Soft condensed matter

Casein micelles, liposomes and bacteria are large colloids, which are widely used in food industry and biology. Some colloids can aggregate to form visco-elastic gels of much greater length, as in the formation of cheese and yoghurt from milk, where the casein micelles of milk cluster together.

These materials can be investigated with the wide range of lengths accessible by the SESANS instrument. Within this range, SESANS is sensitive to correlations of density fluctuations in samples.

Spin-Echo Small Angle Neutron Scattering (SESANS) is capable of probing length scales in real space from 30 nm up to 15 μm, thus making it ideal for measuring the structure of colloidal systems. Large colloidal systems, such as foodstuff, paint and detergents, are difficult to study with conventional scattering techniques.

The structure is measured as a projection of the correlation function of its density distribution. The kinetics in a sample can be studied as the change in its structure over time. For many systems, this can be modeled analytically and simulated numerically for static and kinetic cases, as in aggregation.