Enhanced mechanical strength of chitosan hydrogel beads by impregnation with carbon nanotubes

Chitosan (CS) hydrogel beads were impregnated with carbon nanotubes (CNTs), and their mechanical strength, acid stability and adsorption capacity to the anionic dye, Congo red (CR), were investigated by comparing with a conventional reinforcing method of cross-linking with epichlorohydrin (ECH). CS/CNT hydrogel beads were manufactured by dispersing CNTs (0.01 wt.%) with cetyltrimethylammonium bromide (CTAB) (0.05 wt.%) into CS solution (1 wt.%). Maximum endurable force at complete breakdown of CS hydrogel beads increased from 1.87 to 7.62 N with incorporation of CNTs and its adsorption capacity increased from 178.32 to 423.34 mg g−1 for adsorption of CR.