The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
S V Dubkov - One of the best experts on this subject based on the ideXlab platform.
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Pyroelectricity in graphene oxide doped p vdf trfe films
Polymer Testing, 2018Co-Authors: M Wojtaś, D V Karpinsky, M V Silibin, S A Gavrilov, Artem Sysa, K N Nekludov, S V DubkovAbstract:Abstract The pyroelectric properties of polyvinylidene fluoride/trifluoroethylene doped with graphene oxide were studied. The pyroelectric current measurements were performed for polarized and non-polarized samples with different amount graphene oxide: 5, 10, 15, 20, 25%. The polarization process influence on pyroelectric current was discussed. Moreover the impact of different amount of dopant on pyroelectric properties of polyvinylidene fluoride/trifluoroethylene was analyzed. On the basis of obtained results the phase diagram was performed.
Peizen Chang - One of the best experts on this subject based on the ideXlab platform.
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enhance the Pyroelectricity of polyvinylidene fluoride by graphene oxide doping
Sensors, 2014Co-Authors: Weili Hsu, Yita Wang, Peizen ChangAbstract:The high quality properties and benefits of graphene-oxide have generated an active area of research where many investigations have shown potential applications in various technological fields. This paper proposes a methodology for enhancing the pyro-electricity of PVDF by graphene-oxide doping. The PVDF film with graphene-oxide is prepared by the sol-gel method. Firstly, PVDF and graphene-oxide powders are dispersed into dimethylformamide as solvent to form a sol solution. Secondly, the sol solution is deposited on a flexible ITO/PET substrate by spin-coating. Thirdly, the particles in the sol solution are polymerized through baking off the solvent to produce a gel in a state of a continuous network of PVDF and graphene-oxide. The final annealing process pyrolyzes the gel and form a β-phase PVDF film with graphene-oxide doping. A complete study on the process of the graphene oxide doping of PVDF is accomplished. Some key points about the process are addressed based on experiments. The solutions to some key issues are found in this work, such as the porosity of film, the annealing temperature limitation by the use of flexible PET substrate, and the concentrations of PVDF and graphene-oxide.
Sidney B Lang - One of the best experts on this subject based on the ideXlab platform.
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guide to the literature of piezoelectricity and Pyroelectricity 25
Ferroelectrics, 2006Co-Authors: Sidney B LangAbstract:A bibliography is given containing 1527 references published during 2003 and 2004 on piezoelectric and pyroelectric properties of materials and their applications. It contains listings of journal articles and patents with complete bibliographic citations. The year 2003 references complete the 2003 references in Guides 23 and 24 (published previously in this series). Journal and patent references from 2004 in which the first author's name begins with letters between A and K are given in the current guide. Journal articles and patents by authors with names beginning with the letters L through Z will be published in Guide 26. This bibliography is the continuation of a series published semi-annually.
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Pyroelectricity from ancient curiosity to modern imaging tool
Physics Today, 2005Co-Authors: Sidney B LangAbstract:Changes in the net dipole moment of certain materials form the basis for a broad range of IR detectors.
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guide to the literature of piezoelectricity and Pyroelectricity 23
Ferroelectrics, 2005Co-Authors: Sidney B LangAbstract:A bibliography is given containing 2067 references published during 2002 and 2003 on piezoelectric and pyroelectric properties of materials and their applications. It contains listings of journal articles with complete bibliographic citations. This bibliography is the continuation of a series published semi-annually.
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Pyroelectricity fundamentals and applications
Handbook of Advanced Electronic and Photonic Materials and Devices, 2001Co-Authors: Sidney B Lang, D K DasguptaAbstract:Publisher Summary “Pyroelectricity” is defined as the manifestation of the temperature dependence of the spontaneous polarization of certain anisotropic solids. The chapter contains a brief presentation of the two-and-a-half-millennium history of Pyroelectricity, a detailed discussion of the fundamentals of the phenomenon, and a description of many of its applications. The pyroelectric effect is closely related to piezoelectricity and is the basis for ferroelectricity. Despite many years of research, there are undoubtedly more pyroelectric phenomena and more pyroelectric materials to be discovered. Biological Pyroelectricity may be a particularly fruitful area for future research. Up to the present time, the applications of Pyroelectricity have been principally in the area of infrared detection with a strong emphasis on security uses. The current emphasis on infrared imaging is largely directed toward the consumer market, and this may have a very strong impact on the daily lives of people. It can be safely predicted that the future holds many exciting developments in the fundamentals and applications of Pyroelectricity.
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piezoelectricity Pyroelectricity and ferroelectricity in biomaterials speculation on their biological significance
IEEE Transactions on Dielectrics and Electrical Insulation, 2000Co-Authors: Sidney B LangAbstract:Many thousands of papers have been published on the piezoelectric, pyroelectric and ferroelectric properties of single crystals, ceramics, polymers and liquid crystals. Yet fewer than 100 papers have appeared on these properties in biological materials. Piezoelectric and pyroelectric effects have been measured on a number of plant and animal tissues and the possible existence of ferroelectricity has been suggested also. This paper reviews some measurements and speculates on their significance. Specific examples include piezoelectricity in a crystalline material in the pineal gland of the brain, Pyroelectricity in the heat sensing organs of certain varieties of snakes and beetles, and ferroelectricity in the conduction of action potentials in nerve and muscle cells.
Igor Lubomirsky - One of the best experts on this subject based on the ideXlab platform.
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the contribution of Pyroelectricity of agi crystals to ice nucleation
Angewandte Chemie, 2018Co-Authors: Sofia Curland, Meir Lahav, Elena Meirzadeh, Hagai Cohen, David Ehre, Joachim Maier, Igor LubomirskyAbstract:The Pyroelectricity of AgI crystals strongly affects the icing temperature of super-cooled water, as disentangled from that of epitaxy. This deduction was achieved by the design of polar crystalline ceramic pellets of AgI, with experimentally determined sense of polarity. These pellets are suitable for measuring both their pyroelectric properties as well as the icing temperature of super-cooled water, separately on each of the expressed Ag+ and I- hemihedral surfaces. The positive pyroelectric charge at the silver-enriched side elevates the icing temperature, whereas the negative charge at the iodide side decreases that temperature. Moreover, the effect of pyroelectric charge remains dominant despite the presence of contaminants on both the silver and the iodide-enriched surfaces. Consequently an electrochemical process for ice nucleation is suggested, which might be of relevance for understanding the role played by electric charges in heterogeneous icing processes in general.
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Pyroelectricity in nonpolar directions in crystals enantiomeric disorder and surface wetting in racemic α amino acids
Crystal Growth & Design, 2014Co-Authors: Eran Mishuk, Isabelle Weissbuch, Meir Lahav, Igor LubomirskyAbstract:Display of Pyroelectricity along nonpolar directions of crystals or from surfaces implies structural disorder or presence of polar surface layers. Nonpolar {210} faces of polar dl-alanine crystals display far larger pyroelectric effect than that at the polar {001} faces. Similarly, Pyroelectricity is reported from {110} faces of centrosymmetric crystals of dl-aspartic acid. The origin of the disorder is due to an interchange of enantiomers at specific chiral crystal sites as supported by atom–atom potential energy computations and by pyroelectric effect observed on the nonpolar crystals of l-alanine intentionally doped with opposite enantiomers. These results should explain the riddle of the needle-like morphology of dl-alanine. The {100} faces of dl-serine and the {021} faces of dl-glutamic acid monohydrate crystals exhibit Pyroelectricity due to surface wetting, whereas Pyroelectricity originating from the {210} faces of enantiomerically doped l-alanine crystals could be deciphered as arising both from ...
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water induced Pyroelectricity from nonpolar crystals of amino acids
Angewandte Chemie, 2013Co-Authors: Silvia Piperno, Eran Mishuk, Meir Lahav, David Ehre, Elena Mirzadeh, Sidney R Cohen, Miriam Eisenstein, Igor LubomirskyAbstract:Pyroelectricity, a property of certain crystalline materials, isthe creation of a temporary surface charge upon temperaturechange, resulting in an external electric current. Thermalmovement of the molecules alters their average positionsleading to changes in the crystal dipole moments. The Greekphilosopher Theophrastus discovered this property in themineral tourmaline already in 314 BC. Since then, thisphenomenon has led to a plethora of applications, such asnightvisiondevices,burglaralarms,andportablehigh-voltagegenerators.
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Pyroelectricity in highly stressed quasi amorphous thin films
ChemInform, 2004Co-Authors: Vera Lyahovitskaya, Sidney R Cohen, Ilya Zon, Yishay Feldman, A K Tagantsev, Igor LubomirskyAbstract:Quasi-amorphous BaTiO3 thin films (see Figure) represent a polar ionic solid without spatial periodicity. Most probably, polarity of the quasi-amorphous BaTiO3 is associated with directional ordering of crystal motifs formed in the steep temperature gradient and stabilized by high in-plane mechanical stress. A remarkable characteristic of quasi-amorphous BaTiO3 is expression of strong pyro-and piezoelectric effects in a low dielectric constant material.
H Von Seggern - One of the best experts on this subject based on the ideXlab platform.
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Pyroelectricity in polyvinylidene fluoride influence of polarization and charge
Journal of Applied Physics, 2008Co-Authors: S N Fedosov, H Von SeggernAbstract:Fractional thermally stimulated depolarization (TSD) currents and temperature-dependent Pyroelectricity are experimentally studied in polyvinylidene fluoride samples poled at high direct current field at room temperature. It is demonstrated by a detailed charge balance that the generally assumed proportionality between pyrocoefficients and residual polarization cannot be observed in the low temperature range where polarization irreversibly decreases during heating, while the pyrocoefficient remains constant up to about 60 °C. It is assumed that a portion of the residual polarization results from alignment of the dipoles in the amorphous phase of the polymer. This portion is not related to Pyroelectricity and irreversibly vanishes during heating. For lack of screening charges at the crystallite boundaries, an irreversible back switching of the polarization occurs at temperatures higher than 80 °C. Since the relaxation of the compensating charges and that of the ferroelectric polarization are interrelated, ...
