We report on the formation of ordered arrays of micrometric holes on the surface of polystyrene (PS) films cast from volatile solvents in the presence of humidity at different temperatures. The formation mechanism is investigated for PS having different molecular weights, polydispersities, and carboxylic terminations. Among the chosen materials, a highly regular honeycomb microstructured morphology is obtained on the surface of films prepared with dicarboxy-terminated PS with = 100,000. Experiments and observations on film formation indicate that polar groups are playing a fundamental role in this process. Tuning the surface tension by means of polar terminations allows the film morphology to be modified and in particular the preparation of two- or three-dimensional microstructured films. Finally, we show how these structures can be replicated by soft lithography and then used in the fields of photonic crystals and organic electronics.

The helical‐chiral character of the diradical intermediate 2, which cyclizes quicker than it equilibrates, explains the memory effect of chirality that occurs during the enantioselective photocyclization of alanine derivative 1 to give the proline derivative 3. Ts=H3CC6H4SO2.

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A detailed study on the thermal behaviour of low-molecular-weight poly(3-decylthiophene) (m,,, = 5 700 by gel permeation chromatography) was performed using differential scanning calorimetry, X-ray diffraction, optical microscopy and FTIR techniques. A polymorphism for this polymer was clearly shown: namely two different crystalline phases and a mesophase, probably nematic. A structural model for a 3-dimensional phase was derived. Finally the conditions under which each phase can be obtained were determined.

Polo Scientifico e Tecnologico (PTS), CNR, via Fantoli 16/15, Two simple approaches to build up micropatterned functionalized polymer films are reported here. Both of them are based on the formation of porous films consisting of two-dimensionally ordered void structures, produced by evaporation of a polymer solution in the presence of humidity. In the first approach, we utilize an amino-terminated linear polystyrene to fabricate honeycomb structured films in which the cavities are enriched with amino groups that preserve their chemical reactivity. This allows, in principle, to obtain films with different surface functionality by simply changing the chain-end of the polymer used. In the second approach, we synthesize a luminescent chain-ended polystyrene to show how the honeycomb structures can be easily transformed, by a thermal treatment, into flat micropatterned fluorescent films. Both the microporous and the flat micropatterned films resulting from this study are attractive materials since the chemical functions distributed on their surface can further react with other molecules to provide a more complex array suitable for biological tests.