KH-570表面改性超细SiO_2的研究

利用超重力连续化装置制得超细SiO2的湿滤饼,用硅烷偶联剂KH-570对SiO2表面进行改性以提高其在有机相中的浸润能力。通过红外光谱(FT-IR)、表面羟基数、透射电子显微镜(TEM)、邻苯二甲酸二丁酯(DBP)吸油值、激光粒度分析等表征手段对样品进行了测试分析。结果表明:硅烷偶联剂KH-570是有效的改性剂;改性后样品在有机相中的浸润能力明显提高,样品的DBP吸油值由1.9 mL/g增大到3.1 mL/g;确定了最佳偶联改性条件,反应时间为4 h,改性剂KH-570用量为SiO2质量的10%,改性后样品每平方纳米表面积上的羟基数由1.15nm-2减少到0.9 nm-2。

Experimental studies of the surface modification of silica by the silane coupling agent γ-methacryloxypropyltrimethoxysilane (KH-570)

The ultrafine SiO₂ wet cake produced by a hypergravity continuous precipitation apparatus was modified using the silane coupling agent γ-methacryloxypropyltrimethoxysilane (KH-570) to improve its compatibility with organic solvents. The resulting modified ultrafine silica was characterized by Fourier transform infrared spectroscopy (FT-IR), surface hydroxyl number measurements, transmission electron microscopy (TEM) and di-n-butyl phthalate (DBP) oil absorption measurements. The results showed that KH-570 is an effective modifier as the compatibility of the modified ultrafine silica powder with organic solvents was enhanced, and the DBP oil absorption value increased from 1.9mL/g to 3.1mL/g. The optimum reaction conditions were found to involve a modification time of 4h and a modifier content of 10% of the quantity of silica. The surface hydroxyl number per square nanometer of ultrafine SiO₂ was reduced from 1.15 to 0.9nm^-2 after modification under these conditions.