Pickering乳液聚合法CdS/PS荧光复合微球的制备与表征

通过水相合成法制备水溶性硫化镉(CdS)纳米晶,以CdS纳米晶固体粒子为乳化剂,进行Pickering乳液聚合制得CdS/PS荧光复合微球。通过SEM、XRD、FTIR、UV-vis、PL对CdS/PS荧光复合微球的微观结构、结晶情况及光学性能进行了分析和表征。结果表明,该复合微球具有以PS为核、CdS纳米晶为壳的核壳结构;复合微球的平均粒径为450nm;在复合微球中,CdS纳米晶仍然保持其量子尺寸效应,复合微球表现出了较好的荧光性能。     

种子聚合法制备PS/PAA核壳微球的研究

设计制备了以疏水性聚苯乙烯(PS)为核、以亲水性聚丙烯酸(PAA)为壳的PS/PAA核壳结构复合微球。首先利用无皂乳液聚合法制备了亚微米级的PS微球,再以其为种子,利用种子无皂乳液聚合法制备PS/PAA核壳微球。在种子聚合阶段,选用AIBN当引发剂,经过红外光谱(IR)表征,表明当使用油溶性引发剂偶氮二异丁腈(AIBN),使其最终形成PS/PAA核壳结构微球。这种方法解决了亲水性较强的单体在以水为介质时在PS微球溶于少量的苯乙烯(St),并在引发聚合之前经过充分的吸附溶胀,可使亲水性单体AAc在PS种子微球表面聚合生成壳层,解决表面不容易直接聚合生成壳层的问题。     

MPS-SiO_2/PS核壳型复合粒子的形态与玻璃化转变温度研究

以正硅酸乙酯为原料,调节pH值为碱性,通过溶胶-凝胶工艺制备单分散SiO2球,用偶联剂甲基丙烯酰(3-三甲氧基硅烷)丙酯(MPS)进行改性,得到MPS-SiO2球形粒子。以MPS-SiO2球为种子,苯乙烯为壳单体,乳液聚合法制备核壳结构的MPS-SiO2/PS复合粒子。透射电镜观察复合粒子形态的结果表明,MPS-SiO2球粒径为200 nm左右时,得到覆盆子状核壳结构;MPS-SiO2球粒径为80 nm左右时,得到包含多个MPS-SiO2球的多核壳结构。差示扫描量热法考察MPS-SiO2/PS复合粒子玻璃化转变温度(Tg)的结果表明,随着MPS-SiO2球含量增加,复合粒子的Tg增加;随着MPS-SiO2球粒径减小,复合粒子的Tg也有所增加。     

种子分散聚合法制备PnBA/PSt核壳结构聚合物微球

本文以具有一定交联度的聚丙烯酸正丁酯(Pn BA)为种子微球,苯乙烯(St)为第二单体,通过种子分散聚合法制备了Pn BA/PSt核壳结构聚合物微球。通过红外光谱、热重分析和X射线光电子能谱等对聚合物微球结构和性能进行表征。结果表明成功合成了Pn BA/PSt核壳结构聚合物微球,复合粒子Pn BA-XX/PSt具有正向核壳构型。     

核-壳型聚苯乙烯/二氧化硅复合微球的制备

利用层层自组装的方法制备了粒径和组成可裁剪、具有核-壳式结构的单分散聚苯乙烯(PS)／二氧化硅(SiO2)复合微球．对复合微球进行热处理除去有机物中心，制备出壁厚可剪裁的空腔硅球，并对复合微球的热分解过程进行了研究．透射电镜(TEM)照片显示二氧化硅纳米颗粒在中心外生成均匀壳层，而煅烧后则可得到轮廓分明的球形空腔；比较PS，SiO2和复合球体及热处理后的粉体的红外光谱，可分别验证二氧化硅的成功组装和热处理过程中作为中心的PS的完全去除．在吸附相同层数的前提下，随着所选用的二氧化硅纳米粒子的粒径的增大(10-40nm)，复合微球的粒径增大，空腔球体的壁厚增加，中心粒子热分解的活化能增大．复合微球的热分解机理符合三维扩散机理．     

聚苯乙烯/还原氧化石墨烯核壳微球的制备及表征

以阳离子聚苯乙烯微球(PS)为核,氧化石墨烯(GO)和PS之间通过静电和π-π作用力进行静电自组装,制备得到聚苯乙烯/氧化石墨烯核壳微球(PS/GO),然后采用氢碘酸(HI)进行还原得到聚苯乙烯/还原氧化石墨烯核壳微球(PS/rGO),采用XRD、SEM、TEM对PS/GO和PS/rGO进行了结构表征。探究了自组装过程条件,例如分散形式(搅拌或超声)、反应时间、GO质量浓度对核壳微球形貌的影响。对不同壳层还原氧化石墨烯(rGO)厚度的PS/rGO复合材料进行了导电性能和热稳定性测试,结果表明,改变壳层rGO的含量,会直接影响复合材料的导电和热性能。由于PS/rGO具有独特的核壳结构,其导电性能和热稳定性相比PS有所提高,电子电阻从PS的17.3Ω降到PS/rGO[m(PS)∶m(rGO)=50∶1]的8.3Ω,PS/rGO的起始热分解温度提高近120℃。     

聚苯乙烯/还原氧化石墨烯核壳微球的制备及性能表征

以阳离子聚苯乙烯微球(PS)为核,氧化石墨烯(GO)和PS之间通过静电和π-π作用力进行静电自组装,制备得到聚苯乙烯/氧化石墨烯核壳微球(PS/GO),然后采用氢碘酸(HI)进行还原得到聚苯乙烯/还原氧化石墨烯核壳微球(PS/rGO),采用XRD、SEM、TEM对PS/GO和PS/rGO进行了结构表征。探究了自组装过程条件,例如分散形式(搅拌或超声)、反应时间、GO质量浓度对核壳微球形貌的影响。对不同壳层还原氧化石墨烯(rGO)厚度的PS/rGO复合材料进行了导电性能和热稳定性测试,结果表明,改变壳层rGO的含量,会直接影响复合材料的导电和热性能。由于PS/rGO具有独特的核壳结构,其导电性能和热稳定性相比PS有所提高,电子电阻从PS的17.3Ω降到PS/rGO[m(PS)∶m(rGO)=50∶1]的8.3Ω,PS/rGO的起始热分解温度提高近120℃。     

MoO2/PSt核壳式纳米复合微球的合成与表征

结合了微乳液和γ-射线辐照法的优点,用微乳液控制产物的形貌,用γ-射线辐照法实现了在常温常压下制备出预期的核壳式无机-有机纳米复合微球。以七钼酸铵为无机盐原料,以苯乙烯为有机单体,用OP-10和OP-4作乳化剂,与水、煤油组成反相微乳液。用γ-射线辐射反相微乳液制备了二氧化钼/聚苯乙烯(MoO2/PSt)核壳结构的纳米复合微球。通过改变七钼酸铵的浓度和苯乙烯用量,观察产物形貌的变化。在七钼酸铵浓度为0.05 mol/L,苯乙烯用量为2 mL时,微球核壳结构明显,粒径均匀。     

POSS/PS纳米复合微球的制备与热性能研究

采用乳液共聚法合成了POSS/PS纳米复合微球,研究了反应条件对复合材料热性能的影响.结果表明,合成的微球形态规则、尺寸分布较均匀,微球具有核壳型结构,尺寸可调,微球尺寸可控制在50nm左右.通过共聚引入刚性POSS结构,使得POSS/PS纳米复合材料的玻璃化温度显著高于纯PS,耐热性明显改善.     

MPS-SiO2/PS核壳型复合粒子的形态与玻璃化转变温度研究

以正硅酸乙酯为原料，调节pH值为碱性，通过溶胶-凝胶工艺制备单分散SiO2球，用偶联剂甲基丙烯酰（3-三甲氧基硅烷）丙酯（MPS）进行改性，得到MPS-SiO2球形粒子。以MPS—SiO2球为种子，苯乙烯为壳单体，乳液聚合法制备核壳结构的MPS-SiO2／PS复合粒子。透射电镜观察复合粒子形态的结果表明，MPS—SiO2球粒径为200nm左右时，得到覆盆子状核壳结构；MPS-SiO2球粒径为80nm左右时，得到包含多个MPS—SiO2球的多核壳结构。差示扫描量热法考察MPS-SiO2／PS复合粒子玻璃化转变温度（Tg）的结果表明，随着MPS—SiO2球含量增加，复合粒子的Tg增加；随着MPS-SiO2球粒径减小，复合粒子的Tg也有所增加。     

Preparation of core–shell poly(acrylic acid)/polystyrene/SiO2 hybrid microspheres

Core–shell poly(acrylic acid)/polystyrene/SiO₂ (PAA/PS/SiO₂) hybrid microspheres were prepared by dispersion polymerization with three stages in ethanol and ethyl acetate mixture medium. Using vinyltriethoxysilane (VTEOS) as silane agent, functional silica particles structured vinyl groups on surfaces were prepared by hydrolysis and polycondensation of tetraethoxysilane and VTEOS in core stage. Then, the silica particles were used as seeds to copolymerize with styrene and acrylic acid sequentially in shell stage I and stage II to form PAA/PS/SiO₂ hybrid microspheres. Transmission electron microscope results show that most PAA/PS/SiO₂ hybrid microspheres are about 40 nm in diameter, and the silica cores are about 15 nm in diameter, which covered with a layer of PS about 7.5‐nm thick and a layer of PAA about 5‐nm thick. This core–shell structure is also conformed by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and differential scanning calorimetry. FTIR results show that silica core, PS shell, and PAA outermost shell are bonded by covalents. In the core–shell PAA/PS/SiO₂ hybrid microsphere, the silica core is rigidity, and the PAA outermost shell is polarity, while the PS layer may work as lubricant owning to its superior processing rheological property in polymer blending. These core–shell PAA/PS/SiO₂ hybrid microspheres have potential as new materials for polar polymer modification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1729–1733, 2006     

微米级聚苯乙烯/聚硅氧烷核壳微球的制备、表征及其作为光散射剂的应用

在乙醇/水混合溶剂中采用分散聚合法制备出微米级聚苯乙烯微球,将聚苯乙烯核微球与甲基三甲氧基硅烷的水解溶液混合,加入氨水使硅烷水解产物在核表面缩合交联,制备出微米级聚苯乙烯/聚硅氧烷核壳微球.采用TEM、粒径分布仪、EDX、TG等对核壳微球的形貌、粒径、表面成分和热失重进行了表征.将核壳微球作为光散射剂添加在聚甲基丙烯酸甲酯（PMMA）树脂中,制备出性能良好的光散射材料.当SS6核壳微球的添加浓度为1%（质量）时,制得的PMMA样片（2 mm）的雾度为88.16％,透光率为72.5％;当SS6添加浓度为2%（质量）时,其雾度为92.13％.     

Fabrication of anisotropic janus composite particles based on natural renewable urushiol

Urushiol praseodymium‐polystyrene (UPr‐PS) Janus composite particles were synthesized by emulsion swelling assisted protruding from UPr/PS core‐shell composite microspheres. The effects of sulfonated time and the outer electronic configuration of metal on the shell of urushiol metal/PS composite microspheres, together with the effects of monomer type, monomer dosage and swelling time on the swelling behaviour, were studied. The morphology, chemical composition and thermal performance of UPr/PS core‐shell composite microspheres and UPr‐PS Janus composite particles were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X‐ray analyzer (EDX), Thermogravimetric analysis (TG) and infrared spectrometer (IR). Results showed that the morphology could be controlled by the metal kind, the sulfonated time, the monomer type, the monomer dosage and the swelling time. Attributing to the novel anisotropic structure, the UPr‐PS Janus composite particles will be expected to be applied in oriented catalyst. POLYM. ENG. SCI., 59:411–417, 2019. © 2018 Society of Plastics Engineers     

具有核／壳结构的有机刚性粒子对PVC的改性

制备了以交联聚苯乙烯(XPS)或不交联聚苯乙烯(PS)为核、以PS或聚甲基丙烯酸甲酯(PMMA)为壳、并具有不同粒径的核/壳粒子(记作C/S),再将其与PVC进行熔融共混,构成PVC/(C/S)体系。用拉伸实验和冲击实验研究这些体系的性能。     

Advanced antistatic/anticorrosion coatings prepared from polystyrene composites incorporating dodecylbenzenesulfonic acid‐doped SiO2@polyaniline core–shell microspheres

We present the preparation of advanced antistatic and anticorrosion coatings of polystyrene (PS) incorporating a suitable amount of dodecylbenzenesulfonic acid (DBSA)‐doped SiO₂@polyaniline (SP) core–shell microspheres. First, aniline‐anchored SiO₂ (AS) microspheres that were about 850 nm in diameter were synthesized using the conventional base‐catalyzed sol–gel process with tetraethyl orthosilicate in the presence of N‐[3‐(trimethoxysilyl)propyl]aniline. SP core–shell microspheres were then synthesized by chemical oxidative polymerization of aniline monomers with ammonium persulfate as an oxidizing agent in the presence of the AS microspheres. The polyaniline shell thickness of the as‐prepared core–shell microspheres was estimated to be about 120 nm. The AS and SP microspheres were further characterized using Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy. The as‐synthesized DBSA‐doped SP core–shell microspheres were then blended into PS using N‐methyl‐2‐pyrrolidone as solvent and then cast onto a cold–rolled steel (CRS) electrode to obtain antistatic and anticorrosion coatings with a thickness of about 10 µm. The corrosion protection efficiency of the as‐prepared coating materials on the CRS electrode was investigated using a series of systematic electrochemical measurements under saline conditions. The enhanced corrosion protection ability of the PS/SP composite coatings may be attributed to the formation of a dense passive metal oxide layer induced by the redox catalytic effect of the polyaniline shell of the as‐synthesized core–shell microspheres, as evidenced by electron spectroscopy for chemical analysis and SEM observations. Moreover, the PS composite coating containing 10 wt% of the SP core–shell microspheres showed an electrical resistance of about 3.65 × 10⁹Ω cm^?2, which meets the requirements for antistatic applications. Copyright © 2012 Society of Chemical Industry     

Preparation of polyaniline coated polystyrene‐poly(styrene‐co‐sodium 4‐styrenesulfonate) microparticles and the further fabrication of hollow polyaniline microspheres

In this article, the microparticles of polystyrene‐poly(styrene‐co‐sodium 4‐styrenesulfonate) (PS‐PSS) coated by polyaniline (PANI) were prepared and hollow PANI microspheres were further obtained by dissolving the core. First, surface‐sulfonated monodispersed PS was prepared by copolymerization of sodium 4‐styrenesulfonate (SSS) and styrene with dispersion polymerization method. Then aniline was polymerized on the surface of the surface‐sulfonated PS (PS‐PSS) by chemical oxidative polymerization. After purification, we prepared core‐shell (PS‐PSS)/PANI particles. Hollow PANI microspheres were prepared by dissolving the plastic PS core of the (PS‐PSS)/PANI particles in chloroform. The growth process of PANI on the surface of PS‐PSS particles was investigated and the hollow PANI microspheres were characterized. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Facile fabrication of polystyrene/halloysite nanotube microspheres with core–shell structure via Pickering suspension polymerization

In this article, a facile method for fabrication of core–shell nanocomposite microspheres with polystyrene (PS) as the core and halloysite nanotubes (HNTs) as the shell via Pickering suspension polymerization was introduced. Stable Pickering emulsions of styrene in water were prepared using HNTs without any modification as a particulate emulsifier. The size of the Pickering emulsions varied from 195.7 to 26.7?μm with the water phase volume fraction increasing from 33.3 to 90.9?%. The resulting Pickering emulsions with the water phase volume fraction of above 66.7?% were easily polymerized in situ at 70?°C without stirring. HNTs played an important role during polymerization and effectively acted as building blocks for creating organic–inorganic nanocomposite microspheres after polymerization. The sizes of PS/HNTs microspheres were roughly in accord with that of the corresponding emulsion droplets before polymerization. The effect of the water phase volume fraction on the stability of Pickering emulsions and the morphologies of nanocomposite microspheres was investigated by optical microscopy, confocal laser scanning microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and so on.