Bioelectret state in dextrin: a study by thermally stimulated discharge current technique

Bioelectret state has been proposed to be a universal property of biomolecules and to play an important role in various biological phenomena. In the present investigation bioelectret state in a polysaccharide, dextrin, has been studied using the thermally stimulated discharge current (TSDC) technique. The polysaccharide has been found to be able to manifest the bioelectret state; the TSDC spectrum is characterised by three peaks at temperatures around 170K, 220K and 270K. The bound water molecules are identified as the source of polarisation storage for all peaks. The 170K peak is ascribed to bound water molecules directly attached to the polypeptide backbone; 220K peak is ascribed to a second layer of multiple hydrogen bonded water molecules, proposed to be a chain like structure around the polypeptide backbone and the 270K peak is attributed to the bound water molecules adsorbed on the surface of the polysaccharide matrix.