Related Experiment Video
Updated: Jun 2, 2026
06:07
Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
Structural and microscopic relaxations in glycerol: an inelastic x-ray scattering study
1Brookhaven National Laboratory-National Synchrotron Light Source-II, Upton, New York 11973, USA. acunsolo@bnl.gov
The Journal of Chemical Physics
|May 17, 2011
Summary
This study reveals two relaxations in liquid glycerol using inelastic X-ray scattering. A fast, sub-picosecond relaxation was identified, distinct from the known slow structural relaxation.
Area of Science:
- Condensed matter physics
- Materials science
- Physical chemistry
Background:
- Liquid glycerol exhibits complex dynamics.
- Previous studies identified a slow structural relaxation.
- The nature of faster dynamics remained unclear.
Purpose of the Study:
- To investigate the terahertz (THz) dynamics of liquid glycerol under pressure.
- To identify and characterize fast relaxation processes.
- To elucidate the microscopic origins of these dynamics.
Main Methods:
- Inelastic X-ray scattering (IXS) was employed.
- Experiments were conducted at varying pressures (0.66-3 Kbar).
- Results were compared with existing ultrasound absorption data.
Main Results:
- Two distinct relaxations were identified: a slow structural and a fast microscopic relaxation.
- The fast relaxation has a sub-picosecond timescale.
- This fast relaxation's timescale decreases with increasing wave-vector and is pressure-insensitive.
- A direct link between timescale and strength suggests a single-particle nature.
Conclusions:
- The study characterizes a previously unobserved fast relaxation in liquid glycerol.
- This fast process is attributed to microscopic, single-particle motion.
- IXS provides crucial insights into THz dynamics of liquids.
