A hydrogel based on dialdehyde carboxymethyl cellulose–gelatin and its utilization as a bio adsorbent

Abstract

In the present study, the dialdehyde carboxymethyl cellulose (DCMC) was cross-linked covalently to gelatin via the Schiff base reaction to form a three-dimensional hydrogel (DCMC-cl-G). The crosslinking degree of DCMC and gelatin was estimated to be 50.31 ± 2.65. The maximum swelling capacity of the hydrogel in aqueous medium was around 74 g/g at pH 10.0 and 37 °C with equilibrium swelling attained in three hours and the compressive strength of the hydrogel was found to be 55 ± 0.76 kPa at 60% strain. The biodegradation studies confirmed 82.67% degradation of the hydrogel sample within a period of twelve weeks. Further, the hydrogel was evaluated as a bio adsorbent for the removal of hazardous dyes, namely Rhodamine B (RhB) and Methyl Violet (MV) from water due to its decent swelling capacity and good mechanical strength. The maximum percentage of RhB and MV removed from the respective dye solutions using DCMC-cl-G hydrogel was 96.5% and 90% at pH 6.0, respectively. Both dyes followed Langmuir adsorption isotherm, which considers monolayer adsorption of adsorbate over adsorbent, with a pseudo-second-order kinetic model. An environment friendly hybrid hydrogel of dialdehyde carboxymethyl cellulose was fabricated by crosslinking with gelatin. The use of gelatin improved the compressive strength and thermal characteristics of the hydrogel. It was utilized for the efficient removal of hazardous dyes such as Rhodamine B and Methyl violet. The biodegradation of the hydrogel was achieved up to 82.67% for a period of twelve weeks.