NEW FRONTIERS IN SAXS

Peter Laggner

Institute of Biophysics and X-Ray Structure Research, Austrian Academy of Sciences, Steyrergasse 17, A-8010 GRAZ, AUSTRIA

Recent advances in instrumentation of x-ray small- and wide-angle diffraction have drastically expanded the usefulness and user-friendliness of this method for structural research. In connection with powerful, third-generation synchrotron radiation sources, the field has been opened for sub- millisecond time-resolved studies on structural transitions and supramolecular rearrangement processes. IR- Laser techniques for fast T-jumps, pressure-jump, stopped-flow mixing, tensile stress experiments, and magnetic-field induced reorientation are among the many exciting possibilities recently implemented. Examples from the Austrian SAXS beamline at ELETTRA will be given.

In the standard laboratory environment, the ease of operation and speed of the method has made it possible to use it in an interactive mode to investigate biological and technological systems, e.g. membranes, liquid crystalline or micellar systems, over a broad range of chemical and physical conditions, and to map out phase diagrams in reasonable time. This is particularly important e.g. in the search for new, membrane-active antibiotics, for optimized liquid crystalline immobilization matrices in biocatalysis, or for template moulded nanostructures.

Finally, SAXS, as an advanced analytical technique is about to enter the industrial process control field. A SAXS camera suitable to work continuously as an in-line process control tool has been recently developed in the framework of a EC project and is being introduced into the detergent industry. Other applications in e.g. the oil and fat sector, the pharmaceutical and cosmetic, or the food industry are being explored.