Synthesis of cellulose-based superabsorbent hydrogel with high salt tolerance for soil conditioning

• Published in: International journal of biological macromolecules 2022-06, Vol.209 (Pt A), p.1169-1178
• Main Authors: Guo, Yu, Guo, Rongbo, Shi, Xiaoshuang, Lian, Shujuan, Zhou, Qiannan, Chen, Ying, Liu, Weifeng, Li, Wei
• Format: Article
• Language: English
• Subjects: Cellulose - chemistry; Cellulose-based superabsorbent hydrogel; Hydrogels - chemistry; Nitrogen; Salt Tolerance; Sodium carboxymethyl cellulose; Soil - chemistry; Soil conditioning
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2022.04.039

In this study, cellulose-based superabsorbent hydrogel was synthesized from sodium carboxymethyl cellulose (CMC-Na), acrylic acid (AA), and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to enhance its water absorbency and salt tolerance for soil-conditioning applications in areas suffering from drought and soil salinization. Superabsorbent hydrogels (SHs) were prepared by CMC-Na and AMPS successfully, using chemical graft technology. Structure, morphology, thermal stability, and water absorbency of SHs were deduced. The cellulose-based hydrogel showed a high salt tolerance that the maximum water absorbency reached 604 and 119% in distilled water and saline water, respectively. The swelling behavior in aqueous solvents indicated that the water absorption of hydrogels was improved with the increasing ratio of CMC-Na. All SHs exhibited adsorption of nitrogen with the maximum adsorption of ammonia nitrogen 30 mg·g−1 and the presence of hydrogels could slow down the loss of nutrients in the soil. This study provided a feasible strategy that AMPS was substituted by CMC-Na to synthesize SHs with strong water absorbency and high salt tolerance which could be efficiently applied in agriculture as a soil conditioner.