Advancing the properties of cellulosic aerogels with particular focus on cell scaffolding materials

Abstract

Cellulose aerogels have been attracting immense interest in the last decade, boosted by current efforts towards a more biobased economy and carbon dioxide neutrality, concomitantly trying to implement key principles of the green chemistry philosophy. Main goal of this PhD study was to investigate some fundamental aspects of the preparation of cellulose II aerogels and to explore opportunities to tailor these materials for selected applications, with a main focus on bone tissue engineering. Antisolvent-mediated coagulation of cellulose from solution state is a key step in the preparation of respective aerogels deciding about solid network architecture, mechanical performance, specific surface, porosity and pore size distribution. Since both way and rate of phase separation modulating coagulation depends on the type of cellulose solvent / antisolvent used, this
study compared the respective effects of cellulose solvent systems that had been used before in the preparation of cellulose II aerogels (NMMO · H2O, Ca(SCN)2 · 8 H2O / LiCl, [EMIm][OAc] / DMSO) with TBAF / DMSO / H2O which was explored for the first time. Following the development of a facile procedure for reducing the water content of a 30 wt.% solution of TBAF·3 H2O in DMSO to about 0.95 wt.% in a 16.6 wt.% solution of TBAF in DMSO, cellulose and cellulose phosphate aerogels of low DS were prepared and comprehensively characterized. Hemocompatibility testing of these aerogels confirmed that both phosphorylation of cellulose and partial calcification of phosphate groups reduces the inflammatory response via the alternative pathway and activates hemostasis as required for
osteogenesis and bone-scaffolding materials. The output of this PhD thesis has been compiled in five original research papers and two book chapters, the latter reviewing preparation, characterization, properties and applications of bacterial nanocellulose aerogels as well as of aerogels from plant cellulose.

Date of Award	2021
Original language	English
Awarding Institution	University of Natural Resources and Life Sciences, Vienna
Supervisor	Falk Liebner (Supervisor)