This paper reports recent tests performed on the Bonse–Hart-type ultra-small-angle X-ray scattering (USAXS) instrument at the Advanced Photon Source with higher-order reflection optics – Si(440) instead of Si(220) – and with X-ray energies greater than 20 keV. The results obtained demonstrate the feasibility of high-energy operation with narrower crystal reflectivity curves, which provides access to a scatteringqrange from ∼2 × 10−5to 1.8 Å−1and up to 12 decades in the associated sample-dependent scattering intensity range. The corresponding size range of the scattering features spans about five decades – from less than 10 Å to ∼15 µm. These tests have indicated that mechanical upgrades are required to ensure the alignment capability and operational stability of this instrument for general user operations because of the tighter angular-resolution constraints of the higher-order crystal optics.
<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>
We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.
Higher-order Structure Analysis of Polyethylene Thin Films by In-situ Synchrotron Grazing-incdence Small-angle and Wide-angle X-ray Scattering Measurements