Development and characterization of porous membranes based on kaolin/chitosan composite

Chitosan/kaolin composite porous membranes were successfully prepared by solvent casting and evaporation process. The suspensions with different concentration of kaolin and chitosan showed a Newtonian behaviour. Strong interaction between chitosan and kaolin was revealed by FTIR and thermogravimetric analysis. The effect of kaolin content on the morphology and properties of the obtained membranes was studied. It was found by SEM observation that the kaolin particles were well dispersed in the chitosan matrix generating a porous microstructure. Incorporation of kaolin particles also improved the mechanical and thermal properties of the membranes and reduced drastically the water washout of chitosan in moderate acidic medium. Owing to their porous structure, the water permeability of the composite chitosan/kaolin membrane was significantly enhanced. The better formulation of the dope suspension in the range studied was 4% chitosan and 5% kaolin in acetic acid. These membranes made from naturally occurring materials might play an important role in advanced research in water treatment and environmental science.