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M. Stockhausen

Bio: M. Stockhausen is an academic researcher from University of Münster. The author has contributed to research in topics: Dielectric & Relaxation (physics). The author has an hindex of 8, co-authored 28 publications receiving 282 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the dielectric spectra up to 72 GHz have been measured at 20 °C for binary mixtures of a monohydric and a dihydric alcohol, composed from the following groups of substances.

45 citations

Journal ArticleDOI
TL;DR: In this paper, the dielectric relaxation spectrum is measured at 20°C at frequencies up to 72 GHz for the following alcohols and their aqueous mixtures over the whole mixture range.
Abstract: The dielectric relaxation spectrum is measured at 20°C at frequencies up to 72 GHz for the following alcohols and their aqueous mixtures over the whole mixture range: 1,2-ethanediol; 1,2- and 1,3-propanediol; 1,2-, 1,3-, 1,4- and 2,3-butanediol; for comparison moreover: ethanol; diethyleneglycol and 1,2,3-propanediol. It is found possible to analyze the spectra into discrete spectral components according to one and the same scheme in all cases. Three mixture ranges can be distinguished on the volume fraction scale, the parameters of the intermediate and, particularly, the water rich region being rather insensitive to the nature of the alcoholic component.

36 citations

Journal ArticleDOI
TL;DR: In this article, the excess molar volumes for binary mixtures of eight aliphatic amino alcohols with 1,4-dioxane were determined from density measurements at 293.1 K by means of a vibrating tube densimeter.
Abstract: Excess molar volumes, V m E , for binary mixtures of eight aliphatic amino alcohols (2-aminoethanol 3-amino-1-propanol, 4-amino-1-butanol, 5-amino-1-pentanol, 2-amino-1-propanol, 1-amino-2-propanol, 2-amino-2-methyl-1-propanol, and 2-amino-1-butanol) with 1,4-dioxane have been determined from the density measurements at 293.1 K by means of a vibrating tube densimeter

15 citations

Journal ArticleDOI
TL;DR: In this paper, the static permittivities and the dielectric spectra were measured for the following liquids in the pure state and in mixtures with 1,4-dioxane at 20 °C.

12 citations


Cited by
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Journal ArticleDOI
C. Hansen1, F. Stickel1, T. Berger1, Ranko Richert1, Erhard W. Fischer1 
TL;DR: In this article, the dielectric relaxation of the glass-former 1-propanol for temperatures between 65 and 350 K in the frequency range 10−2 to 2⋅1010 Hz and the photon correlation spectro-scopy decays near Tg.
Abstract: We have measured the dielectric relaxation of the glass-former 1-propanol for temperatures between 65 and 350 K in the frequency range 10−2 to 2⋅1010 Hz and the photon correlation spectro-scopy decays near Tg. Attributing the strong Debye-type process of 1-propanol to distinct -OH group effects leaves two faster processes related to the structural relaxation which can be identified as α-relaxation and Johari–Goldstein type β-relaxation characteristic of nonhydrogen-bonding supercooled liquids. From the temperature dependent relaxation times τ(T) regarding the three distinct loss peaks, we can specify an α-β-bifurcation temperature Tβ, which coincides with characteristic qualitative changes in the τ(T) behavior, as also observed for ortho-terphenyl and other glass-forming liquids. This assignment is confirmed by the correla-tion times derived from incoherent quasielastic light-scattering data obtained from the simultaneously measured photon-correlation spectroscopy.

374 citations

Journal ArticleDOI
TL;DR: A cooperative nucleation-elongation mechanism applies for the aggregation of the present assemblies as revealed by concentration-dependent UV/vis absorption studies with the chiral PBI 1e, providing equilibrium constants for dimerization (= nucleation) of K(2) = 13 +/- 11 L mol(-1) and for elongation of K = 2.3 +/- 0.1 x 10(6) L mol−1 in methylcyclohexane (MCH).
Abstract: A series of highly soluble and fluorescent, at core tetraaryloxy-substituted and in imide positions hydrogen atom containing perylene bisimide (PBI) dyes 1a−e with varying peripheral side chains have been synthesized and thoroughly characterized. The self-assembly of these PBIs has been studied in detail by UV/vis, linear dichroism (LD) and circular dichroism (CD) spectroscopy, and scanning probe microscopy (AFM, STM). These studies revealed that the present PBIs self-assemble into extended double string cables, which consist of two hydrogen-bonded supramolecular polymeric chains of densely packed and strongly excitonically coupled PBI chromophores, providing highly fluorescent J-aggregates. The aggregation strength (“melting” temperature) and the fluorescence properties of these J-aggregates are dependent on the number and chain length of the peripheral alkoxy substituents, thus revealing a structure−property relationship. In contrast to previously reported assemblies of PBIs, for which the aggregation p...

312 citations

Journal ArticleDOI
TL;DR: A review of the current state of understanding of dielectric mixture properties, and approaches to use numerical calculations for their modeling are presented in this article, where it is shown that interfacial polarization can yield different non-Debye dielectrics responses depending on the properties of the constituents, their concentrations and geometrical arrangements.
Abstract: A review of the current state of understanding of dielectric mixture properties, and approaches to use numerical calculations for their modeling are presented. It is shown that interfacial polarization can yield different non-Debye dielectric responses depending on the properties of the constituents, their concentrations and geometrical arrangements. Future challenges on the subject are also discussed.

259 citations

Journal ArticleDOI
TL;DR: The diastereomeric aggregates formed from (R,R)-2 with (R-R)-1 or (S,S)-1 were found to be truly different in structure and strength.
Abstract: Chiral recognition in organogels occurs in the coassembly of the chiral gelator 1 with the chiral guest molecule 2. The diastereomeric aggregates formed from (R,R)-2 with (R,R)-1 or (S,S)-1 were found to be truly different in structure and strength. Cooperativity makes a major contribution to the chiral recognition in this system.

244 citations