Surface-induced undulations in a liquid crystalline polymer

We have carried out X-ray reflectivity as well as X-ray diffuse scattering studies on thin liquid crystalline polymers formed on solid surfaces. Due t o the microphase separation of the siloxane backbone from the mesogenic end group, the polymer films form extremely ordered layers in which the therma l fluctuations are highly quenched. This enables us to probe quantitatively the nature of the static undulations of the layer induced by the roughness of the underlying surface. We show that penetration of depth of surface un dulations is greater than the film thickness of the polymer films, in agree ment with the theoretical predictions of P.G, de Gennes (The Physics of Liq uid Crystals, Oxford University Press, London, 1974). (C) 2000 Published by Elsevier Science Ltd. All rights reserved.