Reversible Hydrophobic-Hydrophilic Transition of Ionic Liquids Driven by Carbon Dioxide
Reversible Hydrophobic-Hydrophilic Transition of Ionic Liquids Driven by Carbon Dioxide
复制标题
二氧化碳驱动的离子液体可逆疏水-亲水转变
DOI：
10.1002/anie.201500695
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发表时间：
2015-06-15
影响因子：
16.6
通讯作者：
Zhang, Suojiang
中科院分区：
文献类型：
--
作者：
Xiong, Dazhen;Cui, Guokai;Zhang, Suojiang
开发了具有可逆疏水-亲水转变的离子液体(ILS)，它们与H2O表现出独特的相行为：在有CO2存在的情况下是单相的，而在室温和常压下脱除CO2时是两相的。因此，在可持续的化学过程中，反应、分离和回收步骤的耦合可以通过这种IL-H2O混合物的可逆液-液相转变来实现。光谱研究和密度泛函理论计算表明，疏水-亲水转变的机理包括CO2与离子液体阴离子的可逆反应和亲水性铵盐的形成。这些独特的IL-H2O体系被成功地用于在环境条件下通过鼓泡CO2一步合成Au多孔膜。然后用N-2气泡将金多孔膜和离子液体同时从水溶液中分离出来，回收的离子液体可以直接在下一步工艺中重复使用。
Ionic liquids (ILs) with a reversible hydrophobic-hydrophilic transition were developed, and they exhibited unique phase behavior with H2O: monophase in the presence of CO2, but biphase upon removal of CO2 at room temperature and atmospheric pressure. Thus, coupling of reaction, separation, and recovery steps in sustainable chemical processes could be realized by a reversible liquid-liquid phase transition of such IL-H2O mixtures. Spectroscopic investigations and DFT calculations showed that the mechanism behind hydrophobic-hydrophilic transition involved reversible reaction of CO2 with anion of the ILs and formation of hydrophilic ammonium salts. These unique IL-H2O systems were successfully utilized for facile one-step synthesis of Au porous films by bubbling CO2 under ambient conditions. The Au porous films and the ILs were then separated simultaneously from aqueous solutions by bubbling N-2, and recovered ILs could be directly reused in the next process.