New smart carrageenan‐based superabsorbent hydrogel hybrid: Investigation of swelling rate and environmental responsiveness

Abstract

Synthesis of novel natural-based superabsorbents with improved properties is of prime importance in many applications. In this article we report an efficient synthesis of new polysaccharide-based superabsorbent hybrid composing carrageenan, acrylic acid, sodium acrylate, and 2-hydroxyethyl acrylate through homogenous solution polymerization process. Infrared spectroscopy and thermogravimetric analysis (TGA) were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). To deeper studies on the structure-property relation in SAP hydrogels, three hydrogels with different acrylic acid/2-hydroxyethyl acrylate (AA/HEA) weight ratios were synthesized and swelling capacity in various media was assessed. The hydrogel hybrid was also tested to be swollen and deswollen alternatively in 0.01 and 0.1 M sodium chloride solution. Moreover, the swelling-deswelling capability of the hydrogel in alternatively changed methanol-water mixtures was studied. Additionally, the swelling kinetics of the synthesized hydrogels were examined. The absorbency under load (AUL) of hydrogel was also investigated by using an AUL tester at various applied pressures.

Controlled release of aspirin from pH‐sensitive chitosan/poly(vinyl alcohol) hydrogel

“…The low swelling of HG10 showed the effect of crosslinking on its swelling response compared to HG2. These macropores in the hydrogel were responsible for the higher degree of swelling and allowed interaction with surrounding hydrophilic groups 29…”

Superabsorbent hydrogel nanocomposites based on starch-g-poly(sodium acrylate) matrix filled with cellulose nanowhiskers

“…These properties are observed because the hydrogel pores disposed in interconnected networks with diameters of several hundred microns create open channels that allow water movement inward the matrix for capillarity. A good strategy applied to produce superabsorbent materials relies on polysaccharides-based ones, which could increase their biocompatibility, biodegradability, water uptake capacity as well as decrease the toxicity broadening their potential of application (Salimi et al 2010;Li et al 2011).…”

Electrically induced swelling and methylene blue release behaviour of poly (N-isopropylacrylamide-co-acrylamido-2-methylpropyl sulphonic acid) hydrogels

“…The high water absorption and rubbery properties of hydrogels make them suitable materials for use in the field of medicine, pharmacy, biotechnology, living cells, actuators, artificial muscles, chemical valves, etc. The environmentally sensitive hydrogels are known as intelligent or smart hydrogels which respond to external environment stimuli such as temperature [1][2][3], pH [4,5], ionic concentration [6] and electric field [7][8][9]. These hydrogels exhibit drastic changes in their swelling behaviour in response to a change in surrounding conditions.…”