Strengthened cellulosic gels by the chemical gelation of cellulose via crosslinking with TEOS

Abstract

Physical and chemical gels of cellulose were obtained by (1) coagulation of dimethyl sulfoxide (LiCl/DMSO) cellulose solution in ethanol and (2) crosslinking by tetraethyl orthosilicate (TEOS) in non-aqueous medium under catalysis with ethylenediamine (EDA). Their structure and properties were studied. The highest storage modulus was 1.08 MPa (physical) and 4.04 MPa (chemical), respectively. The surface area (SBET) of cellulose chemical gels, which were composed of three-dimensional networks of long silica-modified fibrils, was as high as 296.8 m2/g. It is noticeable that it is not simple self-condensation of organic silicate that occurred but instead the ostensive silicic ester of cellulose was formed. This novel cellulose derivative and its chemical gelation may lead to a new category of cellulose-based organic–inorganic hybrid materials.