2.7 Summary

Modern Raman techniques such as surface-enhanced Raman spectroscopy (SERS) and micro-Raman spectroscopy have been utilized to investigate adsorption of polymers onto metal surfaces, adhesive–adherent interactions, polymer–polymer inter-diffusion, surface segregation in polymer blends, stress transfer at the fiber/polymer interface, and surface structure of carbon materials. The results obtained have contributed to the understanding of chemical and physical processes at the interface for further development of advanced composite materials.

SERS has been shown to be a nondestructive technique for characterization of interfaces between polymers and SERS-active metal substrates without interference by normal Raman scattering from the bulk of the polymer. However, much fundamental work is necessary to extend this unique technique to other interfacial processes. It is well known that the enhancement factors and spatial ranges of SERS depend on the surface morphologies of SERS substrates. If the experimental parameters for preparations of SERS substrates are well controlled, the short-range and long-range enhancement then can be discriminated. As a result, SERS potentially can be used for depth-profiling the surface regions of polymer films and for probing the interfaces between p....