Novel Dioscorea hispida starch-based hydrogels and their beneficial use as disinfectants

Abstract

Starch-grafted polyacrylamide hydrogels were successfully prepared via chemical polymerization method in basic solution, which provides a homogeneous suspension in the reaction system. The results obtained from Fourier transform infrared–attenuated total reflectance confirmed that the monomer polyacrylamide was grafted onto the starch backbone as shown by the cross-linked peak at 1638 cm−1. Scanning electron microscopy showed that the morphology of starch-grafted polyacrylamide hydrogels has a highly porous structure which provides excellent water absorption capacity with a swelling ratio up to 124%. The X-ray diffraction showed no significant crystallization peaks, indicating that an amorphous hydrogel has been produced. Supported by differential scanning calorimetry, the highest transition glass temperature was observed at 101°C. The starch-grafted polyacrylamide hydrogel extracts inhibited Escherichia coli, Staphylococcus aureus, Saccharomyces cerevisiae, and Salmonella typhimurium growth The fish embryo toxicity test demonstrated that the hydrogel with 2:1 ratio of polyacrylamide: starch has an acceptable level of toxicity. This result indicates that the synthesized hydrogel is applicable for biological purposes with further modifications.