Flux enhancement by hydrophilization of thin film composite reverse osmosis membranes
Flux enhancement by hydrophilization of thin film composite reverse osmosis membranes
复制标题
DOI：
10.1016/0376-7388(95)00271-5
复制
发表时间：
1996-05-29
影响因子：
9.5
通讯作者：
Gill, WN
中科院分区：
文献类型：
--
作者：
Kulkarni, A;Mukherjee, D;Gill, WN
研究了质子酸，包括氢氟酸、盐酸、硫酸、磷酸和硝酸，作为改性薄膜复合（TFC）反渗透膜表面的增透剂。HR 95 PP和HR 98 PP膜在暴露于各种浓度的这些酸时，通量增加高达一个数量级，而没有任何离子排斥损失。HR 98 PP膜的通量增强约为一个数量级，高通量HR 95 PP膜的通量增强约为两倍。接触角测量的表面表征表明膜表面的亲水性增加。在沿聚合物链沿着的可溶剂化位点处，引起部分水解的反应可能是导致亲水性增加的原因，从而导致所观察到的通量增加。暴露于乙醇和2-丙醇（异丙醇，IPA）等温和溶剂也会增加通量，而不会损失截留率;事实上，在某些情况下会显著增加截留率。选择性溶解和消除的缺陷可能是负责的增加率transmitt.Exposure的酸和乙醇的混合物引起的通量增加，在实验误差范围内拒绝没有损失。这种用质子酸和醇处理的方法可以用作开发未来高通量和高截留率膜的可行的后处理方法。
Protic acids, including hydrofluoric, hydrochloric, sulfuric, phosphoric and nitric acids, are studied as hydrophilizing agents for modifying the surfaces of thin film composite (TFC) reverse osmosis membranes. HR95PP and HR98PP membranes on exposure to various concentrations of these acids increase in flux up to an order of magnitude without any loss in ion-rejection. The flux enhancement is about an order of magnitude in HR98PP and a factor of two in high flux HR95PP membranes.Surface characterization with contact angle measurements indicate an increase in hydrophilicity of the membrane surface. At solvatable sites along the polymer chain, reactions causing partial hydrolysis may be responsible for the increase in hydrophilicity resulting in the observed flux increase. Exposure to mild solvents like ethanol and 2-propanol (isopropyl alcohol, IPA) also increases the flux with no loss in rejection; in fact a significant increase in rejection is obtained in some cases. Selective dissolution and elimination of defects probably are responsible for the increased rates of transport.Exposure to a mixture of acid and ethanol caused an increase in flux with no loss in rejection within experimental error. This method of treatment with protic acids and alcohols could be used as a viable post treatment method in developing high flux and high rejection membranes of the future.