 292( Issue 5) pp:1171-1179

Publication Date(Web):2014 May

DOI:10.1007/s00396-014-3166-3

A novel approach was proposed to the synthesis of poly(styrene-divinyl benzene-acrylic acid)/poly [3-(methacryloxy)propyl trimethoxysilane-styrene] [P(St-DVB-AA)/P(MPS-St)] hybrid particles. The morphologies of the particles could be tuned from raspberry-like to snowman-like by simply changing the feeding amount of second monomer or inorganic precursor. The fabricated raspberry-like ones could be modified to obtain hydrophobic surface with a contact angle up to 146°. And the snowman-like ones could be used as solid surfactant to stabilize water/styrene (W/St) mixtures, thus hierarchical porous materials could be obtained after the polymerization of monomer phase. The preliminary application of such soap-free block materials in oil-polluted water treatment was also investigated.

Facile Preparation of Raspberry-Like Superhydrophobic Polystyrene Particles via Seeded Dispersion Polymerization

Co-reporter:Rui-kun Wang, Hua-rong Liu, and Feng-wei Wang

Langmuir 2013 Volume 29(Issue 36) pp:11440-11448

Publication Date(Web):August 14, 2013

DOI:10.1021/la401701z

A simple and facile approach was developed to fabricate raspberry-like or snowman-like particles via seeded dispersion polymerization by just changing the ratio of second monomer styrene (St) to seeds in which poly(styrene-co-hydrolyzed-methacryloxypropyltrimethoxysilane) [P(St-co-MPS)] latex was used as seeds with hydrolyzed-MPS as a cross-linking agent. The morphologies of final products were confirmed by field-emission scanning electron microscopy and transmission electron microscopy. Interestingly, the seed part of snowman-like particles showed raspberry-like with adsorbing quantities of PS particles while the other part smooth. The formation mechanism of the raspberry-like particles was also discussed. The superhydrophobic surface with both the static contact angle of 158° and high adhesion to water could be achieved by the hydrophobization of the particulate film with octadecyltrimethoxysilane that was formed from the raspberry-like particles decorated by a thin layer of silica nanoparticles. Further, through encapsulating Ag nanoparticles within the surface, the obtained raspberry-like PS/Ag/SiO2 nanocomposite particles exhibited excellent antibacterial property simultaneously.

Preparation and characterization of film-forming raspberry-like polymer/silica nanocomposites via soap-free emulsion polymerization and the sol–gel process

Co-reporter:Xiangtian Zhou;Hong Shao;Huarong Liu

Colloid and Polymer Science 2013 Volume 291( Issue 5) pp:1181-1190

Publication Date(Web):2013 May

DOI:10.1007/s00396-012-2847-z

Herein, we report on the synthesis of film-forming poly(styrene-co-butyl acrylate-co-acrylic acid)/SiO2 [P(St-BA-AA)/SiO2] nanocomposites by in situ formation of SiO2 nanoparticles from TEOS via sol–gel process in the presence of poly(acrylic acid) (PAA)-functionalized poly(styrene-co-butyl acrylate) [P(St-BA)] particles fabricated by soap-free emulsion polymerization. The formed silica particles could be absorbed by polyacrylate chains on the surface of PAA-functionalized P(St-BA) particles; thus, raspberry-like polymer/silica nanocomposites would be obtained. Transmission electron microscopy, Fourier transform infrared spectroscopy, attenuated total reflectance infrared spectrum, ultraviolet–visible transmittance spectra, and thermogravimetric analysis were used to characterize the resulting composites. The results showed that the hybrid polymer/silica had a raspberry-like structure with silica nanoparticles anchored on the surface of polymer microspheres. The thermal, fire retardant, and mechanical properties and water resistance of the film were improved by incorporating silica nanoparticles, while the optical transmittance was seldom affected due to nanosized silica particles uniformly dispersed in the film.

Erratum to: Preparation of macroporous polyHIPE foams via radiation-induced polymerization at room temperature

Co-reporter:Donglin Mao;Tingting Li;Huarong Liu;Zichao Li;Hong Shao

Colloid and Polymer Science 2013 Volume 291( Issue 7) pp:1657

Publication Date(Web):2013 July

DOI:10.1007/s00396-013-2934-9

Preparation of macroporous polyHIPE foams via radiation-induced polymerization at room temperature

Co-reporter:Donglin Mao;Tingting Li;Huarong Liu;Zichao Li;Hong Shao

Colloid and Polymer Science 2013 Volume 291( Issue 7) pp:1649-1656

Publication Date(Web):2013 July

DOI:10.1007/s00396-013-2899-8

PolyHIPEs are highly porous, crosslinked polymer foams typically synthesized within high internal-phase emulsions (HIPEs). Two kinds of polyHIPEs including poly(styrene-divinylbenzene) [P(St-DVB)] and poly(methyl methacrylate-divinylbenzene) [P(MMA-DVB)] foams are synthesized in this work, which are fabricated from HIPEs template via radiation-induced polymerization at room temperature. Traditional free radical polymerization initiated by potassium peroxydisulfate (KPS) at 60 °C for producing polyHIPE P(St-DVB) foams is also conducted for comparison. It is found that the amount of emulsifier can be reduced greatly in the radiation-induced polymerization of HIPEs at room temperature, compared with the traditional polymerization approach. Besides, P(MMA-DVB) PolyHIPE foams with a fine microstructure of highly interconnected pores have been successfully fabricated via radiation-induced polymerization in this work, which is usually difficult to be prepared by thermal-initiation method because of the intermediate hydrophobicity of methyl methacrylate monomer. The influences of the fraction of internal aqueous phase and the concentration of emulsifier on the structure and performance of foams are carefully explored. The structure and compression strength of the foams are characterized by scanning electron microscopy and a mechanical testing machine, respectively.

Synthesis of triangle hybrid particles by radiation-induced seeded emulsion polymerization based on polystyrene/SiO2 core–shell particles

Co-reporter:Dezhi Xu, Xiang Ji, Huarong Liu, Mozhen Wang, Xuewu Ge, Michael Hon-Wah Lam

Materials Letters 2012 Volume 79() pp:61-64

Publication Date(Web):15 July 2012

DOI:10.1016/j.matlet.2012.03.102

A novel strategy has been designed for the preparation of triangle polystyrene/SiO2 (PS/SiO2) hybrid particles using γ-ray radiation-induced seeded emulsion polymerization from core–shell structured PS/SiO2 seed particles. SEM results indicate that the weight ratio of monomer to seed particles (WSt/Seed) and the thickness of silica-shell coated on the core–shell PS/SiO2 seed particles are crucial for the subsequent formation of triangle hybrid particles. Moreover, the size of the protruded PS bulbs of the resultant triangle particles obviously increases with WSt/Seed from 1.25 to 5. This novel method is applicable to the preparation of anisotropic hybrid particles from polymer/inorganic core–shell particles.Highlights► Triangle particles were prepared via radiation seeded emulsion polymerization. ► Micron-sized core-shell PS/SiO2 particles were used as seeds. ► Silica-shell thickness is crucial for the formation of the triangle particles. ► This strategy is promisingly applicable to preparation of anisotropic particles.

Synthesis of snowman-like magnetic/nonmagnetic nanocomposite asymmetric particles via seeded emulsion polymerization initiated by -ray radiation

Co-reporter:Feng-Wei Wang;Jin-De Zhang;Xiang-Tian Zhou ;Xing-Yuan Zhang

Journal of Polymer Science Part A: Polymer Chemistry 2012 Volume 50( Issue 22) pp:4599-4611

Publication Date(Web):

DOI:10.1002/pola.26274

Abstract

We report on the synthesis of snowman-like magnetic/nonmagnetic nanocomposite asymmetric particles (SMNAPs) via seeded emulsion polymerization initiated by γ-ray radiation. In situ formation of magnetite in the presence of the emulsified poly(styrene-divinylbenzene-acrylic acid) microspheres affords raspberry-like magnetic nanocomposite particles, which are used as seeds for further seeded emulsion polymerization induced by γ-ray radiation. We study the effect of the kind of surfactant, the kind and content of second monomer, and the content of swelling agent on the morphologies of the final nanocomposite particles. It is found that SMNAPs can be fabricated in high yield using 12-acryloxy-9-octadecenoic acid as the surfactant and styrene as the second monomer with the addition of 2-butanone (a swelling agent). The as-synthesized SMNAPs may serve as magnetically controllable solid surfactants to stabilize O/W immiscible mixtures, which preferentially orientated at the interface. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Macroporous magnetic poly(styrene–divinylbenzene) nanocomposites prepared viamagnetite nanoparticles-stabilized high internal phase emulsions

Co-reporter:Tingting Li, Huarong Liu, Lai Zeng, Song Yang, Zichao Li, Jinde Zhang and Xiangtian Zhou

Journal of Materials Chemistry A 2011 vol. 21(Issue 34) pp:12865-12872

Publication Date(Web):25 Jul 2011

DOI:10.1039/C1JM10799B

Macroporous magnetic poly(styrene–divinylbenzene) [P(St–DVB)] nanocomposites with an open-cell structure have been synthesized through high internal phase emulsion (HIPE) templates solely stabilized by surface-modified magnetite nanoparticles (MPs). When the particle concentration was below 20% based on monomers, the compression strength increased with the increasing concentration of particles, while the average void size became small and the size distribution of voids tended to be narrow. On the other hand, the mechanical properties decreased as the internal phase weight fraction was changed from 80% to 90%. However, interconnected pores appeared after polymerization when an internal phase of HIPE was up to 90% stabilized by only 6% of MPs. The magnetic properties of the obtained macroporous P(St–DVB) nanocomposites were also investigated in this article.

Study of emulsion polymerization stabilized by amphiphilic polymer nanoparticles

Co-reporter:Tingting Li;Huarong Liu;Lai Zeng;Weifeng Miao;Ying Wu

Colloid and Polymer Science 2011 Volume 289( Issue 14) pp:

Publication Date(Web):2011 September

DOI:10.1007/s00396-011-2477-x

Submicron-sized polystyrene (PS) microspheres with a relatively narrow particle size distribution can be easily produced through emulsion polymerization induced by γ-ray at room temperature using a new type of amphiphilic cross-linked poly(stearyl methacrylate-co-acrylamide-co-acrylic acid) particles as stabilizer. The properties of these amphiphilic particles were described, including morphology, size, ζ potential, and contact angles. The effect of the pH value and the content of amphiphilic particles on the formation and stability of emulsions were also investigated. Meanwhile, the obtained PS microspheres were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. In addition, through observing the morphology and size of emulsion droplets at different times under an optical microscope, we found it is interesting that Pickering emulsions formed initially disappeared gradually, which is different from the common Pickering emulsions stabilized by inorganic particles. Thus, the mechanism was further discussed.

Synthesis of the raspberry-like PS/PAN particles with anisotropic properties via seeded emulsion polymerization initiated by -ray radiation

Co-reporter:Haofeng Huang ;Huarong Liu

Journal of Polymer Science Part A: Polymer Chemistry 2010 Volume 48( Issue 22) pp:5198-5205

Publication Date(Web):

DOI:10.1002/pola.24319

Abstract

We herein report a facile method to prepare the submicron-sized raspberry-like polystyrene/polyacrylonitrile particles with anisotropic properties and controllable structure via γ-radiation-induced seeded emulsion polymerization under ambient pressure and at room temperature, in which the monodisperse crosslinked styrene-divinylbenzene-acrylic acid terpolymer (P(S-DVB-AA)) particles were used as seed particles and acrylonitrile (AN) as the second monomer. The influence of the weight ratio of polymer/monomer, the absorbed dose rate, the absorbed dose, and the dispersion medium on the morphology of the as-prepared particles was investigated. The final products were thoroughly characterized by Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy, and transmission electron microscopy. The results showed that the raspberry-like particles could be fabricated in high yield. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

Controlled Synthesis of Different Shapes of Cu2O via γ-Irradiation

Co-reporter:Huarong Liu, Weifeng Miao, Song Yang, Zengming Zhang and Jiafu Chen

Crystal Growth & Design 2009 Volume 9(Issue 4) pp:1733-1740

Publication Date(Web):February 19, 2009

DOI:10.1021/cg800703n

Herein, we report a facile synthesis of submicrometer-to-micrometer-sized single-crystalline Cu2O particles with cetyltrimethylammonium bromide (CTAB) as a capping material or template by γ-irradiation under ambient conditions. The morphologies of Cu2O single-crystalline particles, such as eight-pod cubic, six-armed star-like, octahedral, and spindle-like structures, were obtained in high yield by controlling the ratio of the concentration of CTAB to that of copper ions, in which CTAB serves as a nucleation and growth controller. Moreover, we demonstrated that the dose rate and radical scavengers (e.g., small molecular alcohols) can also influence the morphologies of Cu2O through adjusting the reduction rate of Cu2+ ions, making the γ-irradiation method more versatile to control the shapes of inorganic crystals. The band gap of six-armed star-like Cu2O calculated from the UV−vis spectrum corresponds to 2.85 eV, which is larger than the direct band gap (2.17 eV) of the bulk Cu2O. Another value of 1.97 eV hints excitonic discrete energy level in forbidden band arising from the crystal defects of as-prepared Cu2O single crystal.

Design and fabrication of hollow, magnetic and fluorescent CdS–magnetite–poly(styrene-co-methyl methacrylate) microspheres

Co-reporter:Song Yang, Huarong Liu and Zhicheng Zhang

New Journal of Chemistry 2009 vol. 33(Issue 3) pp:620-625

Publication Date(Web):11 Dec 2008

DOI:10.1039/B811418H

Herein, we report a facile method for fabricating multifunctional CdS–magnetite–poly(styrene-co-methyl methacrylate) microspheres (CMPM) which possess simultaneously magnetic, fluorescent and hollow properties under room temperature and at ambient pressure. Based on the synthesized hollow magnetite–poly(styrene-co-methyl methacrylate) microspheres (HMPM), CdS nanoparticles are formed at the surface of HMPM through γ-radiation. The as-obtained HMPM and CMPM were thoroughly characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron diffraction (TEM), field-emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS), which showed the formation of HMPM and CMPM. The quantum-confined effect of CMPM is confirmed by the ultraviolet-visible (UV-vis) and photoluminescent (PL) spectra. Magnetic hysteresis loop measurements revealed that CMPM displayed superparamagnetism and still showed strong magnetic induction.

The effect of irradiation on morphology and properties of the PET/HDPE blends with trimethylol propane trimethacrylate (TMPTA)

Co-reporter:Zeming Xiang;Huarong Liu;Pengyang Deng;Meihua Liu;Yuan Yin

Polymer Bulletin 2009 Volume 63( Issue 4) pp:587-597

Publication Date(Web):2009 October

DOI:10.1007/s00289-009-0109-0

The mechanical properties of poly(ethylene terephthalate)/high-density poly(ethylene) (PET/HDPE) blends were improved by γ-ray irradiation combined with using a cross-linking agent—trimethylol propane trimethacrylate (TMPTA). The effect of the weight ratio of PET/HDPE, the content of TMPTA and the absorbed dose on the phase morphology and the mechanical properties of the PET/HDPE blends were investigated through scanning electron microscopy (SEM), gel fraction, Fourier transform infrared spectroscopy (FTIR), tensile and impact tests. SEM images showed that the phase structure changed significantly as TMPTA coexistence. The results of tensile and impact tests indicated that their mechanical properties depended on their structures. FTIR spectra suggested that a new structure of HDPE-g-PET was generated. When the weight ratio of PET/HDPE blend was 80/20, the content of TMPTA was 1 wt% and the absorbed dose was 30 kGy, the tensile strength, elongation at break and impact strength of irradiated blends were improved greatly compared with non-irradiated blends.

Large-scale growth and shape evolution of micrometer-sized Cu2O cubes with concave planes via γ-irradiation

Co-reporter:Weifeng Miao, Huarong Liu, Zengming Zhang, Jiafu Chen

Solid State Sciences 2008 Volume 10(Issue 10) pp:1322-1326

Publication Date(Web):October 2008

DOI:10.1016/j.solidstatesciences.2008.01.015

Single-crystalline micrometer-sized Cu2O cubes with concave planes were synthesized via γ-irradiation reducing reaction under ambient conditions without any surfactant. Selected area electron diffraction (SAED) investigation reveals that these cubes are single crystals. The powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to investigate the nucleation and crystal growth process of Cu2O cubes. The UV–vis absorption spectrum is used to estimate the band gap energies of the Cu2O cubes. The band gap of the products calculated from the UV–vis spectrum corresponds to 2.53 eV, which is larger than the direct band gap (2.17 eV) of the bulk Cu2O. Another value of 1.97 eV hints excitonic discrete energy level in forbidden band, arising from the crystal defects of as-prepared Cu2O single crystal.Single-crystalline micrometer-sized Cu2O cubes with concave planes were synthesized through nucleation and anisotropic crystal growth processes via gamma-irradiation under ambient conditions without using any surfactant. Unlike most of other methods, our experiments are carried out under mild conditions, hydrated electrons generated through γ-radiolysis of water act as reducing agent. The band gap of the as-prepared products calculated from the UV–vis spectrum corresponds to 2.53 eV, another value of 1.97 eV hints excitonic discrete energy level in forbidden band of as-prepared Cu2O material.

Fabrication of Novel Multihollow Superparamagnetic Magnetite/Polystyrene Nanocomposite Microspheres via Water-in-Oil-in-Water Double Emulsions

Co-reporter:Song Yang, Huarong Liu and Zhicheng Zhang

Langmuir 2008 Volume 24(Issue 18) pp:10395-10401

Publication Date(Web):August 21, 2008

DOI:10.1021/la800657k

We herein present a novel and simple synthetic strategy for fabricating multihollow superparamagnetic magnetite/polystyrene nanocomposite microspheres via water-in-oil-in-water double emulsions. Amphipathic magnetite nanoparticles surface-modified with oleic acid act as an oil-soluble emulsifier and sodium dodecyl sulfate acts as a water-soluble surfactant in the system. The final products were thoroughly characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, and field-emission scanning electron microscopy, which showed the formation of multihollow magnetite/polystyrene nanocomposite microspheres. Preliminary results of magnetic properties of multihollow magnetite/polystyrene microspheres were reported. The effect of the content of amphipathic magnetite nanoparticles on the morphology of nanocomposite microspheres was studied. Furthermore, the mechanism of formation of multihollow magnetic nanocomposite microspheres was also discussed.

Synthesis and characterization of MoO2/P(St-co-MMA-co-AA) microspheres via microemulsion by γ-ray radiation

Co-reporter:Huarong Liu, Jinhua Du

Solid State Sciences 2006 Volume 8(Issue 5) pp:526-530

Publication Date(Web):May 2006

DOI:10.1016/j.solidstatesciences.2005.12.002

MoO2/P(St-co-MMA-co-AA) nanocomposite microspheres have been successfully synthesized in microemulsion system by γ-ray radiation at room temperature and under ambient pressure. The influence of experimental conditions on the formation of nanocomposites was discussed, such as the ratio of oil/water, monomers content and concentration of ammonium molybdate. The possible mechanism of nanocomposites was also proposed. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). From XRD patterns, it is can be seen that the product is amorphous and the pure monoclinic MoO2 phase was gained by annealed at 400 °C in argon flow. TGA curve has only one big weight loss of polymer from 350 to 460 °C, hinting the formation of copolymer in the reaction. XPS spectra indicated that MoO2 exists on the surface of nanocomposite microspheres. The catalytic property was investigated in the conversion of CO into CO2, which showed about 80% conversion gained at 300 °C.

Design of yolk–shell Fe3O4@PMAA composite microspheres for adsorption of metal ions and pH-controlled drug delivery

Co-reporter:Linling Zhao, Huarong Liu, Fengwei Wang and Lai Zeng

Journal of Materials Chemistry A 2014 - vol. 2(Issue 19) pp:NaN7074-7074

Publication Date(Web):2014/03/17

DOI:10.1039/C4TA00976B

Macroporous magnetic poly(styrene–divinylbenzene) nanocomposites prepared viamagnetite nanoparticles-stabilized high internal phase emulsions

Co-reporter:Tingting Li, Huarong Liu, Lai Zeng, Song Yang, Zichao Li, Jinde Zhang and Xiangtian Zhou

Journal of Materials Chemistry A 2011 - vol. 21(Issue 34) pp:NaN12872-12872

Publication Date(Web):2011/07/25

DOI:10.1039/C1JM10799B