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Sylwester J. Rzoska

Bio: Sylwester J. Rzoska is an academic researcher from Polish Academy of Sciences. The author has contributed to research in topics: Dielectric & Liquid crystal. The author has an hindex of 33, co-authored 216 publications receiving 3570 citations. Previous affiliations of Sylwester J. Rzoska include University of Silesia in Katowice & Silesian University.


Papers
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01 Sep 2021
TL;DR: In this paper, a ferroelectric ceramic-polymer composites based on barium-strontium titanate and water-thinnable polymeric dispersions were obtained by using tape casting method.
Abstract: The paper presents research on ferroelectric ceramic-polymer composites based on barium-strontium titanate and water-thinnable polymeric dispersions, obtained by using tape casting method. Barium strontium titanate with the assumed stoichiometry Ba0,65Sr0,35TiO3 was synthesized by the high temperature solid-state reaction. Water-thinnable polymeric dispersions were synthesized from butyl acrylate, styrene and tert-butyl acrylate containing different amounts of individual monomers. Then, the ceramic-polymer composites were obtained by tape casting. The influence of the chemical structure of synthesized binders on the rheological properties of the slurries and on physicochemical and electrical properties (characterized by using Broadband Dielectric Spectroscopy, BDS) of ceramic-polymer composites were investigated.

2 citations

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TL;DR: In this paper , a monotectic-type phase diagram was found for Rod-like thermotropic nematogenic liquid crystalline (LC) compounds and their mixtures with a molecular solvent (Sol) enabling insights into universal features.
Abstract: The transition from the isotropic (I) liquid to the nematic-type (N) uniaxial phase appearing as the consequence of the elongated geometry of elements seems to be a universal phenomenon for many types of suspensions, from solid nano-rods to biological particles based colloids. Rod-like thermotropic nematogenic liquid crystalline (LC) compounds and their mixtures with a molecular solvent (Sol) can be a significant reference for this category, enabling insights into universal features. The report presents studies in 4′-methoxybenzylidene-4-n-butylaniline (MBBA) and isooctane (Sol) mixtures, for which the monotectic-type phase diagram was found. There are two biphasic regions (i) for the low (TP1, isotropic liquid-nematic coexistence), and (ii) high (TP2, liquid-liquid coexistence) concentrations of isooctane. For both domains, biphasic coexistence curves’ have been discussed and parameterized. For TP2 it is related to the order parameter and diameter tests. Notable is the anomalous mean-field type behavior near the critical consolute temperature. Regarding the isotropic liquid phase, critical opalescence has been detected above both biphasic regions. For TP2 it starts ca. 20 K above the critical consolute temperature. The nature of pretransitional fluctuations in the isotropic liquid phase was tested via nonlinear dielectric effect (NDE) measurements. It is classic (mean-field) above TP1 and non-classic above the TP2 domain. The long-standing problem regarding the non-critical background effect was solved to reach this result.

2 citations

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TL;DR: An alternative design of the measurement capacitor for high-pressure studies of complex liquids or soft matter systems is presented and results for the precritical anomaly of dielectric constant in 1-nitropropane-octane critical mixture are reported.
Abstract: An alternative design of the measurement capacitor for high-pressure studies of complex liquids or soft matter systems is presented. Subsequently, results for the precritical anomaly of dielectric constant in 1-nitropropane-octane critical mixture are reported. First, the pressure dependence of the critical consolute temperature T_{C} up to P=0.55GPa was determined and portrayed using the derivative-based analysis. Second, temperature and pressure evolutions of dielectric constant on approaching the critical consolute point at (T_{C}=304.1K and P_{C}=403MPa) were studied. They revealed that the pretransitional anomaly ɛ(P→P_{C}) is notably more pronounced than for ɛ(T→T_{C}). For both paths, the static domain extends even to as low frequency as f=100Hz, whereas for tests under atmospheric pressure, they require at least f=100kHz. The discussion of the impact of correction-to-scaling terms, including the unique case of the pressure paths, is also presented.

2 citations

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TL;DR: In this article, temperature studies of electric conductivity, for a few frequencies from 100 Hz to 100 kHz, in liquid glass-formers: dibutyl phthalate, glycerol and salol, were presented.
Abstract: Results are presented of temperature studies of electric conductivity, for a few frequencies from 100 Hz to 100 kHz, in liquid glass-formers: dibutyl phthalate, glycerol and salol. It has been shown that the analysis of experimental data similar to that applied in non-critical liquid mixtures of limited miscibility may offer a relatively precise and simple estimation of the mode-coupling critical temperature (TC) and exponent (). Preliminary pressure studies point to the possibility of isomorphic behaviour for the temperature and the pressure paths approaching the mode-coupling critical point.

2 citations


Cited by
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TL;DR: In this paper, the critical behavior of spin systems at equilibrium is studied in three and two dimensions, and the results in three-dimensional space are presented in particular for the six-loop perturbative series for the β -functions.

1,363 citations

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TL;DR: This work identifies the class of secondary relaxations that bears a strong connection or correlation to the primary relaxation in all the dynamic properties and proposes that only these should be called the Johari-Goldstein beta-relaxation.
Abstract: Dynamic properties, derived from dielectric relaxation spectra of glass-formers at variable temperature and pressure, are used to characterize and classify any resolved or unresolved secondary relaxation based on their different behaviors. The dynamic properties of the secondary relaxation used include: (1) the pressure and temperature dependences; (2) the separation between its relaxation time τβ and the primary relaxation time τα at any chosen τα; (3) whether τβ is approximately equal to the independent (primitive) relaxation time τ0 of the coupling model; (4) whether both τβ and τ0 have the same pressure and temperature dependences; (5) whether it is responsible for the “excess wing” of the primary relaxation observed in some glass-formers; (6) how the excess wing changes on aging, blending with another miscible glass-former, or increasing the molecular weight of the glass-former; (7) the change of temperature dependence of its dielectric strength Δeβ and τβ across the glass transition temperature Tg; ...

715 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the mechanisms underlying the relaxation properties of glass-forming liquids and polymers is provided, with an emphasis in the insight provided into the mechanism underlying the glass relaxation properties.
Abstract: An intriguing problem in condensed matter physics is understanding the glass transition, in particular the dynamics in the equilibrium liquid close to vitrification Recent advances have been made by using hydrostatic pressure as an experimental variable These results are reviewed, with an emphasis in the insight provided into the mechanisms underlying the relaxation properties of glass-forming liquids and polymers

638 citations

Journal ArticleDOI
TL;DR: Although differential scanning calorimetry is the most widely used thermal analytical technique applied to the characterization of amorphous solid dispersions, there are many established and emerging techniques which have been shown to provide useful information.

399 citations