BIOPOLYMER-BASED HYDROGELS: SYNTHESIS AND APPLICATIONS

Abstract

The thesis focuses on the synthesis of biopolymer-based hydrogel composites under ambient conditions, with emphasis on their applications in water remediation, drug delivery, sensing, and agricultural applications. The synthesized matrices were characterized using various spectroscopic and analytical techniques, which include X Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analyser (TGA), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy (SEM). In recent years, sustainable biomaterials have garnered significant attention across a wide range of applications. In this work, inorganic and organic materials were incorporated in Carboxymethyl Tamarind Kernel Gum (CMTKG)-Polyacrylamide (PAM) based matrix to assess their applicability in diverse fields. The potential application of a synthesized graphene oxide/carboxymethyl tamarind kernel gum/polyacrylamide (GO/CMTKG/PAM) hydrogel composite was investigated for the sequestration of cationic organic dyes, namely crystal violet and methylene blue, from aqueous medium. The synthesized hydrogel composite as an adsorbent showed more than 95 % removal efficacy for both organic dyes, indicating its potential as an effective adsorbent for dyes sequestration. Additionally, the effect of polymer (sodium polyacrylate (PSA) and polyacrylamide (PAM)), with or without GO incorporation in CMTKG-based hydrogel composites, were studied for the ciprofloxacin delivery. The observed drug release behavior revealed that the Korsmeyer-Peppas model was found to be the best-fitted. The CMTKG-PSA-GO and CMTKG-PSA hydrogel composites follow the Fickian diffusion mechanism, while the non-Fickian diffusion mechanism was followed by CMTKG-PAM-GO and CMTKG PAM. The incorporation of GO into hydrogel matrices enhanced properties such as the swelling ratio, gel content, and porosity of the hydrogel and the drug release behavior. Therefore, the synthesized hydrogel composites could serve as a promising substitute for the oral delivery of the ciprofloxacin drug. Furthermore, iron oxide nanoparticles (IONPs) were incorporated into CMTKG-PAM hydrogel. The green synthesis of IONPs using citrus limetta peel and then the synthesis of IONPs incorporated with CMTKG-PAM was performed, characterized, and employed for the administration of the levofloxacin drug. The experimental study reveals that the v drug release mechanism was found to have good correlation with the Korsmeyer-Peppas model, and the drug release in CMTKG-PAM-IONPs hydrogel was governed by a non Fickian diffusion mechanism. The drug release was found to be maximum in stimulated pH 7.4, highlighting the potential of CMTKG-PAM-IONPs as a targeted drug delivery system. Additionally, to deliver the azithromycin drug, a series of hydrogels was formulated using sodium alginate, CMTKG, and PAM (SA/CMTKG/PAM) hydrogel. The optimized hydrogel was characterized, and the observed results reveal that drug release follows the Korsmeyer-Peppas and Higuchi models in both the pH’s solutions. Furthermore, on incorporating m-BPDM into CMTKG/PAM hydrogel as a potent candidate for colorimetric sensing of Zinc, cadmium, and mercury ions from aqueous solution for real-time application. Moreover, to evaluate its agricultural application, the CMTKG/PAA/IA hydrogel was used for a dual purpose: as a soil conditioner and as a carrier for delivering iron as a micronutrient to the field. Overall, it can be concluded that this thesis provides a comprehensive study on biopolymer-based hydrogels by incorporating different inorganic and organic materials as fillers into CMTKG-based hydrogel and their potential application in a variety of fields.