Overview
Research Interests
My research has concerned aspects of the behaviour of complex materials, and particularly polymers, in terms of their molecular structure, organisation and motion, especially the application of neutron scattering techniques to such problems. Neutrons are unique probes for polymeric systems both because of their wavelength and energy characteristics and because isotopic substitution of deuterium for hydrogen allows whole molecules or parts of molecules to be highlighted within a sample in order to understand their behaviour. Of course other laboratory based spectroscopic and scattering techniques are also used to give a complete picture.
A current focus is mixtures of polymers. Some binary mixtures are miscible at a molecular level but only over a limited range of temperature and composition. One large area focusses on understanding these miscibility limits in terms of the molecular components and their interactions, studying the process of separation into two co-existing phases when these limits are exceeded, and in particular studying the effect of flow on the limits and the phase separation process. Another is the study of interfaces between polymers - either observing the interdiffusion as they form in order to understand bonding and adhesion of composites, or looking at the activity of copolymer additives as interfacial agents to improve properties of blends of thermodynamically immiscible polymers.
Selected research projects
- "Polymer Blends : Stretching What We Can Learn Through The Combination of Experiment and Theory." Julia S. Higgins, Michael Tambasco and Jane E. G. Lipson. Progress in Polymer Science, 30, (2005) 832-843.
- "Small Angle Neutron Scattering From the Highly Interacting Polymer Mixture TMPC/PSd: No Evidence of Spatially Dependent χ Parameter." João T. Cabral and Julia S. Higgins, Macromolecules, 42, 9528-9536 (2009).
- "Real Time Neutron Reflectivity Study of The Early Stages of Diffusion Into and Dissolution of Glassy Polymers." D. G. Bucknall, Julia S. Higgins and S. A. Butler. J. Pol. Sci., Part B, Pol. Phys., 42, 3267-3281 (2004).
- "New Correlations in Polymer Blend Miscibility." Ronald P. White, Jane E. G. Lipson and Julia S. Higgins, Macromolecules, 43, 4287-4293, (2010).