Smart polymer surfaces: mapping chemical landscapes on the nanometre scale

We show that Scattering Infrared Near-field Microscopy (SNIM) allows chemical mapping of polymer monolayers that can serve as designed nanostructured surfaces with specific surface chemistry properties on a nm scale. Using s-SNIM a minimum volume of 100 nm × 100 nm × 15 nm is sufficient for a recording of a "chemical" IR signature which corresponds to an enhancement of at least four orders of magnitudes compared to conventional FT-IR microscopy. We could prove that even in cases where it is essentially difficult to distinguish between distinct polymer compositions based solely on topography, nanophase separated polymers can be clearly distinguished according to their characteristic near-field IR response. Scattering Infrared Near-field Microscopy (SNIM) allows label free mapping of polymers yielding their chemical composition with nm lateral resolution.