Patent ID: 9206414
Filing Date: 2015-12-08
Classification: C08L,C12N,C12P

Abstract:
1. A process of producing a nanocomposite hydrogel with an anisotropic stress-strain curve, comprising the steps of: forming a suspension of microbially-produced cellulose fibers in a solvent wherein said cellulose comprises fibers having nanometer scale cross sectional dimensions, the cellulose fibers having been formed via agitated culture or shaken culture, thereby preventing the formation of a pellicle; adding a hydrogel-forming material to the cellulose suspension, such that the hydrogel-forming material is dissolved in the suspension; crosslinking said hydrogel-forming material to obtain a nanocomposite hydrogel; applying a longitudinal strain to said nanocomposite hydrogel; and thermal cycling said nanocomposite hydrogel over a predetermined temperature range at least once while maintaining said longitudinal strain; such that said nanocomposite hydrogel has an increased ratio of longitudinal to perpendicular stress under application of strain, compared to an anisotropic hydrogel formed in the absence of said cellulose; wherein the hydrogel-forming material is present in an amount from 5% by weight to 15% by weight and the microbially-produced cellulose fibers are present in a range from 0.05% by weight to 0.5% by weight; wherein the hydrogel-forming material is selected from the group consisting of polyvinyl alcohol (PVA), poly(vinyl pyrrolidone) (PVP), poly(ethylene glycol) (PEG), poly(hydroxyethyl methacrylate) (PHEMA) and polyacrylamide; and wherein the solvent is a hydroxylic solvent or an aprotic solvent capable of forming effective hydrogen bonding to dissolve the hydrogel material.