本体光接枝制备温敏核孔膜

Preparation of temperature-sensitive track membrane by bulk Photografting

以N 异丙基丙烯酰胺 (NIPAAm)为单体 ,二苯甲酮 (BP)为引发剂 ,采用本体光接枝方法制备了具有温度敏感特性的PET核孔膜。FTIR ATR和SEM证明 ,接枝主要在膜的向光表面进行 ,膜的背光侧和膜孔内没有接枝。接枝过程中 ,增大光强和增加引发剂在反应混合物中的比例有利于提高接枝程度 ;常温下 ,接枝程度随反应时间的延长呈线性增长 ;随着反应温度的升高 ,接枝程度迅速增加 ,90s后增加趋于平缓 ;提高反应温度可以显著的提高接枝程度 ,但是当温度高于单体熔点时 ,接枝程度反而大幅降低。膜表面的接枝链对膜孔产生封盖 ,从而影响膜的滤过特性。通量测试表明 ,接枝膜在较高接枝程度时 ,水通量在 30～ 35℃附近有跃升现象 。

The composite membrane with thermo sensitive effect was prepared by bulk photografting NIPAAm onto the PET track membrane substrate. The grafted membrane was characterized by FTIR ATR and SEM. It was found that photograft mainly proceeds on the membrane surface exposing to UV radiation and no graft polymerization occurs on the backside surface and inside pores. Increasing the UV intensity and the ratio of initiator in reaction mixture results in the increase in grafting degree. At room temperature, the grafting degree increases linearly with the prolongation of radiation time. At higher temperature, the increase in grafting degree becomes smooth when radiation time exceeds ninety seconds. Once the temperature is higher than the melt point of NIPAAm, the grafting degree decreases strikingly. The grafted poly NIPAAm has pore covering effect and thus regulates the filtration properties of grafted membranes. The test results show that the flux of grafted membrane with high D g has a leap near the temperature range of 30 to 35?℃; Grafted membrane act as a valve by response to the temperature.