Surfactant aggregation in CO2/heptane solvent mixtures.
Surfactant aggregation in CO2/heptane solvent mixtures.
复制标题
CO2/庚烷溶剂混合物中的表面活性剂聚集。
DOI：
10.1021/la901897w
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
Hollamby MJ
中科院分区：
文献类型：
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作者：
Hollamby MJ
采用高压小角中子散射（HP-SANS）技术，研究了正庚烷助溶剂改善纯液态co2的“溶剂质量”对市售表面活性剂相行为和胶束化的影响。发现非离子型c12e5在纯co2和溶剂混合物中都具有高度可溶性，但HP-SANS对所研究的任何组合物都没有检测到聚集，即使达到12 vol %的表面活性剂。另一方面，通过添加30 vol %以上的庚烷来改善co2溶剂的质量，可以促进双（乙基己基）磺基琥珀酸钠（AOT）的溶解度和团聚体的形成。用于预测表面活性剂在纯烃溶剂中聚集的溶剂质量指数Hildebrand溶解度参数（Langmuir,2008,24(21), 12235−12240）已经在这里对CO2 -庚烷混合物进行了测试。结果表明，与纯二氧化碳相比，AOT（一种商业上可行的、众所周知的、常用的表面活性剂）在含烷烃的富二氧化碳流体中的溶解度和效率可以提高。
The effect of improving “solvent quality” of pure liquid CO2with a heptane cosolvent on the phase behavior and micellization of commercially available surfactants has been explored using high-pressure small-angle neutron scattering (HP-SANS). The nonionic C12E5was found to be highly soluble in both pure CO2and the solvent blends, but no aggregation was detected by HP-SANS for any of the compositions studied, even up to 12 vol % surfactant. On the other hand, improving CO2solvent quality by adding heptane above 30 vol % promoted solubility and aggregate formation with normal sodium bis(ethylhexyl)sulfosuccinate (AOT). The solvent quality index Hildebrand solubility parameter, used to predict surfactant aggregation in pure hydrocarbon solvents (Langmuir,2008,24(21), 12235−12240) has been tested here for CO2−heptane mixtures. The results show how solubility and efficiency of AOT, a commercially viable, well-known, and commonly used surfactant, can be boosted in alkane-containing CO2-rich fluids compared to pure CO2alone.