Radiation Synthesis Of Super-Water-Absorbed Hydrogel From Starch, Acrylic Acid And Diatomite For Adaptation To The Drought Condition

Abstract

Global warming is a human-induced phenomenon that eventually raises the actual evaporation, or evapotranspiration in plants and crops, reducing agricultural productivity. To overcome the consequences of global warming, especially the drought condition, biocompatible super water absorbent hydrogels have been researched thoroughly. In this study, the hydrogel was prepared from starch (St), acrylic acid (AAc), and diatomite (DA) using the radiation technique. The optimal product (St/AAc/DA) was synthesized at 5 kGy of irradiation dose, with the components of 7.5% (w/w) starch, 15% (w/w) acrylic acid, and 25% (w/w) diatomite. The final product had a gel content of around 90% (w/w), while the swelling degree was about 279 times. The addition of diatomite was also proved to increase hydrogel's stability via possible covalent and intermolecular bonds based on experimental evaluations and Fourier Transform Infrared spectroscopic analysis. These spectra also revealed the general chemical structures of hydrogels and their contents, which are necessary for the characterization process. In addition, the morphology of hydrogel was highly porous, which was clearly observed by using Scanning Electron Microscope (SEM). The water-retaining, preserving conditions, and stability of hydrogels containing diatomite were also improved. Owing to these advancements, the applications of synthesized suitable hydrogels in agriculture are promising to overcome the drought condition at a reasonable price and high effectiveness. However, further larger-scale experiments are required before being applied to the industrial scale.