油酸钠改性对凹凸棒黏土理化性能的影响

Effects of sodium oleate on physicochemical properties of the modified attapulgite

用阴离子表面活性剂油酸钠对凹凸棒黏土进行有机改性,探讨了油酸钠用量、pH值和反应温度对有机改性的影响。通过红外光谱、流变和ζ电位测定,比较了改性前后凹凸棒黏土的理化性质。结果表明,随油酸钠用量的增加有机化度逐渐增大,随pH值的增加有机化度先增大后减小,反应温度对有机化度没有本质影响。红外光谱表明,油酸根已结合在凹凸棒黏土的表面;流变和ζ电位结果表明,油酸根通过静电和空间位阻作用影响悬浮液黏度;在油酸钠用量为黏土量4.56%时,所得有机凹凸棒黏土剪切黏度最低。

Organically modified attapulgite clays were prepared using sodium oleate as modifier. The influences of sodium oieate concentrations, pH values and temperatures on the organification reaction were investigated. The physicochemical properties of raw attapulgite and organo attapulgite clays were characterized hy infrared spectroscopy, rheometer and ζ potential. The results showed that the organifieation degree of attapulgite increases with increasing the concentration of sodium oleate, while the organifieation degree firstly increases with increasing pH value, reaching a maximum and then decreases. No obvious influence of temperature on reactions can be observed. The infrared spectroscopy showed that oleate anions were already adsorbed onto attapulgite surfaces. The rheological and electrokinetic properties showed that the viscosities of suspensions modified by different levels of sodium oleate were controlled by electrostatic and steric interactions, and the lowest viscosity of suspension was obtained when 4.56% sodium oleate was added to the suspension.