The thermoelectric performance of synthetic conductive polymers, poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), is explored. The effects of the dielectric solvent, dimethyl sulfoxide (DMSO), and of the ratio of PEDOT to PSS in the polymeric PEDOT/PSS thin films were studied systematically. Within the parameter range studied in this work, the variation of electrical conductivity overwhelmed the variation of the Seebeck coefficient, and the optimal power factor is basically determined by the highest electrical conductivity, because the Seebeck coefficient remains small over a wide range of DMSO concentrations and PEDOT:PSS ratios.

Organic superhydrophobic films were prepared by utilizing TA-N fluoroalkylate (TAN) and methyl methacrylate (MMA) copolymer as water-repellent materials and inorganic silica powder as surface roughness material has been developed. Coating solutions prepared by adding silica powders into copolymer solution directly (one-step method) and by adding silica powders into monomers and allowing them to react (two-step method). The results showed that contact angles of the films prepared by one-step method (37.6 wt % of silica powders in the coating solution) were greater than 1508, but the transmittance of the film at visible light was only 30%. On the other hand, the contact angle of films prepared by two-step method (20 wt % of silica powders in the coating solution) was greater than 1608 and the transmittance of the film was greater than 90%. The contact angle of the film prepared by poly(octyl acrylate), POA, was 32.18, but while introducing silica powder into the system, the contact angle of the film was reduced to be smaller than 58. Thus, superhydrophobic and superhydrophilic films can be obtained by introducing a roughening material on the hydrophobic surface and the hydrophilic surface, respectively.

Preparation of superhydrophobic silica-based surfaces via sol-gel process by adding polyethylene glycol (PEG) polymer into the precursor solution has been developed. Surface roughness of the films was obtained by removing the organic polymer at 5008C and then the hydrophobic groups bonded onto the films were obtained by self-assembly modification with a monolayer. Characteristic properties of the as-prepared films were analyzed by contact angle measurements, scanning electron microscopy, atomic force microscopy, UV-vis scanning spectrophotometer, and X-ray photoelectron spectrophotometer. The experimental parameters were varied by the type of silane species, the R ratio, the hydrolysis time of the precursor solution, the molecular weight of PEG, the pH value of mixing solution, and the different reagents for modification. The results showed that optimum ratio of TEOS/H 2 O/ethanol in the sol-gel process for precursor solution was set to 1/10/4. The better contact angles of the films can be obtained by the acid catalyst reaction, especially the pH value of mixing solution was adjusted to 0. When the as-prepared rough films were modified with (tridecafluoro-1,1,2,2-tetrahydrooctyl) dimethylchlorosilane (TFCS), the contact angle of the film can be promoted to 150.48, and the transmittance of the films in the visible light region was greater than 94.5%.

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Characterizations of InN films on Si (111) substrate grown by metal-organic chemical vapor deposition with a predeposited In layer and a two-step growth method J. Vac. Sci. Technol. A 25, 701 (2007); 10.1116/1.2740293Growth and characterization of single crystal ZnO thin films using inductively coupled plasma metal organic chemical vapor deposition Growth of single crystalline GaN thin films on Si(111) substrates by high vacuum metalorganic chemical vapor deposition using a single molecular precursor Properties of phase-pure InSe films prepared by metalorganic chemical vapor deposition with a single-source precursor