Soft matter

Polymers – Gels- surfactants – Lubricants - Liquid crystals – Emulsions – Colloids - Cosmetics

The expression Soft Matter was first used by French physics Nobel prize winner Pierre-Gilles de Gennes to define “molecular systems giving a strong response to a very weak command signal”. The field is very broad involving polymers, proteins, colloids, lipids, liquid crystals and all those systems that are easily deformed by small external fields, including thermal stresses and thermal fluctuations. The relevant energy scale, comparable with room temperature (~KBT), and the structures in the size range of nanometers to a few micrometers, make these systems ideally suited for neutron scattering studies.
Furthermore soft matter systems are rich in light elements and can be deuterated, improving the quality of information that neutrons can provide.
At the ILL the structure of soft matter is probed by large scale structures instruments, like small angle scattering machines, reflectometers, small angle diffractometers, while their dynamics is studied by neutron scattering spectroscopy with motions probed from the fs time scale (eV) to ~100ns (neV), by using inelastic scattering, backscattering, spin-echo instruments.
Soft matter represents about 20-25% of the ILL output in terms of beam-time use and publications, and benefits from a vibrant scientific environment with the facilities implemented in the Soft Matter Science and Support group in the Science Building, which has the responsibility of running the Partnership for Soft Condensed Matter activities in collaboration with the ESRF.