多孔结构ZnO及其电致发光性能

利用Sol-gel法制备了含制孔剂P123的ZnO前驱体,通过无皂乳液聚合法和分步乳液聚合法制备了不同粒径的PS小球,采用共沉积法得到P123-PS-ZnO凝胶。高温煅烧去除有机模板剂P123和PS,从而制备出系列孔径可控的多孔ZnO电致发光材料。研究表明,多孔结构可以显著改善ZnO的电致发光性能;ZnO发光强度随PS粒度的改变而改变,当使用100nm PS小球为模板时,多孔ZnO材料的相对发光强度较未使用PS模板提高了4.03倍。     

单分散聚苯乙烯微球合成及在三维有序大孔材料制备中的模板作用

通过乳液聚合得到了单分散的聚苯乙烯(PS)微球乳液并通过阳离子破乳沉降法实现PS微球自组装,得到了紧密堆积的PS微球的胶体模板剂。向PS胶体模板的空隙填充硅溶胶,再通过焙烧去除模板得到三维有序大孔(3DOM)二氧化硅(SiO_2)材料。采用扫描电子显微镜、透射电子显微镜、红外和热重分析等对合成的3D大孔SiO_2材料进行表征。结果表明:使用粒径不同的PS微球作为模板,制得的3D大孔SiO_2材料的孔径在200~400nm之间。该制备方法为多孔材料的制备开拓了一条可行、便捷的途径。     

单分散纳米聚苯乙烯微球的制备及在多孔炭材料中的应用

在超声波辅助下通过微乳液聚合法制备出纳米PS微球,利用重力沉降法制备出聚苯乙烯胶晶阵列,以该阵列为大孔模板制备出大孔一介孔分级炭材料,利用激光粒度仪、场发射扫描电镜、红外和N2物理吸附及解吸附技术对产品的形貌、微观结构及性能进行表征与研究,结果表明,采用超声波辅助微乳液聚合可实现粒径在50nm-500nm范围内聚苯乙烯纳米球的可控制备,增大KPS和PVP用量,PS粒径均会变小,St／SDSN要有适合的比例才能保证PS粒径小且单分散均一。     

偶氮二异丁基盐酸脒引发甲基丙烯酸甲酯微球的无皂乳液聚合

采用偶氮二异丁基盐酸脒(AMPMDHC)为引发剂,用无皂乳液聚合方法制备单分散性PMMA微球,合成粒径为500nm的单分散PMMA微球的聚合条件是:MMA/H2O=20:100(m1),温度为70℃,AMPMDHC用量为0.06g,反应时间为1.5h.实验结果表明:(1)引发剂用量越多,PMMA微球粒径越小,但对微球粒径分布影响较小;(2)反应温度升高,微球粒径增大,单分散性降低;(3)微球的粒径随着水的用量增大而降低,当MMA/H2O小于1/6时,微球粒径趋于180nm.     

聚苯乙烯微球模板法制备反蛋白石型光子晶体水凝胶薄膜

用乳液聚合法制备了系列单分散且粒径均一的聚苯乙烯纳米微球,以正交试验优化反应中各物质的用量对聚苯乙烯纳米微球的粒径大小及分布的影响,实现了在150~350nm范围内PS纳米微球的可控制备。以不同粒径的PS纳米微球作为模板,以丙烯酰胺和丙烯酸作为原料制备了一系列反蛋白石型光子晶体水凝胶。通过比较它们之间的初始反射峰位置及反射峰变化范围,表明以300nm左右的PS纳米微球作为模板制备的水凝胶在可见光范围内有较大的变化范围,并且有较好的形貌。     

粒径及壁厚可控的二氧化硅空心微球的研究(英文)

二氧化硅空心微球是由模板/溶胶?凝胶法制备的,其中模板选用的是阳离子型聚苯乙烯(PS),前驱体采用的是正硅酸乙酯(TEOS).二氧化硅空心微球的空腔大小由PS模板的尺寸决定,所以通过改变聚合反应的参数(单体、引发剂、稳定剂、分散介质的极性),可以制得粒径范围在0.71～1.80μm的二氧化硅空心微球.改变TEOS的浓度为0.4～0.8mmol/L,可以得到壁厚为20～60nm的二氧化硅空心微球.空心微球的粒径和壁厚将会影响粉体的堆积密度,而这同样会影响到以二氧化硅空心微球为原料制备的材料的热导率及强度.     

PS微球的制备及三维胶晶模板的组装和应用

研究了PS微球合成中单体、引发剂和乳化剂浓度以及聚合温度对粒径及分布的影响。采用高速离心沉淀法、恒温加热蒸发诱导法和自然沉降法对单分散PS微球进行了组装,得PS胶体晶体模板,并以其为模板制备了锂离子筛前驱体Li4Mn5O12。用纳米粒度及ZETA电位分析仪、扫描电子显微镜(SEM)、饱和交换容量等表征了材料的粒径及分布、形貌、结构和离子交换性能。结果表明:通过控制反应条件可以在一定范围内制得粒径均一、单分散性好、表面规整光滑的PS微球;PS胶体晶体模板三维有序,排列规整;酸改性后的离子筛前驱体对Li+饱和交换容量为7.49mol/g锂离子筛。     

双模板法制备分级孔ZnO及其电致发光性能

以P123为介孔模板、以Zn(Ac)2·2H2O和LiOH·H2O为原料制备ZnO前驱体溶胶,对聚苯乙烯(PS)微球模板进行填充,55℃干燥后形成凝胶。经过600℃高温煅烧除去有机模板剂P123和PS,从而得到了具有介孔/大孔分级结构的ZnO材料。采用扫描电子显微镜、傅立叶变换红外光谱仪对分级孔结构ZnO材料进行了表征,并研究了其电致发光性能。结果表明,相同条件下介孔/大孔分级结构ZnO材料的发光强度是介孔ZnO材料的3.3倍。     

无皂乳液聚合法制备单分散聚苯乙烯微球

以苯乙烯(St)为单体,过硫酸钾(KPS)为引发剂,采用无皂乳液聚合法制备了聚苯乙烯微球。研究了单体、引发剂的浓度,引发剂加入方式,聚合温度对制备PS微球粒径的影响。运用傅立叶红外光谱(FT-IR)、透射电子显微镜(TEM)、场发射扫描电镜(FE-SEM)、电势与纳米粒径分析仪等手段,对微球的组成成分、表面形态、粒径及其分布、表面电势进行了表征。结果表明微球粒径均匀,在100～200nm范围内,球形度良好且呈单分散性。     

块状无裂纹介孔碳的合成和表征

以P123、F127作为模板剂,间苯二酚-甲醛为碳前驱体,利用水热合成技术制备了蠕虫状结构的块状无裂纹介孔碳。采用TG、FT-IR、TEM、N2吸附-脱附和元素分析等方法对介孔碳材料的结构进行了表征,分别研究了模板剂用量、模板剂种类对介孔碳结构的影响。结果表明:以F127和P123为模板剂制备的介孔碳均为蠕虫状结构。模板剂用量增加,介孔碳比表面积、孔径和孔容有所变大,但微孔的比表面积有所下降。模板剂种类不同,比表面积、微孔比表面积、孔容相差不大,但孔径相差较大。     

乳液聚合制备聚苯乙烯纳米微球

采用乳液聚合法制备了聚苯乙烯(PS)微球,对制备条件进行了研究.采用FT-IR、TEM对PS粒子的表面结构进行了表征.电镜分析表明,PS微球平均粒径约为50nm,且随乳化剂浓度的增加而减小.实验结果表明,聚合温度、乳化剂浓度等对PS微球大小和尺寸分布产生较大影响.     

气-液界面二元共沉积法制备三维有序大孔SiO2

采用乳液聚合法制备粒径为229nm的单分散聚苯乙烯(PS)微球,以单分散PS微球和粒径为10nm的硅溶胶为原料,采用蒸发自组装法在气-液界面上二元共沉积,制备了大孔SiO2材料。结果表明,当SiO2体积分数为11%时,大孔SiO2材料呈现有序规整的FCC结构,其填充率为42%,收缩率仅为2%。低温N2吸附表明该材料在大孔孔壁上存在6.4nm左右的介孔,是一种具有大孔/介孔复合孔道结构的功能材料。     

Preparation of PS/TiO2 core-shell microspheres and TiO2 hollow shells

PS/TiO₂ core-shell microspheres were prepared by a hydro-thermal method at 105°C. Different-sized PS/TiO₂ core-shell microspheres were obtained with various PS cores, which were prepared by emulsion polymerization and seeds polymerization. Furthermore, intact hollow TiO₂ shells with different shell thickness were obtained by calcining PS/TiO₂ core-shell microspheres at 600°C. Light scattering of core-shell microspheres and hollow shells was tested.     

Ni/PS核壳结构纳米复合微球的制备及磁性能

采用乳液聚合法制备了纳米级聚苯乙烯微球,利用化学沉积法在微球表面镀镍,制备出了具有磁性的金属/高分子(Ni/PS)纳米复合微球。利用透射电子显微镜(TEM)、X射线衍射仪(XRD)和能量色散谱仪(EDS)分别对镀镍前后纳米微球的形貌结构、相组成、化学成分进行表征分析,用振动样品磁强计(VSM)测试了不同制备工艺条件下复合微球的磁学性能。结果表明,活化工艺、还原剂浓度、镀液pH值和温度对镀后复合微球的磁性能有显著影响。根据磁性能结果,优化工艺参数,制备了具有规则球形、单分散性好、粒径约为100nm、镀层完整、均匀的磁性Ni/PS核壳结构纳米复合微球,并获得最大的饱和磁化强度Ms=8.8764emu/g。     

Preparation of polystyrene–polyisoprene core–shell nanoparticles for reinforcement of elastomers

Latex-formed core–shell nanoparticles composed of cross-linked polystyrene (PS) core and polyisoprene (PI) shell were successfully synthesized by means of a two-stage emulsion polymerization. The PS core possessed a Z-average diameter of 50.3 nm, and the PS–PI particles took a spherical shape with a Z-average size of 50–70 nm in diameter. Shell thickness was controlled by varying isoprene loading. Necessary interphase interactions between the core and shell domains were also achieved by grafting and swelling polymerization. Latex compounding method was employed to prepare the filled elastomer compounds. As expected, the PS–PI core–shell nanoparticles exhibited excellent reinforcement to elastomeric matrix, enhancing the tensile strength of the styrene–butadiene rubber by approximately 400%. The lower density, better interfacial interactions, and latex compounding process would benefit the PS–PI nanoparticles reinforced elastomer nanocomposites in energy saving.     

微波辐射乳液聚合制备聚氰基丙烯酸正丁酯磁性微球

通过化学共沉淀法制备Fe3O4纳米粒子,再用油酸钠和十二烷基磺酸钠(SDS)对Fe3O4进行改性,制得稳定的水基磁流体。在自制的磁流体存在下,以氰基丙烯酸正丁酯(BCA)为单体,用微波辐射乳液聚合的方法制备了Fe3O4/聚氰基丙烯酸正丁酯磁性微球。并用X射线衍射仪(XRD),透射电子显微镜(TEM),傅立叶红外光谱仪(FT-IR),振动样品磁强计(VSM)对制备的磁性高分子微球的结构形貌和磁性能进行表征测试。结果表明,在适当的pH值条件下,得到了粒径为150 nm~200 nm,饱和磁化强度为20.23 emμ/g,粒径均一的聚氰基丙烯酸正丁酯磁性微球。     

微波辐射乳液聚合制备磁性高分子微球

用化学共沉淀法制备了Fe3O4纳米粒子,并用油酸和十二烷基硫酸钠对Fe3O4纳米粒子进行表面修饰,得到了稳定的水分散性纳米Fe3O4磁流体。在Fe3O4磁流体存在下,以苯乙烯和丙烯酰胺为单体,采用微波辐射乳液聚合法制备了Fe3O4/聚(苯乙烯-丙烯酰胺)磁性高分子微球,表征了磁性高分子微球的形态与结构,研究了磁性高分子微球的粒径、热稳定性、磁含量与饱和磁化强度。研究发现,在选定合适的聚合条件下,通过微波辐射乳液聚合法可以制得粒径为70 nm~80 nm、磁含量为18.2%的磁性高分子微球。     

Adsorption behavior of carbon nanotubes on polystyrene surfaces

Polystyrene (PS) was prepared using two different polymerization methods (dispersion polymerization and seed polymerization) to investigate the steric stabilizer effect during the adsorption process of carbon nanotubes (CNTs) on the surface of PS microspheres. Experiments with different microsphere diameters and difference types of CNTs were conducted to analyze the curvature effect of the spheres on the adsorption mechanism. The results showed that PS microspheres prepared through dispersion polymerization exhibited preferable adsorption behavior compared to PS spheres prepared through seed polymerization, suggesting that poly(N-vinylpyrrolidone) led to improved adsorption interactions between the CNTs and the PS microspheres in the CNTs dispersion. Additionally, the PS diameter and CNT curvature were examined with respect to the adsorption behavior between the PS microspheres and the CNTs. Multiwalled carbon nanotubes (MWCNTs) were found to be well adsorbed on the surface of PS microspheres measuring 2 microm. However, the MWCNTs were adsorbed much less on the surface of submicron-sized PS microspheres, compared with thinwalled carbon nanotubes (TWCNTs). On the other hand, TWCNTs were found to be suitable for adsorption on submicron-sized PS microspheres. These results also indicate that the curvature of the CNTs and the polymer microspheres are important to the CNT adsorption process.     

羧基功能化聚苯乙烯荧光微球的制备及表征

以苯乙烯、丙烯酸为单体,引入疏水性荧光染料罗丹明6G(Rh6G),采用微乳聚合法制备羧基聚苯乙烯荧光微球,并分析了表面活性剂、引发剂、丙烯酸用量对产物粒径分布的影响,考察了羧基聚苯乙烯荧光微球的浓度对荧光强度的影响。通过粒度分析仪、扫描电子显微镜、红外光谱仪、紫外吸收光谱以及荧光光谱仪对样品的纳米特性、形貌、结构和荧光性能进行了表征。结果表明,用微乳聚合法制备出50~250nm的羧基聚苯乙烯荧光微球,粒径均一且呈单分散性。紫外光谱图测试表明,在533nm左右有吸收峰。荧光光谱测试表明,羧基功能化的荧光聚苯乙烯微球浓度≤0.01%,其荧光最大激发峰为527nm,最大发射峰在555nm处;浓度高于0.01%时,荧光光谱出现红移,且荧光强度减弱。     

Preparation of micron-sized PA6/12 copolymer microspheres via successive in-situ polymerization

Micron-sized polyamide 6/12 (PA6/12) copolymer microspheres were firstly synthesized via successive in-situ polymerization of styrene (free radical polymerization), equimolar Laurolactam (LL) and Caprolactam (CL) (anionic ring-opening polymerization). The resulting PA6/12 microspheres were regular sphericity, with diameter ranging from 9.2 to 138.0 microns and narrow size distribution (size distribution ranging from 1.2 to 3.3), as confirmed by scanning electron microscopy (SEM) and Laser diffraction size Analyzer. Furthermore, the study on the PA6/12 microspheres in PA6/12 and PS (PA6/12/PS) blends confirmed that the particle size distribution, diameter of PA6/12 microspheres were controllable, and closely related to the content of PS in the blends, which indicated that the formation of the PA6/12 microspheres in the PA6/12/PS blends can be elucidated via a phase inversion mechanism.