二氧化碳辅助制备高稳定性支撑型离子液体膜的热力学基础及其表征

为克服现有支撑型离子液体膜(SILMs)制备方法的缺点，本项目提出低温下高压CO2辅助制备SILMs的创新方法，以提高液膜稳定性和使用寿命，实现SILMs的可控制备。该方法偶合降粘减阻和压差驱动原理，借助CO2可溶于离子液体，且能显著降低其粘度提高扩散系数的优势，达到离子液体液膜相厚度、负载量的可控制备，有望极大拓展用于液膜相离子液体的种类，尤其对酸性气体溶解度大的高粘性离子液体更具重要意义；同时有望克服因液膜粘度高对载体孔径的限制，从而扩大基膜材料的选择范围。 项目拟通过对以下科学问题的研究：(1)ILs+CO2二元体系热力学相行为；(2) CO2对ILs粘度调节的基本规律和控制参数；(3)ILs+CO2混合液在多孔介质中的渗透扩散规律；(4)高压CO2辅助制备SILMs过程研究与评价，为酸性气体脱除和节能减排用液膜分离过程设计提供实验依据和理论指导。

A novel method for preparing supported ionic liquid membranes (SILMs) under low temperature assisted by high pressure carbon dioxide (CO2) is proposed, in order to remarkably improve the stability and life of the liquid membrane and to accomplish the controllable preparation of SILMs. High pressure CO2 is able to be dissolved in ILs, and offers advantages of reducing significantly the viscosity of ILs and providing the pressure difference as the driving force for ILs to diffuse into the membrane pores. By making use of the advantages of high pressure CO2,the proposed method is expected to accomplish the controllable preparation of ILs membrane with uniform thickness and loading capacity. With the assistence of CO2, the number of ILs types that are suitable for preparing the SILMs will be expanded greately, and it is of particularly importance to those ILs with a large solubility for acidic gases but with a high viscosity.Furthermore, CO2-assisted method is expected to overcome the limitation of membrane pore size due to ILs' high viscosity and to provide a wider choice of membrane supports. This project will focus on the study of the following fundamental issues in CO2-assisted SILMs: (1) Thermodynamic phase behavior of ILs+CO2 binary systems; (2) The basic rules and controllable parameters on tuning the ILs viscosity by adding CO2; (3) The penetration and diffusion mechanisms of ILs+CO2 mixtures in the porous supports; (4) The investigation and evaluation of the preparation process of the SILMs using high pressure CO2. With these fundamental studies, the project will provide theoretical basis for the design and fabrication of SILMs which are used for the removal of acid gases as well as energy-saving and emission reduction.