Hierarchically porous composites fabricated by hydrogel templating and viscous trapping techniques

Thompson, Benjamin R.; Horozov, Tommy S.; Stoyanov, Simeon D.; Paunov, Vesselin N.

Abstract

© 2017 Elsevier Ltd Two methods for the preparation of hierarchically porous composites have been developed and explored. The first involved templating mixed slurries of hydrogel beads with two different average bead size distributions with gypsum slurry which allows for precise control over the porosity, pore size distributions and hierarchical microstructure of the hardened composite after the evaporation of the water from the hydrogel beads. The other technique utilised the viscosity of methylcellulose solution to suspend gypsum particles as they form an interlocked network. By varying the volume percentage of methylcellulose solution used, it is possible to control the porosity of the dried sample. The mechanical and thermal insulation properties of the composites as a function of both their porosity and pore size were investigated. Both methods demonstrate an inexpensive approach for introducing porosity in gypsum composites which reduces their thermal conductivity, improves their insulation properties and allows economic use of the matrix material whilst controlling their mechanical properties. Such composites allow for tuneable porosity without significantly compromising their strength which could find applications in the building industry as well as structuring of other composites for a variety of consumer products.

Citation

Thompson, B. R., Horozov, T. S., Stoyanov, S. D., & Paunov, V. N. (2018). Hierarchically porous composites fabricated by hydrogel templating and viscous trapping techniques. Materials & design, 137, 384-393. https://doi.org/10.1016/j.matdes.2017.10.046

• Journal Article Type: Article
• Acceptance Date: Oct 14, 2017
• Online Publication Date: Oct 16, 2017
• Publication Date: 2018-01
• Deposit Date: Nov 2, 2017
• Publicly Available Date: Oct 18, 2018
• Journal: Materials and design
• Print ISSN: 0261-3069
• Electronic ISSN: 1873-4197
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 137
• Pages: 384-393
• DOI: https://doi.org/10.1016/j.matdes.2017.10.046
• Keywords: Hydrogels; Porous materials; Methylcellulose; Agar; Hydrogel templating; Viscous trapping; Thermal conductivity; Compressional strength; Hierarchical porosity
• Public URL: https://hull-repository.worktribe.com/output/456287
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0264127517309735?via%3Dihub
• Additional Information: Authors' accepted manuscript of article published in: Materials and design, 2018, v.137