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Updated: Aug 8, 2026

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Forces in the isotropic phase of a confined nematic liquid crystal 5CB
Abstract:
Using a temperature controlled atomic force microscope, we have measured the temperature dependence of the force between a flat silanated glass surface and a silanated glass microsphere, immersed in the isotropic phase of the nematic liquid crystal 5CB (4'-n-pentyl 4-cyanobiphenyl). At separations of several nanometers, we observed a weak, short range attractive force of the order of 100 pN, which was increased by decreasing the temperature. The temperature dependence of the amplitude and the range of this attractive force can be described by a combination of van der Waals and a mean-field prenematic force due to the surface-induced nematic order. This is supported by ellipsometric study and allows for the determination of the surface coupling energy of 5CB on a silanated glass surface.
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