nano-FTIR for probing molecule orientation and conformation in thin polymer brush films with nanoscale spatial resolution

The properties of ultrathin functional surface coatings such as polymer brushes strongly depends on orientation and conformation of their polymer chains.

Assessing these properties on nanometer length scales is vital for obtaining important insights into the structure-function relation and consequently for optimizing the polymer brush formation parameters. Neutron reflectometry as well as infrared spectroscopy, have been successfully utilized for studying polymer chain conformation and orientation in polymer brush films, respectively, those lack the spatial resolution for probing these properties on the nanoscale.

nano-FTIR is an emerging new optical super resolution microscopy technique that enables IR spectroscopy and chemical mapping down to 10nm spatial resolution. Exploiting the inherent sensitivity of nano-FTIR spectroscopy to molecule orientation, it was successfully utilized for analyzing the molecule orientation in polymer fibers and thin biological membranes 

In this presentation we will demonstrate the capability of nano-FTIR for visualizing and distinguishing between nanometer sized phases with different crystallinity as well as for determining the molecule orientation and conformation in a few-nanometer-thin poly(ethylene oxide) polymer brush film.