论文部分内容阅读
利用机械化学法对纳米SiO2进行了表面修饰改性。首先通过高速机械冲击将纳米SiO2粒子镶嵌在微米级的CaCO3粒子表面形成草莓结构的CaCO3/SiO2复合粒子,从而阻止纳米SiO2的团聚。而后又以六甲基二硅氮烷(hexmethyldisilazane,HMDS)和γ-氨丙基三乙氧基硅烷KH550为改性剂对CaCO3/SiO2复合粒子进行了表面改性。用红外光谱和热重分析对复合粒子进行了表征与分析。考察了搅拌速度、CaCO3/SiO2配比、改性温度、改性时间和改性剂用量对CaCO3/SiO2复合粒子形貌和表面改性效果的影响。结果表明:在搅拌速度为6500r/minCaCO3与SiO2的质量比为5:1,以HMDS为改性剂在200℃反应90min时,对纳米SiO2的改性效果最好。CaCO3/SiO2复合粒子既保持了纳米SiO2的纳米效应,同时又具有多重表面结构,在橡胶补强填料和超疏水涂层制备方面有着广阔的应用空间。
The surface modification of nano-SiO2 was carried out by mechanochemical method. Firstly, the nano-SiO2 particles are inlaid on the surface of the micron-sized CaCO3 particles through high-speed mechanical impact to form the strawberry structure CaCO3 / SiO2 composite particles, thus preventing the nano-SiO2 from agglomerating. Then, CaCO3 / SiO2 composite particles were modified with hexamethyldisilazane (HMDS) and γ-aminopropyltriethoxysilane (KH550) as modifiers. The composite particles were characterized and analyzed by infrared spectroscopy and thermogravimetric analysis. The effects of stirring speed, CaCO3 / SiO2 ratio, modification temperature, modification time and amount of modifier on the morphology and surface modification of CaCO3 / SiO2 composite particles were investigated. The results showed that the modification effect of nano-SiO2 was the best when the mass ratio of CaCO3 and SiO2 was 5: 1 at a stirring speed of 6500r / min and HMDS was used as a modifier at 200 ℃ for 90min. CaCO3 / SiO2 composite particles not only maintain the nano-effect of nano-SiO2, but also have multiple surface structures, which have broad application space in the preparation of rubber reinforcing fillers and superhydrophobic coatings.