Preparation of high-strength dynamic polysaccharide nanocomposite hydrogels and their application towards dye adsorption

The preparation and application of natural dynamic polysaccharide hydrogels have been attractive in recent years. Herein, carboxymethyl chitosan (CMCht) and oxidized acetoacetate cellulose (OCAA) were used to prepare polysaccharide nanocomposite hydrogel for dye adsorbent by one pot method mixing glutaraldehyde (GA) and cellulose nanofibers (CNFs), and mechanical, rheological, self-healing and dye adsorption properties were investigated. Consequently, compared with CMCht/OCAA hydrogel, the addition of GA crosslinker together with 1 % CNF increased strengths by ∼520 %, tensile strengths from 259 KPa to 1.35 MPa and compressive strength from 450 KPa to 2.35 MPa, respectively. The nanocomposite hydrogels demonstrated excellent anti-fatigue performance, and its experimental modulus result was fit Halpin-Kardos and Ouali model. Moreover, the freeze-dried gels showed a good removal effect for methylene blue dye from water, and its adsorption capacity and removal efficiency could reach up to 564.64 mg/g and 94 % due to the presence of dynamic covalent and hydrogen bonds in the composite hydrogel. This work developed a high-strength dynamic polysaccharide hydrogels incorporation of CNFs, which shows promising applications in environmental fields especially water pollution adsorption treatment.