In situ synchrotron radiation X-ray microspectroscopy of polymer microcontainers.

Direct, real-time analytical techniques that provide high-resolution information on the chemical composition and submicrometer structure of various polymer micro- and nanoparticles are in high demand in a range of life science disciplines. Synchrotron-based scanning transmission X-ray microspectroscopy (STXM) combines both local-spot chemical information (assessed via near-edge X-ray absorption fine structure spectroscopy) and imaging with resolution of several tens of nanometers, and thus can yield new insights into the nanoscale properties of these materials. Furthermore, this method allows in situ examination of soft-matter samples in aqueous/gaseous environments and under external stimuli, such as temperature, pressure, ultrasound, and light irradiation. This Minireview highlights some recent progress in the application of the STXM technique to study the temperature-dependent behavior of polymer core-shell microcapsules and to characterize the physicochemical properties of the supporting shells of gas-filled microbubbles in their natural hydrated state.