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通过超支化聚酯(HPE)末端的羟基与戊二醛(GA)之间的羟醛缩合反应,采用简单的浸涂-交联方法,制备了一种以聚砜超滤膜为支撑层,交联的HPE为活性分离层的复合纳滤膜.采用衰减全反射红外光谱(ATR-FTIR)、接触角测定、扫描电子显微镜(SEM)对纳滤膜的表面化学组成、亲水性和膜形貌进行了表征.考察了HPE溶液浓度、GA溶液浓度对膜分离和渗透性能的影响,优化的HPE和GA溶液浓度分别为9.8 g/L和7.4 g/L,此时在0.4 MPa下膜的水通量达69.6 L/(m2.h),对Na2SO4脱除率为93.2%,表现出低操作压力、高通量、高脱盐率的优异性能.纳滤膜对无机盐的截留顺序为Na2SO4>NaCl>MgSO4>MgCl2,呈现明显的荷负电特征.
A polysulfone ultrafiltration membrane was used as a support layer by a simple dip-coating-crosslinking method by the aldol reaction between hydroxyl groups at the end of hyperbranched polyester (HPE) and glutaraldehyde (GA) Crosslinked HPE is a composite nanofiltration membrane with active separation layer.The surface chemical composition, hydrophilicity and membrane surface of the nanofiltration membrane were characterized by ATR-FTIR, contact angle measurement and scanning electron microscope (SEM) The effects of concentration of HPE solution and GA solution on membrane separation and osmotic performance were investigated. The optimum concentrations of HPE and GA were 9.8 g / L and 7.4 g / L, respectively. Of water flux reached 69.6 L / (m2.h), the removal rate of Na2SO4 was 93.2%, showing the excellent performance of low operating pressure, high flux and high desalination rate.The entrapment order of inorganic salts to nanofiltration membrane was Na2SO4> NaCl> MgSO4> MgCl2, showing obvious negative charge characteristics.