Morphological, optical and thermal characterisation of aerogel/epoxy composites for thermal insulation applications

The present work explores the possibility of introducing aerogel particles at different stages of the epoxy resin cure to find the most effective method that ensures minimal destruction of the former along with a high degree of mouldability for the composite material. 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 electron microscope with energy dispersive X-ray spectroscopy 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 seen 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. Therefore, the aerogel/epoxy/wetting agent sample with the aerogel added at the 1 hour mark is the most promising material. A 13.3% decrease in thermal conductivity when compared with the pure resin/hardener sample along with the calculated aerogel damage coefficient value of 0.227 (22.7%) confirms its promise and potential for thermal insulation applications.