Single-Step Fabrication of a Dual-Sensitive Chitosan Hydrogel by C-Mannich Reaction: Synthesis, Physicochemical Properties, and Screening of its Cu2+ Uptake

Uncovering the value of waste materials is one keys to sustainability. In this current work, valorization chitosan was pursued fabricate a novel modified functional hydrogel using process-efficient protocol. The fabrication proceeds by one-pot and single-step C-Mannich condensation (3% w/v), glutaraldehyde (20 eq.), 4-hydroxycoumarin (40 eq.) at 22 °C in 3% v/v acetic acid. Mannich base (CS-MB) exhibits dual-responsive swelling behavior response pH temperature that has not been observed any other systems. Combining pre-defined optimal (pH = 4) (T °C), CS-MB screened for its Cu2+ adsorption capacity condition. achieved an 12.0 mg/g with 1.2 g/L adsorbent dosage after 36 h agitation. on surface verified EDS, overview sites exhibited FT-IR. simply fabricated under investigation presents unique external stimuli promise heavy metal removal from aqueous media.