Superabsorbent hydrogel made of NaAlg-g-poly(AA-co-AAm) and rice husk ash: Synthesis, characterization, and swelling kinetic studies

Abstract

The sodium alginate-g-poly(acrylic acid-co-acrylamide)/rice husk ash (NaAlg-g-P(AA-co-AAm)/RHA) superabsorbent nanocomposite was synthesized by the free-radical graft copolymerization of alginate (NaAlg), acrylic acid (AA), acrylamide (AAm), and RHA in aqueous solution. FTIR spectra revealed that the monomers were grafted onto NaAlg chains, and the nanocomposite was formed successfully. Incorporation of RHA into hydrogel matrix formed porous interlinked channels within hydrogel network. Superabsorbent nanocomposite showed greater equilibrium swelling capacity (1070g/g) compared with neat hydrogel (830g/g). Moreover, water transport mechanism of all hydrogels was non-Fickian diffusion type. Rheological measurements confirmed effective role of RHA in improving gel strength of superabsorbent nanocomposite. The influence of various factors, such as different loads (0.3, 0.6, 0.9 psi), solution pH, saline solution, and temperature on the swelling behavior of hydrogels was also assessed. Superabsorbent nanocomposite exhibited good pH-dependent swelling reversibility and high water retention capability, making it more efficient water-saving material for agricultural and horticultural applications.

Temperature‐responsive alginate‐g‐poly(N,N‐diethylacrylamide) copolymer: Synthesis, characterization, and swelling behavior

“…7 It is constituted blocks of (1-4)-linked b-D-mannuronic acid (M) and a-L-guluronic acid (G) units. 8,9 It has been widely used in tissue engineering, nutrition supplements, and drug delivery. 7 It can be easily modified via physical interactions and chemical functionalizations to obtain alginate derivatives having numerous properties, structures, applications, and functions.…”

Fast swelling behaviors of thermosensitive poly(N‐isopropylacrylamide‐co‐methacryloxyethyltrimethyl ammonium chloride)/Na2WO4 cationic composite hydrogels

“…The microporous structure and thin wall of the N 5 D 1 W 17 hydrogel increased the surface area and was conducive to water infiltration into the hydrogel network. 33,34 It was confirmed by the subsequent swelling kinetics experiments.…”

Preparation, Characterization, and Swelling Behavior of PEGylated Guar Gum @ Ag Nanoparticles

“…The swelling behavior was explained by applying different kinetic models such as Fickian diffusion and Schott second-order dynamic model given in Eqs. (2)-(7) [29,30]. To identify the swelling kinetic mechanisms of the prepared samples, the swelling kinetic parameters were evaluated according to models:…”