PAA-PSF交联复合膜的制备及对低浓度有机醇水溶液反渗透分离性能研究

The preparation of PAA-PSF crosslinked composite membrane and properties for aqueous solutions of alcohols by RO separation

进行了ＰＡＡ（ＰｏｌｙａｃｒｙｌｉｃＡｃｉｄ）－ＰＳＦ（Ｐｏｌｙｓｕｌｆｏｎｅ）交联复合膜的制备，研究了交联剂、添加剂对膜性能的影响，并通过扫描电镜观察了膜的断面结构．研究了ＰＡＡ－ＰＳＦ交联复合膜对低浓度有机醇类水溶液反渗透分离性能．发现对于１０００×１０－６乙醇水溶液截留率达到６６．２％，透过流束可达０．９×１０－６（ｍ３·ｍ－２·ｓ－１）．随醇的分子量的增加，截留率不断上升，对戊醇的截留率达９４．３％，而透过流束则保持相对稳定．对不同结构醇类的分离性能研究表明，截留率存在有：ｔｅｒｔ－＞ｓｅｃ－＞ｉｓｏ－＞ｎ－的规律．

PAA (polyacrylic acid) - PSF(polysulfone) crosslinked composite membrane has been prepared. The effects of crosslinking agent and additive on the properties of membrane have been studied. The reverse osmosis separation properties of PAA-PSF crosslinked composite membrane for aqueous solutions of alcohols have been investigated. It is found that the solute rejections ( R a) for n-alkyl alcohols increased with the increase of the molecular weight of alcohol, while the volume fluxes of solutions ( J v) are almost changeless. The R a and J v for 1 000×10 -6 ethanol and n-amyl alcohol aqueous solutions can reach 66.2%, 94.3% and 0.9×10 -6 , 1.0×10 -6 m 3 /m 2 ·s,respectively in the conditions of 50 kg/cm 2 and 30 ℃. The order of solute rejections for alcohols with different structures is tert->sec->iso->n- . The morphologic structures of PAA-PSF crosslinked composite membranes have also been observed by SEM.