Organic Bio-Based Aerogel from Food Waste: Preparation and Hydrophobization
Giulia Gaggero,
Raman P. Subrahmanyam,
Baldur Schroeter,
Pavel Gurikov,
Marina Delucchi
Affiliations
Giulia Gaggero
Department of Civil, Chemical and Environmental Engineering, University of Genoa, Via All’Opera Pia 15, 16145 Genoa, Italy
Raman P. Subrahmanyam
Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
Baldur Schroeter
Institute of Thermal Separation Processes, Hamburg University of Technology, Eißendorfer Straße 38, 21073 Hamburg, Germany
Pavel Gurikov
Laboratory for Development and Modelling of Novel Nanoporous Materials, Hamburg University of Technology, Eissendorfer Strasse 38, 21073 Hamburg, Germany
Marina Delucchi
Department of Civil, Chemical and Environmental Engineering, University of Genoa, Via All’Opera Pia 15, 16145 Genoa, Italy
In this work, organic aerogels from spent ground coffee and apple pomace were prepared and characterized for the first time. Apple aerogel was found to be much lighter than that from coffee (0.19 vs. 0.016 g/cm3, whereas the specific surface areas are comparable (229 vs. 208 m2/g). Being intrinsically hydrophilic, these aerogels were silanized, both in liquid and gas phase, to increase stability in aqueous media. The latter modification method allowed chemical grafting of the silane to the aerogel surface (evidenced by FTIR and TGA) and resulted in certain hydrophobicity, as was evidenced via contact angle measurements: both aerogels possess a contact angle of ca. 100° after the gas hydrophobization, while for the pristine aerogels it was 50°. Furthermore, it was observed that the gas-phase silanization process is more applicable to apple aerogels.
