Capillary nematisation of colloidal rods in confinement

Kira E Klop, Roel PA Dullens, Paul M Lettinga, Sergei A Sergei, and Dirk GAL Aarts

Mol. Phys. 2018 116 2864

We confine a colloidal liquid crystal between parallel plates separated down to several times the rod length. By connecting the system to a reservoir we effectively create a grand canonical system, in which the liquid crystal displays an isotropic phase in the reservoir, but upon strong confinement becomes nematic between the parallel plates. This capillary nematisation transition can be followed down to the single particle level by means of laser scanning confocal microscopy. We compare the experimental findings to density functional theories (DFTs), within the Zwanzig model as well as a more advanced DFT, in which the effect of rod flexibility is taken into account.