Micropatterned thin films have received increased interest in the past few years. Besides preparation by conventional lithography, self-assembly of materials around a template can be used for patterning. Recently a method that utilizes the condensation of micrometer-size water droplets on solutions of block copolymers was reported for the preparation of ordered micrometer-size honeycomb structures. Here we show that the formation of honeycomb-like porous films is a general method that can be used for patterning many materials, e.g., block copolymers, amphiphilic polyion complexes, organic/inorganic hybrids, and homopolymers, such as polystyrene. Stabilization of water droplets is indispensable for regular pattern formation.

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It could be shown that by a simple casting process from solution two-dimensionally ordered arrays of mesoscopic (i.e., in the range of submicrometer to micrometer) polymer aggregates on solid substrates can be formed. Patterns were investigated by optical microscopy and atomic force microscopy. The pattern formation was observed in situ by optical and fluorescence microscopy and it was found that a "fingering instability" at the three-phase-line of a solution droplet is the crucial process for pattern formation. (c) 1999 American Institute of Physics.

The preparation of mesoporous honeycomb films, also known as breath figure arrays (BFAs), from poly(styrene‐co‐maleic anhydride) is reported. Films containing regular arrays of micrometer‐sized air‐holes were prepared by evaporation of a chloroform solution of a mixture of the above polymer including 10 % of an amphiphilic polyion complex under high humidity that leads to the formation of a hexagonally packed monolayer of water droplets in the polymer film. The porous films were characterized by optical and scanning electron microscopy. Crosslinking was achieved by immersion in an ethanol solution of an α, ω alkyldiamine and the chemical reaction was monitored by infrared spectroscopy. The non‐crosslinked films are hydrophobic with a water contact angle of more than 90°, whereas the crosslinked films became hydrophilic, so that a water drop penetrated into the films. After crosslinking, the honeycomb structure was stable to up to 350 °C, an increase of more than 150 K as compared to the non‐crosslinked films.

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Previously it was shown that molecular recognition occurs between complementary vesicles containing either a lipid with a 2,4,6-triaminopyrimidine (TAP) or with a barbituric acid (BAR) head group separated from the alkyl chains by an tetraoxyethylenic spacer. In view of better understanding the nature of the interaction, Langmuir monolayers and LB films of these complementary lipids are investigated. The selective binding of the TAP−Lipid with various barbituric acids is studied by π/A isotherms, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and fluorescence microscopy. The effects of the subphase pH and ionic strength on this molecular recognition point out an electrostatic contribution due to the acido−basic properties of TAP and BAR in addition to an hydrogen bonding interaction. The comparison with a melamine compound (diCl2mela) shows that this recognition is still efficient in the presence of the tetraoxyethylenic spacer.

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