Summary

The BCFN is seeking applications from exceptional graduates in science disciplines for a fully-funded industry studentship with Bayer on our doctoral training programme, commencing on 13 January 2020.

You benefit from completing the Spring/Summer term of the BCFN PhD programme and at the extended project phase you will move on to this industry project. For full details please visit our website – www.bristol.ac.uk/bcfn

Objectives

Collapse of colloidal gels has significant consequences for a tremendous range of products. Gel collapse is a complex process, as gels are non-equilibrium materials whose properties change over time, and the processes that lead the material to spontaneously collapse are not understood. Among the key challenges is to understand the cause of the delay time prior to collapse where apparently little happens, and through this understanding to have a better ability to predict the stability suspensions, and especially newly developed products.

Like most materials the macroscopic behaviour of gels ultimately stems from their microscopic properties and their time-evolution. We have been working for some time, focusing on the microscopic behavior. In particular, we have investigated the change in microscopic structure over time [1], and determined the local structures which give gels their rigidity in the first place [2].

Proposed Project: connecting between microscopic and macroscopic behavior

The work to date has revealed a depth of knowledge of the microscopic gel system. We know the structure and why the materials are rigid, i.e. solid. We know how the stresses are distributed in the material. But how does this microscopic behaviour cause gel collapse?

To answer this question we will extend our techniques to consider collapsing gels. This we will do with confocal microscopy of a model system which we have developed. The 3d confocal microscopy will reveal the changes in local structure and the forces between the particles, which we expect to underlie the failure of the gel network which leads to collapse. Among the key challenges will be pinpointing the precise failure point where the gel collapse begins.

[1] Zhang I, Royall CP, Faers MA and Bartlett P, “Phase separation dynamics in colloid-polymer mixtures: the effect of interaction range”, Soft Matter, 9 2076-2084 (2013).

2] Royall CP, Williams SR, Ohtsuka T and Tanaka H, “Direct observation of a local structural mechanism for dynamic arrest” Nature Mater. 7 556 (2008).

You will need to meet the standard BCFN PhD programme entry requirements, be classed as a Home/EU student and attend an interview either in person at Bristol or via Skype.  If you are submitting an application, please state that you are applying for the BCFN/Bayer studentship in your application.

Interviews are likely to take place week commencing 16 December 2019.