Journal Article

Synthesis of Potato Starch-Acrylic-Acid Hydrogels by Gamma Radiation and Their Application in Dye Adsorption

Rahman, Nazia, Chandra Dafader, Nirmal, Rahman, Md. Mizanur, Mizanur Rahman Khan, Mohammad, Hara, Kazuhiro, Bhuyan, Md. Murshed, Okabe, Hirotaka, Hidaka, Yoshiki

2016

Overview

Several kinds of acrylic-acid-grafted-starch (starch/AAc) hydrogels were prepared at room temperature (27°C) by applying 5, 10, 15, 20, and 25 kGy of gamma radiation to 15% AAc aqueous solutions containing 5, 7.5, and 15% of starch. With increment of the radiation dose, gel fraction became higher and attained the maximum (96.5%) at 15 kGy, above which the fraction got lowered. On the other hand, the gel fraction monotonically increased with the starch content. Swelling ratios were lower for the starch/AAc hydrogels prepared with higher gamma-ray doses and so with larger starch contents. Significant promotions of the swelling ratios were demonstrated by hydrolysis with NaOH: 13632±10% for 15 kGy radiation-dosed [5% starch/15% AAc] hydrogel, while the maximum swelling ratio was ~200% for those without the treatment. The authors further investigated the availability of the starch/AAc hydrogel as an adsorbent recovering dye waste from the industrial effluents by adopting methylene blue as a model material; the hydrogels showed high dye-capturing coefficients which increase with the starch ratio. The optimum dye adsorption was found to be 576 mg per g of the hydrogel having 7.5 starch and 15% AAc composition. Two kinetic models, (i) pseudo-first-order and (ii) pseudo-second-order kinetic models, were applied to test the experimental data. The latter provided the best correlation of the experimental data compared to the pseudo-first-order model.

• Publisher: Hindawi Publishing Corporation,John Wiley & Sons, Inc,Wiley
• Subject: Acids / Adsorbents / Adsorption / Correlation / Dyes / Equilibrium / Gamma radiation / Gamma rays / Hydrogels / Pharmacy / Starches / Studies / Swelling ratio / Water pollution