Green route for the fabrication of self-healable hydrogels based on tricarboxy cellulose and poly(vinyl alcohol).

A new approach for the preparation of poly (vinyl alcohol) (PVA) - cellulose based composite hydrogels by freezing/thawing method was conceived. We synthesized firstly the tricarboxy cellulose (OxC) (bearing three carboxyl groups in one anhydroglucose unit) using a one shot oxidation procedure and subsequently, the aqueous solutions of OxC were mixed with PVA solutions in different ratios, in the absence of any supplementary cross-linking agent. The spectral methods, FTIR, 1H, 13C NMR, as well as rheology measurements were used to assess the degree of interaction between the two components. The morphology studies of the resulted hydrogels, performed by SEM shows an excellent distribution of the tricarboxy cellulose inside the PVA matrix, the addition of tricarboxy cellulose contributing to an increase of the pore size. The rheological investigation reveals the synergistic network when an optimum amount of tricarboxy cellulose was introduced. In addition, the self-healing behavior reveals by the viscoelastic behavior, strongly recommend these hydrogels as potential candidates in tissue engineering applications.