Author(s):
Linhares, Teresa Conceição Amaral ; Carneiro, Vítor Hugo Pimenta ; Amorim, M. T. Pessoa de ; Durães, Luisa
Date: 2023
Persistent ID: https://hdl.handle.net/1822/87002
Origin: RepositóriUM - Universidade do Minho
Project/scholarship:
info:eu-repo/grantAgreement/FCT/FARH/SFRH%2FBD%2F131819%2F2017/PT;
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F00102%2F2020/PT;
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F00264%2F2020/PT;
Subject(s): Silica aerogel composites; Aerogel reinforcement; Thermoacoustic insulation; Textile industry; Reclaimed fibres
Description
Silica aerogels are highly porous materials with exceptional thermal insulation performance. They become even more attractive if combined thermal and acoustic insulation is achieved. Silica aerogel composites reinforced with fibres are an ingenious way to surpass the fragility stemmed from the aerogel’s intrinsic porosity, and textile fibres are good sound absorption materials. Reclaimed fibres are a relatively low-cost feedstock and were obtained in this work exclusively through mechanical processes from textile wastes, thus promoting the concept of circular economy, namely for cotton, polyester and wool fibres. These reclaimed fibres were used as reinforcement matrices for silica aerogel composites obtained from sol–gel transformation of tetraethyl orthosilicate and isobutyltriethoxysilane/or vinyltrimethoxysilane precursors and dried at ambient pressure after silylation. Silica aerogel composites reinforced with reclaimed cotton fibres had the best sound absorption coefficient (a peak value of 0.89), while the polyester-reinforced composite exhibited the lowest thermal conductivity (k = ~24 mW m−1 K−1, Hot Disk). The better combined results on thermal and acoustic insulation were achieved by the wool-reinforced composites. The thermal conductivity values were less than 27 mW m−1 K−1, and the sound absorption coefficient achieved a peak value of 0.85. Therefore, the aerogel composites developed here can be selected for thermal or/and acoustic barriers by choosing a suitable type of fibre. Their design and preparation protocol followed environmental-friendly and cost-effective approaches.
Teresa Linhares acknowledges the PhD grant Ref. SFRH/BD/131819/2017, attributed by Fundação para a Ciência e Tecnologia, I.P. (FCT, Portugal), funded by national funds from MCTES (Ministério da Ciência, Tecnologia e Ensino Superior) and, when appropriate, co-funded by the European Commission through the European Social Fund. Consumables for the syntheses and characterizations performed at CIEPQPF and 2C2T research units were funded by the European Regional Development Fund (ERDF), through COMPETE 2020 Operational Programme for Competitiveness and Internationalization, combined with Portuguese National Funds, through FCT, I.P. under the projects POCI-01-0145-FEDER-006910 and POCI-01-0145-FEDER-007136 (FCT Refs. UIDB/EQU/00102/2020 and UID/CTM/00264/2020, respectively).
