pH值敏感响应膜的制备和性能研究

The Study on the Preparation and Characterization of pH-responsive Membranes

研究了两步光接枝法制备pH敏感响应分离膜的过程中接枝率随实验条件的变化及其对响应性的影响。实验以聚丙烯为基膜、丙烯酸（AA）为接枝单体，用水作溶剂，考察了光引发剂二苯甲酮（BP）的浓度、丙烯酸的浓度以及反应时间对接枝率的影响，采用傅氏变换红外光谱和扫描电镜分别对高分子膜的化学成分和膜的形貌进行了表征。研究结果表明，控制接枝率在1％～6％时，接枝膜具有较为显著的pH值响应性；接枝率为3％时，接枝膜的pH值响应系数达2．3，当接枝率大于6％和接枝率小于1％时，膜几乎不具pH值敏感响应性。为获得满意的pH值敏感响应性，必须将其接枝率控制在适当的范围内。

pH-responsive membrane is prepared by sequential photoduced graft polymerization method. The relationships between the grafting yield and experimental conditions, and the effect of the grafting yield on the pH-responsiveness of membrane are investigated. The influences of the concentration of photo-initiator（BP）, the concentration of monomer（AA）and the reaction time on the grafting yield are discussed based on the condition condition that water is used as the solvent and polypropylene as the host membrane. Meanwhile, ATR-FTIR technique is used to characterize the structure of the grafted membranes,and SEM is used to observe the surfaces or corss sections of the membranes. pH responses are observed when grafting yields are in the range of 1% -6%, and the pH responsive coefficient reachs 2. 3 with the grafting yield of 3%. However,when the grafting yield is higher than 6% and lower than 1%, the membrane doesn＇t show response to pH changes. Therefore, in order to obtain satisfactory pH responsive membrane, the grafting yield must be kept in a proper range.