CO2-Induced Foaming and Gelation for the Fabrication of Macroporous Alginate Aerogel Scaffolds
Year: 2025
Type: article
Abstract: Alginate aerogels are attractive candidates for biomedical scaffolds because they combine high mesoporosity with biocompatibility and can be processed into open, interconnected macroporous networks suitable for tissue engineering. Here, we systematically investigate how CO2-induced foaming parameters govern the hierarchical pore structure of alginate aerogels produced by subsequent supercritical CO2 drying. Sodium alginate–CaCO3 suspensions are foamed in a CO2 atmosphere at 50 or 100 bar, depressurization rates of 50 or 0.05 bar·s−1, temperatures of 5 or 25 °C, and, optionally, under pulsed pressure or with Pluronic F-68 as a surfactant. The resulting gels are dried using supercritical CO2 and characterized by micro-computed tomography and N2 sorption. High pressure combined with slow depressurization (100 bar, 0.05 bar·s−1) yields a homogeneous macroporous network with pores predominantly in the 200–500 µm range and a mesoporous texture with 15–35 nm pores, whereas fast depressurization promotes bubble coalescence and the appearance of large (>2100 µm) macropores and a broader mesopore distribution. Lowering the temperature, applying pulsed pressure, and adding surfactant enable further tuning of macropore size and connectivity with a limited impact on mesoporosity. Interpretation in terms of Peclet and Deborah numbers links processing conditions to non-equilibrium mass transfer and gel viscoelasticity, providing a physically grounded map for designing hierarchically porous alginate aerogel scaffolds for biomedical applications.
Source: Gels
DOI: 10.3390/gels12010017
Authors: Natalia Menshutina, Eldar Golubev, Andrey Abramov, Pavel Tsygankov
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,534
Funder: Russian Science Foundation
Award: G4119338235
OpenAlex ID: W7117126282