摘要
添加少量聚乙二醇（PEG）于TEOS－H_2O－C_2H_5OH－NH_4OH溶胶体系中，可以改变SiO_2溶胶粒子的生长过程和网络结构的分形结构。通过小角X光散射（SAXS）、透射扫描电镜（TEM）、激光粒度分布仪（SDP）等手段对这一过程进行分析测试，同时探讨了PEG对SiO_2溶胶－凝胶的修饰机理，有力地证明了分形行为的存在，着重研究了其分数维的变化规律，并提出PEG在该溶胶中的作用模型。
PEG was added into TEOS - water - etahanol - ammounia sol system , which could change the particle growth and then tailor the fractal network of the SiO_2 sol. By means of SAXS, ThM and SDP, the effects of PEG on sol partide was discussed and the mechanism on sol partide growing was suggested in terms of sol -gel chemistry , and the fractal behaviors of SiO_2 -PEG sol were proved to be present and the change of the fractal dtansion was studied emphatically , the results showed that PEG additive ldried partcle growth but also accelerated partide agglomeation. It was found that the acton of PEG was similar to that of organic structure -directing agent and made the sol duster cross-linked ring-like network in short order, and the model of the PEG behavior in the SiO_2 sol-gel proass was described. The SiO_2-PEG sol-gel proass was recognized quantitatively at a more essential level.
基金
国家杰出青年科学基金
