Figure 1: Exfoliation of vermiculite crystals and resulting dispersions of few-layer flakes.
From: Self-assembled two-dimensional nanofluidic proton channels with high thermal stability
(a) Structural model of vermiculite layers. (b) Thermally expanded vermiculite crystals (scale bar, 5 mm), which can be exfoliated by ion exchange to form (c) a single to few-layer dispersion in water. (d) The dispersion exhibits strong birefringence when viewed through crossed polarizers, suggesting nematic ordering originating from the high aspect ratios of the flakes. (e) SEM (scale bar, 50 μm). (f) Atomic force microscopy (AFM) image and (g) corresponding AFM height profile of exfoliated flakes shows that they are few-layer stacks with lateral dimensions of tens of microns.
