SDS的提纯及其临界胶束浓度的测定

Purification of SDS and Determination of its Critical Micelle Concentration

制备SDS(十二烷基硫酸钠)的方法通常是十二醇用椰子油还原后,经浓硫酸处理,再用氢氧化钠中和制得,通常含有的杂质为烷基硫酸盐的同系物、没有反应的醇(如十二醇)和电解质(如硫酸钠)。众所周知,含有少量杂质的表面活性剂会给实验造成很大的影响,因此采用乙醚处理后水溶液重结晶的方法提纯市售SDS,并用酸碱滴定法测定SDS的纯度,并用滴体积法测临界胶束浓度。结果表明,经过抽提,重结晶后的的SDS纯度提高了11.4%,且临界胶束浓度为8.47×10^(-3) mol/L。

The preparation of SDS （sodium dodecyl sulfate） is usually dodecyl alcohol in coconut oil reduction, and then concentrated sulfuric acid treatment, and then sodium hydroxide prepared by the neutral, usually contain impurities for the alkyl Sulfate homologues, unreacted alcohols such as dodecanol and electrolytes such as sodium sulphate.It is well known that surfactants containing a small amount of impurities will have a great effect on the experiment.Therefore, the commercially available SDS is purified by recrystallization of the aqueous solution of ether and the purity of SDS is determined by acid-base titration method.Critical micelle concentration.The results showed that the purity of SDS was 11.4% after recrystallization, and the critical micelle concentration was 8.47×10^-3 mol/L.