Organic/Inorganic Superabsorbent Hydrogels Based on Xylan and Montmorillonite

Abstract

The unique organic/inorganic superabsorbent hydrogels based on xylan and inorganic clay montmorillonite (MMT) were prepared via grafting copolymerization of acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) withN,N-methylenebisacrylamide (MBA) as a cross-linking agent and potassium persulfate (KPS) as an initiator. The effect of variables on the swelling capacity of the hydrogels, such as the weight ratios of MMT/xylan, MBA/xylan, and AMPS/AA, was systematically optimized. The results indicated that the superabsorbent hydrogels comprised a porous cross-linking structure of MMT and xylan with side chains that carry carboxylate, carboxamide, and sulfate. The hydrogels exhibit the high compressive modulus (E), about 35–55 KPa, and the compression strength of the hydrogels increased with an increment of the MMT content. The effect of various cationic salt solutions (LiCl, CaCl2, and FeCl3) on the swelling has the following order: Li+> Ca2+> Fe3+. Furthermore, the influence of pH values on swelling behaviors showed that the superabsorbent composites retained around 1000 g g−1over a wide pH range of 6.0–10.0. The xylan-based hydrogels with the high mechanical and swelling properties are promising for the applications in the biomaterials area.

Amphoteric gellan gum-based terpolymer–montmorillonite composite: synthesis, swelling, and dye adsorption studies

“…The decreases in GP as the content of monomers increases could be attributed to the less reactive side on the GG as its content remains constant, and hence, there are more molecules of DMAPMAm and AMPS than GG and this could lead to the formation of homopolymer and hence low yield. is assigned to C-O bond stretching frequencies [32].…”

Single-step microwave-assisted hot water extraction of hemicelluloses from selected lignocellulosic materials – A biorefinery approach

“…Recent studies on xylan-based hydrogels have also shown the possibility of modifying and further synthesizing them into newly functionalized biomaterials for innovative applications in nanomedicine (Pahimanolis et. al Despite their potential applications, the path towards large scale production of hemicelluloses for high-value bio-based products largely remains underexplored (Zhang et al, 2014;Spiridon and Popa, 2008). One viable approach in realizing their ultimate economic value is the development of a lignocellulosic biorefinery system, whereby hemicellulosic biopolymers are co-produced with cellulosic ethanol (Chantal et al, 2012; Ragauskas et al, 2006).…”

Preparation and Physicochemical, Structural and Morphological Characterization of Phosphorylated Starch

“…On the other hand, the spectrum of the ST-TP sample presented, in addition to small variations in intensity, a new band at 3630 cm -1 associated with O-H stretching of unbound water, probably adsorbed on the surface of the sample 24,25 , a band at 1214 cm -1 assigned to symmetrical stretching P=O 19,20 , a band at 1129 cm -1 related to symmetrical and asymmetrical stretching of the PO 2 group 26 and a band at 889 cm -1 may be related with the P-O bond 27 . Such alterations in the absorption in the infrared region, evidenced the occurrence of the phosphorylation process, especially for the spectra of the ST-TP sample.…”