A novel experimental method based on SERS to study polymer interdiffusion

CARLA D. MANA; J. PABLO TOMBA

Santa Fé

Simposio; XI Simposio Argentino de Polímeros (SAP 2015); 2015

Characteristic diffusion distances related in systems comprised by rather large polymer chains are in the scale of the chain radius of gyration. Here we describe and implement a new experimental concept to investigate polymer interdiffusion between ultra-thin films of deuterated-polystyrene (DPS) and polystyrene (PS), based on Surface Enhanced Raman Scattering (SERS) produced on commercially available substrates (Klarite). Diffusion between layers was promoted by annealing above PS?s glass transition temperature. First, the spectral response was consistent with amplified signal of the polymer deposited onto Klarite (DPS). With time, characteristic PS bands appear in the spectra. The time evolution of the overall intensity of PS bands is consistent with a diffusive process. Data were compared with numerical simulations of Fickean diffusion models that consider the region of Klarite where SERS effect is produced. These results indicate that interdiffusion is tridimensional nearby the detection zone, which actually comprises a region of ~10 nm.