Separation of two relaxation processes in bulk polymers using photon correlation spectroscopy at high pressures

1982 ◽  
Vol 15 (1) ◽  
pp. 214-216 ◽  
Author(s):  
G. Fytas ◽  
G. Meier ◽  
T. Dorfmueller ◽  
Adam Patkowski
Keyword(s):  
High Pressures ◽  
Photon Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Relaxation Processes ◽  
Photon Correlation ◽  
Bulk Polymers

Slow relaxation processes in molten ZnCl2studied by photon correlation spectroscopy

1987 ◽  
Vol 56 (2) ◽  
pp. 155-165 ◽  
Author(s):  
S. Magazú ◽  
G. Maisano ◽  
F. Mallamace ◽  
P. Migliardo ◽  
F. Aliotta ◽  
...  
Keyword(s):  
Photon Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Slow Relaxation ◽  
Relaxation Processes ◽  
Photon Correlation

Nanocomposite Material, Liquid Crystal-Aerosil Particles: Dielectric and Photon Correlation Spectroscopy Investigations

1999 ◽  
Vol 581 ◽  
Author(s):  
F.M. Aliev ◽  
G.P. Sinha
Keyword(s):  
Liquid Crystal ◽  
Photon Correlation Spectroscopy ◽  
Low Frequency ◽  
Correlation Spectroscopy ◽  
Relaxation Processes ◽  
Photon Correlation ◽  
Optoelectronic Application ◽  
Broadband Dielectric Spectroscopy ◽  
Tumbling Motion ◽  
Frequency Relaxation

ABSTRACTNematic liquid crystal filled with Aerosil particles prospective inorganic-organic nanocom-posite material for optoelectronic application has been investigated by broadband dielectric spectroscopy (BDS) and photon correlation spectroscopy (PCS). The aerosil particles of diameter ≈ 10 nm in filled nematic liquid crystals form a network structure with linear size of LC domains about 250 nm and with random distribution of the director orientation of each domain. This material has a very developed liquid crystal-solid particle interface that makes the role of the surface layers of LC important in the determination of the properties of the material. BDS provides information on reorientational motion of polar molecules of liquid crystal while PCS probes dynamics of collective modes associated with director fluctuations. We found that the properties of 5CB are considerably affected by the network. Two bulk-like dielectric modes due to the rotation of molecules around short axes and the tumbling motion were observed in filled 5CB. Additionally, a low frequency relaxation process and dispersion of dielectric permittivity due to conductivity were observed. The treatment of the surface of filling particles has strongest influence on the properties of the slow process and it is less important for molecular modes. PCS experiment shows that two new relaxation processes appear in filled 5CB in addition to the director fluctuations process in bulk.

scholarly journals From Femtoseconds to Hours–Measuring Dynamics over 18 Orders of Magnitude with Coherent X-rays

2021 ◽  
Vol 11 (13) ◽  
pp. 6179
Author(s):  
Felix Lehmkühler ◽  
Wojciech Roseker ◽  
Gerhard Grübel
Keyword(s):  
Time Scales ◽  
Free Electron Laser ◽  
Photon Correlation Spectroscopy ◽  
Signal To Noise Ratio ◽  
Coherent Scattering ◽  
Correlation Spectroscopy ◽  
X Rays ◽  
Photon Correlation ◽  
X Ray ◽  
Scattering Technique

X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it benefits from the increased brilliance of the next-generation synchrotron radiation and Free-Electron Laser (FEL) sources. In this article, we will introduce the XPCS concepts and review the latest developments of XPCS with special attention on the extension of accessible time scales to sub-μs and the application of XPCS at FELs. Furthermore, we will discuss future opportunities of XPCS and the related technique X-ray speckle visibility spectroscopy (XSVS) at new X-ray sources. Due to its particular signal-to-noise ratio, the time scales accessible by XPCS scale with the square of the coherent flux, allowing to dramatically extend its applications. This will soon enable studies over more than 18 orders of magnitude in time by XPCS and XSVS.

scholarly journals Grain Growth and Coarsening Dynamics in a Compositionally Asymmetric Block Copolymer Revealed by X-ray Photon Correlation Spectroscopy

2020 ◽  
Vol 53 (19) ◽  
pp. 8233-8243
Author(s):  
Ronald M. Lewis ◽  
Grayson L. Jackson ◽  
Michael J. Maher ◽  
Kyungtae Kim ◽  
Suresh Narayanan ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Grain Growth ◽  
Photon Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Photon Correlation ◽  
X Ray ◽  
Coarsening Dynamics
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