Crystalline Plates Research Articles

Reflectance Properties of Brown Mass Dyed Poly(ethylene terephthalate) Filament Yarns in the Visible-near Infrared Region

Near infrared and visible reflectance properties of brown mass dyed poly(ethylene terephthalate) melt spun filament yarns were studied compared to natural brown hue of desert areas. Pigment Red 177, Pigment Green 7 and carbon black particles were used in this investigation. Near-infrared reflectance, mechanical and thermal properties as well as crystallinity of the camouflage poly(ethylene terephthalate) mass dyed filament yarns were measured. The obtained result indicated that by using an optimal content of the mentioned colored pigments and carbon black particles during the melt spinning operation could be achieved to desirable near infrared reflectance properties in the poly(ethylene terephthalate) drawn filament yarns. Also, mechanical properties of the samples were acceptable evaluated. The samples with the highest concentration of pigments had the highest percentage of crystallinity. XRD results indicated that 2 sample with the highest concentration of pigments and additives among other samples had the greatest distance between the crystalline plates. Maximum space between crystal layers is about 4.01-4.08 A. Also, microstructural uniformity of the sample was confirmed by a low variation of samples.

Laser operation of cleaved single-crystal plates and films of Tm:KY(MoO4)2.

We report on the crystal growth, spectroscopy and first laser operation of a novel double molybdate compound - Tm:KY(MoO4)2. This orthorhombic (sp. gr. Pbna) crystal exhibits strong anisotropy of the spectroscopic properties due to its layered structure. The maximum stimulated emission cross-section for the 3F4 → 3H6 transition is 2.70×10-20 cm2 at 1856nm with a bandwidth of >110 nm (for E || b). The lifetime of the 3F4 state is 2.29 ms. Crystalline films and plates (thickness down to 70 µm) of high optical quality are obtained by mechanical cleavage along the (100) plane. Continuous-wave diode-pumped laser operation is achieved in such thin films and plates yielding a maximum output power of 0.88 W at ∼1.9 µm with a slope efficiency of 65.8% and a linearly polarized laser output. Vibronic lasing is demonstrated at ∼2.06 µm. Tm:KY(MoO4)2 is promising for microchip and thin-disk lasers.

Comparative Modeling of Power Hardening Micro-scale Metallic Plates Based on Lower and Higher-Order Strain Gradient Plasticity Theories

Present study investigates a comparative study of lower and higher-order strain gradient plasticity (SGP) theories involving the size-dependent micromechanically flexural behaviors of crystalline thin plates. The investigation includes the Mechanism-Based and the Chen–Wang SGP models established on the Taylor dislocation hardening by evoking the statistically stored dislocations and geometrically necessary dislocations. In addition, these models are conjugated with a multiple plastic work-hardening law proposed for the microstructural applications of the SGP. An analytical approach based on energy minimizing method is used for obtaining deflection values in terms of the length scale, exponent of the work-hardening and the tangential module. The obtained results indicate a meaningful dependence of the deflections to the length scale, plastic work hardening and other parameters as well.

Broad angular anisotropy of multiple scattering in a Si crystal

We observed reduction of multiple Coulomb scattering of 855 MeV electrons within a Si crystalline plate w.r.t. an amorphous plate with the same mass thickness. The reduction owed to complete or partial suppression of the coherent part of multiple scattering in a crystal vs crystal orientation with the beam. Experimental data were collected at Mainz Mikrotron and critically compared to theoretical predictions and Monte Carlo simulations. Our results highlighted maximal 7% reduction of the r.m.s. scattering angle at certain beam alignment with the [100] crystal axes. However, partial reduction was recorded over a wide range of alignment of the electron beam with the crystal up to 15^{circ }. This evidence may be relevant to refine the modelling of multiple scattering in crystals for currently used software, which is interesting for detectors in nuclear, medical, high energy physics.

Hydrothermally synthesized MnSe as high cycle stability anode material for lithium-ion battery

Seeking for superior electrode materials is a significant project in lithium-ion battery research interests. In this paper, pure MnSe was synthesized via a simple hydrothermal method, which exhibits high crystalline and lamellar plate microstructure by systematical characterization analysis. Further, the as-synthesized MnSe was investigated for electrochemical performance as anode material of lithium-ion battery via correlative measurements. In the half-cell tests, the MnSe lithium-ion battery has delivered large specific capacity (302.7 mAh g−1 at 0.2 C), proper voltage platform, excellent rate performance, satisfactory reversibility, and outstanding ionic conductivity. It should be noted that the capacity retention of battery can reach up to 70.8% even after 3000 times cycle at 5.0 C current density, demonstrating remarkable cycle stability. This work not only reveals superior performance of MnSe materials from a different perspective but also provides a potential practical candidate for lithium-ion battery anode.

Validation of Some Elements of the New Model of the Nepa-Peleduy Arch Subsurface Structure of the Nepa-Botuoba anteclise in the East of the Siberian Platform

The studies were carried out on the Nepa-Peleduy arch (NPA) of the Nepa-Botuoba anteclise, the territory strategically important for the Russian Federation, where large and unique hydrocarbon deposits were discovered including those for the ESPO oil pipeline and the “Siberian Force” gas pipeline, which is under construction. The problem is in increasing the oil resource volume, as the hydrocarbon potential of the sedimentary mantle is largely exhausted. The evidence for the hypothesis by B.A. Sokolov, the Corresponding Member of the RAS, that the allochthonous crystal plate overlapping the aulacogen with Riphean deposits underlies in NPA, opens the possibility of increasing the hydrocarbon reserves in the “subfoundation” formations in the arch. Moreover, it can as clarify the controversial nature of the NPA deposits, which sedimentary mantle lacks deposits with a high content of organic carbon . We observe the Hilbert transform of the time section of the CDP method for the fragment of the “Batolith- 1” geotraverse, passing through the Katanga Saddle, the NPA and the Cis-Patom foredeep, and geophysical materials and the data of the wells on it. Based on the original constructions on geological and geophysical data and modeling, related to the development of the abovementioned hypothesis arguments for confirming the existence of a crystalline plate opened by the wells at the base of the NPA and the reality of the development of the Lower Vendian and Riphean deposits beneath it were obtained. The inversion paleorift’s western side position is outlined, the thickness of the plate and the oilfield characteristics of the deposits under it predicted are estimated, which can serve as a justification for the expediency of exploration of “subfoundation” deposits.

Evaluation of corrosion behavior of an amorphous Ni60Nb40–alloy with its crystalline form in stimulated PEMFC conditions

Ni60Nb40 amorphous ribbon was prepared by melt spinning method and its corrosion property compared with its crystalline counter part i.e., Ni60Nb40 crystalline plate were prepared by copper mold suction casting technique. The amorphicity of these alloys were characterized by XRD technique. The corrosion properties of these alloys were also tested by electrochemical potentiodynamic polarization technique as well as chemical immersion test in 1 M H2SO4 (80 °C) with air and H2 bubbling to simulate cathodic and anodic conditions of Polymer Exchange Membrane Fuel Cell (PEMFC), respectively. The corrosion resistance property of amorphous alloy was found to be more than one order higher than that of its counterpart. The stability and occurrence of pitting during corrosion were monitored by cyclic polarization technique. The changes in surface morphologies of alloys before and after corrosion were characterized by EPMA. The change in cationic concentrations and passive layer thickness on the surfaces during corrosion were measured by using XPS technique.

Using the Solc optical filter for determination of crystalline plates thickness

Using the Solc optical filter for determination of crystalline plates thickness

Silica-graphene nanohybrid supported MoS2 nanocatalyst for hydrogenation reaction and upgrading heavy oil

Abstract Application of nanoparticles in enhanced heavy oil recovery has drawn numerous attentions in the last decade. The nanoparticles can act as carries for catalytic species, e.g., metals for in situ reactions, such as oxidation and hydrogenation, which are efficiently used to improve the heavy oil recovery process. Herein the facile ball-milling method is reported for the synthesis of silica-graphene nanohybrid supported molybdenum disulfide (MoS2) nanocatalyst with different weight percentages of MoS2 (silica-graphene/MoS2), which can be used for upgrading heavy crude oil. The morphological analyses show that adding nanohybrids containing graphene sheets in ball-milling process for the synthesis of silica-graphene/MoS2 increases the distance between crystalline plates in MoS2 and improves catalytic activity. Hydrogenation reactions of phenanthrene and crude oil were carried out at a total pressure of 60 bar (900 psi), at 200 °C. Reaction products were analyzed by a gas chromatograph-mass spectrometer. Furthermore, the effect of the amount of catalyst (10 wt% and 20 wt% of MoS2) loading on the supported in hydrogenation reactions is investigated. The silica-graphene/MoS2 containing 10 wt% MoS2 can significantly increase the API gravity of crude oil (up to 7.7°) and decrease its viscosity (up to 81%).

Morphology-dependent third-order optical nonlinearity of a 2D Co-based metal-organic framework with a porphyrinic skeleton.

A two-dimensional (2D) Co-based metal-organic framework (MOF) with porphyrinic skeleton forms crystalline plates, flower-shaped clusters, and ultrathin films under optimized conditions, including the use of polyvinylpyrrolidone (PVP) as a surfactant. Ultrathin films demonstrate the best solution-based third-order nonlinear optical properties, featuring a nonlinear transmittance (T) value of 0.54, absorption coefficient (α2) of 9.5 × 10-10 m W-1 and second hyperpolarizability (γ) value of 1.37 × 10-28 esu, which are slightly better than those of the flower-shaped clusters (T = 0.65, α2 = 7.0 × 10-10 m W-1; γ = 1.27 × 10-28 esu), but marginally better than those of the crystalline thin plates (T = 0.94, α2 = 2.4 × 10-10 m W-1; γ = 0.24 × 10-28 esu).

The Organic Crystalline Materials of Vision: Structure-Function Considerations from the Nanometer to the Millimeter Scale.

Vision mechanisms in animals, especially those living in water, are diverse. Many eyes have reflective elements that consist of multilayers of nanometer-sized crystalline plates, composed of organic molecules. The crystal multilayer assemblies owe their enhanced reflectivity to the high refractive indices of the crystals in preferred crystallographic directions. The high refractive indices are due to the molecular arrangements in their crystal structures. Herein, data regarding these difficult-to-characterize crystals are reviewed. This is followed by a discussion on the function of these crystalline assemblies, especially in visual systems whose anatomy has been well characterized under close to in vivo conditions. Three test cases are presented, and then the relations between the reflecting crystalline components and their functions, including the relations between molecular structure, crystal structure, and reflecting properties are discussed. Some of the underlying mechanisms are also discussed, and finally open questions in the field are identified.

Synthesis of highly crystalline phase pure calcium metastannate by molten salt method

Calcium metastannate CaSnO3 with orthorhombic crystal system has been synthesized at low temperature by molten salt method using KCl-LiCl as a reaction medium and equimolar of SnO2 and CaCO3 as precursors. The process parameters including the reaction temperature, salt type, and salt to precursor weight ratio were investigated. Rietveld refinements on X-ray powder diffraction patterns were performed using X'Pert HighScore Plus software to calculate phase percent of each phase present in the obtained powder. The results of these calculations were followed in order to choose the salt system that requires the least reaction temperature to produce the highest CaSnO3 percent. The as-prepared compound was characterized by various techniques such as X-Ray diffraction (XRD), energy dispersive X-Ray spectrometry (EDX), Fourier transform infrared spectrometry (FTIR), and field emission scanning electron microscope (FE-SEM). The experimental results showed that highly crystalline phase pure CaSnO3 laminar plates could be prepared at 1000 °C for short period of time without any other detectable secondary phases.

Recycling of LCW produced form water plants for synthesizing of nano FeO(OH), Al(OH)3, and layered double hydroxide: Effect of heat-treatment

Liquid concentrate waste (LCW) is a high concentrated liquid produced as a by-product from water plants. It contains huge amounts of aluminum and iron residues. Its disposal causes many environmental problems, so it is significant to recycle this waste for production of interested nano materials such as FeO(OH) or Fe2O3·H2O, Al(OH)3 and layered double hydroxide (LDH) to be used for different applications. In the present work, these materials were chemically prepared using suitable chemicals and under appropriate conditions to get nano powders. The synthesized Al(OH)3 was utilized for preparation of Mg-Al-LDH in the presence of magnesium salt. The synthesized nano powders were investigated by X-ray diffraction (XRD), fourier transform infrared (FTIR), transmission electron microscope (TEM) and scanning electron microscope (SEM). The crystallite size was also calculated using XRD data by Scherrer equation. Effect of temperature up to 1000 °C on the phase composition and morphology of LDH was also studied. The results revealed that well crystalline Al(OH)3 and weak crystalline FeO(OH) nano powders were successfully synthesized by the suggested chemical method. Al(OH)3 exhibited ultrafine, fiber-like crystalline forms consisted of tiny hexagonal-like plates with size of about 30 nm, whileas FeO(OH) exhibited hexagonal prism particles with size of about 60 nm. Well crystalline hexagonal plate LDH having size of 80 nm was obtained after precipitation at 75 °C; its crystallinity was increased after hydrothermally treated at 140 and 180 °C. LDH having gel structure with very small particles was obtained at 180 °C. Heat treatment of LDH up to 1000 °C led to dissociation with the formation MgAl2O4 spinel. Grain growth was happened after heat treatment but the size was still in the nano range.

Environment-Adaptive Coassembly/Self-Sorting and Stimulus-Responsiveness Transfer Based on Cholesterol Building Blocks.

Manipulating the property transfer in nanosystems is a challenging task since it requires switchable molecular packing such as separate aggregation (self‐sorting) or synergistic aggregation (coassembly). Herein, a unique manipulation of self‐sorting/coassembly aggregation and the observation of switchable stimulus‐responsiveness transfer in a two component self‐assembly system are reported. Two building blocks bearing the same cholesterol group give versatile topological structures in polar and nonpolar solvents. One building block (cholesterol conjugated cynanostilbene, CCS) consists of cholesterol conjugated with a cynanostilbene unit, and the other one (C10CN) is comprised of cholesterol connected with a naphthalimide group having a flexible long alkyl chain. Their assemblies including gel, crystalline plates, and vesicles are obtained. In gel and crystalline plate phases, the self‐sorting behavior dominates, while synergistic coassembly occurs in vesicle phase. Since CCS having the cyanostilbene group can respond to the light irradiation, it undergoes light‐induced chiral amplification. C10CN is thermally responsive, whereby its supramolecular chirality is inversed upon heating. In coassembled vesicles, it is interestingly observed that their responsiveness can be transferred by each other, i.e., the C10CN segment is sensitive to the light irradiation, while CCS is thermoresponsive. This unprecedented behavior of the property transfer may shine a light to the precise fabrication of smart materials.

Periodical poling of LiNbO3:MgO by electron beam

ABSTRACTWe have studied the features of periodical poling by focused electron beam irradiation of MgO-doped lithium niobate (MgOLN) single crystalline plate covered by the resist layer. We have distinguished the main types of the domain structure depending on the irradiated dose. We have revealed that total domain area and width of the domain stripes depend linearly on the dose and irradiated stripe width. We have observed the highly regular domain structures with duty-cycle close to desirable value of 0.5 on both polar surfaces.

Curved diamond-crystal spectrographs for x-ray free-electron laser noninvasive diagnostics.

We report on the manufacturing and X-ray tests of bent diamond-crystal X-ray spectrographs, designed for noninvasive diagnostics of the X-ray free-electron laser (XFEL) spectra in the spectral range from 5 to 15 keV. The key component is a curved, 20-μm thin, single crystalline diamond triangular plate in the (110) orientation. The radius of curvature can be varied between R = 0.6 m and R = 0.1 m in a controlled fashion, ensuring imaging in a spectral window of up to 60 eV for ≃8 keV X-rays. All of the components of the bending mechanism (about 10 parts) are manufactured from diamond, thus ensuring safe operations in intense XFEL beams. The spectrograph is transparent to 88% for 5-keV photons and to 98% for 15-keV photons. Therefore, it can be used for noninvasive diagnostics of the X-ray spectra during XFEL operations.

In Situ Evaluation of Calcium Phosphate Nucleation Kinetics and Pathways during Intra- and Extrafibrillar Mineralization of Collagen Matrices.

We revealed that nucleation sites within collagen fibrils determined pathways for calcium phosphate (CaP) nucleation and its transformation, from amorphous species to crystalline plates, during the biomineralization process. Using in situ small-angle X-ray scattering (SAXS), we examined the nucleation and growth of CaP within collagen matrices and elucidated how a nucleation inhibitor, polyaspartic acid (pAsp), governs mineralization kinetics and pathways at multiple length scales. Mineralization without pAsp led initially to spherical aggregates of CaP in the entire extrafibrillar spaces. With time, the spherical aggregates transformed into plates at the outermost surface of the collagen matrix, preventing intrafibrillar mineralization inside. However, mineralization with pAsp led directly to the formation of intrafibrillar CaP plates with a spatial distribution gradient through the depth of the matrix. The results illuminate mineral nucleation kinetics and real-time nanoparticle distributions within organic matrices in solutions containing body fluid components. Because the macroscale mechanical properties of collagen matrices depend on their mineral content, phase, and arrangement at the nanoscale, this study contributes to better design and fabrication of biomaterials for regenerative medicine.

Influence of Electrolyte Solvent Properties on Li-O2 Battery Discharge Product Morphology

Li-air batteries (LAB) can theoretically enable energy storage with 5-fold increased specific energy in comparison to that of Li-ion systems. A number of fundamental problems prevent LAB from being reversibly rechargeable however. Precipitation of the discharge products, e.g. lithium peroxide (Li2O2), inside a positive electrode is one of the key processes that control battery performance [1], thus detailed understanding of product deposition mechanisms is required to achieve deeper discharge and complete reversibility. Product formation is a result of multistep chemical process ending up with crystallization. Depending on the discharge conditions and, especially, electrolyte solvent, different growth mechanisms occur giving rise to quite different morphologies. Recently, it has been reported that solvent’s donor number play a key role in lithium peroxide formation processes [2]. Here we test the proposed theory in a wider range of solvents, including DMA and sulfolane. Carbon paper was used as an electrode material with controlled porosity. Solvent list included DMSO, MeCN, DMA, DME and sulfolane and was demonstrated to be relatively stable to ORR products and intermediates. Composition, structure and morphology of the discharge products formed during potentiostatic discharge were analysed. It was shown that oxygen reduction in the presence of lithium ions in the electrolyte proceeds with the formation of plate-like particles Li2O2 that form a film or agglomerate complex morphology. The formation of Li2O2 crystalline plates proceeds via superoxide disproportionation in solution [3]. [1] Christensen J, Albertus P, Sanchez-Carrera RS et al. A Critical Review of Li-Air Batteries// J. Electrochem. Soc. 2012, 159:R1. [2] Johnson L, Li C, Liu Z et al. The role of LiO2 solubility in O2 reduction in aprotic solvents and its consequences for Li–O2batteries// Nature Chem. 2014, 6:1091–1099. [3] T.K. Zakharchenko, A. Y. Kozmenkova, D.M. Itkis et al. Lithium peroxide crystal clusters as a natural growth feature of discharge product in Li-O2 cell// Beilstein J. Nanotechnol., 2013:4.

Stable non-covalent labeling of layered silicate nanoparticles for biological imaging

Layered silicate nanoparticles (LSN) are widely used in industrial applications and consumer products. They also have potential benefits in biomedical applications such as implantable devices and for drug delivery. To study how nanomaterials interact with cells and tissues, techniques to track and quantify their movement through different biological compartments are essential. While radiolabels can be very sensitive, particularly for in vivo studies, fluorescent labeling has been preferred in recent years because of the array of methods available to image and quantify fluorescent nanoparticles. However, labeling can be problematic, especially if it alters the physical properties of the nanomaterial. Herein is described a novel non-covalent labeling technique for LSN using readily available fluorescent dimeric cyanine dyes without the need to use excess amounts of dye to achieve labeling, or the need for removal of unbound dye. The approach utilizes the cationic binding properties of layered silicate clays and the multiple quaternary nitrogens associated with the dyes. Preparation of YOYO-1 labeled LSN with optimal dispersion in aqueous media is presented. The utilization of the labeled particles is then demonstrated in cell binding and uptake studies using flow cytometry and confocal microscopy. The labeled LSN are highly fluorescent, stable and exhibit identical physical properties with respect to the unlabeled nanoparticles. The general approach described here is applicable to other cyanine dyes and may be utilized more widely for labeling nanoparticles that comprise a crystalline plate structure with a high binding capacity.

Crystalline Structure, Surface Morphology and Optical Properties of Nanolamellar Composites Obtained by Intercalation of InSe with Cd

A material composed of InSe and CdSe crystallites was obtained by heat treatment at 753K of InSe single crystalline plates in Cd vapour for 3÷24hours. The average diameters of CdSe and InSe crystallites determined from diffraction lines analysis are respectively equal to 20nm and 22nm. The photoluminescence spectra at 300K and 80K of composite decompose well into two Gaussian curves, one is in good correlation with the photoluminescence of CdSe crystals and the other is shifted to higher energies than the width of the band gap of CdSe crystals.