The surface structure and adsorption conditions of biphenylthiol (BPT) self-assembled monolayers (SAMs) on Au(111) were examined using scanning tunneling microscopy (STM) and X-ray photoelectron microscopy (XPS). STM imaging revealed that the structural order of BPT SAMs formed in a 0.01 mM ethanol solution at 60 degrees C decreases with increasing immersion time. Interestingly, BPT SAMs formed after 30 min have unique ordered domains containing well-ordered (square root of 3 x square root of 3)R30 degrees structures and bright rows that are connected by small aggregated domains with a periodicity of approximately 10 angstroms, results that have never been observed for other thiol SAM systems. Distances between the bright rows were 20-35 angstroms. The bright small domains contained five or six BPT molecules each, which may have originated from differences in the adsorption orientations of biphenyl groups that were induced by localized interactions between them. XPS measurements for BPT SAMs on Au(111) showed the two sulfur peaks at 161.2 and 162.2 eV, implying the formation of chemisorbed monolayers. Our results are anticipated to be useful for understanding the formation and structure of BPT SAMs on gold surfaces.

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Polycarbosilane was synthesized from polydimethylsilane in the presence of ZSM-5 (Si/Al=30) as a catalyst at 350oC-400oC. Characterization of synthesized polycarbosilane was performed with 29Si Solid NMR, FT-IR, and GPC analysis. Number average of molecular weight (Mn) of the polycarbosilane was ranged from 350 to 2340.

Polyimide (PI)‐based nanocomposites containing aminophenyl functionalized multiwalled carbon nanotubes (AP‐MWCNTs) obtained through a diazonium salt reaction was successfully prepared by in situ polymerization. PI composites with different loadings of AP‐MWCNTs were fabricated by the thermal conversion of poly(amic acid) (PAA)/AP‐MWCNTs. The mechanical and electrical properties of the AP‐MWCNTs/PI composites were improved compared with those of pure PI due to the homogeneous dispersion of AP‐MWCNTs and the strong interfacial covalent bonds between AP‐MWNTs and the PI matrix. The conductivity of AP‐MWNTs/PI composites (5:95 w/w) was 9.32 × 10−1 S/cm which was about 1015 times higher than that of Pure PI. The tensile strength and tensile modules of the AP‐MWCNTs/PI composites with 0.5 wt % of AP‐MWCNTs were increased by about 77% (316.9 ± 10.5 MPa) and 25% (8.30 ± 1.10 GPa) compared to those of pure PI, respectively. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 960–966