Recently, a new member of the nanocellulose family was introduced, a cellulose II gel consisting of nanostructured and spherical particles. In this study, we compared two different drying techniques to obtain highly porous powders from this gel with preserved meso-and macroporous nanostructure: first, freeze-drying after solvent exchange to tBuOH and second, supercritical drying of the respective EtOH alcogel. The approaches yielded aerogel powders with surface areas of 298 and 423 m 2 /g, respectively. Both powders are amphiphilic and possess energetically heterogeneous surfaces with dominating dispersive term of the surface energy in the range of 50-52 mJ/m 2 , as determined by a combination of physicochemical surface characterization techniques, such as iGC, BET and SEM. Despite the lower surface area, the cheaper and more widespread method, freeze-drying, yields a more polar and reactive cryogel.Keywords Nanocellulose Á Lyocell Á Inverse gas chromatography Á Thermoporosimetry Á Freezedrying Á Supercritical drying Abbreviations CNFCellulose nanofibrils FD Freeze-drying scCO 2 Supercritical CO 2 Electronic supplementary material The online version of this article

A new regioselective route is introduced for surface modification of biological colloids in the presence of water. Taking the case of cellulose nanofibers (CNFs), we demonstrate a site-specific (93% selective)...

A c c e p t e d M a n u s c r i p t  BET specific surface areas were determined by Inverse Gas Chromatography for samples of flax, kenaf and cellulose fibres.  The effect of experimental conditions on the BET surface area values were investigated.  Bast fibres showed a large variability within a batch compared to synthesised cellulose fibres.  An experimental procedure to determine the BET surface area values for natural fibres is proposed.

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