Neutron scattering of confined and sheared thin soft films

The study of soft materials confined between surfaces is central to the understanding of interactions that lead to adhesion, lubrication and colloidal stability. Force measurements have long been able to describe the potential that exists between various coated surfaces, but it is only more recently that scattering techniques, particularly reflectometry, have permitted the detailed study of surface layers under confinement. Specifically, the recent development of a confinement cell that consists of a solid surface confined by an expanding flexible film has been able toaddress key factors that have hampered these investigations for a long time by achieving parallelism and good contact over a large area. These advances have enabled new fields of research for studying surfaces under confinement using neutron reflectometry. 

In this project, a researcher from Malmö University will collaborate with the team behind the development of this cell and with researchers from ILL, ISIS and ESS to build on this success towards a next-generation surface confinement apparatus. Specifically, the key deliverable will be to develop a sample environment capable of applying shear under confinement which can be integrated with neutron grazing incidence scattering and reflection geometries to provide information on the structural changes in all dimensions. To achieve this goal, the cell will be designed and manufactured in collaboration with ILL, and fully optimized for full integration on to the beamlines at ESS and ISIS. There is significant private and public sector interest in understanding lubrication and developing nanomaterials to mimic nature. Thus, the huge potential of this project to significantly expand the research field accessible with neutrons will be demonstrated by employing it to investigate the mechanism underlying the outstanding performance of aqueous lubricants, in particular polymer brushes and mucin films. 

Facts about the project
Project leader

Juan Francisco Gonzalez Martinez, Malmö University