Crystal structure of vermiculite and exfoliated single nanolayers.

The aim of the following proposal is to determine crystal structure of natural vermiculite clays of different types using synchrotron powder x-ray diffraction, before and after exfoliation into single nanolayers. Vermiculite is a 2:1 layered silicate, composed of 1 nm thin sheets kept together by interlayer cations. The structure of the thin nanolayer is complex, it consists of octahedral sheet sandwiched between the two tetrahedral sheets. We have acquired 12 types of vermiculite originating from different areas in the world, and we have managed to exfoliate most of them into the single nanolayers. However, the exfoliation process does not work the same for all of these vermiculite types. As we do not know the exact crystal structure of our vermiculites, we hence cannot estimate the charge of the nanolayers, that will explain the exfoliability of the material.