Abstract: The membrane characteristics of capsules composed of sodiumcellulose sulfate (NaCS) and poly[dimethyl(diallyl)ammonium chloride] (PDMDAAC) were investigated under the condition of introducing other molecules. The small molecules, soluble polymers, soluble polyions, and salts of small molecule were individually added into polyanion (NaCS) solution to check their effects on capsule formation. The membrane thickness and mechanical intensity of capsules were studied under the condition of different concentration of additives. Meanwhile the effects of additives on viscosity and zeta potential of dilute NaCS solution were investigated. The results indicated that the effects of additives on the membrane characteristics could be judged by viscosity and zeta potential variation of dilute polyelectrolytes with addition of other molecules. The effect of additives on the reaction between polyelectrolytes was analyzed, and an explanation correlating the characteristics of capsule to the properties of dilute solution was proposed according to solution lattice theory.

Key words: Polyelectrolyte, PEC membrane, Microcapsule, Zeta potential, Reduced viscosity