Synthesis, characterization, and swelling studies of guar gum‐based pH, temperature, and salt responsive hydrogels

Abstract

Stimuli-sensitive hydrogels constitute an important class of materials. In the present study, a simple method was used to induce temperature sensitivity and salt responsiveness in the guar gum (GG)-based hydrogel, which was synthesized by grafting GG with acrylic acid (AAc) using simultaneous gamma radiation technique. The carboxyl groups of poly(AAc) were partially modified to amide groups to generate a network that has pH-sensitive poly (AAc) and temperature-sensitive poly(N-isopropyl acrylamide). Swelling behavior of hydrogels was studied at various temperature, pH, and the salt sensitivity of the hydrogels was studied by swelling the hydrogels in 0.9% NaCl solution. Characterization of these networks was carried out by X-ray diffraction, FTIR spectroscopy, and scanning electron microscopy to get evidence of the network formation and postreaction carried on the network. The hydrogel synthesized by the postreaction exhibited pH, temperature, and salt sensitivity, while the precursor hydrogel exhibited good salt tolerance.

Modulation of the Viscosity of Guar-Based Fracking Fluids Using Salts

“…The residual O–H stretching bands shown in Figure correspond to aggregated regions of the polysaccharide, where D 2 O does not penetrate. Changes in intermolecular interactions and aggregation of polysaccharide solutions due to the presence of salts have been studied before. − Aggregation limits the interaction with the solvent so that the residual O–H band is from O–H groups of the polysaccharide that interact with each other, rather than with D 2 O. Hence, the D 2 O spectra show that there is more hydrogen bonding (and therefore a shift to lower frequencies) for guar solutions that have the least interaction with the solvent and, therefore, the lowest viscosity.…”

Removal of crystal violet dye using grafted guar gum along with nanoclay and MWCNT

“…However, grafted guar gum with nanoclay shows mixed morphological features with lamellar structure intermixed with agglomerated particles. The morphological part is partly continuous owing to network formation contributed by both inter-chain bonding of carboxylic groups [41]. This also suggests enhanced interactions between guar gum and acrylic acid [42].…”

Surface-Crosslinked Guar Gum-g-Sodium Polyacrylate Superabsorbents: Swelling Characteristics and Mechanics Performance

“…Guar gum (GG), as a representative natural polymer, is a nonionic branched biopolymer with β-D-mannopyranosyl units linked with single membered α-D-galactopyranosyl units occurring as side branches. Known as one of the best water-soluble polymer, guar gum has been reported to be grafted with monomers to design and develop new superabsorbent hydrogels [10][11][12][13]. However, most of the reports focus on the study of water absorption capability, seldom on the mechanics performance such as gel strength, resilience, dispersion and surface-drying.…”