Swelling and Diffusion Characteristics of Interpenetrating Network Films Composed of Sodium Alginate and Gelatin: Transport of Azure B

Abstract

Interpenetrating polymer network (IPN) films have been made from two hydrophilic natural polymers, namely, sodium alginate (NaAlg) and gelatin (Gltn) in the presence of glycerol (Glrl) using Ca²⁺ as crosslinkers. Films have been prepared with varying amounts of crosslinking agent, plasticizer and the component polymers. The effect of these parameters, the preparation conditions and the pH of the medium on the swelling behavior of these gel films has been investigated. Dynamic swelling studies have been carried out and the kinetic parameters for the swelling process have been evaluated. The influence of film characteristics and pH of the medium on the permeability behavior of the films has been studied for a cationic dye, Azure B (AzrB). The results revealed pH sensitivity of the films towards swelling and solute transport. Based on the results, possible mechanisms of water and dye transport through the films have been proposed.

Keywords:

• dye-diffusion
• IPN polymers
• kinetics
• pH sensitivity
• swelling