Time-Resolved X-Ray Small-Angle Diffraction with Synchrotron Radiation on Phospholipid Phase Transitions. Pathways, Intermediates and Kinetics

Author(s):  
P. Laggner ◽  
M. Kriechbaum
1990 ◽  
Vol 205 ◽  
Author(s):  
Haydn Chen ◽  
M.S. Yu ◽  
H. Okuda ◽  
M. Tanaka ◽  
K. Osamura

AbstractStructure change during the reversion process in an Al−12at.%Li alloy above the metastable δ′ solvus was investigated using a time-resolved small-angle x-ray scattering technique with synchrotron radiation. Results showed that the reversion process started after a short incubation time and that the growth of the stable δ phase began before completion of the δ′ dissolution. The radius of gyration of the second phase particles showed little change in the initial stage of reversion, then increased with time, suggesting the presence of diffuse interfaces between the dissolving δ′ particles and the matrix. It is suggested that the undissolved δ′ particles serve as the nuclei of the more stable δ precipitates, which continue to grow with their radii of gyration showing a parabolic power law in the early stage of growth followed by the familiar coarsening kinetics.


1997 ◽  
Vol 30 (5) ◽  
pp. 816-821 ◽  
Author(s):  
W. Bras ◽  
A. J. Ryan

The high X-ray intensity of synchrotron radiation (SR) beamlines makes it possible to perform time-resolved small-angle X-ray scattering (SAXS) experiments. The information that can be obtained by collecting the wide-angle diffraction pattern simultaneously not only increases the information content of an experiment but also increases the reliability of the time-correlations between SAXS and WAXS (wide-angle X-ray scattering) patterns. This is a great advantage for experiments with a time resolution below the level of 1 s per frame. With appropriate instrumentation, this is a time domain that is routinely accessible for a large group of research fields. This has had a considerable impact upon the understanding of fundamental aspects of phase transformations. Not only fundamental processes but also more applied fields have benefited from these developments. In polymer research this has led to a situation in which it has become possible to simulate materials processing techniques on-line. With the advent of third-generation synchrotron-radiation sources (e.g. ESRF, APS, Spring8), it has become possible to develop SAXS/WAXS beamlines that will open up new research opportunities by utilizing the higher intensity, the tuneability and the higher collimation offered by these SR sources. However, some of the instrumentation limits in detector and sample environments that have become apparent in research on second-generation synchrotron-radiation sources still have not been appropriately addressed, which means that in some fields it will not be possible to take full advantage of the superior X-ray beam quality that third-generation synchrotrons can offer. A way in which these instrumentation limits can be overcome is discussed, and the instrumentation for a new bending-magnet beamline at the ESRF is used as an example.


1997 ◽  
Vol 30 (5) ◽  
pp. 592-596 ◽  
Author(s):  
H. Okuda ◽  
M. Tanaka ◽  
K. Osamura ◽  
Y. Amemiya

The reversion process of very small Guinier-Preston (GP) zones in Al–Zn binary alloys has been studied by time-resolved synchrotron-radiation small-angle X-ray scattering (SR-SAXS) measurements. Al–15 at.% Zn alloys with GP zones of 1.0 to 1.3 nm in radius formed by aging at 274 K were up-quenched up to 463 K. During reversion, the Guinier radius increased rapidly while the integrated intensity decreased. This rapid increase of the radius was completely different from what was found during the reversion of larger GP zones above the miscibility gap. It is concluded that a process of simultaneous dissolution and coarsening has been observed.


Langmuir ◽  
2005 ◽  
Vol 21 (8) ◽  
pp. 3559-3571 ◽  
Author(s):  
Julia Kraineva ◽  
R. Aravinda Narayanan ◽  
Elena Kondrashkina ◽  
Pappannan Thiyagarajan ◽  
Roland Winter

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell

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.


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