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Rzoska SJ, Drozd-Rzoska A, Bulejak W, Łoś J, Starzonek S, Szafran M, Gao F. Critical Insight into Pretransitional Behavior and Dielectric Tunability of Relaxor Ceramics. MATERIALS (BASEL, SWITZERLAND) 2023; 16:7634. [PMID: 38138776 PMCID: PMC10744929 DOI: 10.3390/ma16247634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 11/22/2023] [Accepted: 11/27/2023] [Indexed: 12/24/2023]
Abstract
This model discussion focuses on links between the unique properties of relaxor ceramics and the basics of Critical Phenomena Physics and Glass Transition Physics. It indicates the significance of uniaxiality for the appearance of mean-field type features near the paraelectric-to-ferroelectric phase transition. Pretransitional fluctuations, that are increasing up to the size of a grain and leading to inter-grain, random, local electric fields are responsible for relaxor ceramics characteristics. Their impact yields the pseudospinodal behavior associated with "weakly discontinuous" local phase transitions. The emerging model redefines the meaning of the Burns temperature and polar nanoregions (PNRs). It offers a coherent explanation of "dielectric constant" changes with the "diffused maximum" near the paraelectric-to-ferroelectric transition, the sensitivity to moderate electric fields (tunability), and the "glassy" dynamics. These considerations are challenged by the experimental results of complex dielectric permittivity studies in a Ba0.65Sr0.35TiO3 relaxor ceramic, covering ca. 250 K, from the paraelectric to the "deep" ferroelectric phase. The distortion-sensitive and derivative-based analysis in the paraelectric phase and the surrounding paraelectric-to-ferroelectric transition reveal a preference for the exponential scaling pattern for ε(T) changes. This may suggest that Griffith-phase behavior is associated with mean-field criticality disturbed by random local impacts. The preference for the universalistic "critical & activated" evolution of the primary relaxation time is shown for dynamics. The discussion is supplemented by a coupled energy loss analysis. The electric field-related tunability studies lead to scaling relationships describing their temperature changes.
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Affiliation(s)
- Sylwester J. Rzoska
- Institute of High-Pressure Physics Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.J.R.); (J.Ł.)
| | - Aleksandra Drozd-Rzoska
- Institute of High-Pressure Physics Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.J.R.); (J.Ł.)
| | - Weronika Bulejak
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland;
| | - Joanna Łoś
- Institute of High-Pressure Physics Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland; (S.J.R.); (J.Ł.)
| | - Szymon Starzonek
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia;
| | - Mikołaj Szafran
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland;
| | - Feng Gao
- State Key Laboratory of Solidification Processing, MIIT Key Laboratory of Radiation Detection Materials and Devices, NPU-QMUL Joint Research Institute of Advanced Materials and Structures (JRI-AMAS), School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
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Raczyńska V, Górny K, Raczyński P, Dendzik Z, Starzonek S. Two-dimensional phases of confined 5-cyano-biphenyl: Computer simulation study. Phys Rev E 2023; 108:034702. [PMID: 37849085 DOI: 10.1103/physreve.108.034702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/25/2023] [Indexed: 10/19/2023]
Abstract
The properties of composites of mesogens and two-dimensional (2D) materials are of great interest due to their practical applications in flexible displays, optoelectronics, microelectronics, and novel nanodevices. The properties of such composites are very complex and strongly depend on the interactions between the host material and the mesogen filling. We have performed molecular dynamics simulations for 4-cyano-4^{'}-pentylbiphenyl embedded between graphene and hexagonal 2D boron nitride layers. The structural and dynamical properties of such systems were investigated in terms of the order parameters, density profiles, mean square displacement, and autocorrelation function of the single-molecule dipole moment. Our simulations have shown that the mesogenic molecules form highly stable ordered layered structures and that their dynamics are strongly related to the structural properties. We have investigated not only the effects of the polarization of the host material, but also the effects of the spatial repetition of such composites by using two models of mesogens embedded in 2D layers: the direct sheet and the structure formed by multiplying a single unit of the composite in the direction perpendicular to the substrate surface.
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Affiliation(s)
- Violetta Raczyńska
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Krzysztof Górny
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Przemysław Raczyński
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Zbigniew Dendzik
- Faculty of Science and Technology, University of Silesia in Katowice, ul. 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - Szymon Starzonek
- Laboratory of Physics, Faculty of Electrical Engineering, University of Ljubljana, Tržaška 25, 1000 Ljubljana, Slovenia
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Łoś J, Drozd-Rzoska A, Rzoska S. Critical-like behavior of low-frequency dielectric properties in compressed liquid crystalline octyloxycyanobiphenyl (8OCB) and its nanocolloid with paraelectric BaTiO3. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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Łoś J, Drozd-Rzoska A, Rzoska SJ, Czupryński K. The impact of ionic contribution to dielectric permittivity in 11CB liquid crystal and its colloids with BaTiO 3 nanoparticles. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2022; 45:74. [PMID: 36074208 PMCID: PMC9458595 DOI: 10.1140/epje/s10189-022-00228-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
The report shows the temperature behavior of the real part of dielectric permittivity in the static (dielectric constant) and low-frequency (LF) domains in bulk samples of 11CB and its BaTiO3-based nanocolloids. The study covers the isotropic liquid (I), nematic (N), smectic A (SmA), and solid crystal (Cr) phases. For each phase, the dominance of pretransitional fluctuations, significantly moderated by nanoparticles, is shown. The authors consider separate focuses on the dielectric constant [Formula: see text] evolution in the static domain, yielding mainly response from permanent dipole moment and its arrangement, and in the low-frequency (LF) domain [Formula: see text] (where [Formula: see text] is for the real part of dielectric permittivity in the LF domain), which is associated solely with ionic-related polarization mechanisms. All of these led to new experimental evidence concerning I-N, N-SmA, and SmA-solid transitions, focusing on the strength and extent of pretransitional effects, critical exponents, and phase transitions discontinuities. The strong evidence for pretransitional effects near the SmA-Cr transition is notable, particularly regarding [Formula: see text]. Studies are supplemented by the discussion of DC electric conductivity-a parameter also related to the LF domain. Finally, the validity of the relation [Formula: see text] (where f stands for frequency, and A is a constant parameter), often used for discussing dielectric spectra in LC compound and its nanocolloids in the LF domain, is examined.
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Affiliation(s)
- Joanna Łoś
- Institute of High Pressure Physics, Polish Academy of Sciences, X-PressMatter Lab, ul. Sokołowska 29/37, 01-142, Warsaw, Poland.
| | - Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics, Polish Academy of Sciences, X-PressMatter Lab, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
| | - Sylwester J Rzoska
- Institute of High Pressure Physics, Polish Academy of Sciences, X-PressMatter Lab, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
| | - Krzysztof Czupryński
- Faculty of Advanced Technologies and Chemistry, Military University of Technology, ul. gen. Sylwestra Kaliskiego 2, 00-908, Warsaw, Poland
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Rzoska SJ, Drozd-Rzoska A. Criticality-related fundamental bases for new generations of gas-liquid, liquid-liquid, and liquid (LE) extraction technologies. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2022; 45:67. [PMID: 35947227 PMCID: PMC9365757 DOI: 10.1140/epje/s10189-022-00218-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
The report presents experimental results, which can be considered as the reference for innovative generations of supercritical fluids (SCF), liquid-liquid (LL), and liquid (L) extraction technologies. They are related to implementations of Critical Phenomena Physics, for such applications not considered so far. For the gas-liquid critical point, the shift SuperCritical Fluids (SCF) ⇒ SubCritical Fluids, due to the additional exogenic impact of ultrasounds, is indicated. For LL technology, the possibility of increasing process effectiveness when operating near the critical consolute under pressure is indicated. Finally, the discovery of long-range precritical-type changes of dielectric constant in linseed oil, standing even 50 K above the melting temperature, is presented. It suggests that extraction processes linking 'SCF' and 'L' technologies features and exploring the natural carrier, such as linseed oil, are possible. The report recalls the fundamental base for extraction processes via Kirkwood and Noyes-Whitney relations and presents their implementations to 'critical conditions,' including pressure.
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Affiliation(s)
- Sylwester J Rzoska
- Institute of High Pressure Physics Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland.
| | - Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
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Łoś J, Drozd-Rzoska A, Rzoska SJ, Starzonek S, Czupryński K. The fluctuation-driven dielectric properties of liquid crystalline 8OCB and its nanocolloids. SOFT MATTER 2022; 18:4502-4512. [PMID: 35678229 DOI: 10.1039/d2sm00105e] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Results of broadband dielectric spectroscopy studies in liquid crystalline octyloxycyanobiphenyl (8OCB) and its colloids with BaTiO3 nanoparticles (paraelectric, diameter d = 50 nm) are presented. Studies were carried out in isotropic liquid, nematic, smectic A and solid crystalline phases. They are supported by derivative-based and distortion-sensitive analyses, revealing a set of universal scaling patterns for temperature evolution of static and dynamic dielectric properties. All these yielded evidence for a pretransitional fluctuation impact on the dielectric constant, primary relaxation time, loss curve maximum and translational-orientational decoupling associated with anomalous values of the fractional Debye-Stokes-Einstein (DSE) exponent 0.2 < S < 2.2. The evidence for critical like changes in a distribution of relaxation times is shown. For mesophases, a tiny addition of nanoparticles causes permanent orientation of LC molecules, leading even to a 16% increase of the dielectric constant above a maximal value in pure 8OCB. A split of two regions, dominated by pre-isotropic and pre-smectic fluctuations, is evidenced. Model explanations for detected phenomena, particularly in the isotropic liquid phase, are presented. New evidence for a premelting effect in the solid phase is also shown.
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Affiliation(s)
- Joanna Łoś
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland.
| | - Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland.
| | - Sylwester J Rzoska
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland.
| | - Szymon Starzonek
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland.
| | - Krzysztof Czupryński
- Military University of Technology, ul. gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland
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Abstract
In pressurized glass-forming systems, the apparent (changeable) activation volume Va(P) is the key property governing the previtreous behavior of the structural relaxation time (τ) or viscosity (η), following the Super-Barus behavior: [Formula: see text], T = const. It is usually assumed that Va(P) = V#(P), where [Formula: see text] or [Formula: see text]. This report shows that Va(P) ≪ V#(P) for P → Pg, where Pg denotes the glass pressure, and the magnitude V#(P) is coupled to the pressure steepness index (the apparent fragility). V#(P) and Va(P) coincides only for the basic Barus dynamics, where Va(P) = Va = const in the given pressure domain, or for P → 0. The simple and non-biased way of determining Va(P) and the relation for its parameterization are proposed. The derived relation resembles Murnaghan - O'Connel equation, applied in deep Earth studies. It also offers a possibility of estimating the pressure and volume at the absolute stability limit. The application of the methodology is shown for diisobutyl phthalate (DIIP, low-molecular-weight liquid), isooctyloxycyanobiphenyl (8*OCB, liquid crystal) and bisphenol A/epichlorohydrin (EPON 828, epoxy resin), respectively.
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Affiliation(s)
- Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics Polish Academy of Sciences, ul. Sokołowska, 29/37.01-142, Warsaw, Poland.
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8
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Starzonek S, Drozd-Rzoska A, Rzoska SJ, Zhang K, Pawlikowska E, Kȩdzierska-Sar A, Szafran M, Gao F. Polymer matrix ferroelectric composites under pressure: Negative electric capacitance and glassy dynamics. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2019; 42:118. [PMID: 31493015 DOI: 10.1140/epje/i2019-11876-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 07/28/2019] [Indexed: 06/10/2023]
Abstract
This report presents the results of high-pressure and broadband dielectric spectroscopy studies in polyvinylidene difluoride (PVDF) and barium strontium titanate (BST) microparticles composites (BST/PVDF). It shows that the Arrhenius behaviour for the temperature-related dynamics under atmospheric pressure is coupled to Super-Arrhenius/Super-Barus isothermal pressure changes of the primary relaxation time. Following these results, an explanation of the unique behaviour of the BST/PVDF composite is proposed. Subsequently, it is shown that when approaching the GPa domain the negative electric capacitance phenomenon occurs.
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Affiliation(s)
- Szymon Starzonek
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland.
| | - Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
| | - Sylwester J Rzoska
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
| | - Kena Zhang
- State Key Laboratory of Solidification Processing, MIIT Key Laboratory of Radiation Detection Materials and Devices, NPU-QMUL Joint Research Institute of Advanced Materials and Structure, School of Material Science and Engineering, Northwestern Polytechnical University, 710072, Xi'an, China
| | - Emilia Pawlikowska
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
| | - Aleksandra Kȩdzierska-Sar
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
| | - Mikolaj Szafran
- Faculty of Chemistry, Warsaw University of Technology, ul. Noakowskiego, 00-664, Warsaw, Poland
| | - Feng Gao
- State Key Laboratory of Solidification Processing, MIIT Key Laboratory of Radiation Detection Materials and Devices, NPU-QMUL Joint Research Institute of Advanced Materials and Structure, School of Material Science and Engineering, Northwestern Polytechnical University, 710072, Xi'an, China
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9
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Corsaro C, Fazio E, Mallamace D. The Stokes-Einstein relation in water/methanol solutions. J Chem Phys 2019; 150:234506. [DOI: 10.1063/1.5096760] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- C. Corsaro
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università di Messina, Viale F. Stagno d’ Alcontres, 31, 98166 Messina, Italy
| | - E. Fazio
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università di Messina, Viale F. Stagno d’ Alcontres, 31, 98166 Messina, Italy
| | - D. Mallamace
- Dipartimento di Scienze Matematiche e Informatiche, Scienze Fisiche e Scienze della Terra, Università di Messina, Viale F. Stagno d’ Alcontres, 31, 98166 Messina, Italy
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Drozd-Rzoska A, Starzonek S, Rzoska SJ, Kralj S. Nanoparticle-controlled glassy dynamics in nematogen-based nanocolloids. Phys Rev E 2019; 99:052703. [PMID: 31212529 DOI: 10.1103/physreve.99.052703] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Indexed: 11/07/2022]
Abstract
Results of broad-band dielectric spectroscopy studies in liquid crystal (pentylcyanobiphenyl, 5CB)-based nanocolloids are presented. They reveal the strong impact of BaTiO_{3} nanoparticles on dynamics and uniaxial ordering. Studies were carried out in an extreme range of temperatures (∼150 K), including the supercooled nematic phase. For the latter, the unique "pretransitional" effect for dielectric constant on approaching solid state is reported. The distortion-sensitive analysis revealed super-Arrhenius dynamics but associated with critical-like behavior. In the isotropic phase, translational-orientational decoupling, unusual for the high temperature dynamic domain, was detected. It can be directly link to heterogeneities-prenematic fluctuations. The model linking the classical Landau-de Gennes approach with Imry-Ma arguments has been developed to discuss experimental results.
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Affiliation(s)
- Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics of the Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland
| | | | | | - Samo Kralj
- Faculty of Natural Sciences and Mathematics, University of Maribor, Koroska 160, 2000 Maribor, Slovenia and Condensed Matter Physics Department, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
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Drozd-Rzoska A. Universal behavior of the apparent fragility in ultraslow glass forming systems. Sci Rep 2019; 9:6816. [PMID: 31048717 PMCID: PMC6497650 DOI: 10.1038/s41598-019-42927-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 04/04/2019] [Indexed: 11/08/2022] Open
Abstract
Despite decades of studies on the grand problem of the glass transition the question of well-defined universal patterns, including the key problem of the previtreous behavior of the primary (structural) relaxation time, remains elusive. This report shows the universal previtreous behavior of the apparent fragility, i.e. the steepness index mP (T > Tg) = d log10τ(T)/d( Tg/T). It is evidenced that mP(T) = 1(T - T*), for T → Tg and T*= Tg - Δ T*. Basing on this finding, the new 3-parameter dependence for portraying the previtreous behavior of the primary relaxation time has been derived: τ(T) = CΩ((T - T*)/T)-Ω × [exp((T - T*)/T)]Ω. The universality of obtained relations is evidenced for glass formers belonging to low molecular weight liquids, polymers (melt and solid), plastic crystals, liquid crystals, resins and relaxors. They exhibit clear preferences either for the VFT or for the critical-like descriptions, if recalled already used modeling. The novel relation can obey even above the dynamic crossover temperature, with the power exponent Ω ranging between ~17 (liquid crystals) to ~57 (glycerol), what may indicate the impact of symmetry on the previtreous effect. Finally, the emerging similarity to the behavior in the isotropic phase of nematic liquid crystals is recalled.
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Affiliation(s)
- Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland.
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12
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Starzonek S, Kędzierska-Sar A, Drozd-Rzoska A, Szafran M, Rzoska SJ. Unique dynamic crossover in supercooled x,3-dihydroxypropyl acrylate (x = 1, 2) isomers mixture. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2018; 41:108. [PMID: 30229319 DOI: 10.1140/epje/i2018-11714-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
The previtreous dynamics in the glass-forming monomer, glycerol monoacrylate (GMA), was tested using the broadband dielectric spectroscopy (BDS). The measurements revealed a clear dynamic crossover at the temperature [Formula: see text] K and the time scale [Formula: see text] ns for the primary (structural) relaxation time and no hallmarks for the crossover for the DC electric conductivity [Formula: see text]. This result was revealed via the derivative-based and distortions-sensitive analysis [Formula: see text] vs. [Formula: see text] , where [Formula: see text] stands for the apparent activation energy. Subsequent tests of the fractional Debye-Stokes-Einsten relation [Formula: see text] showed that the crossover is associated with [Formula: see text] [Formula: see text] (for [Formula: see text]. The crossover coexists with the emergence of the secondary beta relaxation, which smoothly develops deeply into the solid amorphous phase below the glass temperature [Formula: see text].
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Affiliation(s)
- Szymon Starzonek
- Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland.
- Warsaw Dielectrics Group, Warsaw, Poland.
| | - Aleksandra Kędzierska-Sar
- Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
- Department of Chemical Technology, Warsaw University of Technology, ul. Noakowskiego 3, 00-664, Warsaw, Poland
| | - Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
- Warsaw Dielectrics Group, Warsaw, Poland
| | - Mikołaj Szafran
- Department of Chemical Technology, Warsaw University of Technology, ul. Noakowskiego 3, 00-664, Warsaw, Poland
| | - Sylwester J Rzoska
- Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142, Warsaw, Poland
- Warsaw Dielectrics Group, Warsaw, Poland
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13
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Starzonek S, Rzoska SJ, Drozd-Rzoska A, Czupryński K, Kralj S. Impact of ferroelectric and superparaelectric nanoparticles on phase transitions and dynamics in nematic liquid crystals. Phys Rev E 2017; 96:022705. [PMID: 28950608 DOI: 10.1103/physreve.96.022705] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Indexed: 11/07/2022]
Abstract
Results of broadband dielectric spectroscopy (BDS) studies of pure liquid crystalline (4-pentyloxy-4-biphenylcarbonitryle) 5OCB and its nanocolloids with BaTiO_{3} nanoparticles (NPs) under varying pressure and temperature are presented. The notable impact of NPs on phase transitions and dynamics was found. Particularly strong impact on pretransitional behavior was observed for relatively low concentrations of NPs, which can be related to the NPs-induced disorder. There are also notable differences between pressure and temperature paths of studies for nanocomposites, absent for the pure LC compound. For instance, tests focused on the translational orientational decoupling via the fractional Debye-Stokes-Einstein relation yielded S=0.71 and S=0.3 for the temperature and pressure paths, respectively: S=1 is for the complete coupling. The possible theoretical frame of observed phenomena is also proposed.
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Affiliation(s)
- Szymon Starzonek
- Institute of High Pressure Physics of Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Sylwester J Rzoska
- Institute of High Pressure Physics of Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Aleksandra Drozd-Rzoska
- Institute of High Pressure Physics of Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Krzysztof Czupryński
- Military University of Technology, Institute of Chemistry, ulica Kaliskiego 2, 00-908 Warsaw, Poland
| | - Samo Kralj
- Condensed Matter Physics Department, Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia and Faculty of Natural Sciences and Mathematics, University of Maribor, Koroska 160, 2000 Maribor, Slovenia
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14
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Rzoska SJ, Starzonek S, Drozd-Rzoska A, Czupryński K, Chmiel K, Gaura G, Michulec A, Szczypek B, Walas W. Impact of BaTiO(3) nanoparticles on pretransitional effects in liquid crystalline dodecylcyanobiphenyl. Phys Rev E 2016; 93:020701. [PMID: 26986276 DOI: 10.1103/physreve.93.020701] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Indexed: 11/07/2022]
Abstract
The pretransitional behavior of dodecylcyanobiphenyl (12CB) (isotropic-smectic-A-solid mesomorphism) with d=50nmBaTiO(3) nanoparticles (NPs) linked to the cubic phase was monitored via temperature studies of dielectric constant. Tests were carried out in the isotropic, liquid crystal mesomorphic, and solid phases. For each phase transition the same value of the critical exponent α∼0.5 was obtained, including nanocolloids. All phase transitions show the weakly discontinuous nature. The temperature metric of the discontinuity ΔT notably decreases when adding nanoparticles. The addition of nanoparticles first decreases the dielectric constant by approximately 50% in comparison with pure 12CB, but already for a concentration ∼x=0.4% NP an increase over 50% takes place. It is notable that for the latter concentration unique hallmarks of the pretransitional effect emerge also for the solid-mesophase transition. All these indicate the important impact of nanoparticles on multimolecular mesoscale fluctuations.
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Affiliation(s)
- S J Rzoska
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.,Institute of High Pressure Physics, Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - S Starzonek
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.,Institute of High Pressure Physics, Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - A Drozd-Rzoska
- Institute of High Pressure Physics, Polish Academy of Sciences, ulica Sokołowska 29/37, 01-142 Warsaw, Poland
| | - K Czupryński
- Military University of Technology, Institute of Chemistry, ulica Kaliskiego 2, 00-908 Warsaw, Poland
| | - K Chmiel
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - G Gaura
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - A Michulec
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - B Szczypek
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
| | - W Walas
- Silesian Intercollegiate Centre for Education and Interdisciplinary Research & Institute of Physics, University of Silesia, ulica 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland
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