ENERGY-DISPERSIVE X-RAY REFLECTIVITY STUDY OF THE MODEL MEMBRANES AT THE AIR-WATER-INTERFACE

The results of the first energy-dispersive reflectivity measurements w ith a (membrane coated) liquid surface are reported. They rely on the calibration curve measured with pure water and can be done without any sample or detector movement with a low-intensity, laboratory-based X- ray generator within less than 1 h. As an illustration, the structural parameters of a diarachidoylphosphatidylcholine monolayer at the air/ water interface are determined. It is argued that the energy-dispersiv e detection in combination with the intense synchrotron radiation can be used for the time-resolved reflectivity measurements on the time-sc ale of minutes.