多巴胺修饰法镀银玻璃微球的表征及其在导电硅橡胶中的应用

摘要

通过多巴胺修饰对玻璃微球的预处理和银的还原反应,批量制备了镀银玻璃微球(SiO2/PDA/Ag),进行了X射线光电子能谱(XPS)、广角X射线衍射(WAXD)、扫描电子显微镜(SEM)等测试.结果表明,镀银玻璃微球的银含量稳定,表面银层均匀、连续、致密.与国外进口镀银玻璃微球的SEM对比实验显示,镀银玻璃微球表面粗糙度更大,有利于达到逾渗效应.镀银玻璃微球在甲基乙烯基硅橡胶中的应用实验结果显示,镀银玻璃微球在经过混炼后银层保持完好,在硅橡胶中分散均匀且黏结紧密.使用镀银玻璃微球制备的导电硅橡胶的力学和电学性能显示,拉伸强度为2.54 Mpa,扯断伸长率为122.3％,体积电阻及老化后电阻分别为3.9和9.0 mΩ·cm.%The bulk production of silver coated silica microsphere (SiO2/PDA/Ag) was realized by dopamineassisted functionalization and subsequent elelctroless plating.X-ray photoelectron spectroscopy (XPS),wide-angle X -ray diffraction (WAXD) and scanning electron microscope (SEM) results show that the silver layer on the surface of silica microsphere was homogenous,continuous and compact with stable silver contents.The surface of SiO2/PDA/Ag microsphere was much rougher than the one imported from U.S.The roughness will facilitate the electron tunneling effect of particles.The SiO2/PDA/Ag microsphere maintains its intactness and strongly adheres to ethyl vinyl silicone rubber after the blending with silicone rubber.The mechanical and electrical characterizations of conductive silicone rubber show that tensile strength is 2.54 MPa,elongation at rupture is 122.3％,volume resistivity before and after thermal aging is 3.9 and 9.0 mΩ·cm.