Study On The Preparation Of Functionalized Ionic Liquid-polymer Membranes And Pervaporation Separation Performance

As a new type of low energy consuming, high efficient, environment protecting, pervaporation has been a promising membrane technique in industry application. In this paper, Polymer/ionic liquid hybrid membranes were prepared by method of physical embedded and interpenetrating network method(IPN), Ag+-ionic liquid/polymer membranes were also prepared by physical blending. All these membranes were used as pervaporation membranes for the separation of ethyl acetate (EtAc) from its dilute aqueous solution and benzene/cyclohexane mixture, respectively.Firstly, P(VDF-HFP)/[bmim]BF4hybrid membranes were prepared by solvent evaporation using P(VDF-HFP) as polymer matrix and room temperature [bmim]BF4as filler. The swelling and pervaporation experiments were investigated for EtAc, water and its mixtures. The Scanning Electro Micrograph(SEM) results shown:[bmim]BF4ionic liquid were embedded in the polymer matrix. The thermal stability were investigated by TGA and the result is shown:under the300℃, the hybrid membranes were good thermal stability for pervaporation. The diffusion coefficient of membranes increased with increasing content of [bmim]BF4in P(VDF-HFP) membranes. The permeate flux and separation factor of the hybrid membranes increased from427g·m-2·h-1to626g·m-2·h-1and from73to142with content of [bmim]BF4increasing doped in P(VDF-HFP) membranes.Secondly, the interpenetrating network structure membranes for pervaporation were synthesized by used contain vinyl functional ionic liquid as monomers by free radical polymerization. The microstructures, characteristic functional groups and thermal stability were measured by SEM, FTIR, TGA. The diffusion coefficient of IPN membranes were measured for EtAc and water. The result shown:the permeate flux and separation factor of the IPN membranes were increased with increasing content of Poly[amim]Br by ensured that the mechanical and integrity of IPN membranes were fine.Finally, Ag+-[bmim]BF4composite carrier were synthesized by mixing AgNO3, AgC104, AgBF4with [bmim]BF4. Ag+-[bmim]BF4/TPU facilitate transport membranes were prepared by method of physical blending. The microstructures of the facilitate transport membranes were investigated by SEM. The effec of silver content, carried kinds on pervaporation performance of benzene/cyclohexane were investigated. The SEM results shown that the carriers were evenly distributed in the TPU matrix. The pervaporation result shown that the AgBF4-IL was the best facilitated transport carrier for benzene molecule. the hybrid membrane containing10wt%loading of carrier show the good sepration performance, and the hybrid membrane show good mechanical and integrity propeties.