Plastic instability of shells

Koval’chuk, B. I.

doi:10.1007/bf01523201

Cited by 5 publications

(8 citation statements)

References 4 publications

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“…The equivalent circuit of an LC cell consists of parallel connected resistance R and capacity C. By using the oscilloscopic method [15,16], these parameters were mea- sured as functions of the frequency of a sine-like testing electric field applied across the LC cell. The amplitude of the measured signal was 0.25 V. The frequency f was varied within the range 5 × 10 −2 -10 6 Hz.…”

Section: Methodology Of Dielectric Measurementsmentioning

confidence: 99%

Dielectric Properties of Nematic Liquid Crystal Modified with Diamond Nanoparticles

et al. 2012

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In the present study, the influence of diamond nanoparticles (DNPs) on dielectric properties of nematic liquid crystal (LC) E7 from Merck has been considered. It is established that the insertion of DNPs leads to an increase in the dielectric constant ε', as well as to a significant change in the electric conductivity σ of the LC. The growth of ε' with the concentration of DNPs, CDNP, is mainly caused by a contribution of the DNP permittivity to the effective permittivity of the composite. The character of the σ(CDNP) curves depends on the ionic purity of LC E7: for the samples based on pure E7, an increase of the electric conductivity with the concentration of DNPs is detected, whereas the reverse trend is observed for the samples containing impure E7. This behavior is attributed to the competitive adsorption and desorption of ions on/from the surface of DNPs and the ion transfer along the percolation network of theseparticles.

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Section: Methodology Of Dielectric Measurementsmentioning

confidence: 99%

Dielectric Properties of Nematic Liquid Crystal Modified with Diamond Nanoparticles

et al. 2012

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“…The high values of permittivity ðe 0 > 10 5 Þ in the low frequency region might be caused by the non-uniform distribution of electrical field, because of blocking the electro-chemical processes of charge exchange at the interfaces [20,22]. Assuming that electric field is applied mainly to anode [20,22] and taking into account the approximation made in References [23,24] one can calculate thickness of the near-electrode charge exchange layers, d e :…”

Section: =[508]mentioning

confidence: 99%

“…Dielectric properties of samples were measured in frequency range 10 À2 À10 6 Hz by oscilloscope method [19,20]. The measured signal was delta shaped with a maximum value of 0.25 V. All measurements were carried out at 293 K. We defined capacity C and resistance R of samples by analysis of the oscillogram obtained.…”

Section: =[506]mentioning

confidence: 99%

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The Peculiarities of Photopolymerization in the Composite “Pre-polymer–TiO₂Nanoparticles”

Koval’chuk

Dolgov

Bugayova

et al. 2005

Molecular Crystals and Liquid Crystals

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The photo-conversion of pre-polymer mixture NOA65 (Norland, USA) doped with TiO 2 nanoparticles is studied by the method of dielectric spectroscopy. The photopolymerized composites show low frequency relaxation and ion conductivity typical for liquids. This is explained by the reaction of TiO 2 particles with components of NOA65 mixture that blocks photopolymerization of pre-polymer and increases concentration of ion carriers. In addition, strong photochromism of NOA65-TiO 2 composites is observed which makes this system quite attractive for non-linear optics and associated applications. It may be caused by formation of titanium mercaptide and its transfer from IV to III valency state under UV irradiation.

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“…LFDS studies [2][3][4][5][6][7][8] have shown that the near-electrode relaxation processes in LC have exceedingly long duration (tens and hundreds of seconds, and even more). Our previous study [8] demonstrated that such relaxation times are much longer than those associated with the transport of individual ions in the near-electrode layer (whose thickness ranges from several to tens of nanometres).…”

Section: Introductionmentioning

confidence: 99%

Relaxation processes and charge transport across liquid crystal-electrode interface

Koval’chuk

2001

J. Phys.: Condens. Matter

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At U<1 V nearly the entire voltage in liquid crystals (LC) and in solutions of dyes in LC is applied to the near-electrode regions. In this range of voltages, the Schottky emission through a dielectric layer is the electric current flow mechanism transport. A thin (several nanometres) dielectric layer is formed through adsorption on the electrode of not only ions, but also neutral impurities. According to estimates, the concentration of such molecules in pure LC may much exceed that of ions. It is demonstrated experimentally that the barrier controlling the charge transport lies at the anode and characterizes the ionization of LC molecules. Similarities and distinctions between the observed tunnel charge transport in dielectric liquids and the Schottky effect in solids are analysed. It is shown that the low-frequency dielectric dispersion is caused by voltage redistribution. Comparison of the parameters characterizing the carrier transport with those of the relaxation processes in the diffusion region of the electric double layer shows that long-term near-electrode processes are controlled by charge transport across the electrode-LC interface.

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Plastic instability of shells

Cited by 5 publications

References 4 publications

Dielectric Properties of Nematic Liquid Crystal Modified with Diamond Nanoparticles

Dielectric Properties of Nematic Liquid Crystal Modified with Diamond Nanoparticles

The Peculiarities of Photopolymerization in the Composite “Pre-polymer–TiO₂Nanoparticles”

Relaxation processes and charge transport across liquid crystal-electrode interface

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Plastic instability of shells

Cited by 5 publications

References 4 publications

Dielectric Properties of Nematic Liquid Crystal Modified with Diamond Nanoparticles

Dielectric Properties of Nematic Liquid Crystal Modified with Diamond Nanoparticles

The Peculiarities of Photopolymerization in the Composite “Pre-polymer–TiO2Nanoparticles”

Relaxation processes and charge transport across liquid crystal-electrode interface

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The Peculiarities of Photopolymerization in the Composite “Pre-polymer–TiO₂Nanoparticles”