(中南大學(xué) 化學(xué)化工學(xué)院，長沙 410083)
摘 要: 研究芳香聚酰胺納濾膜在不同電解質(zhì)溶液中的流動電位，考察膜兩側(cè)壓差、電解質(zhì)濃度、離子價態(tài)及溶液pH值對流動電位的影響，用Helmoltz-Schmolukovski方程與Gouy-Chapmann方程計(jì)算膜表面的Zeta電位與電荷密度。結(jié)果表明：芳香聚酰胺膜表面荷負(fù)電荷；流動電位和Zeta電位絕對值均隨電解質(zhì)濃度的增大而減小；溶液pH值對流動電位和Zeta電位的影響較大；當(dāng)電解質(zhì)溶液濃度相同時，芳香聚酰胺膜的流動電位和Zeta電位的絕對值在二價陽離子電解質(zhì)溶液中比一價陽離子的電解質(zhì)溶液中均要小，但前者中的等電位點(diǎn)的pH值略大。
關(guān)鍵字: 芳香聚酰胺膜；流動電位；Zeta電位；動電現(xiàn)象
membrane in electrolyte solutions
(
（School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:The streaming potential of aromatic polyamide(APA) nanofiltration membrane was investigated in different kinds of electrolyte solutions, the effects of trans-membrane pressure, electrolyte concentration, ion valence and pH value of solution on the streaming potential of the membrane were investigated. The Zeta potential and the surface charge density of the membrane were calculated according to Helmoltz-Schmolukovski and Gouy-Chapmann equations. The results show that the aromatic polyamide membrane is negatively charged, the absolute values of the streaming and Zeta potentials decrease with increasing solute concentration under the same pressure, the pH value of electrolyte solution has great effects on the streaming and Zeta potentials of the membrane surface. Both the absolute values of the streaming potential and Zeta potential of APA membrane in the electrolyte solution with bivalence cation are smaller than those with monovalence cation, but the pH value of IEP of the former is a little greater than that of the later.
Key words: aromatic polyamide membrane; streaming potential; Zeta potential; electrokinetic phenomena
