Fast transport diffusion of bound water in cellulose fiber network

Abstract A remarkable property of cellulose-based materials is that they can absorb huge amounts water (25% the dry mass) from ambient vapor, in form bound confined at a nanoscale amorphous regions cellulose structure. The control dynamics sorption and desorption major stake for reduction energy consumption material or structure damages, but absence direct observations this process still poorly known. Here we present measurements transport thanks to Nuclear Magnetic Resonance relaxometry Imaging measurements. We show transported along fibers throughout network contact. For each single diffusion coefficient value allows represent processes over whole range saturation. dependence on fiber density orientation then analyzed deduce (elementary) axis. This constitutes fundamental physical data which may be compared with molecular simulations, opens way prediction all cellulosic other hygroscopic materials.