We study colloids and self-assembled amphiphilic systems with scattering techniques like small-angle X-ray and neutron scattering (SAXS & SANS) and with static and dynamic light scattering (SLS and DLS). In the beginning we focused on dilute systems only in order to facilitate data evaluation. The possibility to transform the scattering data from reciprocal space (scattering curve) back to real space (pair distance distribution function PDDF) with the Indirect Fourier Transformation (IFT) technique opened new ways of data interpretation, i.e. shape determination of monodisperse colloids like proteins. The deconvolution of the PDDF to the radial electron density distribution allowed the determination of the internal density profiles of micelles, lamellae and micro-emulsions.
An important progress was possible with the incorporation of particle interaction in the evaluation technique (Generalized Indirect Fourier Transformation GIFT). This made it possible to study concentrated systems directly without dilution. It is well known that self-assembled systems can show structural changes with concentration.
When studying hierarchically organized systems one wants to determine structural de-tails in a wide size regime. That’s where the combination of SAXS & SANS with SLS and DLS becomes important. While SLS is useful to study the static structure for systems up to several micrometers in size, DLS can help to get further information about diffusion dynamics of the sample studied, including the determination of the sol – gel transition. With modern instruments such studies can be time-resolved when studying non-equilibrium systems. These experiments can also be performed in turbid samples.
I shall show typical results for the different systems discussed above with special em-phasis to unexpected results.
otto.glatter@uni-graz.at
