PhD project: Interfacial properties in complex particulate formulations
Project description
Formulated consumer products, such as cosmetics or snack foods, are complex multi-component mixtures. Optimising performance, or replacing components to help achieve environmental sustainability, is a substantial challenge as the varied components can interact with both each other and how the product is processed, stored or used. To facilitate predictive reformulation, i.e. without exhaustive and time-consuming testing by variation over a wide ranging parameter space, it is vital to understand the components’ roles at a microphysical level in terms of general soft-matter science principles, for example, emulsion stabilisation or gel formation. This offers the opportunity to translate science to industrial impact, but also to inform new soft matter science that could have application across multiple sectors.
Project aims
Many consumer formulations are highly loaded with a solid particulate phase, for example the mineral filters in sunscreens, the active ingredients of agrochemicals and even the sugar in chocolate. How this solid phase interacts with a liquid-liquid interface is vital for performance, controlling the SPF, active dispersion or sweetness perception, respectively. While the interaction of solid colloidal particles with liquid-liquid interfaces is well understood in the dilute regime with pure solvents, consumer formulations have the additional complexity of high solid volume fractions and additional components, such as dispersants or structuring agents (e.g., thickeners or waxes) that may modify how particles behave both in bulk and at the interface.
The project will begin by developing various simplified formulations based on a subset of the components in a commercial formulation to disentangle the multiple potential roles. This approach would particularly suit a curiosity-driven student, with multiple potential avenues for the lab-based development of model systems. These systems will be mechanically and structurally characterised using a suite of rheological and imaging techniques based within the Soft Matter Physics Group. Novel techniques developed include contactless interfacial rheology, rheo-microscopy and differential dynamic microscopy. These will be leveraged to investigate the interaction of a concentrated suspension of solid particles with the interface of an immiscible liquid drawing on the research areas of the academic supervisors, Dr James Richards (suspensions and rheology) and Dr Job Thijssen (particle-stabilised interfaces). Over the course of the project, it is envisioned that correlative models between simplified and commercial formulations will be developed. This offers the scope for a host of data science or multi-scale physical modelling approaches, an aspect of the project that may suit students with a strong mathematical foundation or programming interest. This project will be in close connection with the Edinburgh Complex Fluids Partnership a group of researchers and academics focussed on knowledge exchange with industry across multiple sectors from food and cosmetics to wastewater treatment.
Application
Informal enquiries can be directed to Dr James Richards (james.a.richards [at] ed.ac.uk (subject: Sunscreen%20formulation%20PhD%20project%20enquiry) ) to discuss funding opportunities, e.g., a previous project has been funded through an EPSRC IDLA award. We are interested in hearing from students who are highly motivated to work in a multi-disciplinary scientific team with close industrial collaboration and have, or be on track to achieve, II.I or above (or international equivalent) integrated masters or undergraduate degree in physics, chemistry, chemical engineering or related subject.
Project supervisors
- Dr James Richards (School of Physics & Astronomy, University of Edinburgh)
- Dr Job Thijssen (School of Physics & Astronomy, University of Edinburgh)
The project supervisors welcome informal enquiries about this project.
Find out more about this research area
The links below summarise our research in the area(s) relevant to this project:
- Find out more about Soft Matter Physics.
- Find out more about the Institute for Condensed Matter and Complex Systems.
What next?
- Find out how to apply for our PhD degrees.
- Find out about fees and funding and studentship opportunities.
- View and complete the application form (on the main University website).
- Find out how to contact us for more information.