Synthesis and characterization of CMC–HEC natural polymer hydrogels reinforced with rice husk ash–derived SiO2: swelling kinetics, mechanical performance, and soil water retention
Natural polymer hydrogels derived from renewable biopolymers represent a sustainable alternative to synthetic soil conditioners. This study synthesized amorphous silica (SiO₂) from rice husk ash (RHA) via alkaline dissolution–acid precipitation under four preparation conditions, and incorporated it as a particulate fil...