磺酸盐型Gemini表面活性剂合成及清洗石油污染土壤性能

Synthesis of sulfonate Gemini surfactants and performance in cleaning petroleum-contaminated soil

摘要:

基于绿色化学理念以长链烷基胺、1,3-丙磺酸内酯以及环氧氯丙烷为原料设计合成4个磺酸盐型Gemini表面活性剂,采用1HNMR与FTIR进行结构表征,并对其表(界)面性质以及清洗石油污染土壤性能进行研究。结果表明：不同链长的Gemini-Cn表(界)面性质各异,其中Gemini-C12溶液有较低的表面张力(28.25mN/m)和CMC值(0.00867mmol/L), Gemini-C14溶液与原油之间的界面张力最小,为0.055mN/m,除了Gemini-C8外,其表(界)面活性都高于市售十二烷基苯磺酸钠(SDBS)。清洗效果Gemini-C10最佳,用量仅为SDBS的1/4时即可达到SDBS相同的除油效果；同样用量下,除油率比SDBS提高21%。结合表(界)面性质与清洗性能关系分析推测其清洗机理为润湿、卷起-乳化、增溶三步,并且在能够充分润湿污染土壤的前提下,增溶过程占据主导作用。

Abstract:

Based on the principles of green chemistry, four sulfonate Gemini surfactants were designed and synthesized using long-chain alkylamine, 1,3-Propanesultone, and epichlorohydrin as raw materials. Their structures were characterized by 1HNMR and FTIR, and their surface properties and performance in cleaning petroleum-contaminated soil were investigated. The results showed that the surface properties of Gemini-Cn surfactants varied with different chain lengths. Gemini-C12 solution exhibited a low surface tension (28.25 mN/m) and critical micelle concentration (0.00867 mmol/L), while Gemini-C14 solution had the lowest interfacial tension (0.055 mN/m) with the crude oil. Except for Gemini-C8, all other surfactants had better surface activity than the commercially available sodium dodecylbenzenesulfonate (SDBS). The cleaning performance was best for Gemini-C10, which required only a quarter of the amount of SDBS to achieve the same oil removal effect; at the same dosage, the oil removal rate was 21% higher than that of SDBS. The cleaning mechanism, inferred from the relationship between surface properties and washing performance, was analyzed and hypothesized to involve three steps: wetting, rolling-emulsification, and solubilization. Moreover, under the condition of sufficient wetting of the contaminated soil, the solubilization process played a dominant role.