Journal ArticleDOI
Detailed comparison of the Williams–Watts and Cole–Davidson functions
C. P. Lindsey,G. D. Patterson +1 more
TLDR
In this paper, the distribution function of relaxation times underlying the nonexponential relaxation function of Williams and Watts is derived and compared with the analogous Cole-Davidson distribution function, and several useful relations between relaxation and distribution functions are summarized or derived, and the limitations of deriving distribution functions from relaxation functions are discussed.Abstract:
The distribution function of relaxation times underlying the nonexponential relaxation function of Williams and Watts is derived and compared with the analogous Cole–Davidson distribution function. In order to make the comparison between the two distribution functions, a simple empirical relationship between the Cole–Davidson and Williams–Watts parameters was determined which may be used to compare data analyzed using the two fitting functions. Although the relaxation functions are similar to each other, the distribution functions are quite dissimilar. The Cole–Davidson distribution shows a sharp long time cutoff, while the Williams–Watts distribution decays approximately exponentially at long times. Finally, several useful relations between relaxation and distribution functions are summarized or derived, and the limitations of deriving distribution functions from relaxation functions are discussed.read more
Citations
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Ultraviolet and visible Brillouin scattering study of viscous relaxation in 3-methylpentane down to the glass transition.
TL;DR: Evidence of a shear relaxation with a characteristic time of 100 s at the glass transition is found which only partly accounts for the relaxation observed in the propagation and attenuation of the longitudinal modes, and a consistent picture of relaxed shear and bulk moduli as a function of temperature is derived.
A new determination of molecular mobility in amorphous materials
TL;DR: In this paper, the steadystate and time-resolved emission and intensity of vanillin (4-hydroxy-3methoxy benzaldehyde), a commonly used flavor compound, can be used to probe molecular mobility when dispersed within amorphous pure sucrose films.
Journal ArticleDOI
Nanocharacterization of Relaxation Properties in Organic Thin Film Electronic Materials
Tomoko Gray,René M. Overney +1 more
TL;DR: In this article, the mobility properties of polymer thin-film electronics are characterized using scanning probe microscopy (SFM) and isothermal friction analysis (NIFA) techniques, which can be used to infer energy barriers for sub-molecular motions (relaxations) and critical transition temperatures.
Journal Article
Effects of temperature and dissolved LiClO$_{4}$ on the viscoelastic and dynamic properties of poly(ethylene oxide), (PEO) melts
TL;DR: In this paper, a fiber-optic coupled triple-pass Fabry-Perot interferometer was used to study the Brillouin light scattering spectra of PEO melts and PEO melt/LiClO4 solutions for various salt concentrations and in the temperature range from the melting point up to 140oC.
References
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Journal ArticleDOI
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Kenneth S. Cole,Robert H. Cole +1 more
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Graham Williams,David C. Watts +1 more
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Journal ArticleDOI
Further considerations of non symmetrical dielectric relaxation behaviour arising from a simple empirical decay function
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