Synthesis and characterisation of nanofibrillar cellulose aerogels

We prepared from cellulose fibres monolithic aero- and cryogels. Cellulose is dissolved in hydrated calciumthiocyanate melt, gelled, aged and dried by several methods. The density of cellulose aerogels produced by supercritical drying is in the range between 10 and 60 kg/m³ with a surface area of 200-220 m²/g. The cellulose cryogels produced by freeze drying exhibit a maximum surface area of 160 m²/g. Sputtered cellulose aero- and cryogels are examined with a scanning electron microscope. The results are discussed with respect to the literature and simple mathematical models.