中文摘要：

选用油酸（OA）、硬脂酸（SA）和12-羟基硬脂酸（HAS）3种脂肪酸在正辛烷溶液中分散纳米铋粉。用紫外可见光分光光度计表征了脂肪酸修饰后的粉体在正辛烷溶液中的分散稳定性。结果表明：3种脂肪酸都能将粉体表面改性成Bi-脂肪酸型疏水性表面；悬浮液的分散稳定性随着分散剂在粉体表面吸附量的增多而增强，12-羟基硬脂酸在纳米铋粉表面吸附量最大，其悬浮稳定性最好；脂肪酸对悬浮液的稳定机制是，不仅能减小粉体间的范德华吸引力而且能产生一定的空间位阻作用。

英文摘要：

Three types of fatty acids--oleic acid, stearic acid, and 12-hydroxystearic acid--were used to disperse nano-sized bismuth powders in octane solvents. The surface characteristics of bismuth powders were modified to be hydrophobic in nature, and the bismuth-fatty acid formed on the surface. Stability property of the suspension was measured by ultraviolet-visible spectrophotometer. Results indicate that better suspension stabilization can be achieved when the 12-hydroxystearic acid is used. Adsorption behavior reveals that a greater affinity at the solid/liquid interface occurred for the 12-hydroxystearic acid than that for stearic acid or oleic acid. This observation suggests that the adsorption of 12-hydroxystearic acid may lead to a better packing of the acid molecules onto the solid surface than others and also results in better suspension stability. It is also evidenced by the results of theoretical calculation of potential energies that the colloidal stability of organic bismuth suspension is caused by fatty acid reducing the attractive interparticle potential and by steric repulsion mechanism.