中文摘要：

采用甲苯二异氰酸酯（TDI）接枝聚乙二醇（PEG）对纳米SiO2进行表面改性,并利用红外光谱（FTIR）和热重（TG）、扫描电镜（SEM）、粒径分析、重力沉降法等方法对改性前后的纳米SiO2的表面形貌和在介质中的分散稳定性进行了表征和分析。结果表明,改性后的纳米SiO2表面接枝上了TDI、PEG的有机官能团,降低了颗粒的团聚程度,提高了纳米SiO2在介质中的分散性。当n（TDI）：n（PEG）=1：0.8时,分散性最好,接枝率为54.03%。

英文摘要：

The particle surface of Nano-SiO2 powder was modified with toluene diisocyanate（TDI） grafted polyethylene glycol（PEG）.The effect of surface modification and dispersion stability in medium were characterized by means of FTIR,TG,SEM,particle size analysis and gravity sedimentation method.It was found that the organic functional groups of TDI and PEG were grafted on the surface of modified nano-SiO2,the agglomeration degree of nano-SiO2 was reduced and the dispersion was improved greatly.Oplimized molar ratio of TDI to PEG was 1：0.8,and the corresponding grafting rate was 54.03%.