Synthesis and characterization of xylan-gelatin cross-linked reusable hydrogel for the adsorption of methylene blue. (15th March 2021)

• Record Type: Journal Article
• Authors: Seera, Sai Dileep Kumar; Kundu, Debashis; Gami, Pratik; Naik, Papu Kumar; Banerjee, Tamal
• Is Part Of: Carbohydrate polymers. Volume 256(2021)
• Publication Date: 2021-03-15
• Subjects: Xylan -- Gelatin -- Hydrogel -- Adsorption -- Methylene blue; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2020.117520
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: Highlights: Novel xylan, gelatin based chemically crosslinked hydrogels were synthesized. The adsorption of methylene blue fitted well with Langmuir adsorption isotherm and kinetics with pseudo-second-order model. The increase in xylan amount favoured towards more adsorption of methylene blue. The hydrogel showed good pH responsive character, swelling and reusability. Adsorption of methylene blue is thermodynamically favourable and exothermic in nature. Abstract: Xylan and gelatin-based hydrogels are prepared in different molar ratios using ethylene glycol diglycidyl ether cross-linker. The hydrogels are characterized by Fourier transform infrared spectroscopy, morphology, thermal analysis, and swelling ratio. The rheological experiment shows the gels are cross-linked successfully by revealing the viscoelastic nature. The xylan-gelatin gel synthesized in a 5:1 molar ratio (hence XG5) has higher storage modulus, gelation temperature, and time among the synthesized gels. The adsorption behaviour of the synthesized gels is studied for the removal of methylene blue, by varying adsorbate concentration, pH, and temperature. Among the synthesized hydrogels, XG5 shows the highest adsorption capacity of 26.04 mg g −1 at pH = 5.84 and 25 °C. The kinetics of the adsorption process follows the pseudo-second-order model, and monolayer adsorption is adequately represented by the Langmuir isotherm model. The adsorption process is established as spontaneous, exothermic, and physisorption from the thermodynamic parameters.