Alkanethiol-oxidized copper interface: the critical influence of concentration.

In this contribution, self-assembled monolayers of n-dodecanethiol (C(12)H(25)SH) at different concentrations on polycrystalline copper have been elaborated. Using XPS, PM-IRRAS, and electrochemical methods (cyclic voltammetry curves and cathodic desorption), the effect of the C(12)H(25)SH concentration on the reduction of the oxide layer has been studied. In all cases, a monolayer of good quality has been obtained. Results provide proof that while the concentration is increased, the thickness of the oxide layer is decreased, to a point that leads to metallic copper for the higher concentration. The results presented in this publication indicate the importance of controlling the interface when forming SAMs of organothiols on oxidizable metals.

Note on the dispersion in perfluoropolyether lubricants of multi-walled carbon nanotubes functionalized with (tridecafluoro-1,1 ,2,2-tetrahydrooctyl)trichlorosilane.

Multi-walled carbon nanotubes functionalized with F3C-(CF2)5-(CH2)2-SiCl3, a molecule bearing a fluorinated terminal group is found to favor the carbon nanotubes dispersion in three perfluoropolyether fluids (Galden SV70, Fomblin Y25 and Fomblin YR1800). The stability of the suspension appears to be related to the perfluoropolyether viscosity. With respect to time, Fomblin YR1800, the more viscous fluid, leads to the most stable solutions, followed in order by Fomblin Y25 and Galden SV70. In general the smallest particles stay in suspensions. Stability extending over more than one year is observed in the case of Fomblin YR1800.

Comparison between CH3(CH2)15SH and CF3(CF2)3(CH2)11SH monolayers on electrodeposited silver.

In this paper, two monolayers self-assembled on a silver substrate are compared: a monolayer of n-hexadecanethiol and a monolayer of n-11-perfluorobutylundecanethiol. The protecting properties of both monolayers have been extensively studied by X-ray photoelectron spectroscopy, contact angle, polarization modulation infrared reflection absorption spectroscopy, conventional electrochemical techniques (polarization curves and electrochemical impedance spectroscopy), and scanning vibrating electrode technique. Both monolayers were successfully self-assembled but organization is slightly different, the fluorinated segment introduces small disorganization. Nevertheless, good homogeneous corrosion protection is observed for each monolayer.