Temperature-dependent X-ray microspectroscopy of phase-change core–shell microcapsules

The temperature behavior of phase-change microcapsules was investigated by scanning transmission X-ray microscopy. The microcapsules were examined while their interior wax material changed from liquid to solid upon cooling and vice versa. Small shifts in the main resonances of the C K-edge near-edge X-ray absorption fine structure spectra of the wax material with varying temperature were detected. These spectral shifts are interpreted in terms of intermolecular spacing of the molecules upon phase transition.