渗透蒸发复合膜的选材与制备

与对称膜、非对称膜相比,渗透蒸发复合膜有扩散阻力小、渗透通量高、机械强度好等优点,同时在选材和制备方面也有其自身的特点。活性层材料主要依据Flory huggins相互作用参数理论或溶解度参数理论进行粗略选择,再通过一些实验手段做进一步筛选。支撑层材料多为无机或有机多孔材料,选择的主要依据是材料的物理化学性质、机械性质及结构。另外,活性层与支撑层之间的黏合与孔渗也是必须考虑的问题。介绍了相关的黏合理论,列举了常用的防止孔渗发生的措施。最后结合近年来渗透蒸发复合膜的研究实例详细介绍了复合膜的常用制备方法,如界面聚合法、浸涂法、等离子聚合法和自组装法等。

Material selection and preparation of composite pervaporation membranes for separation

In comparison to symmetric membrane and asymmetric membrane,composite pervaporation membrane has some outstanding advantages such as lower mass transfer resistance,higher permeation flux and better mechanical performance.Meanwhile,composite membrane has some distinct characteristics regarding to the material selection and membrane preparation.The suitable material for active layer of composite membrane is mainly chosen by the rough screening based on Flory-huggins interaction parameter theory or solubility parameter theory and further screening based on the chromatography experiment or contact angle measurement.The porous inorganic and organic support layer is mainly chosen according to the physical,chemical and mechanical property,and microstructure of the candidate materials.In addition,the conglutination and intrusion problems are two important issues that must be taken into account.The related conglutination theory was described,and the feasible strategies to prevent pore intrusion were presented.The most commonly employed preparation methods of composite membrane,such as interfacial polymerization,dip-coating,plasma polymerization and self-assembly,were introduced in details with some application examples of composite pervaporation membrane in them.