Cellulose/nanocellulose superabsorbent hydrogels as a sustainable platform for materials applications: A mini-review and perspective

Superabsorbent hydrogels (SAH) are crosslinked three-dimensional networks distinguished by their super capacity to stabilize a large quantity of water without dissolving. Such behavior enables them to engage in various applications. Cellulose and its derived nanocellulose can become SAHs as an appealing, versatile, and sustainable platform because of abundance, biodegradability, and renewability compared to petroleum-based materials. In this review, a synthetic strategy that reflects starting cellulosic resources to their associated synthons, crosslinking types, and synthetic controlling factors was highlighted. Representative examples of cellulose and nanocellulose SAH and an in-depth discussion of structure-absorption relationships were listed. Finally, various applications of cellulose and nanocellulose SAH, challenges and existing problems, and proposed future research pathways were listed.

Synthesis of a Novel and Salt Sensitive Superabsorbent Hydrogel Using Soybean Dregs by UV-Irradiation

A biomass based hydrogel soybean dregs-Poly(acrylic acid) (SD-PAA) was synthesized under UV radiation while using agricultural waste soybean dregs. Maximum absorption of SD-PAA is 3587 g·g⁻¹ in distilled water and 302.0 g·g⁻¹ in 150 mM NaCl aqueous solution. Moreover, the influence of granularity, salt solution, and ions in the solutions on water absorption is systematically studied. Sensitivity sequence of the hydrogel to cations was K⁺ < Na⁺ < NH₄⁺ < Al³⁺ < Fe³⁺ < Mg²⁺ < Ca²⁺, and that to anions was PO₄³⁻ > SO₄²⁻ > Cl⁻. Moreover, the experimental results showed that SD-PAA water retention capability remained 37% after centrifugating for 60 min and 0.2% being dried at 60 °C for 70 h. Meanwhile, the swelling data agree well with the pseudo-second-order kinetic model and Fickian diffusion mechanism.

Microwave-assisted one-step synthesis and characterization of a slow release nitrogen fertilizer with inorganic and organic composites

Microwave-assisted one-step synthesis of a novel high-performance slow release nitrogen fertilizer with inorganic and organic composites.

Eco-friendly superabsorbent composite based on sodium alginate and organo-loess with high swelling properties

A novel superabsorbent composite with high swelling properties was synthesized by the grafted co-polymerization of partially neutralized acrylic acid (AA) onto a sodium alginate (NaAlg) backbone in the presence of organo-loess.