Effect of activated carbon on the properties of carboxymethylcellulose/activated carbon hybrid hydrogels synthesized by γ-radiation technique

Activated carbon (AC) was incorporated into carboxymethylcellulose (CMC) to form CMC/AC hybrid hydrogels with excellent elasticity and flexibility by radiation crosslinking. The effect of AC on the formation, properties and structure of CMC/AC hybrid hydrogels was discussed in terms of gel fraction, gel strength, gel swelling, TGA, FTIR spectra and SEM image. Compared with pure CMC hydrogel, the gel fraction, gel strength and thermal stability were improved obviously after incorporating AC into CMC hydrogels, and similar swelling ability were maintained up to the hybrid of 5%AC. FTIR and TGA spectra of the prepared gels after extracting sol revealed two findings: (1) radiation crosslinking reaction of CMC occurs in side chain of CMC molecules due to the presence of –OH and –CH2 groups; (2) AC enhanced the radiation crosslinking of CMC because AC was binding to CMC through physical adsorption and hydrogen bond as well as other interactions. From SEM images, it was found that AC particles were embedded in the network of CMC gels to form a uniform structure.