Synthesis of Acrylamide-<i>co</i>-3-Allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt Hydrogel for efficient Adsorption of Methylene blue dye
Amin Mohamed Elkony, Ahmed G. Ibrahim, Maher Hamed Abu El-Farh, Farag Abdelhai
Abstract
In this work, novel copolymer hydrogel was designed from acrylamide (AAm) and 3-Allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt (AHPS) through the free radical mechanism to produce an efficient adsorbent for removing the methylene blue dye from its aqueous solution. Tracking the gel fraction showed a decrease by increasing the AHPS concentration. The obtained polymers were characterised by FTIR, TGA, and SEM. The swelling behaviour was investigated, and the results indicated the enhancement in the swelling ratio for the hydrogels containing AHPS, and the maximum swelling ratio (4353.8%) was achieved after increasing the molar ratio of AHPS to 15%. The influence of different parameters such as contact time, dye concentration, pH, polymer dose, and temperature on the adsorption of methylene blue was studied. Studying the adsorption kinetics and isotherm showed that the adsorption process was well described by the pseudo-second-order and the Langmuir model, and the maximum adsorption capacity (qm) was 703.2 mg/g. Estimation of the thermodynamic parameters showed negative values of ∆G indicating the spontaneous nature of the adsorption process, the positive ∆H value (13.7 kJ mol−1) confirming the endothermic nature of MB adsorption, and the positive value of ∆S (0.048 KJ K−1 mol−1) indicating increased randomness at the solid/solution interface.