Hydrophobic Surface Modification of Nano-Silica and Its Oil Displacement Performance
摘要
Surface modification of nano-SiO2 was carried out in solution with 3-methacryloxypropyltrimethoxysilane (KH-570) and amphoteric surfactant dodecyl dimethyl ammonium oxide (OA-12). The structure and performance of modified nano-SiO2 were analyzed by infrared spectroscopy, X-ray diffraction, and thermogravimetry. The influence factors such as stirring time, temperature, and modifier amount on modified performance have been discussed. The results showed that optimal modification conditions with OA-12 and KH-570 were as follows: temperature 80 ℃, initial reaction time 4.5 h, post-reaction time 3 h, KH570 25% (w/w) and OA-12 3% (w/w). As an oil-displacing agent, nano-SiO2 enhances the oil recovery via molecular modification and manipulates the interfacial characteristics.