25/06/2009
- Time resolved micro-diffraction at NHM London.
Monitoring fast kinetic reaction in case of clays dehydration is an issue of major importance. Traditional X-ray sources performances are not sufficient to reveal very short time scale events.
At NHM a microfocus sealed source was replaced by the high brightness GeniX Cu High Flux beam delivery system which made it possible to well-resolve XRD patterns within one second-snapshots even with a 100μm illumination on the sample.
NHM is now able to resolve all three waterinterlayer states and sequential transitions within an experiment of only 200 seconds.
Latest results acquired with the GeniX indicate that the real lattice response in clay on water loss is probably much quicker and more uniform than previously reported with the previous setup.
The Figure at right shows the development of the basal (001) reflection with time during dehydration of Na-montmorillonite. All three states of clay dehydration (3-, 2-, 1- water interlayer) become resolvable using one-second X-ray snapshots.
07/07/2010 - Small spot grazing incidence x-ray diffraction and reflectometry