Heritage and Forensic Science

Supervisor: Multiple potential supervisors across the MEE Group with efforts led by Dr Donna Arnold, Co-director of the Centre for Heritage

Understanding the history of our cultural heritage as well at its preservation is critical if we are to be able to protect artefacts for the future. Identifying materials present as a result of the artefact, its storage, it proximity to other materials and/or recovery are crucial to develop remedial processes or optimise protective display environments. Likewise, identifying materials present in trace evidence are important for comparison and being able to weigh up evidential value. These projects look to utilise complementary techniques such as x-ray diffraction, electron microscopy and Raman spectroscopy to understand cultural heritage artefacts and trace evidence with forensic value.

 

The search for new ferrotoroidal materials

Supervisor: Dr Donna Arnold

Multiferroic materials (those with electric and magnetic ordering) continue to attract extensive research attention due to their potential in next generation devices particularly higher power, lower energy electronic devices. However, generation of these materials is not without challenges primarily as a result of difficulties trying to incorporate magnetic and electrically active ions into a single phase. One class of materials which offers real promise in this area are ferrotoroidal materials which simultaneously show electric ordering arising as a result of toroidal order of magnetic spins. Projects will look to provide a deeper understanding of ferrotoroidicty through the synthesis and characterisation of new ferrotoroidal materials.

 

Antiferroelectric materials for energy storage

Supervisor: Dr Donna Arnold

Energy storage materials remain at the forefront of tackling climate change. In order to continue to move towards a carbon neutral society we need a variety of energy storage systems that can operate and store energy in different ways to meet the variety of needs. Antiferroelectric materials exhibit and antiparallel ordering of the electric dipole and offer enhanced storage capacities with smaller losses in comparison with other types of electric order. However, our understanding of what drives antiferroelectric order and how to optimise it is still lacking. Projects in this area will look to develop new antiferroelectric materials (synthesis and characterisation) and crucially look to bridge the gap between discovery and optimisation providing new insight into these materials.

 

Understanding novel magnetic topographies in geometrically frustrated materials

Supervisor: Dr Donna Arnold

Frustration in magnetic materials occurs when the underlying crystal structure is incompatible with supporting antiferromagnetic (antiparallel) spin order. Often in these materials exotic magnetic behaviour can be realised alongside exciting quantum phenomena. We have been looking to understand how to synthesise materials with new magnetic topographies and to understand the role these play in promoting particular magnetic orders. Projects in this area will look at the synthesis and characterisation of new magnetic materials with the aim of continuing to understand the compositional flexibility in these materials and develop new understanding.

 

Induction effect in Polyanion compounds used in energy storage cathodes

Supervisor: Dr Maria Alfredsson

Current research on cathode materials in Li-ion batteries is too a large degree focused on nickel manganese oxides with variable content of cobalt (Co) to achieve voltages above 4V. From an environmental aspect Co is an unwanted element. In this project you will combine computational chemistry with machine learning to identify alternative materials as potential cathodes in Li-ion batteries. One type of materials, polyanionic compounds, will form the basis of this study varying the cations and anions in the structure.

 

Aqueous Batteries reaching above 2 V

Supervisor: Dr Maria Alfredsson

Batteries running on water as opposed to organic solvents struggle to work at a voltage above 1.7V as the water breaks down. In this project you will be challenged to find novel chemistry solutions to develop and design aqueous batteries, which can be used in healthcare devices. The battery need to work above 2V, required to power the sensors used to monitor the patient. Another aim of the project is to identify materials that comply with the above criteria, while being biocompatible, as well as biodegradable or recyclable.

 

Printed batteries for health care devices and sensors

Supervisor: Dr Maria Alfredsson

In our search for energy storage solutions with higher capacity, voltage and safety, much research has focussed on finding alternative electrode materials, which contain active material; binders; carbon additives etc. However, the common binder, polyvinylidene difluoride (PVDF), is a non-polar molecule, requiring the use of an organic solvent, N-Methyl-2-pyrrolidone (NMP), recently added to the restricted substances list. Aqueous soluble binders, replacing PVDF, can lead to improved battery performance and introduce safer manufacturing solutions. These batteries can be applied to sensors for healthcare and environmental monitoring. The aim of this project is to develop aqueous inks for flexible printed energy storage solutions in light-weight flexible batteries.

 

Inspirational chemists/forensic scientists

Supervisor: Dr Aaron Berko

There is a lack of diversity equality in the Chemical Sciences, markedly after the BSc degree. Several complex reasons have been identified for this lack of diversity, including a lack of role models. This project will look at how pedagogical strategies can be employed to improve diversity. For example, researching and showcasing the chemistry contributions of individuals from minority representations. This project will include literature searches of research papers, presenting the body of work of a chosen scientist (or group) within a pedagogical framework.

The results of the project will be aimed towards publications in chemical education related journals.

The project will allow the student to gain insight into pedagogical approaches in chemistry how that affects student outcomes and progression. It will provide useful contributions to reforms and development in pedagogy in natural sciences.

 

Studying the effects of acid and chelating agents on historic wooden artefacts using analytical techniques

Supervisor: Dr Aaron Berko

One of the issues facing conservators of wooden marine archaeological artefacts is the oxidation of sulfur compounds to sulfuric acid which can further degrade the wood structure by causing the breakdown of cellulose which is responsible for the mechanical strength of wood. These acidic species are generated from within the artefacts themselves, especially those submerged under seawater for a considerable amount of time like the Mary Rose.  Analyses show the presence of various iron species present in the timbers of The Mary Rose and other historic ships from corroding iron bolts and fastenings used in timber ship building.

It is believed that the iron (II) sulfide species is primarily responsible for the production of sulfuric acid. The use of chelating agent in treatment of cellulose-based manuscripts written with iron gall ink is now established. DTPA (due its low toxicity and strong iron chelating properties), EDTA and citric acid are favoured chelators in removing Fe species from ship timbers.

This project will use complementary techniques (SEM, XRD, XRF) to investigate the effects of acid and selected chelating agents on the wood structure to provide insight into optimum length of treatment and concentrations required for sequestering Fe species whiles preserving wood structure.

 

Titania-based aerogels for environmental remediation

Supervisor: Professor Anna Corrias

The aim of this project is to design highly efficient and non-toxic titania-based aerogels for cost effective water remediation. Aerogels, which are sponge-like materials, with up to 98% of their total volume being air (hence the name), are very well suited because of their intrinsic adsorption properties. The aerogels developed in this project will combine superhydrophobic properties with photo-catalytic activity provided by titania to easily degrade pollutants in waste waters. The project involves the use of sol-gel to synthetise the aerogels, a multi-technique approach to characterise them in detail and photo-catalysis tests.

 

Functional Materials by Design

Supervisor: Professor Mark Green

The synthesis and characterization of new functional materials is vital for future development. Our research program focusses on new electronic and energy such as new solar, battery and magnetic materials. Global warming is dangerously high and radical energy changes are required. The sun generates enough energy to provide the world with all its power demands many times over. We develop new cheap and efficient photovoltaic perovskite materials for solar applications. We synthesis and characterise new Magnetic Materials that are used extensively in electronic applications and are key for the development of quantum computing.

 

Computational Chemistry of Energy Materials for Batteries, Solar, Green Hydrogen, and Net Zero

Supervisor: Dr. Gavin Mountjoy

Materials chemistry is needed to transition from fossil fuels to alternative energy technology with reduced carbon emissions (net zero).  Key such energy materials are electrodes for batteries photovoltaics for solar, and catalysts for green hydrogen.  Training will be given in chemical databases, visualisation software, and molecular dynamics.  These techniques will be used to discover new material properties dependent on composition and temperature.  The project results will be published in physical chemistry journals (as in Dr. Mountjoy’s publication record).  The student will gain expertise in computational solid state chemistry, and energy materials (as have Dr. Mountjoy’s previous MSc and PhD students).

 

Developing low dimensional transition metal frameworks for efficient cryogenic cooling

Supervisor: Dr Paul Saines

Cooling to temperatures below 20 K is key for quantum computing, medical imaging and liquefaction for the hydrogen economy. Magnetocalorics offer an efficient solid-state method for such cryogenic cooling, via an entropically drive process driven by cycled magnetic fields; magnetocalorics offer a replacement for increasingly scarce and expensive liquid helium. We have recently shown that frameworks with ferromagnetic lanthanide chains with weaker coupling between them via polyatomic ligands are promising magnetocalorics. We will explore frameworks incorporating 3d metals into similar 1D structures to develop more sustainable magnetocalorics. It will provide training in coordination framework synthesis, crystal structure analysis and magnetic property characterisation.

 

Metal-organic frameworks for cathodes for alkali-metal batteries

Supervisor: Dr Paul Saines

We are heavily dependent on Li-ion batteries for storing clean energy creating a need for new cathode materials that both enhance capacity and cyclability but also allow us to replace Li with cheaper, more abundant alkali metals. The redox properties of oxalate ligands has been recently shown to lead to metal-organic frameworks (MOFs) cathodes with enhanced cyclability and capacity. This should be enhanced by the increased conjugation in related ligands so we will exploit the underexplored chemistry of fumarate frameworks combining alkali and transition metals for new cathode materials. The project will provide training in MOF synthesis, structural characterisation and battery preparation/testing.

 

Luminescent Detection of Gunshot Residue

Supervisor: Dr Paul Saines

Adding materials that glow under UV light to the primer and propellant in ammunition provides a method to aid the initial “presumptive” presence of gunshot residue (GSR). This potentially reduces cost and improves reliability compared to current chemical techniques. Many lanthanide coordination frameworks have such useful luminescent properties. We will apply these frameworks to detecting GSR including understanding how best to optimise luminescence while reducing cost by tuning their chemistry and establish how they change under the high temperatures generated when a gun is fired. This is planned to involve using the School’s new ballistic facility working with Dr Chris Shepherd.

 

Thermal and shock processing of planetary analogue materials

Supervisor: Dr Jon Tandy

Most planetary bodies experience large fluctuations in their temperature, harsh cosmic irradiation and crater forming impacts. Understanding the chemical and mineralogical modification of planetary materials by thermal and impact (shock) processing is therefore crucial for the interpretation of samples retrieved by current and future space missions. A suite of analytical techniques (XRD, SEM-EDS, Raman spectroscopy, AES and XRF) will therefore be used to characterise thermal and shock processed planetary analogue materials. Temperature variation will be mimicked using a cryogenic cold finger under high vacuum, with shock processing achieved using a light gas gun to simulate hypervelocity projectile impacts of meteoroids.