Morphological, optical and thermal characterisation of aerogel-epoxy composites for enhanced thermal insulation

Abstract

The present work explores the possibility of introducing aerogel at different stages of the epoxy resin cure to identify the most effective method that ensures minimal destruction of the aerogel particles. The aerogel particles are added at 0.5 hours, 1 hour and 1.5 hours after the resin and the hardener are mixed together. Additionally, the effect of a wetting agent that improves the interface between the aerogel and the resin is also investigated. The different materials are characterised using optical images and ESEM-EDX to determine the most effective processing route. Additional data is also provided by determining the different material's optical transmittance and reflective characteristics. From the experimental results, it is observed that the addition of aerogel at the 1 hour mark proves to be the most efficient route to follow. In addition, the wetting agent displays a negligible effect on the samples in the study; hence its usage is advocated due to its influence on the interface strength. Therefore, the aerogel/epoxy/wetting agent sample with the aerogel added at the 1 hour mark looks promising. A 13.3% decrease in thermal conductivity when compared with the pure resin/hardener sample along with damage coefficient value of 0.183 demonstrates the material's potential for thermal insulation applications.

Investigation of the effects of silica aerogel particles on thermal and mechanical properties of epoxy composites

“…Nevertheless, no mechanical testing was performed in their study. Finally, Krishnaswamy et al investigated the morphology, optics and thermal character of aerogel/epoxy composites by increasing the resin viscosity to the point where aerogel pores were no longer infiltrated following mixing [16]. The resulting composites presented a 13.3% decrease in thermal conductivity when 3 wt% silica aerogel particles were added.…”

“…Under microscopy it was found, however, that physical destruction of the aerogel particles had occurred due to epoxy curing shrinkage. Such destruction indicated a larger surface area of the particle through which the resin could now enter the aerogel interior pore network [16].…”

Aerogel/epoxy thermal coatings for carbon fibre reinforced plastic substrates

“…The properties of the substrate and coating used are presented in Table 1. The coating's thermal conductivity was the experimental value of the bulk material determined previously [25]. The other properties of the coating were calculated using the rule of mixtures and individual properties of aerogel and epoxy .…”

Microstructure, hygrothermal, and mechanical properties of interlaminar toughening of CFRP composite using polyamide veil

“…[3][4][5] Compared with the in situ toughening of resin matrixes, interlaminar toughening inserts a toughening agent in the designated zone by separating the resin and the toughening components. [6][7][8][9] Hence, the toughening agent at the designated area is enriched. [10][11][12][13] When toughening materials are added, the weight of the CFRP increases, and its in-plane mechanical properties decrease.…”