Morphological phase transitions of thin fluid films on chemically structured substrates

Using an interface displacement model derived from a microscopic density fu nctional theory we investigate thin liquid-like wetting layers adsorbed on flat substrates with an embedded chemical heterogeneity forming a stripe. F or a wide range of effective interface potentials we find first-order phase transitions as well as continuous changes between lateral interfacial conf igurations bound to and repelled from the stripe area. We determine phase d iagrams and discuss the conditions under which these morphological changes arise.