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Low-temperature casting of high molecular weight (HMW > 40 kDa) regioregular poly(3-hexylthiophene) (P3HT) is demonstrated to yield highly crystalline P3HT thin films with well defined and preferentially edge-on oriented [(100) contact plane] nanocrystallites on the pure and silanized Si/SiO2 substrates. Transmission electron microscopy and X-ray diffraction provide evidence for the increase in preferential edge-on orientation of P3HT-conjugated backbone while decreasing the film preparation temperature below room temperature. The optimum growth temperature is about −12°C for the given concentration (2 mg/mL in CHCl3). The reduced evaporation rate of the solvent results in a better selection of the thermodynamically stable orientation of nanocrystallites onto the substrate. The degree of preferential orientation and size of the crystallites can be further increased on n-octadecyltrichlorosilane-treated SiO2 substrates as well as by annealing the films at 200°C for 1 h. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

In the present work the role of the thermal treatment on the reorganization of gold nanoparticles (AuNPs) functionalized with a π-conjugated dithiol ligand, namely 9,9-didodecyl-2,7-bis-thiofluorene, is studied by grazing incidence X-ray diffraction technique. For a detailed investigation of the structural changes and reorganization occurring in the AuNPs network and of the monitoring of complex interactions between nanoparticles, the line profiles are analyzed in out-of-plane and in-plane directions. The obtained data support the idea of the formation of a uniform network of nanoparticles that after annealing are extended from hexagonal to cubic arrangement. [ABSTRACT FROM AUTHOR]