Impact of selected solvent systems on the pore and solid structure of cellulose aerogels

• DOI: 10.1007/s10570-016-0896-z
• Publication Date: 2016-03-07T03:55:27Z
• Authors: Nicole Pircher; Leticia Carbajal; Christian Schimper; Markus Bacher; Harald Rennhofer; Jean-Marie Nedelec; Helga C. Lichtene...; Thomas Rosenau; Falk Liebner
• Keywords: Original Paper; [CHIM.POLY]Chemical Sciences/Polymers; Polymers and Plastics; Cellulose solvents; Cellulose aerogels; [CHIM.MATE]Chemical Sciences/Material chemistry; 02 engineering and technology; Thermoporosimetry; 0210 nano-technology; Porous solids

The impact of selected cellulose solvent systems based on the principal constituents tetrabutylammonium fluoride (TBAF), 1-ethyl-3-methyl-1H-imidazolium-acetate, N-methylmorpholine-N-oxide, or calcium thiocyanate octahydrate (CTO) properties II aerogels prepared from these has been investigated as a means towards tailoring aerogel with respect to specific applications. Cotton linters were used representative plant cellulose. Cellulose was coagulated solutions comparable content, and dried supercritical carbon dioxide after exchange. resulting bulk comprehensively morphologically mechanically tested relate structure mechanical properties. Different caused considerable differences in samples, such internal surface area (nitrogen sorption), morphology, porosity (He pycnometry, thermoporosimetry), stability (compression testing). results SAXS, WAXS, solid-state 13C NMR spectroscopy suggest that this is due different mechanisms self-assembling supramolecular nanostructural level, respectively, reflected by broad ranges crystallinity, fibril diameter, fractal dimension skeletal density. Both solid state WAXS experiments confirmed sole existence allomorph for all aerogels, crystallinity reaching maximum 46-50 % CTO-derived aerogels. Generally, higher degree hence increased density associated good preservation shape throughout conversion lyogels enhanced stability, but somewhat reduced area. Amorphous, yet highly rigid derived TBAF/DMSO mixtures deviated trend, most likely their particular homogeneous nanostructured morphology.