Role of rheological properties on physical chitosan aerogels obtained by supercritical drying

Antonio Tabernero; Lucia Baldino; Alexander Misol; Stefano Cardea; Eva M Martín Del Valle

doi:10.1016/j.carbpol.2020.115850

Role of rheological properties on physical chitosan aerogels obtained by supercritical drying

Carbohydr Polym. 2020 Apr 1:233:115850. doi: 10.1016/j.carbpol.2020.115850. Epub 2020 Jan 11.

Authors

Antonio Tabernero¹, Lucia Baldino², Alexander Misol³, Stefano Cardea⁴, Eva M Martín Del Valle⁵

Affiliations

¹ Department of Chemical Engineering, University of Salamanca, Plaza los Caídos s/n, 37008, Salamanca, SA, Spain. Electronic address: [email protected].
² Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, SA, Italy.
³ Department of Inorganic Chemistry, University of Salamanca, Plaza los Caídos s/n, 37008, Salamanca, SA, Spain.
⁴ Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, SA, Italy. Electronic address: [email protected].
⁵ Department of Chemical Engineering, University of Salamanca, Plaza los Caídos s/n, 37008, Salamanca, SA, Spain; Instituto de Investigación Biomédica de Salamanca, Hospital Virgen de la Vega, Paseo San Vicente, 58-182, 37007, Salamanca, SA, Spain.

PMID: 32059901
DOI: 10.1016/j.carbpol.2020.115850

Abstract

Chitosan aerogels were obtained after using supercritical carbon dioxide to dry physical hydrogels, studying the effect of the rheological behavior of hydrogels and solutions on the final aerogels properties. An increase on the solutions pseudoplasticity increased the subsequent hydrogels physical entanglement, without showing a significant effect on aerogels morphology (nanoporous) and textural properties (pores of about 10 nm). However, an increase of hydrogel physical entanglement promoted the formation of aerogels with a higher compressive strength (from 0.2 to 0.80 MPa) and higher thermal decomposition range, while decreasing the porosity (from 90 % to 94 %). Aerogels stress-strain responses were also successfully fitted using a hyperelastic equation with three adjustable parameters (Yeoh), showing that this type of models must be taken into account when large stresses are studied.

Keywords: Aerogels; Chitosan; Physical hydrogels; Rheology.