Materials Chemistry

The increase in resistance of bacteria to antibiotics is one of the biggest issues facing the world and many commentators have written on the catastrophic effects of the descent into a post-antibiotic world. New therapies are clearly required to combat infectious diseases but also new diagnostic techniques are required to provide better understanding of infected states. This project addresses the latter by providing polymer materials that bind selectively to bacteria and then respond to their presence; by changing conformation.1-3 The change in conformation can then be assessed using dyes that are sensitive to their environment.

We will work in collaboration with microbiologists at the University of Sheffield, who will test the polymers in established microbiological assays. The key polymers are highly branched poly(N-isopropyl acrylamide)s with bacteria binding ligands at the chain ends. The ligand in this case is a peptide, VPHNPGLISLQG, which has been identified by phage display techniques to selectively bind to Staphylococcus aureus.

The project will mainly involve the synthesis of these polymers and their characterisation in terms of molecular structure and physical properties with their microbiological properties being assessed at University of Sheffield. We will also examine the toxicity of the polymers in cell culture assays at Bradford.

Entry requirements

A 2:1 MChem or MSc in Materials Chemistry or a related subject.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

Growing antimicrobial resistance (AMR) is one of the major global challenges and it is often linked to the use of unnecessarily high doses of orally administered antibiotics following medical surgeries and infections. With a rise in life expectancy globally the demand for such medical intervention increases, and so does the associated use of antibiotics, increasing the risks of AMR. Reducing the use of antibiotics and the need for revision surgery is a long term challenge, so optimal dosing, duration of therapy and developing alternatives to antibiotics can also be considered as strategies to reduce AMR. In this project we will develop a class of biodegradable hybrid material that can be used to manufacture suture materials and other medical devices, such as patches which can simultaneously store and deliver antibiotics to specific targeted sites. Upon successful development these materials can be also used for delivering anti-inflammatories and nitric oxide in a slow and controlled rate to specific targeted sites.

Metal-organic frameworks (MOFs) are a versatile class porous materials, developed recently, with very high accessible surface area. The functional groups inside the pores of the MOFs can be modified to interact and store different drug molecules, and this class of materials has shown promising results for drug delivery applications. However, the majority of the MOFs suffer from poor stability. This project will take advantage of this drawback, so that the MOFs will decompose with time together with biodegradable polylactic acid (PLA) and polycaprolactone (PCL) polymer matrices thus delivering guest drug molecules to targeted sites.

The size of the MOF particles play an important role in delivering the drugs and part of this project will investigate the optimization of the MOF particles for effective penetration of cell walls for delivering the drug across cell membranes.

Both MOFs and PLA/PCL are of interest for drug delivery applications and are the subject of significant levels of research. However, the combination of these two classes of materials offers exciting potential for bioresorbable drug carriers which can be integrated into novel biomedical devices such as implants. This project will explore this highly promising area to develop novel composite materials which can be used to manufacture devices that can deliver antimicrobial drugs locally, without exposing the rest of the body to the drugs unnecessarily. This will reduce the usage of strong non-targeted antibiotics in excess, and therefore, help to reduce the growing problem of AMR which is a global problem recognised by World Health Organization.

The project will focus on identifying appropriate MOFs that can host a number of drugs that are used to treat external and internal bacterial infections. The selected MOFs will be synthesized in the first six months of the project. This part will follow loading of the MOFs using antimicrobial drugs, and in parallel optimization of size of the MOF particles in nanometer range using continuous flow technique (in collaboration with Edinburgh). The student will receive training on required techniques (synthesis, and equipment: X-ray diffraction, spectroscopic techniques, HPLC, UV-Vis, Thermal analysis, electron microscopy). The characterization of the MOFs and drug loading will generate significant amount of data at this phase.

In the following phase, research will focus more on optimization of MOF-size, drug loading, and synthesis of polymer composites.

In the next and final part of the project the focus will be more on drug delivery/release studies, and optimization of polymer-MOF composites. The composites will be then used to develop patches and threads using compress molding and extrusion techniques, and their drug release properties will be studied for potential medical applications.

Entry requirements

Minimum 2:1 in Chemistry or a BSc (Hons)/MSc in Chemistry or an equivalent degree. Synthetic inorganic and organic chemistry skills would be an advantage.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

Tissue engineering requires the availability of polymer materials that can support cells and the development of tissues. Many synthetic materials are tough, easily fabricated and non-toxic. However, many synthetic materials can illicit immune responses to varying degrees. The best polymers in this respect are hydrogels containing little or no charge but high water content hydrogels are often weak materials and this limits their use. In this project we will bring together a number of aspects of our work in this area. We will use the observation that alkyl amines promote the growth of epithelial tissue, the synthesis of functional polymers using ozonolysis techniques, and the synthesis and cytocompatibility of conetworks.

Our aim will be to produce tough hydrogels based on polyurethanes (some of which will be degradable, with amine functionality for the support of epithelial cells and carboxylic acid groups for the support of other cells). The work will involve novel polymer synthesis, characterisation and cell culture, using techniques established in our laboratories.

Entry requirements

A 2i MChem or MSc in Chemistry or a related subject.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

Nanoscience and technology, which involves the manipulation of materials using the property of size to bring about specific desired changes in the electronic structure of materials, has proven to be a powerful additional tool permitting the materials scientist to effect greater control over the charge transport properties in materials. While this is considered to be an exciting prospect, one of the challenges yet to be overcome is how to manipulate the transport of multicomponent materials (MCMs) at the nanoscale. In order to gain an understanding of how MCMs can be manipulated in order to achieve desirable electronic properties for device manufacture the materials need to be reproducibly made, attached to substrates and their charge carrier transport properties investigated.

This project aims to: (i) intelligently design a number of different semiconductor material combinations and characterise their comparative electronic structure via the optical response of their dilute solutions (ii) manipulate the surface chemistry of the different material architectures with short chained ligands and assess any changes in their electronic structure that result from such attachments (iii) assemble the materials with the appropriate surface chemistry into different device architectures as single non-interacting nano-objects (core, core-shell) and (iv) characterise their optical and optoelectronic properties in device architectures to determine their charge transport efficiency.

Entry requirements

A 2i MChem or MSc in Materials Chemistry or a related subject.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

The creation of complexes between polymeric compounds drives many industrial / biological processes and has been extensively studied in well-defined biological compounds with uniform structures. However such understanding is severely lacking for industrially relevant synthetic materials. This project aims to ascertain fundamental mechanistic properties of these systems to develop the ability to design and create functional materials.

The project will investigate molecular level binding of acrylamide / acid functional groups across a polymeric backbone through computational and experimental methods. The role of chain length and functional group orientation on complex formation will be investigated computationally to determine controlling factors. This will involve both ab initio quantum mechanical and force field based energy optimisations alongside molecular dynamics studies. The results of the simulations will determine the choice of benchtop characterisation of short chain polymers to obtain experimental data to confirm the computational results. This will involve oligomer synthesis and characterisation through diffusion & complexation measurements.

The University of Bradford is a leading technology university with a strong history of polymer engineering and chemical research. This project will allow an ambitious candidate to develop computational and analytical skills relevant to a range of material sciences.

Techniques and Methodology

Computational research programme; energy optimisation of structures using atomic force fields, re-optimisation at higher quantum mechanical levels, gas phase and implicit solvation tests, molecular dynamic studies. Polymer synthesis and characterisation using DOSY NMR, GPC, Mass Spec and Fluorescence Tagging.

Scientific Impact

Synthesic Polymers are used across the board in materials science, incorporated into products as diverse as food additives, cement mixtures and paint latexes. However the interaction of these polymers in solution with themselves and solvated materials are not well understood. This PhD will generate high quality, highly publishable research that will enhance the students’ career prospects in a diverse range of academic and industrial disciplines.

Entry requirements

2:1 BSc (Hons) and/or merit at MSc level in Chemistry, Maths, Engineering or other relevant science.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

The oxides of a number of materials are very appealing candidates as substitutes for conventional anodes in lithium-ion batteries because of their high theoretical capacity, high electric conductivity low potential of lithium ion intercalation, as well as superior electron mobilities, with one such material, SnO2 being particularly appealing. For example nanostructured SnO2 materials have attracted wide interest due to their potential for use in a wide variety of applications from gas sensors and photocatalysts to transparent electrodes for energy conversion and energy storage devices.

The wide applicability of nanostructured materials in general arises from their quantum size effect, large surface area and high surface activity. Despite significant progress already made using standard synthetic methods, many potentially interesting oxidic materials are still far from commercialisation. Therefore, it is imperative that new oxidic anode materials with novel architectures are investigated to further the development of commercially viable electrodes with high energy and power densities. Self-assembled hybrid nanoparticles can satisfy many requirements required for energy storage, making them interesting anode materials.

The aim of this project is to:

1. Develop a general approach for the synthesis of a number of crystalline oxide materials of interest for lithium ion storage (SnO2, LiCoO2 and LiMn2O4)
2. Develop the technology to attach multilayers of these materials to conducting substrates
3. Characterise the materials as
   1. monolayers
   2. multilayers within a device architecture
4. Determine the potential of these nanomaterials for their charge storage capacity.

Entry requirements

A 2i MChem or MSc in Materials Chemistry or a related subject.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

Metal-organic frameworks or MOFs are a class of porous materials made of metal ions and rigid organic linkers, which are known as secondary building units or SBUs. Synthesis and study of MOFs is a very hot area of contemporary research because of their potential applications in versatile areas, like gas storage, separation, drug delivery, catalysis, etc. Despite of their high potential in different applications, most of these materials lack stability in aqueous medium. This acts a limiting factor for this highly interesting class of materials.

This project will focus on development of highly stable composite membranes using metal-organic frameworks (MOFs) and polymers for separation of greenhouse gases, like carbon dioxide. Selected water-stable MOFs will be identified and used to develop composite membranes followed by their screening for carbon dioxide capture and separation.

During this project the student will be introduced with one of the most topical area of research in chemistry, and will receive intensive training on synthesis of porous MOFs and their polymer composite. The student will also receive intensive training in handling various analytical techniques which includes (but not limited to), X-ray diffraction (PXRD, and SMX), IR, NMR, UV-Vis, TGA, BET-surface area analysis, permeability study etc. The student will be guided to interpret, communicate, and disseminate the results generated from the research project in form of publications and conferences.

Entry requirements

Minimum 2:1 in Chemistry or a BSc (Hons)/MSc in Chemistry or an equivalent degree. Synthetic inorganic and organic chemistry skills would be an advantage.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

Molecule-based magnets are highly interesting with their potential applications in high-density data storage devices and quantum computing.

This project will focus on strategic synthesis and magnetic studies of high nuclearity paramagnetic clusters and networks. Various Schiff-base ligands will be synthesized with additional hydroxyl groups to bridge between different transition metals and lanthanoids. First-row transition metals will be used in combination with different lanthanoids to achieve high ground state spin and magnetic anisotropy. Cluster complexes will be particularly studied for single-molecule magnetism and the coordination polymers will be studied for their magnetocaloric effects. Computational methods will be developed to predict the properties and structures of the magnetically active polynuclear complexes to direct and explain the experimental studies.

Entry requirements

Minimum 2:1 BSc (Hons.), MChem or MSc in Chemistry, or an equivalent degree; knowledge of crystallisation and computational chemistry would be an advantage.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

In this project, we propose to use a combination of computational and experimental techniques to develop a predictive method for co-crystallisation. Many modern pharmaceuticals suffer from low solubility and other undesirable physical properties. A promising approach to address these issues is to co-crystallise the biologically active compound with an excipient (an approved additive). This is a very hot topic in pharmaceutical research and of great interest to the pharmaceutical industry; many academic and industrial research groups are active in this area.

Despite considerable effort, there is currently no validated approach to predict from first principles which excipient gives the most stable co-crystal when crystallised with a particular pharmaceutical. However, a recent pilot study (Chan, Kendrick, Neumann & Leusen, CrystEngComm, 15: 3799 – 3807 (2013)) has shown that a state-of-the-art crystal structure prediction method, which has been developed and validated by Avantgarde Materials Simulation in collaboration with our team at the University of Bradford, can be utilised to predict whether a given co-crystal will form. The method also predicts the relative stability of potential cocrystals. We aim to build on the success of the pilot study by predicting from first principles which excipients would be the most suitable co-formers for a selection of simple pharmaceuticals (e.g., aspirin, paracetamol, ibuprofen) and then verifying the predictions through standard crystallisation experiments. There is an opportunity to commercialise the method.

Entry requirements

At least a 2:1 in Chemistry, or a MSc in Chemistry, or an equivalent degree. Knowledge of crystallisation and computational chemistry would be an advantage.

Funding

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

Ionic liquids are salts which are liquids at room temperature. Ionic liquids have a wide range of applications due to their unique physicochemical properties such as chemical, thermal stability, low melting point, nonvolatility, nonflamability, low toxicity and recyclability which offer unique and interesting potential for pharmaceutical applications.

Currently, many research groups are working on the development of ionic liquids to use in the pharmaceutical field but there is limited understanding about relationship between structure and activities. Similarly, there is need to develop scalable method for manufacturing of pharmaceutical ionic liquids and formulations based on ionic liquids. The objective is to develop novel ionic liquid based advanced formulation systems and manufacturing technologies for the same.

This project provides opportunity to work with an interdisciplinary supervisory team and develop your skills in the area of advanced manufacturing technologies and analytical techniques leading to innovation.

Funding Notes

Applicants will need to have their own funding or external sponsorship. A bench fee may be payable in addition to the tuition fees.

Name: Prof. Stephen Rimmer

Research Interests:

Synthesis of functional polymers (radical, cationic, ring-opening and step-growth of polyesters, polyurethanes, polyaryls); biological applications of functional polymers especially stimuli responsive polymers, peptide functional polymers, functional hydrogels and production of functional particles

Characterisation Expertise:

Gel Permeation Chromatography (GPC); Matrix Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI TOF MS), High Pressure Liquid Chromatography (HPLC) of polymers

Orcid iD.: 0000-0002-1048-1974

Dr. Stephen Hickey

Stephen is Reader in Physical Chemistry in the School of Chemistry and Bioscience at the University of Bradford. He was awarded a PhD in 2000 (University of Bristol) for work on charge transport in quantum dot based electrodes. He spent five years as a post-doctoral fellow, two years with Prof. Daniel vanmaekelbergh (University of Utrecht, The Netherlands) and three with Prof. Horst Weller (University of Hamburg, Germany). His research goals as a postdoctoral fellow was to investigate charge transport in both metal and semiconductor nanoparticles. In 2006 he was appointed as a researcher in the group of Alexander Eychmüller at the Technische Universität Dresden (Dresden, Germany). From 2012 to 2013 he was also the Walton Research Fellow (Visiting Professor) at Trinity College Dublin. In 2014 he moved to the University of Bradford to take up the position of Reader in Physical Chemistry. His research interests can be divided into two main areas: (1) Synthesis and Applications of Metal and Semiconductor Nanostructures and (2) Charge Carrier and Phononic Transport in Assemblies of Nanomaterials. He has significant expertise in the synthesis of nanomaterials as well as their optical, electrochemical and optoelectrochemical characterisation. He also takes an interest in the production of hybrid functional nanomaterials and metamaterials composed of nanosized building blocks.

Name: Dr. Sanjit Nayak

Research Interests:

Coordination chemistry; Metal-organic frameworks (MOFs); Supramolecular chemistry; Hybrid nanomaterials; Polynuclear complexes; Gas storage and separation; Molecule-based magnets; and Catalysis.

Characterisation Expertise:

Single-crystal X-ray diffraction, Powder X-ray diffraction, Thermogravimetric analysis, Surface area analysis; Infrared spectroscopy; Scanning electron microscopy

Orcid iD.: 0000-0002-0342-9860

Name: Dr. Nadeem Javid

Research Interests:

Supramolecular Chemistry, Bio-nanotechnology, Peptidic Hydrogel Scaffolds for Tissue Regeneration, Catalysis, Green Routes for Nano particle Synthesis, Drug Delivery and Crystallization of Pharmaceutical Ingredients in nano-scaffolds.

Characterisation Expertise:

Small angle x-ray scattering (SAXS), Small angle neutron scattering (SANs), Static and Dynamic Light scattering (SLS/DLS), Fourier-transform Infrared spectroscopy (FT-IR), Circular Dichroism Spectroscopy and Raman Spectroscopy.

Orcid iD.: 0000-0002-6413-5014

Name: Dr. Tom Swift

Research Interests:

Functional polymers, stimuli responsive materials, material properties and applications.

Characterisation Expertise:

Gel permeation chromatography (GPC); Diffusion Ordered NMR; MicroDSC; Fluorescence Spectroscopy; Time Ordered Anisotropic Fluorescence Decay

Orcid iD.: 0000-0002-8616-8458

Name: Dr. Maria Katsikogianni

Research Interests:

Design of bio-inspired multifunctional materials with non-fouling/antimicrobial properties for a number of applications; medical, environmental

Characterisation Expertise:

Material physicochemical and mechanical characterisation; contact angle measurements and surface energy evaluation, Scanning Electron Microscopy and Atomic Force Microscopy, roughness measurements, thermal analysis, drug release profiles

Orcid iD.: 0000-0002-1560-3993

Name: Dr. Beverly Stewart

Research Interests:

Simulation of polymeric systems with application in sensing technologies; Simulation of electron/energy transfer systems based on functionalised polymers; Simulation of polymers as organic cores for nanoparticles.

Characterisation Expertise:

Application of molecular dynamic and quantum mechanical methods to the study of functionalised polymeric systems using computational chemical software; molecular     orbital/surface visualization for electron/energy transfer at both ground and excited states both in the bulk and at the single molecule level.

Orcid iD.: 0000-0003-1455-8462

Name: Dr. Colin Seaton

Research Interests:

Crystal Engineering: Crystallisation, Polymorphism, Multi-component crystals (co-crystals, salts, solid solutions); Chiral Resolution; Crystal Morphology; Phase Diagrams for Crystallisation Design; Development of Computational Methods to Model Crystalline Materials

Characterisation Expertise:

Crystal Structure Determination by X-ray diffraction (single crystal and powder); Thermal Analysis; Optical Microscopy; Crystallisation Studies (Nucleation, Polymorph/Co-crystal/Salt screening); Computational Chemistry - optimisation through evolutionary algorithms, lattice energy calculations, crystal structure prediction, intermolecular interactions

Orcid iD.: 0000-0003-4094-720X