单价选择性阳离子交换膜的制备及工艺优化

Preparation and process optimization of monovalent selective cation exchange membrane

以吡咯为改性材料,采用浸渍表面改性法,对普通均相阳离子交换膜进行表面改性来制备单价选择性阳离子交换膜.通过电渗析试验,研究不同制备因素对改性膜选择分离性能的影响,从而优化制膜条件;并在最佳制备条件下,对改性膜进行膜面表征与基本性能测试.结果表明,最佳制膜条件为浸渍温度40℃,浸渍时间6h,吡咯浓度0.2mol/L,氧化剂浓度与种类为0.8mol/L的FeCl3;膜改性后表面更为平整,离子交换容量、含水率与溶胀度分别为0.78 mmol/g、17.3%与8.5%;Ca2+的泄漏率仅为7.7%,Na+的透过率为60.3%,选择透过性系数可达7.8,有优良的离子选择分离性能.

Using pyrrole as the modification material and surface impregnation as the modification method,the monovalent selective cation exchange membranes are prepared by modifying the ordinary homogeneous cation exchange membrane.The influence of different factors on the separation performance of the membranes is studied by the electrodialysis experiment,thereby optimizing the membrane preparation conditions.Under the optimal preparation conditions,the surface characterization and basic properties of the modified membrane are tested.The results show that the optimum condition of membrane preparation is determined as follows:the impregnation temperature is 40℃,the impregnation time is 6hours,the pyrrole concentration is 0.2mol/L,the oxidant concentration and type is 0.8mol/L FeCl3;the surface of modified membrane is smoother,the ion exchange capacity,water content and swelling degree are 0.78mmol/g,17.3%and 8.5%,respectively;the leakage rate of Ca2+is only 7.7%,the transmission rate of Na+is 60.3%,and the selective permeability coefficient is 7.8,It has excellent ion selective separation performance.