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PhD Opportunities

If you are considering applying for one of the PhD projects below, please feel free to contact the associated supervisor(s) for more information. Applying is relatively straightforward and can be done electronically. Some of the projects below have funding; others will require you to apply for funding from external sources. More information about available scholarships (for UK, EU and international students) can be found here.

Our department is proud to create inclusive student, research, and working cultures that are supportive and welcoming to those from all backgrounds, genders, ages, disabilities, religions, and other protected groups. We are committed to providing a postgraduate program that not only equips you with the technical and professional skills you will need in your career, but which is also enjoyable, supportive, diverse, and inclusive. We welcome all applications, but especially those from the under-represented groups in physics. Everybody’s needs will be supported, but if you do have any concerns, you can contact us, in confidence, to discuss how we can support your particular needs during a research degree at the University of Leeds.

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IOP Bell Burnell Graduate Scholarship Fund

The IOP Bell Burnell Graduate Scholarship Fund is for full or part-time graduates wishing to study towards a doctorate in physics and from groups that are currently under-represented in physics. This is a great opportunity for students that fit within this remit to be encouraged to study for a PhD. This year the School will be supporting UK only applicants. For more information on the Scholarship and remit, please visit the IOP page.

There will be a Q&A session run by the IOP on 5 December for any staff or students that are interested in the scholarship.

We have an internal deadline of 15 December 2023. You must have interviewed and sent an offer letter by this date.

If you would like to talk to us about this scholarship then please email Mike Ries .

Watch this YouTube video from Jocelyn Bell Burnell herself, talking about this funding.

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Centre for Doctoral Training in Soft Matter and Functional Interfaces

 

Up to 16 fully funded four-year PhD studentships per year are available for graduates in physical science subjects, food science, mathematics or engineering.
Find out more ›

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SMP PRIORITY PROJECT

The physics of polymer glasses in confined geometries and in the bulk

Supervisors: Dr Johan Mattsson and Dr Simon Connell

The formation and behaviour of glassy disordered non-equilibrium solids is one of the deepest unsolved questions in physics, as demonstrated by the seminal contributions to the problem by the 2021 Nobel laureate in physics, Giorgio Parisi. The fact that neither the microscopic mechanisms involved in glass formation, nor the behaviour of the glassy state, are well understood makes this a key problem both within the fundamental and applied sciences.

For long-chain molecules – polymers – our present understanding of glass-formation is particularly poor due to the complexity provided both by chain connectivity and chain flexibility; this means that the molecular motions linked to glass-formation involves an intricate interplay between intra- and inter-molecular molecular cooperativity [1]. In turn, this leads to fascinating observations including polymer-specific memory behaviour observed in the slow evolution (aging) of the out-of-equilibrium glassy state, and polymer-specific transport of ions important for the construction of safe and flexible polymer-based battery materials. Generally, polymer glasses are common for instance in construction materials, in medical implants, in optical components and in membranes for controlled transport of ions or gases. Thus, understanding polymer glass-formation directly impacts our ability to design better or totally new polymer-based applications.

Polymers in restricted geometries, such as in thin polymer films, often show dramatic changes in behaviour, which are not well understood. This include a remarkable reduction in the glass transition temperature of ~70 K for thin free standing polystyrene films [2]. The high surface-to-volume ratio of thin films means that interfacial interactions play a strong large role and the change in molecular motions at the interfaces are transferred to the film interior; we do not presently understand how this transfer takes place. Thin film polymers are highly important for coatings, in microelectronics, and in a wide array of nanotechnology applications. For the development of better, and more sustainable, technologies of the future, it is thus essential to understand how geometric confinement changes the behaviour of polymers.

To address these questions, detailed experimental studies of model polymers both in thin film geometries and in the bulk are needed. Advanced experimental techniques including broadband dielectric spectroscopy, ellipsometry, calorimetry, (light, neutron and x-ray) scattering, rheology, and atomic force microscopy will be used to investigate both thin polymer films and the corresponding bulk polymers. We have recently [1] proposed a new framework for understanding polymer glass-formation, whereby the `local’ molecular motions are coupled to longer-range structural relaxations through so-called `Dynamic Facilitation’. These ideas, and their implications for the behaviour of both bulk polymers and thin polymer films will be investigated. In addition, we are interested in determining how the generated fundamental knowledge can be utilised in relevant important appllications.

You will work in an international dynamic research environment characterized by close collaborations between experimentalists and theorists and an inspiring mix of fundamental and applied research.

1. Baker, D., Reynolds, M., Masurel, R., Olmsted, P.D., Mattsson, J., Phys. Rev. X 12, 021047 (2022)
2. Mattsson, J., Forrest, J.A., Börjesson, L., Phys. Rev. E 62, 5187 (2000)

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SMP PRIORITY PROJECT

High performance liquid crystals and liquid crystal polymers for organic electronics devices

Supervisors: Dr Mamatha Nagaraj and Dr Richard Mandle

Organic electronics offer numerous advantages and capabilities for the next generation of electronic devices. Devices integrated with organic electronic components span a wide range of fields including security gadgets, environmental health, biomedical research, information technology and so on. The successful use of organic materials as electrical conductors, in light emitting diodes, field effect transistors, photorefractive devices and photovoltaic cells require high performing organic semiconducting materials. This project focuses on using liquid crystals and liquid crystal polymers to address some of the challenges in material performance and device fabrication in organic electronic devices. It makes use of the ability of liquid crystals to spontaneously self-assemble into one and two dimensional nanostructures to optimise their performance. The project will be mainly experimental in nature and involves device fabrication, material optimisation and characterisation.

The project will take place in the Soft Matter Physics group in the School of Physics and Astronomy at Uni. Leeds. Within the group, we have a variety of activities across soft matter. We work with world-leading chemists, engineers and theoreticians and our research is truly interdisciplinary. During the course of the PhD project a variety of experimental and device fabrication techniques will be employed offering an excellent practical training to the PhD student. Data analysis and computer modelling will be employed both to understand the systems and predict behaviour and performance. The student will obtain a thorough training in soft matter characterisation techniques, electronics, modelling of functional materials and devices. The research environment offers superb facilities, provides a high quality research training and delivers an exceptional student education. Suitable candidates would have a background in soft matter physics, condensed matter physics, electronics, material physics or engineering, physical chemistry, or a closely related field.

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Combining 3D printing, rheology and x-ray scattering to learn how we should 3D print sustainable soft robots

Supervisor: Dr. Devesh Mistry

Application deadline: 8 January 2024

Inspired by the complexity, variety and performance of biological actuating materials, “soft” robotics aim to transform industries from healthcare to exploration of extreme environments. Take surgical probes, presently cumbersome and large bronchoscopes cannot access the deeper tissues of the lung to enable biopsy, diagnosis, treatment of lung cancer at its early stage. Another example is exploration of and environmental sensing in aquatic environments and close to living organisms where traditional robots are struggling to move and perform accurate measurements.

Liquid crystal elastomers (LCEs) are a class of soft materials which have the potential to solve both these and other similar challenges which require new soft robotic devices. 3D printing and new chemistries has revolutionised LCEs, enabling complex and reprocessible actuators – such as those needed for the above challenges. However, before we can truly exploit 3D printed soft robotic LCE devices, we need to first understand precisely how their molecular structure and monomer sequence controls and optimises the molecular order instilled during 3D printing, and how this affects the final material properties.

In this project you will create range of reprocessible and 3D printable liquid crystalline materials, and will perform the first combined rheological and x-ray scattering studies to precisely understand how structure affects the processing conditions required to create soft robotic devices. Then by using direct-ink-writing 3D printing, you will create soft robotic LCE devices and will perform experiments to characterise their ability to do work, and their dynamic responsiveness as a soft robot. The aim will be to link understand what molecular orders and structures your 3D printing conditions created, and how those affected the performance of the devices produced.

This project will suit candidates with physics and materials science backgrounds who are keen to broaden their knowledge and expertise across experimental soft matter science. Candidates are not expected to have specific expertise in experimental soft matter science, however a motivation to learn polymer physics, x-ray scattering techniques and mechanical testing methods is required. Through a personalised training plan developed between you and the project supervisors you will learn any necessary skills.

Full description
For further background information, please see the following papers:

Soft-Elasticity Optimises Dissipation in 3D-Printed Liquid Crystal Elastomers, https://arxiv.org/abs/2106.02165
Processing and reprocessing liquid crystal elastomer actuators, https://aip.scitation.org/doi/full/10.1063/5.0044533

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Vitrimers – a new class of materials for sustainable re-processable plastics and novel battery designs

Supervisors: Dr Johan Mattsson and Prof. Andy Wilson (School of Chemistry)

For many materials applications, so-called thermosets i.e. polymers with permanent inter-chain cross-links are the optimum choice due to their long-term mechanical and thermal stability. However, the presence of permanent cross-links makes these materials very difficult to process and almost impossible to effectively re-process and thus recycle. Thus, finding a route to produce polymers that behave like thermosets across their relevant operational temperature range, but which can be readily processed and are malleable above this temperature range, is key for moving towards more sustainable plastics and a more circular economy. This project is focused on a new class of supramolecular polymers, so-called vitrimers [1] which provide a solution to this problem.

Supramolecular materials are based on fundamental molecular units which cross-link to form networks. The cross-links impart physical properties such as mechanical rigidity and by controlling the nature of the cross-links, supramolecular materials can be designed with tuneable and switchable properties, where the trigger could include temperature, a catalyst, or an applied electric or magnetic field. Due to the nature of the chosen type of cross-link interactions, the number of cross-links is always fixed; this gives vitrimers unique properties. Typically, at low temperatures (relevant for a particular application) the cross-links stay intact and the vitrimer mimics a thermoset. At high temperatures, however, cross-link rearrangements allow material shape changes, which makes the vitrimers malleable and processable.

In this project, the link between the nature of the polymeric building-blocks, the cross-link interactions and concentration, and the resulting molecular motions and mechanical response will be systematically characterized for chosen model vitrimer systems. The project aim is to develop a proper understanding of these novel materials and use this understanding to devise design rules, which will help developing materials for practical applications. We are here particularly interested in the design of more sustainable, recyclable, polymers and the incorporation of vitrimers into the design of new types of solid state batteries. The vitrimer systems will be synthesized in Leeds and investigated using a wide range of experimental techniques including dielectric broadband spectroscopy, calorimetry, rheology, scattering (light, x-ray, neutron), and atomic force microscopy.

You will work with Dr. Johan Mattsson in the Soft Matter Physics Group in the School of Physics and Astronomy and Prof. Andrew Wilson in the School of Chemistry in Leeds. You will work in an international dynamic research environment characterised by close collaborations between experimentalists and theorists and an inspiring mix of fundamental and applied research.

[1] D. Montarnal et al., Science 334, 965 (2011)

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Engineering biomaterials through liquid crystal imprinting

Supervisor: Dr Mamatha Nagaraj

Liquid crystals are a fascinating soft materials that elegantly combine characteristics of the conventional solid and isotropic liquid. There are a number of liquid crystal phases and they show unique molecular arrangements and functionalities. The process of transferring of functionalities of liquid crystals into polymer matrices is called as imprinting. In this project you will work on creating and investigating imprinted structures of liquid crystals using biomolecules for applications in medicine and tissue engineering. The student will have the opportunity to learn a number of experimental techniques vital to soft matter physics such as polarizing optical microscopy, X-ray scattering, dielectric spectroscopy, device fabrication techniques and electron microscopies.

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Materials from nature: All Natural Composites

Supervisors: Prof. Mike Ries and Dr Peter Hine

Each year we produce 300 million tonnes of plastic waste, with 8 million tonnes entering our oceans and a staggering 100 million tonnes being dumped in landfill. Therefore, we need to develop alternative sustainable processing systems that can generate bio-based products with less environmental impact; all-natural-composites have the potential to replace synthetic plastics in a wide variety of applications. As these materials will be formed entirely from one natural material their recyclability is greatly simplified. This work will incorporate natural biopolymers such as cellulose, silk and keratin, to form a variety of all-natural-composites.

All polymer composites is a growing area of research and development in which the Leeds Soft Matter Physics group has been one of the foremost pioneers. Research to date, on melt processable polymer systems, has led to a number of major patents and via a University spin-off company, to commercial applications. In the view of replacing synthetic polymers by renewable matter, all-natural based composites have great potential. In this project we shall manufacture and study all-natural composites using “green” processing routes. Selective surface solvation of the biopolymer fibres, via environmentally friendly solvents such as ionic liquids, will be used. Preliminary studies (using flax, hemp and cotton fibres) have shown that excellent bonding can be achieved, but composite morphology and mechanical properties are not yet understood. The composition of the solvent (type of solvent and fraction of cosolvent), pre-activation of fibres (distilled water / caustic soda), the fibre type and hence properties (different biopolymer sources), the fibre arrangement (unidirectional, woven) and processing variables (solvation time, temperature and pressure) will be varied. The mechanical properties (tensile, bending, impact) of the composites will be studied and correlated with their structures (WAXS, NMR, SEM).

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The physics of glass – fundamental mechanisms and novel applications

Supervisor: Dr Johan Mattsson

The formation and behavior of glassy disordered non-equilibrium solids is one of the deepest unsolved fundamental questions in physics. Moreover, to better understand the physics of glassy materials is important for a wide range of technologies, for battery and other energy materials, pharmaceuticals, foods, paints and for our understanding of biological matter such as proteins and cells. The fact that neither the microscopic mechanisms involved in glass formation nor the behaviour of the glassy state is well understood makes this a key problem both within the fundamental and applied sciences.

This project will focus on using advanced experimental techniques to investigate the physics of glass-formation, with a particular focus on the effects of molecular topology, the introduction of specific interactions such as hydrogen bonding and the molecular response to high pressures and mechanical deformations. The molecular structure and dynamics will be investigated using techniques including advanced light, x-ray and neutron scattering, dielectric relaxation spectroscopy and calorimetry.

You will work in an international dynamic research environment characterized by close collaborations between experimentalists and theorists and an inspiring mix of fundamental and applied research. The project will also include significant international collaborations with leading international research groups.

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Developing novel mechanical metamaterials

Supervisor: Dr Mamatha Nagaraj

Nature uses unique mechanisms to produce robust architectures such as biological exoskeletons, bones and wood. The internal lattice architectures of these materials are responsible for the structures being simultaneously lightweight and exhibit outstanding mechanical properties. Inspired by nature, the research on lattice miniaturization has developed rapidly over recent years. Artificial nano-lattice materials find numerous applications in biomedical implants, load-bearing structures, fast charging and high capacity batteries, porous membranes and cancer therapy. The focus of this project will be to establish routes to fabricate intricate three dimensional nano-lattices using liquid crystals, polymers and colloidal dispersion and test their applicability as mechanical meta materials.

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Controlled self assembly of nanoparticles for photonic and plasmonic applications

Supervisor: Dr Mamatha Nagaraj

Self-assembly is a remarkable phenomenon in nature and developing novel self-assembled systems for new technology areas is both exciting and important. Examples of new systems include ones where nanomaterials have been dispersed in liquid crystals to enhance their physical properties and to achieve alignment and self-assembly of nanomaterials into large organized structures in different dimensions. Such systems are potentially important because of their unusual switching properties which could be exploited in devices including, optical switches and diffraction gratings, as well as their novel architectures that will interact with light (photonic structures). The focus of this project will be to develop novel functional materials by combining liquid crystals and nanomaterials. The student will work on uniquely grafted nanoparticles, which allow controlled assembly of nanoparticles into regular lattice structures, hence allow applications in photonics and plasmonics.

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The physics of microgels and other soft colloids

Supervisor: Dr Johan Mattsson

Transitions where a material goes from a fluid state to an arrested but still disordered state arise in a diverse range of systems (colloidal dispersions, molecular or polymeric fluids, granular systems, emulsions, foams, pastes, and biological cells). Colloidal dispersions made from ‘soft’ elastic microgels provide an excellent model system for such behaviour and are also industrially highly important. Microgels are used in applications including biosensing and medical diagnostics, in pharmaceutical delivery systems and switchable materials and are regularly used to control the rheological properties of industrial products such as paints, motor oils, foods, cosmetics and inks. Many applications of microgels are based on highly crowded states, but we presently have little understanding of the rich and fascinating behaviour that takes place in the packing of such soft colloids. This project is aimed at directly addressing key fundamental aspects of the physics of microgel dispersions where important open questions include how the motions of the microgel particles are correlated in time and space, how the motions, arrangements and rheology are affected by the individual microgel particle shape, elasticity (heterogeneity) and by the inter-particle interactions. An important component of the project is the use of the 3D-photon correlation light scattering set-up in Leeds, which will be combined with other light scattering techniques, microscopy and rheology as well as colloidal synthesis techniques to provide a full characterisation and control of these experimental systems

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