Preparation Of SiO₂ Particles And Self-Assembly On The Surface Of Quartz Fiber

Quartz fiber have a wide range of applications in aviation, aerospace, military, semiconductor, high temperature insulation due to its excellent properties in dielectric, heat-resistant. However, the decreasing of mechanical properties of the fiber as the result of heat damage limited its application. There is epoxy resin which has low heat-resistance and can be carbonized at 400-500℃often on the surface of quartz fiber, so the interfacial behavior of the composites will be influenced. In this article, we have prepared the silica particles self-assembly which can improve the mechanical properties of the quartz fiber at high temperature on the surface of quartz fiber after eliminating the epoxy resin-coating.The agents on the surface of quartz fiber were eliminated by using heat treatment and toluene treatment. Tensile strength, XPS, TG-DSC and SEM were used to analyze optimum condition of the surface treated quartz fiber. The results showed that the best method to eliminate the agents on the surface of quartz fiber was heat treated at 400℃and toluene treated about 9 hours.The monodisperse silicon dioxide spherical particles were synthesized by TEOS, H2O, ammonia and ethanol as solvent. The scanning electron microscopy(SEM) was employed to monitor particle growth and particle size distribution with the changing of the TEOS concentration, H2O concentration, ammonia concentration, reaction time and stir velocity.The microstructure of the surface of quartz fiber after gravity sedimentation self assembly, ultrasound mixing self assembly and vertical capillary self assembly respectively were studied by the SEM. The quartz fiber after aluminum sol treated and dipped into silica sol was covered completely by silica particles at nearly one layer.Tensile strength of different heat treated quartz fiber was tested. With the treated temperature increasing, the tensile strength of the quartz fiber with silica particles assembled reduced lowest.