新型动态膜预涂剂交联聚乙烯醇微球的制备及表征

提出用乳液聚合法制备交联聚乙烯醇(PVA)微球,使其吸附在膜表面实现膜的改性.通过聚乙烯醇(PVA)与戊二醛(GA)的乳化交联试验制备PVA微球粉末,并考察了W/O型乳状液内相的浓度、内外相体积比、乳化剂的性质和含量对形成稳定乳状液的影响.结果表明,当内相PVA水溶液浓度为2.7%、内外相体积比为40∶60、交联剂司盘-80的浓度为1.30 g/dL时,乳状液的稳定性好,形成的交联PVA微球满足需要.在乳化剂浓度足够的前提下,提高乳化机转速,制备的微球的粒径减小.随着理论交联度的提高,微球粒径有变小的趋势,而对Zeta电位影响不大.对制备的微球进行接触角、SEM和FTIR表征,考察了微球的亲水性、表面形态和交联反应对微球官能团的影响.

Preparation and Characterization of Cross-linked Polyvinyl Alcohol Microspheres as a Novel Precoating Reagent in Dynamic Membrane

In order to modify the membrane surface by adsorbing a precoated layer, cross-linked Poly(vinyl alcohol) microspheres were prepared via an emulsion polymerization that PVA cross linked with glutaraldehyde which was extracted by anhydrous aether. Effects of concentration of PVA solution, the volume ratio of aqueous phase to oil phase, the selection of surface active agent (SAA) and its concentration on the stabilization of emulsion were studied. When the concentration of PVA solution was 2.7%, the volume ratio of PVA solution/n-heptane was 40:60 and the concentration of span-80 was 1.30g/dL, the prepared microspheres contented our needs. The size of microspheres diminished with the stirring speed increasing under the condition of enough span-80. It became smaller with the accretion of an aimed cross-linking degree which has little affection on surface charge. The contact angle of PVA microspheres with distilled water showed that these microspheres were hydrophilic. Morphology of PVA microspheres were observed by SEM. The FTIR results suggested that functional groups varied with the change of aimed cross-linking degrees.