Thesis
Investigation of key challenges facing aerogel composites development through multiscale approach
- Creator
- Rights statement
- Awarding institution
- University of Strathclyde
- Date of award
- 2022
- Thesis identifier
- T16185
- Person Identifier (Local)
- 201781728
- Qualification Level
- Qualification Name
- Department, School or Faculty
- Abstract
- The aerogel particulate and fibre reinforced composites are becoming more and more popular due to their exceptional properties, nevertheless, they do face a range of challenges that need to be overcome for wider applications. The main ones include a lack of understanding of the interactions between aerogels and reinforcing fibre materials, lack of appropriate models to predict their performance, and finally, lack of property database, allowing for an informative selection of aerogel composites as a viable alternative to other materials. The primary goal of this work is to tackle those challenges and provide a better fundamental understanding of some cases of aerogel composites. In order to fulfil the thesis' goals, the aerogel influence on the various thermal and mechanical properties of epoxy and vinyl ester polymers were investigated. By incorporating various weight contents and sizes of silica and polyimide aerogel particles into these polymers, their thermal conductivity, compressive properties, and other thermomechanical properties in these particle-filled polymers have been evaluated. Overall, created composites presented a significant decrease in thermal conductivity, while the introduction of porous particles deteriorated composite mechanical response. Additionally, micromechanical testing of the interface between aerogel and fibre reinforcement has been performed for the first time to understand their bonding ability. By designing a method to deposit an aerogel droplet surrounding the fibre, the microbond tests were enabled, and the results revealed poor adhesion between aerogel and selected fibre type in general. In addition to the experimental part, this study also focused on modelling aerogels and aerogel composites, which provided insight into the interactions between aerogels and most common reinforcement materials using a multiscale approach. As a result, the nanoscale analysis using molecular dynamics allowed to estimate thermal and mechanical properties of low density silica and polyimide. What is more, the aerogel-fibre interfacial properties values have also been obtained though modelling. Finally, the microscale model was used to model the thermal and mechanical properties of epoxy composites. A close match between experimental and modelled thermal conductivity and compressive modulus of epoxy combined with low density silica or polyimide particles has been achieved by incorporating the nanoscale properties into the micromechanical model.
- Advisor / supervisor
- Yang, Liu
- Resource Type
- DOI
- Date Created
- 2021
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PDF of thesis T16185 | 2022-04-08 | Public | Download |