Fourier-transform surface enhanced Raman scattering studies of molecular self-assembly of disulfides on metals and the application in adhesion promotion

Abstract

The adsorption and molecular orientation of phenyl disulfide and 4-aminophenyl disulfide on silver surface has been investigated by the use of Fourier transform (FT) surface enhanced Raman scattering (SERS). There is a concentration dependence of the molecular orientation of adsorbed disulfides on silver surface. Disulfides could be adsorbed on Ag surface as self-assembled, well oriented monolayers from a very dilute solution. The amino group exposed outwards on the 4-aminophenyl disulfide adsorbed on metal can take part in chemical reactions with epoxy group. Modification at the interface has been achieved for polymer/metal systems by using 4-aminophenyl disulfide as a coupling agent, resulting in adhesion promotion.

Spectral proof for the 4-aminophenyl disulfide plasma assisted catalytic reaction

“…Parallel with this, the characteristic peak at 1086 cm −1 , which was attributed to the phenylene-S stretching vibration mode in the NRS spectrum of APDS, is shifted to 1078 cm −1 in the SERS spectrum. This observation also clearly shows that the S-S bond in APDS breaks and forms an S-Ag bond with the silver nanoparticles 25, 26 .

Figure 3Raman and SERS spectra of pure APDS and APDS covered with silver nanoparticles irradiated using a 785 nm laser at 0.00005% power.

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