Jute cellulose nanocrystal/poly(N,N-dimethylacrylamide-co-3-methacryloxypropyl trimethoxysilane) hybrid hydrogels for removing methylene blue dye from aqueous solution

Abstract Jute fiber is the most common source of cellulosic fibers in Bangladesh. Cellulose nanocrystals (CNCs) extracted from jute fibers are moderately high in length (up to 1200 nm) and diameter (up to 90 nm). Poly(N,N-dimethylacrylamide-co-3-methacryloxypropyltrimethoxysilane) (pSiDm) is a custom made copolymer with trimethoxy silane groups at one end which facilitates to react with cellulose in an aqueous solution. A very simple, efficient, rapid, and eco-friendly method was developed to prepare j-CNC reinforced pSiDm hydrogel to remove methylene blue (MB) dye from an aqueous solution. The reaction between j-CNCs and pSiDm in the hydrogel was revealed by the increased intensity ratio of –OH band to C–H band and shifting of a peak for C=O from 1604 cm-1 to 1608 cm-1 in the FT-IR spectrum of the hydrogel compared to those of the copolymer. Glass transition temperature of the copolymer increases from 99 to 111°C after being applied into the hydrogel. The prepared hydrogel showed a significant swelling at a ratio of 16 g/g in deionized water. In good accordance with the Langmuir adsorption isotherm, a maximum adsorption value of MB onto the hydrogel was achieved 131.58 mg/g. Kinetic studies of the adsorption process fit well with a pseudo-second-order reaction model. The j-CNCs/pSiDm hydrogel is a moderately resilient and completely biodegradable material to be utilized for the adsorption of cationic toxic materials from waste effluent.