The slow dielectric Debye relaxation of monoalcohols in confined geometries.
نویسندگان
چکیده
Broadband dielectric relaxation measurements have been performed on monoalcohols confined in the quasi-two-dimensional space between clay platelets and the quasi-one-dimensional pores of approximately 10 Å diameter in a molecular sieve. Interestingly, the results show that the slow Debye-like process is present even in these severe confinements, proving that structural models that are based on two-dimensional or three-dimensional cluster formations as the structural origin of the Debye-like process can be excluded. Rather, the insensitivity of its time-scale to confinements suggests that it is of local character and in some way related to the lifetime or breaking and reformation of hydrogen bonds.
منابع مشابه
Insights on the origin of the Debye process in monoalcohols from dielectric spectroscopy under extreme pressure conditions.
The dielectric spectra of most simple liquids are characterized by two relaxation processes: (i) the alpha-process, an intense, broad non-Debye relaxation with a non-Arrhenius temperature dependence and (ii) a beta process, evident mainly below the glass transition and having nearly Arrhenius temperature behavior. However, the dielectric spectra of monoalcohols show three processes: two that re...
متن کاملProbing the Debye Dielectric Relaxation in Supercooled Methanol
The explanation of the dielectric dynamics in methanol would offer knowledge of the Debye relaxation in supercooled monoalcohols. However, due to the fast crystallization, it is hard to attain the dynamics of pure methanol in the deeply supercooled region. In this paper, we studied the dynamics of methanol – 2-ethyl-1-hexanol mixtures with methanol concentration up to 80 mol% using dielectric a...
متن کاملInvestigation of the shear-mechanical and dielectric relaxation processes in two monoalcohols close to the glass transition.
Shear-mechanical and dielectric measurements on the two monohydroxy (monoalcohol) molecular glass formers 2-ethyl-1-hexanol and 2-butanol close to the glass-transition temperature are presented. The shear-mechanical data are obtained using the piezoelectric shear-modulus gauge method covering frequencies from 1 mHz to 10 kHz. The shear-mechanical relaxation spectra show two processes, which fol...
متن کاملOn the low frequency loss peak in the dielectric spectrum of glycerol.
We measured dielectric spectra of glycerol at pressures exceeding 1 GPa in order to examine the slow Debye-like peak. This peak is not a relaxation process, but its frequency is consistent with an origin in dielectric discontinuities due to impurities. These heterogeneities have a non-negligible bulk modulus and are identified as volatile, relatively non-polar liquid contaminants. Although this...
متن کاملHidden slow dynamics in water.
It is well known that the structural and dynamical properties of water are of central importance for life on our planet. However, despite this knowledge its structural and dynamical properties are still far from fully understood. In this Letter we show for the first time that water exhibits an anomalously slow relaxation process, which is about 4 orders of magnitude slower than the viscosity-re...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of chemical physics
دوره 134 10 شماره
صفحات -
تاریخ انتشار 2011