Effect of process variables on optimisation of mechanical properties of silica/poly(tetrahydrofuran) sol-gel hybrids
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Published version
Author(s)
Type
Journal Article
Abstract
Inorganic/organic sol-gel hybrid materials consist of inorganic and organic co-networks which interact at the molecular level and behave as a single material. The aim is to gain synergy of properties between the two components, with the inorganic providing mechanical strength and organic providing elasticity. This becomes more challenging as the thickness of a sol-gel material increases, due to risk of cracking. Here, we investigate the effect of sol-gel processing variables for large silica/poly(tetrahydrofuran) (SiO2-PolyTHF) monolithic hybrids (a size range of several centimetres) to optimise their mechanical properties. Cracking on drying can occur due to combinations of shrinkage and capillary stresses inside the monoliths, but can be mitigated by optimisation of process variables and hybrid composition. The effect of these variables on success rate of producing crack-free monoliths was assessed, then full characterisation carried out on samples made with successful protocols. Computational scribe calculations on X-ray micro-computed tomography images determined the shrinkage during different drying methods. Chemical, thermal, mechanical, and structural analyses were applied to devise a reproducible synthesis method for hybrid monoliths. The monolithic hybrids, prepared using both oven-dried (OD) and freeze-dried (FD) techniques, demonstrated compressive strengths of 44.1 MPa and 30.5 MPa, respectively, when made with an inorganic content of ~31 wt.%. These materials can withstand strains of up to 54.5%. Mechanical testing in wet and dry conditions, i.e. after 60 days immersion in phosphate buffered saline solution (PBS), enabled observation of the viscoelastic response after 1000 cycle compression loading, demonstrating that the materials can work under wet conditions.
Date Issued
2025-10-01
Date Acceptance
2025-03-03
Citation
Journal of Sol-Gel Science and Technology, 2025, 116, pp.619-633
ISSN
0928-0707
Publisher
Springer
Start Page
619
End Page
633
Journal / Book Title
Journal of Sol-Gel Science and Technology
Volume
116
Copyright Statement
© The Author(s) 2025 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
License URL
Identifier
10.1007/s10971-025-06725-5
Publication Status
Published
Date Publish Online
2025-03-22