中文摘要：

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。

英文摘要：

Modified silica （SiO2） nano-particles were prepared by the mechano-chemical method.Silica nano-particles were used to encapsulate calcium carbonate （CaCO3） particles surface to form mulberry-like composite particles through violent stirring,which prevented agglomeration of silicon dioxide nano-particles and maintained their nano characteristics.And then,the CaCO3/SiO2 composite particles were modified with hexmethyldisilazane （HMDS） or γ-aminopropyl triethoxysilicane （type KH550） as modifying reagent.The hydroxyl on the surface of CaCO3/SiO2 composite particles was formed by hydrolyzing.The modifying reagent reacted with hydroxyl on the surface of SiO2 nano-particles so that the particles transformed from hydrophilic to hydrophobic.In this process,the effects of stirring speed,CaCO3/SiO2 mass ratios,reaction temperature,reaction time and modifying reagent dosage on the lipophilicity of particles were studied and optimized.Infrared spectrum and thermogravimetry analysis were used to characterize the modified particles.The results show that the modification of CaCO3/SiO2 composite particles at 200 ℃ for 90 min by HMDS is best at the stirring rate of 6 500 r/min with a mass ratio of CaCO3 to SiO2 at 5：1.CaCO3/SiO2 composite particles maintain nano-effect of nano-SiO2 and have multiple surface structures,which leads to vast potential applications in reinforcing filler of rubber and superhydrophobic surface preparation.