Probing polymer interdiffusion in ultrathin films by Surface-Enhanced Raman Scattering

CARLA D. MANA; J. PABLO TOMBA

Jena

Conferencia; 24th International Conference of Raman Spectroscopy; 2014

Leibniz Institute of PhotonicTechnology e.V. (IPHT)

Polymer interdiffusion plays an important role in several technological applications that involves the use of multiphase materials. Here we described the use of Surface Enhanced Raman Scattering (SERS) to investigate interdiffusion between polystyrene (PS) and deuterated polystyrene (DPS), in regions of the order of 10 nm. DPS ultra-thin films (~100 nm) were coated on commercially available SERS substrates (Klarite). A second thin film (~100 nm) was deposited on top, to form a bi-layered system. Diffusion between layers was promoted by temperature (175 °C). The spectral response was consistent with a dramatic amplification of the signal of the polymer deposited onto Klarite (dPS). With time, PS chains of the film on top reach the detection zone, as revealed by the appearance of characteristic PS bands in the SERS spectra. The time evolution of the intensity of PS bands is fully consistent with a diffusive process which occurs in range with the diffusion rates observed in the past for this polymer pair (D = 10-13 cm2/s).