聚合物/SiO2核壳结构单分散微球的制备

摘要

聚合物/SiO2核壳结构单分散微球比聚合物微球具有更好的稳定性,有望在较高的温度和有机溶剂中得到使用.为了制备出这种微球,作为模板的聚合物微球首先进行表面胺化处理,然后正硅酸乙酯被诱导在其表层水解缩合从而形成SiO2壳层;采用扫描电子显微镜(SEM)、傅里叶红外光谱仪(FTIR)、激光粒度仪,烧蚀质量损失等手段分析表征了所得微球.结果表明:2μm和5μm 2种粒径的聚合物/SiO2核壳结构单分散微球被成功制备出来,壳层厚度从数纳米到数十纳米可调.复合微球的SiO2壳层厚度和采用的胺化试剂种类密切相关;胺化微球的Zata 电位说明了这种核壳结构的形成是基于表面氨基催化诱导的静电自组装机理.%Polymer (PGMA, PGMA/PS)/SiO2 core-shell monodispersed microspheres are more stable than polymer microspheres when they are used at high temperature or in organic solvent. To prepare the composite microspheres,monodispersed polymer (PGMA, PGMA/PS) microspheres were modified with amino-group at the first step, and then the microspheres were coated with SiO2 shell by catalyzing the hydrolysis of tetra ethoxy silane (TEOS) and adsorbing the hydrolyzate. The obtained microspheres were characterized by scanning electron microscope (SEM),Fourier transform infrared spectrometer (FTIR), laser particle analyzer, and mass loss of ablation. Polymer (PGAM, PGMA/PS )/SiO2 core-shell monodispersed microspheres with diameter of 2 μm and 5 μm were successfully obtained. The shell thickness is in the range of several nanometers to tens of nanometers. The thicknesses of the shell are heavily influenced by the kinds of ammoniation reagents. The electrostatic self-assembly mechanism of ammoniated microspheres was evidenced by Zata potential.