Soft matter and biology

Polymers – Gels - Surfactants – Liquid crystals – Emulsions – Colloids - Proteins – Viruses – Cell membranes – Biological processes - Drug delivery and action

Neutron beams are particularly well suited for soft matter and biology research. As electrically neutral, neutrons can penetrate deep into materials without damaging sensitive samples. They can be generated with energies and wavelengths ideally matched to probe structures ranging from small molecules (like lipids and peptides) to large macromolecular assemblies (such as viruses).

The expression "soft matter" was first used by 1991 Nobel prize in Physics 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 any systems easily deformed by small external fields, including thermal stresses and thermal fluctuations. The relevant energy scale (comparable to room temperature, ~KBT) and the structures size (in the range of nanometers to a few micrometers) make neutron scattering ideal to study these systems.

Why Use Neutrons for Soft Matter and Biology?

Sensitivity to Light Elements: Unlike X-rays, neutrons interact quite strongly with light elements, particularly hydrogen. Pinpointing the location and orientation of hydrogen atoms is often critical to understanding biological behavior.
Isotopic Substitution (Deuteration): Researchers can selectively replace hydrogen with its isotope, deuterium. This process of deuteration significantly improves contrast, allowing specific components within a complex system to be highlighted and detailed.

Capabilities and Environment at the ILL

Research in soft matter and biology accounts for roughly one-third of the ILL’s total beam-time and publication output.

structural probing: large-scale structure instruments—including small-angle scattering instruments, reflectometers, and small-angle diffractometers - are used to map physical structures.
dynamic probing: neutron scattering spectroscopy (including inelastic, backscattering, and spin-echo instruments) tracks molecular motions across timescales from femtoseconds (eV) to approximately 100 nanoseconds (neV).

This world-class instrumentation is supported by a vibrant scientific ecosystem on the EPN campus, providing users with specialised facilities through the Biology, Deuteration, Chemistry and Soft Matter Group, Partnership for Soft Condensed Matter and Partnership for structural Biology (PSB).