Exploring molecular devices and nanostructures with resonant X-rays

Printable, flexible, and biocompatible polymers and small molecules represent an exciting new class of materials with the potential to revolutionize energy technologies, computing, bio-interfacing, and medicine. A grand challenge for progress, however, is in characterizing the molecular-to-mesoscale ordering that governs properties and performance but often confounds traditional nanoprobes. I will discuss our work in developing resonant X-ray nanoprobes to break through this barrier applied to organic photovoltaics (OPVs), mixed conduction devices, and aqueous micelle nanocarriers. We combine device physics with X-ray characterization on OPVs to optimize electron donor-acceptor interfaces for charge generation. In organic mixed ion-electronic conductors (OMIECs) for biointerfacing, we have revealed that hydrophilic ion nanochannels can result in new record ion mobilities, and access to these ion superhighways can be gated by local chemical signaling. Finally, I will describe our development of microfluidic environments for resonant X-rays to probe aqueous micelle nanocarrier chemical ordering and dynamics in a smart medicine platform. With continued development, resonant X-rays will be key to controlling unique properties in soft matter that depend on spatiochemical nanoscopic order for exciting new applications beyond the reach of current materials and technologies.