Energy trapping thickness mode gyroscopes using high performance crystalline materials.

Author(s):  
J. Detaint ◽  
B. Capelle ◽  
Y. Epelboin
2018 ◽  
Vol 3 (11) ◽  
Author(s):  
Matthias Zschornak ◽  
Falk Meutzner ◽  
Jessica Lück ◽  
Arnulf Latz ◽  
Tilmann Leisegang ◽  
...  

Abstract With an increasing diversity of electrical energy sources, in particular with respect to the pool of renewable energies, and a growing complexity of electrical energy usage, the need for storage solutions to counterbalance the discrepancy of demand and offer is inevitable. In principle, a battery seems to be a simple device since it just requires three basic components – two electrodes and an electrolyte – in contact with each other. However, only the control of the interplay of these components as well as their dynamics, in particular the chemical reactions, can yield a high-performance system. Moreover, specific aspects such as production costs, weight, material composition and morphology, material criticality, and production conditions, among many others, need to be fulfilled at the same time. They present some of the countless challenges, which make battery design a long-lasting, effortful task. This chapter gives an introduction to the fundamental concepts of batteries. The principles are exemplified for the basic Daniell cell followed by a review of Nernst equation, electrified interface reactions, and ionic transport. The focus is addressed to crystalline materials. A comprehensive discussion of crystal chemical and crystal physical peculiarities reflects favourable and unfavourable local structural aspects from a crystallographic view as well as considerations with respect to electronic structure and bonding. A brief classification of battery types concludes the chapter.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1099 ◽  
Author(s):  
Anna Poryvai ◽  
Terezia Vojtylová-Jurkovičová ◽  
Michal Šmahel ◽  
Natalie Kolderová ◽  
Petra Tomášková ◽  
...  

Liquid crystals (LCs) are among the most prominent materials of the current information age, mainly due to their well-known application in liquid crystal displays (LCDs). Their unique electro-optical properties stem from their ability to form organised structures (mesophases) on the transition from solid state to isotropic liquid. Molecules of LCs in a mesophase still maintain the anisotropy of solid crystals, while simultaneously exhibiting the fluidity of liquids, which gives the system the ability to react immediately to external stimuli such as electric or magnetic fields, light, mechanical stress, pressure and, of course, temperature. For the proper function of LC-based devices, not only chemical, but also optical purity of materials is strongly desirable, since any impurity could be detrimental to the self-assembly of the molecules. Therefore, in this study we aimed to verify synthetic methods published in the literature, which are used nowadays to prepare chiral building blocks based on lactic acid, for their enantioselectivity. Moreover, we have focused on the development of an analytical chiral separation method for target liquid crystalline materials. Using a chiral polysaccharide-based column operated in liquid chromatography mode, we show that not all published methods of LC synthesis are enantioselective, which could lead to significant differences in the properties of the resulting materials. We show that high-performance liquid chromatography with UV detection and supercritical fluid chromatography with UV and mass spectrometry detection enable full control over the chemical and optical purity of the target LCs and the corresponding chiral building blocks. For the first time, we utilise supercritical fluid chromatography with mass detection for the direct chiral analysis of liquid crystalline materials and impurities formed during the synthesis.


2021 ◽  
Author(s):  
Naoki Sato ◽  
Norihide Kuroda ◽  
Shun Nakamura ◽  
Yukari Katsura ◽  
Ikuzo Kanazawa ◽  
...  

<p><a>Crystalline materials with intrinsically low lattice thermal conductivity (</a><i>κ</i><sub>lat</sub>) pave the way towards high performance in various energy applications, including thermoelectrics. Here we demonstrate a strategy to realize ultralow <i>κ</i><sub>lat</sub> using mixed-anion compounds. Our calculations reveal that locally distorted structures in chalcohalides MnPnS<sub>2</sub>Cl (Pn = Sb, Bi) derives a bonding heterogeneity, which in turn causes a peak splitting of the phonon density of states. This splitting induces a large amount of scattering phase space. Consequently, <i>κ</i><sub>lat</sub> of MnPnS<sub>2</sub>Cl is significantly lower than that of a single-anion sulfide CuTaS<sub>3</sub> with a similar crystal structure. Experimental <i>κ</i><sub>lat</sub> of MnPnS<sub>2</sub>Cl takes an ultralow value of about 0.5 W m<sup>−1</sup> K<sup>−1</sup> at 300 K. Our findings will encourage the exploration of thermal transport in mixed-anion compounds, which remain a vast unexplored space, especially regarding unexpectedly low <i>κ</i><sub>lat</sub> in lightweight materials derived from the bonding heterogeneity.</p>


Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 389 ◽  
Author(s):  
Sang-Hyub Lee ◽  
Cho-Rong Oh ◽  
Dai-Soo Lee

In this study, a highly concentrated graphite nanoplate (GNP)/polyol masterbatch was prepared by the exfoliation of natural graphite in an aqueous system using cetyltrimethylammonium bromide and the replacement of aqueous solution with a polyol, viz. poly(tetramethylene ether glycol), and it was subsequently used to prepare polyurethane (PU) nanocomposites by simple dilution. The polyol in the masterbatch efficiently prevented the aggregation of GNPs during the preparation of PU nanocomposite. In addition, the dispersed GNPs in the masterbatch exhibited rheological behavior of lyotropic liquid crystalline materials. In this study, the manufacture and application methods of the GNP/polyol masterbatch were discussed, enabling the facile manufacture of the PU/GNP nanocomposites with excellent mechanical properties. In addition, the manner in which the GNP alignment affected the microphase separation of PU in the nanocomposites was investigated, which determined the improvement in the mechanical properties of the nanocomposites. High-performance PU/GNP nanocomposites are thought to be manufactured from the GNP/polyol masterbatch by the simple dilution to 0.1 wt% GNP in the nanocomposite.


2021 ◽  
Author(s):  
Naoki Sato ◽  
Norihide Kuroda ◽  
Shun Nakamura ◽  
Yukari Katsura ◽  
Ikuzo Kanazawa ◽  
...  

<p><a>Crystalline materials with intrinsically low lattice thermal conductivity (</a><i>κ</i><sub>lat</sub>) pave the way towards high performance in various energy applications, including thermoelectrics. Here we demonstrate a strategy to realize ultralow <i>κ</i><sub>lat</sub> using mixed-anion compounds. Our calculations reveal that locally distorted structures in chalcohalides MnPnS<sub>2</sub>Cl (Pn = Sb, Bi) derives a bonding heterogeneity, which in turn causes a peak splitting of the phonon density of states. This splitting induces a large amount of scattering phase space. Consequently, <i>κ</i><sub>lat</sub> of MnPnS<sub>2</sub>Cl is significantly lower than that of a single-anion sulfide CuTaS<sub>3</sub> with a similar crystal structure. Experimental <i>κ</i><sub>lat</sub> of MnPnS<sub>2</sub>Cl takes an ultralow value of about 0.5 W m<sup>−1</sup> K<sup>−1</sup> at 300 K. Our findings will encourage the exploration of thermal transport in mixed-anion compounds, which remain a vast unexplored space, especially regarding unexpectedly low <i>κ</i><sub>lat</sub> in lightweight materials derived from the bonding heterogeneity.</p>


2017 ◽  
Vol 66 (2) ◽  
pp. 13-24
Author(s):  
Edyta Prusińska-Kurstak ◽  
Katarzyna Garbat ◽  
Aleksandra Kołakowska ◽  
Stanisław J. Kłosowicz

The application of cholesteric liquid crystals and composites containing them for visualization of thermal field and temperature measurement is very well known. Despite all disadvantages as limited precision and adhesion to the studied surface, this method is still of interest. In this work, we present the results of preliminary studies on polymer-dispersed cholesteric liquid crystal (PDCLC) composites designed for visualization and measurement of point temperature changes which can be used in medical diagnostics. Basing on the results of former studies, the perspective PDCLC preparation method as well as high-performance liquid-crystalline chiral nematics were obtained and applied. The microencapsulation in poly(vinyl, alcohol) has been chosen as the method of PDCLC preparation while as liquid-crystalline materials the chiral nematics were adopted. Keywords: material science, liquid-crystalline composites, medical thermography


2019 ◽  
Vol 23 (01n02) ◽  
pp. 154-165 ◽  
Author(s):  
Morteza Adinehnia ◽  
Jeremy R. Eskelsen ◽  
K. W. Hipps ◽  
Ursula Mazur

Mechanical properties of six different binary ionic porphyrin crystals with variable morphologies were measured and correlated with their structural properties. These solids were formed from stoichiometric combinations of negatively charged tectons, meso-tetra(4-sulfonatophenyl)porphyrin (TSPP), Cu(II) meso-tetra(4-sulfonatophenyl)porphyrin (CuTSPP), Ni(II) meso-tetra (4-sulfonatophenyl)porphyrin (NiTSPP), and four different cationic tectons, namely, meso-tetra (4-pyridyl)porphyrin (TPyP), tetra([Formula: see text]-methyl-4-pyridyl)porphyrin (TMPyP), Cu(II) meso-tetra([Formula: see text]-methyl-4-pyridyl)porphyrin (CuTMPyP), Ni(II) meso-tetra([Formula: see text]-methyl-4-pyridyl)porphyrin (NiTMPyP), and tetra(4-aminophenyl)porphyrin (TAPP). Crystal structures were determined from single crystal and powder X-ray diffraction patterns. Scanning electron and atomic force microscopes (SEM and AFM) provided topographical information. The common arrangement of the porphyrin tectons within the crystals is consistent with alternating face-to-face molecular arrangement forming coherent columns along the fast-growing long axis which are held together by electrostatic and [Formula: see text]–[Formula: see text] interactions as well as hydrogen bonding. In acquiring the indentation data of the porphyrin crystals using AFM, stress was applied perpendicular to the direction where ionic and [Formula: see text]–[Formula: see text] bonds dominate the packing. At indent loads [Formula: see text]50 nN/nm2, all the porphyrin structures deformed elastically. Young’s modulus ([Formula: see text] values for the different crystals range from 6 to 28 GPa. In a broader perspective, this study highlights the extraordinary mechanical behavior of porphyrin assemblies formed by ionic self-assembly. Judicious selection of charged porphyrin synthons can yield crystalline materials with mechanical properties that combine the elastic characteristics of ‘soft’ polymers with the stiffness of composite materials. Such high-performance materials are excellent candidates for deformable optoelectronic devices.


2021 ◽  
Author(s):  
Lu Zhang ◽  
Wen Ma ◽  
Chen Sun ◽  
Lei Fang ◽  
Xueling Song ◽  
...  

Organolead halide crystalline materials are an emerging class of high-performance photocatalysts. However, limited studies have been made to tune their photoactive properties by precise introduction of transition metals. Herein, we...


Author(s):  
L. E. Thomas ◽  
J. S. Lally ◽  
R. M. Fisher

In addition to improved penetration at high voltage, the characteristics of HVEM images of crystalline materials are changed markedly as a result of many-beam excitation effects. This leads to changes in optimum imaging conditions for dislocations, planar faults, precipitates and other features.Resolution - Because of longer focal lengths and correspondingly larger aberrations, the usual instrument resolution parameter, CS174 λ 374 changes by only a factor of 2 from 100 kV to 1 MV. Since 90% of this change occurs below 500 kV any improvement in “classical” resolution in the MVEM is insignificant. However, as is widely recognized, an improvement in resolution for “thick” specimens (i.e. more than 1000 Å) due to reduced chromatic aberration is very large.


Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).


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