共查询到20条相似文献,搜索用时 15 毫秒
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采用无皂乳液聚合法制备了亚微米级聚苯乙烯(PS)微球,考察了苯乙烯(St)单体浓度、引发剂过硫酸钾(K2S2O8)浓度、离子强度(氯化钠浓度)与PS微球粒径及其分布的关系。然后通过加入微量乳化剂或β-环糊精对无皂乳液聚合法进行改进,研究了改进效果。结果表明,PS微球的粒径随St单体浓度和氯化钠浓度的增加而增加、随K2S2O8浓度的增加而减小,通过调节这3种原料的浓度,可制得粒径在450~1000 nm且单分散系数小于0.08的PS微球,但产品收率较低,仅为30%左右。在相同的合成条件下,加入微量乳化剂可制得粒径在100~350 nm且单分散系数小于0.05的PS微球,产品收率提高到75%左右;加入微量β-环糊精可制得粒径在300 nm左右且单分散系数小于0.08的PS微球,产品收率可达80%且反应时间大幅缩短,由原来的12 h缩减到5 h。 相似文献
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采用化学共沉淀法制备了油酸包覆的Fe3O4磁性纳米粒子,以此为核·采用分散聚合法制备了表面带有环氧基团的Fe3O4/聚甲基丙烯酸缩水甘油酯(PGMA)磁性复合微球,探讨了聚合工艺、聚合条件对甲基丙烯酸缩水甘油酯(GMA)利用效率的影响规律,并用傅立叶变换红外光谱仪(FTIR)、热重分析仪(TGA)、振动样品磁强计(VSM)和扫描电镜(SEM)等对磁性复合微球的结构、磁性能和包覆量进行了表征.采用盐酸一丙酮法测定了磁性复合微球表面环氧基的含量。结果表明,在优化的条件下。GMA利用效率高达61.26%。磁性复合微球具有良好的单分散性·粒径为1~2μm.具有超顺磁性.比饱和磁强度为17.12emu·g^-1。环氧基含量达3.5mmol·g^-1。 相似文献
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用分散聚合的方法制得单分散微米级聚苯乙烯微球(PS),以此聚苯乙烯微球作为种子,以邻苯二甲酸二丁酯为溶胀剂,苯乙烯为单体,二乙烯基苯为交联剂,甲苯为致孔剂,采用种子溶胀聚合的方法制得粒径分布较窄的多孔高交联的聚苯乙烯-二乙烯基苯微球(PS-DVB)。研究了交联剂与致孔剂的加入量对微球形貌、粒径及孔结构参数的影响。结果表明,所得多孔微球球形圆整,库尔特测得平均粒径为5.067~5.520μm,粒径分布窄,D90/D10为1.23~1.56,孔结构可控,并以此多孔微球作为反相色谱填料基质,理论塔板数每米可达6 000~15 000,可以用作高效液相色谱(HPLC)填料。 相似文献
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采用分散聚合法以甲基丙烯酸甲酯(MMA)为单体,水/乙醇(H2O/EtOH)作为分散介质,聚乙烯吡咯烷酮(PVP)为分散稳定剂,芬顿试剂硫酸亚铁(FeSO4)和双氧水(H2O2,30%)在pH =3 ~4的弱酸性条件下作为引发剂,制备了粒径约为408 nm的单分散聚甲基丙烯酸甲酯(PMMA)微球.探讨反应机理及分散介质的配比、单体浓度、分散稳定剂用量、聚合反应时间等对PMMA微球粒径和分散性的影响.该工艺选用新型引发剂,无需除氧,聚合时间短,操作简单,和传统工艺相比具有明显的优势. 相似文献
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大粒径单分散聚合物微球的制备及其在LCD中的应用进展 总被引:3,自引:0,他引:3
单分散聚合物微球的制备和应用是近年来人们研究的热点。综述了单分散聚合物微球的制备方法和研究进展,具体介绍了分散聚合和种子聚合。并对其在液晶显示器(Liquid Crystal Display,LCD)中的应用进行了介绍,对其未来的研究方向和应用前景进行了展望。 相似文献
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Ting Huo Meng Wang Jiapeng Long Xiaojiao Liu Xueyan Du 《Polymer-Plastics Technology and Engineering》2015,54(9):889-898
Molecularly imprinted polymer microspheres (MIPMs) for Glutathione had been prepared by the reversed phase suspension polymerization method; MIPMs were synthesized by using acrylamide and N-vinyl pyrrolidone as functional monomers. N,N’-methylenebisacrylamide and dimethyl diallyl ammonium chloride were the cross-linkers and H2O2 and Vc were redox initiators, Span-80 was the surfactant used and cyclohexane was the oil phase. Our work can provide a method to obtain ball MIPMs, and in this way, the destruction of acting sites because powdery MIPMs could be avoided. Moreover, the low concentration of cross-linker results in imprinted sites not being formed during the reversed phase suspension polymerization. The double cross-linkers not only solved this problem, but they also enlarged the selection range of the template, monomer and cross-linker. Simultaneously, there’s obviously a significant amount of synergy between the two cross-linkers that perhaps improve the adsorption capacity and selectivity. The conditions were investigated and optimized, and the optimum conditions were obtained as follows: the ratio of nAM/nNVP was 2; the optimum temperature and time were 50°C and 4.5 h; and, the dosage of GSH, DMDAAC and Vc were 0.8 g, 14 g and 0.023 g, respectively, under the optimum conditions, GSH-MIPM was prepared and showed the adsorption capacity was 75 mg · g?1. Also, based on the samples prepared at the starting process and under optimal conditions, the adsorption kinetics and adsorption isotherm were investigated and analyzed, respectively. 相似文献
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聚合物模板法是实现无机材料高效制备的有效途径.本研究采用交联聚苯乙烯二乙烯基苯聚合物微球为模板,以有机硅源正硅酸四乙酯(TEOS)为前驱体,通过将硅溶胶沉积到多孔聚合物中形成聚合物和二氧化硅的混合物,再经过高温煅烧将聚合物模板去除的方法,可以方便地制备形貌可控的单分散多孔二氧化硅微球.利用扫描电子显微镜(SEM),傅里叶红外光谱仪(FHR),热重分析仪(TGA),X射线衍射仪(XRD),比表面积孔径分布测定仪(BET)对聚合物模板以及制备的二氧化硅微球进行表征.另外,对单分散多孔二氧化硅微球形成机理进行探讨. 相似文献
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以烟酰胺为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,偶氮二异丁腈为引发剂,乙腈为溶剂,采用沉淀聚合法制备了烟酰胺分子印迹聚合物,通过静态平衡吸附和色谱分析对印迹聚合物进行表征,结果表明,印迹聚合物对烟酰胺分子具有很好的吸附能力和特异识别性。 相似文献
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单步溶胀聚合法制备单分散分子印迹聚合物微球 总被引:2,自引:0,他引:2
用无皂乳液聚合法制备了微米级粒径均匀的聚苯乙烯微球(PS).以制得的PS为种球,柚皮素为模板分子,通过单步溶胀聚合法制备了单分散分子印迹聚合物微球(MIPBs).研究了溶胀比及环己醇用量对MIPBs粒径及形态的影响,结果发现,采用粒径为1.50μm的PS作种球,且溶胀比控制在27~60时,可以制得粒径在4.5 μm~6.0 μ.m单分散的MIPBs;随着环己醇用量的增大,MIPBs球形更加规则、表面更加光滑.氮气吸附测量结果表明,制得的MIPBs是一种具有多孔结构、比表面积大的聚合物.Scatchard分析结果表明,在研究的浓度范围内,MIPBs存在一类等同的结合位点,其平衡离解常数Kd和最大表观吸附量Qmax分别为8.61 mmol·L-1和48.50μmol·g-1.制得的MIPBs对模板化合物柚皮素显示出较高的选择性,以槲皮素为竞争底物,其分离因子达1.96. 相似文献
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采用分散聚合的方法,以聚乙烯吡咯烷酮为分散剂、无水乙醇为反应介质、偶氮二异丁腈为引发剂作为反应条件,成功制备出了粒径范围为1~10μm不同粒径级别的单分散(分散系数≤5%)微米级聚苯乙烯(PS)微球。并研究了用分散聚合法制备PS微球时单体浓度、介质、稳定剂、引发剂与温度、反应时间、搅拌速度、气氛等影响因素及微米级PS微球的应用与发展。 相似文献
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Monodisperse Silica‐Polymer Core‐Shell Microspheres via Surface Grafting and Emulsion Polymerization
We describe a flexible method for preparing monodisperse silica‐polystyrene core‐shell microspheres. In this method, silica nanoparticles grafted with 3‐(trimethoxysilyl)propyl methacrylate (MPS) were employed as seeds in an emulsion polymerization. The thickness of the shells could be changed through varying the amount of the monomer. The monodispersity and diameters of the core‐shell microspheres were found to depend on the size of the grafted silica nanoparticles and the concentration of emulsifier. In addition, we investigated the formation mechanism of the core‐shell microspheres.
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