[Preparation and characterization of cross-linked polyvinyl alcohol microspheres as a novel precoating reagent in...

In order to modify the membrane surface by adsorbing a precoated layer, cross-linked polyvinyl 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 1.30 g/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.