荧光纳米SiO2-等规聚丙烯复合材料的制备及其球晶的形态表征

Preparation of fluorescent nano-SiO2-isotactic polypropylene composite and morphological characterization of spherulite

为研究染色纳米颗粒在等规聚丙烯中的分布,观察球晶生长过程中染色剂的分布及再分布情况,系统探究染色剂在球晶边缘的汇聚现象。合成不同粒径接枝荧光分子的纳米二氧化硅(SiO2),并将其加入聚丙烯(iPP)中,通过冷冻干燥法制备了荧光SiO2/iPP纳米复合材料,并利用荧光显微镜(FM)在线观察SiO2/iPP纳米复合材料结晶过程中SiO2纳米粒子的二维扩散过程。结果表明:荧光SiO2纳米粒子能追踪染色剂在球晶边界的聚集行为;经荧光强度统计,SiO2选择性分散在iPP球晶之间的无定形区,最终汇聚在球晶边界。该研究可为聚合物纳米复合材料改良提供一定的参考。

In order to study the distribution of dyed nanoparticles in isotactic polypropylene,the distribution and redistribution of dyes during spherulite growth were observed,and the convergence of dyes at the edge of spherulites was systematically investigated.Nano-silica(SiO2)with different particle size grafted with fluorescent molecules was synthesized and added into polypropylene(iPP).Fluorescent SiO2/iPP nanocomposites were prepared by freeze-drying method.Fluorescence microscopy(FM)was used to observe the two-dimensional diffusion process of SiO2 nanoparticles during crystallization of SiO2/iPP nanocomposites online.The results show that the fluorescent SiO2 nanoparticles can track the aggregation behavior of the dye at the spherulitic boundary.It was found by fluorescence intensity statistics that SiO2 was selectively dispersed in the amorphous region between iPP spherulites and finally concentrated atspherical boundaries.This study can provide certain reference for improvingpolymer nanocomposites.