Supercritical or compressed CO2 as a stimulus for tuning surfactant aggregations.
Supercritical or compressed CO2 as a stimulus for tuning surfactant aggregations.
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DOI：
10.1021/ar300194j
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发表时间：
2013-02
影响因子：
18.3
通讯作者：
Jianling Zhang;B. Han
中科院分区：
文献类型：
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作者：
Jianling Zhang;B. Han
表面活性剂组合物在化学工业、材料科学、生物和提高采收率等领域有着广泛的应用。从理论和实践两个角度研究表面活性剂的聚集行为，一直是研究人员关注的焦点。研究人员通常使用固体和液体化合物，如助表面活性剂、酸、盐和醇作为刺激来调节聚集行为。然而，这些添加剂可能会带来经济和环境成本，并可能污染或修改产品。因此，研究人员希望开发有效的方法来调节表面活性物质的聚集性，具有易移除、经济和环境友好的刺激物。超临界或压缩的CO(2)含量丰富，无毒，不可燃，使用后可以很容易地回收利用。压缩的CO(2)在许多液体中都是相当易溶的，其溶解度取决于压力和温度。因此，研究人员可以通过控制CO(2)的压力或温度来持续影响液体溶剂的性质。在这篇文章中，我们简要地回顾了我们最近关于超临界或压缩CO(2)在不同介质中调节表面活性剂聚集行为的研究。超临界或压缩的CO(2)可作为表面活性剂组件的多种性质的多功能调节剂。用CO(2)可以改变表面活性剂在水中的胶束化，调节反胶束的性质，提高囊泡的稳定性，改变不同表面活性剂组装体之间的转换转变。我们还可以调整乳液的性质，诱导纳米乳液的形成，并构建新型微乳液。利用这些CO(2)响应型表面活性剂组件，我们已经合成了功能材料，优化了化学反应条件，并提高了萃取和分离效率。与传统的固体或液体添加剂相比，CO(2)作为表面活性剂聚集剂具有明显的优势。我们可以通过压力连续调节聚集行为，并且可以很容易地脱除CO(2)而不会对产品造成污染，而且该方法对环境友好。我们可以从分子相互作用的角度来解释这些影响表面活性剂聚集的机理。这些研究扩展了胶体和界面科学、超临界流体科学和技术以及化学热力学的领域。我们希望这项工作将对这些领域的其他基础和应用研究产生影响。
Surfactant assemblies have a wide range of applications in areas such as the chemical industry, material science, biology, and enhanced oil recovery. From both theoretical and practical perspectives, researchers have focused on tuning the aggregation behaviors of surfactants. Researchers commonly use solid and liquid compounds such as cosurfactants, acids, salts, and alcohols as stimuli for tuning the aggregation behaviors. However, these additives can present economic and environmental costs and can contaminate or modify the product. Therefore researchers would like to develop effective methods for tuning surfactant aggregation with easily removable, economical, and environmentally benign stimuli. Supercritical or compressed CO(2) is abundant, nontoxic, and nonflammable and can be recycled easily after use. Compressed CO(2) is quite soluble in many liquids, and the solubility depends on pressure and temperature. Therefore researchers can continuously influence the properties of liquid solvents by controlling the pressure or temperature of CO(2). In this Account, we briefly review our recent studies on tuning the aggregation behaviors of surfactants in different media using supercritical or compressed CO(2). Supercritical or compressed CO(2) serves as a versatile regulator of a variety of properties of surfactant assemblies. Using CO(2), we can switch the micellization of surfactants in water, adjust the properties of reverse micelles, enhance the stability of vesicles, and modify the switching transition between different surfactant assemblies. We can also tune the properties of emulsions, induce the formation of nanoemulsions, and construct novel microemulsions. With these CO(2)-responsive surfactant assemblies, we have synthesized functional materials, optimized chemical reaction conditions, and enhanced extraction and separation efficiencies. Compared with the conventional solid or liquid additives, CO(2) shows some obvious advantages as an agent for modifying surfactant aggregation. We can adjust the aggregation behaviors continuously by pressure and can easily remove CO(2) without contaminating the product, and the method is environmentally benign. We can explain the mechanisms for these effects on surfactant aggregation in terms of molecular interactions. These studies expand the areas of colloid and interface science, supercritical fluid science and technology, and chemical thermodynamics. We hope that the work will influence other fundamental and applied research in these areas.