Role of rheological properties on physical chitosan aerogels obtained by supercritical drying. (1st April 2020)

• Record Type: Journal Article
• Authors: Tabernero, Antonio; Baldino, Lucia; Misol, Alexander; Cardea, Stefano; del Valle, Eva M. Martín
• Is Part Of: Carbohydrate polymers. Volume 233(2020)
• Publication Date: 2020-04-01
• Subjects: Chitosan -- Aerogels -- Rheology -- Physical hydrogels; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2020.115850
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Chitosan aerogels were obtained after SC-CO2 drying of physical hydrogels. Initial chitosan concentration modifies physical hydrogel entanglement. Aerogel textural and morphological properties do not depend on hydrogel rheology. Hydrogel elastic modulus modifies aerogel porosity and mechanical resistance. Stress-strain response was successfully modeled with Yeoh´s model. Graphical abstract: 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.