PhD Project: Recycling of Carbon Fibre Composites with Deep Eutectic Solvents

About the project

Globally, 62,000 tonnes of high-value, “waste” carbon fibre reinforced polymer (CFRP) are sent to landfill each year [1]. There is, therefore, an urgent need to develop sustainable recycling solutions. Pyrolysis, where the polymer is thermally degraded, is the most mature technology, however, the polymer matrix, and its constituents, are lost. The global warming potential of this process is also approximately double that of solvent-based recycling [2]. Historically, these technologies can be divided into either low temperature, or high temperature processes. Low temperature processes involve the use of particularly hazardous solvents, acids, or bases, while high temperature conditions result in a high energy demand [3]. For these reasons, this project will harness the power of deep eutectic solvents (DES) to develop a medium temperature, closed loop recycling process. DES consist of large ions and are usually obtained by combining a quaternary ammonium salt (such as choline chloride) with a metal salt. The molar ratio used is that which gives the lowest melting point of the mixture, hence the name “eutectic” [4]. Although there has been some work on the application of DESs to the recycling of carbon fibre [5], research in this field remains in its infancy.

For this reason, this project will involve evaluating the performance of a range of DESs to assess their ability to degrade the resin of a commercially available CFRP. Following this, it will be necessary to identify and quantify the organic products obtained and develop a separation process which enables the recovery of clean carbon fibres, organic products, and the DES. To ensure high quality material is generated, a range of characterisation techniques will be applied to the recovered carbon fibres. At the end of the project, the recovered fibres and organic products will be used together to create a fully recycled new composite material.

Although well-defined, there is scope to adjust the project aims according to your own goals. Initially, it is suggested that choline chloride is investigated. This is because it is non-toxic, relatively cheap, and produces negligible waste during production, which reflects the green chemistry and engineering principles embedded in this project. Chemical analyses available includes GCMS, FTIR, TGA, and NMR, although you can investigate further techniques. Similarly, fibre characterisation tests include tensile strength, XPS, AFM, single fibre pull-out, and Raman spectroscopy, however, you will be able to explore the use of other methods as you see fit.

You will benefit from the expertise of three academic supervisors. Your primary supervisor, Dr. Matthew Keith, completed his PhD is 2019 and has five years’ experience in the recycling of CFRPs. His work has involved optimisation studies and the development of kinetic models which characterise the degradation reaction, along with characterisaton of the fibrous and organic recyclates. Before rejoining the University as a member of staff, Matthew worked for Johnson Matthey for 2.5 years. Here, he gained significant experience in catalysis, chemical processing, and project management, in addition to providing mentorship to new members of staff. Your secondary supervisor will be Dr. Andrew Ingram. He has >25 years’ experience in academic and industrial research which spans a range of sustainable chemical technologies, alongside expertise in unit operations. He has a strong track record of research excellence with ~2000 citations since 2018. He has supervised 18 PhD students to completion, thus demonstrating his exceptional coaching and mentoring ability, in addition to his technical, chemical engineering knowledge. Finally, additional supervision by Prof. Gary Leeke will bring additional expertise in separation and processing technologies. He has published over 130 papers in peer reviewed journals, three patents and has held numerous advisory roles for industry and government bodies.

Entry Requirements

Applicants will be expected to have a Masters degree awarded by a recognised University in a Chemistry, Chemical Engineering or a related discipline is the main criteria; ideally, this would include some lab-based research but this is not essential.

What does the scholarship provide?

1. Financial Support: Recipients of these scholarships will receive substantial financial support, including a stipend at UKRI rates, which is set at £18,622 per year. This support covers tuition fees, living expenses, and research-related costs, including bench fees. This support is designed to alleviate the financial burden often associated with pursuing a doctoral degree.

2. Mentorship and Guidance: Scholarship recipients will benefit from mentorship opportunities and guidance from accomplished faculty members who are dedicated to helping them succeed in their academic and research endeavours.

3. Research Opportunities: We are committed to providing an exceptional research environment. Students will have access to state-of-the-art facilities, cutting-edge resources, and a vibrant scholarly community.

4. Community Building: A key component of the scholarship programme is the creation of a supportive community of Black British researchers pursuing PhDs. This network will foster collaboration and peer support among scholars.

5. Research Training Support Grant: In addition to financial support, scholarship recipients will receive a research training support grant. This grant is intended to support conference attendance, fieldwork, and other essential activities that enhance their research and academic growth.

6. Commitment to Inclusivity: We are dedicated to building an inclusive academic environment that values diversity and ensures equitable access to education.

Contact the lead supervisor

Once applicants have familiarised themselves with the above project details, they are encouraged to contact the lead PhD supervisor to discuss the project and the applicant’s suitability for the project. This is recommended before you submit an application to the PhD project.