Modulation of composite hydrogel consisting of TEMPO-oxidized cellulose nanofibers and cationic guar gum

The applications of hydrogels are prominently affected by the modulation of their structure and performance. We herein systematically implemented the modulation of an all-polysaccharide hydrogel consisting of TEMPO-oxidized cellulose nanofibers (TOCN) and cationic guar gum (CGG). Four different factors including the carboxylate content and size of TOCN, the freezing-thawing treatment and solid content of hydrogel were studied to disclose their influence on the structure and property of TOCN/CGG hydrogel. The results indicated that the increase of carboxylate content of TOCN, the number of freezing-thawing cycles and solid content all increased the crosslinking density of hydrogel as a result of the improved interactions. Accordingly, the hydrogels exhibited more compact structures and enhanced rheological properties. The influence of TOCN size on the hydrogel structure and property was demonstrated to be dependent on the compromise between the exposed functional groups of TOCN and their ability in generating entanglements inside the hydrogel. This work helps shed light on the modulation of hydrogel structure and performance, which might facilitate the exploration of hydrogel applications.