Kinetics of in-situ swelling and delamination of vermiculite by hydrogen peroxide

The aim of the following proposal is to determine kinetics of the process of swelling of natural clay vermiculite, in H2O2, by synchrotron wide-angle X-ray diffraction, upon complete delamination of vermiculite crystal into the single layers. Vermiculite [1-3] is a 2:1 layered silicate, composed of 1 nm thin negatively charged sheets kept together by interlayer cations. We have acquired 15 vermiculite samples originating from different areas in the world, and we exfoliated the most of them into the single nanolayers using H2O2. From our previous XPS experiments and diffraction experiment at BM01 beamline in ESRF, we know that the exfoliation process does not work the same for all of these vermiculite samples, and depends on the type of interlayer cation and charge of the nanosheets. Study of kinetics of reaction promoted by heat, will optimize conditions for exfoliation of vermiculite nanosheets to achieve maximum performance of exfoliation process.