Highly CO2-Soluble Surfactants for Supercritical Fluid Reaction, Separation & Impregnation Process

良好的环境影响和可调节的溶剂功率的结合导致了超临界二氧化碳的各种提取/分离应用。尽管有这些固有的优势，但高极性或亲水性化合物在非极性二氧化碳中的低溶解度阻碍了超临界流体技术在蛋白质纯化、重金属污染修复和非voc涂料配方等领域的应用。在这种情况下，产生一种高度纯净且易于回收的产品将是一项重大进步。其他小组最近的研究表明，超临界流体中胶束的形成提供了一种方法，通过这种方法可以克服极性化合物在非极性流体中的低溶解度。尽管取得了这一进展，但在二氧化碳（与烷烃相反）中形成稳定的胶束仍然是难以捉摸的，这主要是由于商业上可用的表面活性剂在中等压力下在二氧化碳中的溶解度低。因此，该项目建议合成模型两亲化合物，其中“疏水”尾部包含官能团，如氟醚和硅酮，已知与二氧化碳有利相互作用（在热力学意义上）。匹兹堡大学对氟烷基、氟醚和硅酮材料的初步研究结果表明，这一前提确实是有效的。本项目通过合理合成表面活性剂和相行为研究的程序扩展了这些成功的初步研究。

The combination of benign environmental impact and tuneable solvent power has led to a variety of extraction/separation applications for supercritical carbon dioxide. Despite these inherent advantages, the low solubility of highly polar or hydrophilic compounds in non-polar CO2 has blocked the use of supercritical fluid technology in areas such as protein purification, the remediation of heavy metal contamination, and non-VOC based coatings formulations, where generation of a highly pure and readily recoverable product would be a significant advance. Recent research by other groups has shown that the formation of micelles in supercritical fluids provides a means by which low solubility of polar compounds in non-polar fluids can be overcome. Despite this advance, formation of stable micelles in CO2 (as opposed to alkanes) has remained elusive, due primarily to the low solubility of commercially-available surfactants in carbon dioxide at moderate pressures. Thus this project proposes to synthesize model amphiphiles where the "hydrophobic" tails contain functional groups, such as fluoroethers and silicones, which are known to interact favorably (in a thermodynamic sense) with carbon dioxide. Preliminary results at the University of Pittsburgh with fluoroalkyl, fluoroether, and silicone materials show that this premise is indeed valid. This project extends these successful preliminaries with a program of rational synthesis of surfactants and phase behavior studies.