Energy needs for drying of PAAm- kappa C composites prepared with various kappa C contents

Abstract

Various polyacrylamide (PAAm) - Kappa Carrageenan (kappa C) composite gels were prepared from acrylamide (AAm) N N'- methylenebisacrylamide (BIS) and different kappa C contents by free radical crosslinking copolymerization in water. Pyranine (P) was introduced as a fluorescence probe and scattered light I-sc and fluorescence intensities I from these gels were monitored during drying at different temperature. The fluorescence intensity of pyranine increased as drying time is increased for all samples. The behavior of I was quantified using the Stern-Volmer equation with moving boundary diffusion model. Desorption coefficient D increased as temperature was increased for a given kappa C content. Supporting gravimetrical and volumetric experiments were also carried out during drying of PAAm-kappa C composite gels. The energy Delta E values were measured for the drying processes for each kappa C content gel by using fluorescence gravimetrical and volumetric methods respectively. It is understood that Delta E values increase by increasing kappa C content indicating that energy needs for the drying of high kappa C content gel is larger than low kappa C content gel.