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An increasing number of researchers are interested in studying CsPbBr3 perovskite solar cells (PSCs) due to their high stability. However, the use of methanol during the spin-coating process is extremely hazardous, both to humans and the environment. CsBr is very soluble in water, but owing to its high specific heat capacity, water causes uneven crystallization and the creation of pores, which negatively impact the performance of CsPbBr3 devices. In this paper, water is introduced as the solvent for CsBr in place of methanol to prepare CsPbBr3 films and ethanol is used as the surface treatment solvent. The morphology and crystal quality of CsPbBr3 films are improved by varying the concentration and spin-coating cycles of the CsBr/H2O solution and adding ethanol post-treatment. The results show that high-quality CsPbBr3 films with reduced grain boundaries and high phase-purity were obtained by spin-coating 100 mg/mL CsBr/H2O solution three times and using ethanol as a post-treatment. The CsPbBr3 solar cells yielded a maximum efficiency of 7.65% and demonstrate long-term stability over 1100 h. [ABSTRACT FROM AUTHOR]

Margarine is a water-in-oil food emulsion and is mostly formulated with selected vegetable oils. This favorable tablespread widely consumes as a butter alternative with both nutritional and economical aspects. The quality of margarine is determined by its textural and rheological properties, which dramatically affect consumer acceptance. Speardability and hardness are considered as the most important textural attributes specifying margarine desirability. The textural and rheological properties of margarine noticeably depend on emulsion characteristics, crystal morphology, processing method, storage condition, fatty acid content and origin. The fat phase of margarine with β′ form crystals develops a smooth and pleasant texture. Rheological measurements could evaluate the emulsion stability, shelf life, meltability and viscoelastic behavior of margarine in different conditions. The physical structure of margarine directly influences spreadability, mouthfeel and meltability and even indirectly impresses on flavor and appearance. This paper focuses on different margarine productions, assesses their viscoelastic and textural characteristics to find out suitable formulation and eventually modifies its physical attributes. [ABSTRACT FROM AUTHOR]

In this paper, the influence of magnetron-sputtered AlN nucleation layers with different thicknesses on ultraviolet (UV) light-emitting diode (LED) chips is studied. First, magnetron-sputtered AlN layers with thicknesses of 8, 25, and 42 nm were prepared on a patterned sapphire substrate (PSS). Subsequently, a 2.8 μm-thick GaN layer was epitaxially grown. We found that when the magnetron-sputtered AlN was 25 nm thick, GaN had the best crystal quality and morphology. Therefore, we grew an 800 nm GaN layer on PSS to analyze the initial growth mechanism of the material. The scanning electron microscopy (SEM) images showed that when the thickness of the sputtered AlN layer was 25 nm, the GaN grains on the sidewall of the PSS cone were the least abundant. In addition, according to the selected area electron diffraction (SAED) test, the (011) crystal plane of GaN appeared on the sidewall of the PSS cone. The (011) crystal plane is the semipolar plane of GaN, which is not conducive to the growth of polar GaN materials. Finally, on this basis, we fabricated UV-LED chips. Among them, the UV-LED chips with the 25 nm magnetron-sputtered AlN layer exhibited the best electrical and optical performance. Overall, this work provides a pathway to improve the performance of UV-LED chips. [ABSTRACT FROM AUTHOR]

Glucosamine hydrochloride (GAH) is a kind of natural hexose, which is used to promote the synthesis of mucopolysaccharides and improve the metabolism of articular cartilage. In this paper, the solubility of GAH in pure water and aqueous system with the presence of three kinds of additives (HCl, NaCl, KCl) at temperatures ranging from 278.15 K to 323.15 K was determined by gravimetric method. When there are additives in water, the solubility of GAH increases with the increase of temperature and decreases with the increase of concentration of the three kinds of additives. When the additives were at similar mole fractions, HCl led to the lowest solubility of GAH. The modified Apelblat model and van't Hoff model were used to correlate the solubility data. The average relative deviation (ARD) data of Apelblat and van't Hoff models were less than 5%, indicating good fitting results. Based on the thermodynamic data, the cooling crystallization process of GAH was performed. It was found that the additives could affect the crystal morphology, particle size, and yield of GAH products. This study supplemented the thermodynamic data of GAH and studied the cooling crystallization process in the presence of GAH additives, which provided important guidance for the optimization of the crystallization process. [ABSTRACT FROM AUTHOR]

In order to alleviate the serious problem of scaling in oilfield water injection pipelines, we developed a scale collection device and applied it in the field based on the idea to "change passive descaling to active descaling", but the effect is not stable, so we need to improve the descaling effect. Firstly, this paper analyzed the effect of surface physical properties of eight non-metallic materials on CaCO3 scale growth and their mechanisms through shear experiments. Then, the influence of surface properties (roughness, contact angle, surface energy) on the scale growth characteristics was investigated. Finally, the influence of material surface properties on the friction coefficient was studied by a cyclic experiment. The results showed that except for PTFE (polytetrafluoroethylene), the fouling amount of the other seven materials changed abruptly at 18 h, and the maximum fouling amount of FRP was 2.05 g/m3. It was found by scanning electron microscopy that the fouling particles on the surface of FRP were interconnected and presented in the form of flakes, which was related to the larger surface wettability, surface energy, and roughness. At the same time, the surface properties of the material have a certain relationship with the friction coefficient, and the influence of the contact angle on the friction coefficient is greater than the surface energy and roughness. [ABSTRACT FROM AUTHOR]

The present paper reports a theoretical investigation based on first‐principles density functional theory calculations to predict the external morphology of the tetragonal GdVO4 crystal from its internal structure. The Bravais–Friedel–Donnay–Harker (BFDH) method, attachment energy (AE) method and surface energy (SE) method were used in this study. Slice energies (cohesive, attachment and specific surface) of the three main crystal faces having (110), (101) and (200) orientation and their dhkl thicknesses were computed using CRYSTAL17 code, in the frame of a 2D periodic slab model. The relative growth rate (Rhkl) and the morphological importance (MIhkl) for each unrelaxed and relaxed (hkl) face of interest were determined. Consequently, the crystal shapes predicted based upon BFDH, AE and SE methods were represented by the Wulff construction. The results of the morphology crystal predictions, based on the above methods, were compared both against each other and against the experimentally observed morphologies. A quite satisfactory agreement between the predicted and observed crystal morphologies is noticed. [ABSTRACT FROM AUTHOR]

Materials based on bismuth(III) oxide are candidate to be used in optical and electronic devices because of their properties such as a variable band gap, photoconductivity, photoluminescence, high refractive index, and dielectric permittivity. These properties are dependent of several factors, e.g., present phases and crystal morphology. The microwave-assisted hydrothermal method (MAH) is a fast and efficient approach of synthesis to obtain semiconductor powders. However, the synthesis of monoclinic bismuth oxide (α-Bi2O3) with acicular morphology by MAH was not found in literature. In this paper, microcrystals of acicular α-Bi2O3 (monophasic) were successfully obtained by MAH using a synthesis temperature of 80°C for 0.5 h. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron, and transmission electron microscopies showed the formation of a monoclinic structure (space group P21/c) with acicular morphology that grew along the [001] direction. The temperature and time necessary to synthetize acicular microcrystals were significantly lower than those found for acicular microcrystals obtained by conventional hydrothermal method. [ABSTRACT FROM AUTHOR]

3-Nitro-1,2,4-triazole-5-one (NTO) has received wide attention and has applications owing to its excellent detonation performance and low sensitivity. A new crystal form of NTO was prepared via the solvent evaporation method and named γ-NTO. Its crystal properties were studied through single-crystal X-ray diffraction, and the results indicated that the unit cell of γ-NTO belongs to the monoclinic space group Pc, with eight molecules in the single unit cell. The density of this crystal is calculated to be 1.907 g cm−3, which is higher than that of β-NTO and similar to that of α-NTO. The crystal morphology was calculated to be a polygonal shape with a symmetrical growth pattern using the reactive force field. Based on the analysis of reactive molecular dynamics, the thermal decomposition mechanism of different crystal forms of NTO was elucidated, and the results showed that γ-NTO demonstrates higher gas production, providing a successful way to enhance detonation performance. The results of IR and differential thermal analysis (DTA) support the above conclusions. [ABSTRACT FROM AUTHOR]

In this paper, the melting memory effect generated by a novel cyclic thermal treatment protocol with form II as "seeds" on the polymorphic transformation in isotactic polybutylene-1(iPB-1) was investigated. Polar Optical Microscope (POM), wide angle X-ray diffraction (WAXD) and Fourier transform infrared spectroscopy (FTIR) were used to study the changes of morphology and crystal form II → I transition during aging. Selected crystallization temperature (Tsc) and melting temperature (Tsm) were applied to generate residual nuclei of form II. Both cycled and uncycled samples were analyzed to demonstrate the formation of crystal I and polymorphic transformation. The results indicate that the melting memory has a significant effect on tetragonal modification, leading to an increased nucleation density and an accelerated nucleation speed. The ordered chain sequences in crystal II initiated the formation of crystal nuclei of form I, resulting in a rapid conversion and increased transition degree during the hexagonal crystal growth. Form I was found to have two formation pathways, including the transformation of the unstable crystal form II and the direct formation from residual crystal and melt, which have been rarely discussed before and may shed light on understanding of crystal formation mechanism in polymorphism polybutene-1. [ABSTRACT FROM AUTHOR]

NiO-based materials hold great promise as oxygen evolution reaction (OER) catalysts owing to their high intrinsic OER activity and good chemical stability. Herein, Ni/NiO/C hollow microspheres with high activity were successfully fabricated through a facile one-step mist chemical vapor deposition (mist-CVD) process using ethanolamine and nickel chloride as precursors. The high-temperature pyrolysis of the organic precursor yields a significant quantity of gas, leading to a rapid increase in pressure within the droplet, which prompts the nanoparticles to aggregate on the surface of the droplet and form a hollow structure. The crystal phase and morphology of the samples can be modulated through optimizing the decomposition temperature, and particularly, Ni/NiO/C porous hollow microspheres synthesized at 600 °C (Ni-600) presented the best OER activity, exhibiting an overpotential at 10 mA cm−2 (η10) of 286.4 mV and a Tafel slope of 54.8 mV dec−1. The outstanding OER electrocatalytic performance of Ni/NiO/C hollow microspheres is ascribed to the improved electronic conductivity facilitated by the existence of metallic Ni and amorphous C, coupled with the relatively large specific surface area derived from the unique hollow structure. [ABSTRACT FROM AUTHOR]

Engineering of organic single crystal toward controllable and aligned patterns at microscale is crucial to the realization of highly integrated organic photonic devices and optoelectronics. However, precise positioning and controllable morphology of crystal structures is still challenging due to the strict conditions for crystal growth. In this paper, a solution based crystal regulation strategy with the assistance of template‐constrained growth method and femtosecond laser processing technology is developed to prepare aligned crystalline microribbon arrays. Simple solvent evaporation results in the random distribution and orientation of self‐assembled crystalline microribbons while it tends to form highly crystalline and orderly microribbon arrays assisted by the confined template microchannels. The large‐scale microribbon array can be fabricated as organic photodetectors with sensitive and fast response under 405 nm illumination. By virtue of the femtosecond laser processing technique, the microribbon arrays are precisely processed into a series of crystal subunits and each microribbon subunit can function as an individual microcavity resonator to produce stable, high‐quality organic laser. The facile solution based template‐constrained self‐assembly and femtosecond laser processing method provide novel strategies to generate highly oriented and controllable crystal structures for the potential applications in integrated organic lasers and optoelectronics. [ABSTRACT FROM AUTHOR]

As a non-metallic material, high-purity graphite has been widely used in many high-tech fields and has become an important raw material for its production and processing. As the purity of graphite increases, its application value will also increase. Therefore, it is necessary to purify graphite. In this study, the natural flake graphite is purified by the additive-assisted alkali melting-acid leaching process to produce high-purity graphite. Alkali melting is the main process in the alkali-acid process. Therefore, this paper is mainly to explore the removal mechanism of impurities in the alkali melting process. First, the influence of various factors on the purification efficiency in the process of alkali melting is investigated. The fixed carbon content of graphite can reach 99.9815% and 99.9569%, respectively, when 4% (accounting for graphite mass) of sodium metaborate and potassium pyrosulfate is added as additives under the best process conditions. The results show that the crystal structure and morphology of graphite have no obvious changes. Compared with the traditional alkaline melting-acid leaching process, the carbon content of natural flake graphite can be increased to a higher level by an auxiliary alkaline melting-acid leaching process. [ABSTRACT FROM AUTHOR]

1,1′-Dihydroxy-5,5′-bi-tetrazolium dihydroxylamine salt (TKX-50) is a new type of high-energy low-sense explosive with great application value, but TKX-50 made directly from the reaction has problems such as irregular crystal morphology and relatively large length-diameter, and these factors seriously affect the sensitivity of TKX-50 and limit its large-scale application. The internal defects of TKX-50 crystals have a great influence on their weakness, and studying its related properties is of great theoretical significance and application value. To further investigate the microscopic properties of TKX-50 crystals and to explore the connection between microscopic parameters and macroscopic susceptibility, this paper reports the use of molecular dynamics simulations to construct TKX-50 crystal scaling models with three types of defects—vacancy, dislocation and doping—and conducts molecular dynamics simulations. The influence of TKX-50 crystal defects on the initiation bond length, density, bonding diatomic interaction energy, and cohesive energy density of the crystal was obtained. The simulation results show that the models with a higher bond length of the initiator bond and higher percentage activated the initiator's N-N bond and lowered the bond-linked diatomic energy, cohesive energy density, and density corresponding to higher crystal sensitivities. This led to a preliminary connection between TKX-50 microscopic model parameters and macroscopic susceptibility. The results of the study can provide a reference for the design of subsequent experiments, and the research method can be extended to the research work on other energy-containing materials. [ABSTRACT FROM AUTHOR]

Due to its excellent mechanical properties and high aspect ratio, graphene can significantly improve the water and chloride ion permeability resistance of cementitious materials. However, few studies have investigated the effect of graphene size on the water and chloride ion permeability resistance of cementitious materials. The main issues are as follows: How do different sizes of graphene affect the water and chloride ion permeability resistance of cement-based materials, and by what means do they affect these properties? To address these issues, in this paper, two different sizes of graphene were used to prepare graphene dispersion, which was then mixed with cement to make graphene-reinforced cement-based materials. The permeability and microstructure of samples were investigated. Results show that the addition of graphene effectively improved both the water and chloride ion permeability resistance of cement-based materials significantly. The SEM (scanning electron microscope) images and XRD (X-ray diffraction) analysis show that the introduction of either type of graphene could effectively regulate the crystal size and morphology of hydration products and reduce the crystal size and the number of needle-like and rod-like hydration products. The main types of hydrated products are calcium hydroxide, ettringite, etc. The template effect of large-size graphene was more obvious, and a large number of regular flower-like cluster hydration products were formed, which made the structure of cement paste more compact and thus significantly improved the resistance to the penetration of water and chloride ions into the matrix of the concrete. [ABSTRACT FROM AUTHOR]

The second part of the review presents the results of research on SAPO-11 and SAPO-41 molecular sieves over the last three decades, with particular emphasis on methods to control the acid properties, morphology, and secondary porous characteristics of these molecular sieves, as well as on the catalytic applications of SAPO-11 and SAPO-41 for hydroisomerization of C16+n-paraffins. The paper discusses the current understanding of the acid site formation mechanisms in SAPO-11 and SAPO-41, as well as methods for control over the strength and concentration of the acid sites and the morphology and dispersion of the crystals. Recent advances in the synthesis of SAPO-11 and SAPO-41 with a hierarchical porous structure are described, namely the use of pore-forming templates, crystal growth modifiers, and post-synthetic treatment techniques; the pros and cons of different synthesis methods are analyzed. The report also presents the catalytic properties of bifunctional catalytic systems based on SAPO-11 and SAPO-41, including hierarchical structures, in C16+n-paraffin hydroisomerization. Prospective uses of bifunctional catalytic systems based on SAPO-11 and SAPO-41 for hydroisomerization of base oils are described. Finally, the paper formulates the remaining fundamental problems of SAPO-11 and SAPO-41 synthesis, as well as the prospects for the utilization of these materials as components of high-performance catalysts in the oil refining and petrochemical industries. [ABSTRACT FROM AUTHOR]

Calcium carbonate has different crystal characteristics, which makes it play different roles in various application fields. The control of calcium carbonate crystal structure, morphology and size is a hot research topic in the preparation of inorganic materials. The preparation of nano calcium carbonate produced from calcium carbide slag can realize the transformation of waste into resource, which is one of the important research fields concerning the recycling of calcium- containing solid wastes. The controllable preparation of calcium carbonate with different crystalline structure and morphology from calcium carbide slag can make the worthless calcium carbide slag transform into high value-added nano grade products with good environmental and economic effects. The preparation methods of nano calcium carbonate from calcium carbide slag are summarized in this paper, the research progress of the control of crystal structure and morphology during the preparation process is discussed emphatically. The results indicate that, during the nucleation and growth of calcium carbonate crystals, controlling the process conditions can further achieve the regulation of crystal structure and morphology by influencing the degree of supersaturation, and the action mechanism varies from different kinds of additives. As the basis for controlling the equilibrium of the crystallization processes, thermodynamics and kinetics can be used to explain the mechanism of action of each influencing factor. [ABSTRACT FROM AUTHOR]

The functionality and performance of the electronic product are heavily dependent on its quality of power device and radio frequency device, thus further determined by the quality of SiC substrate. Hence, the manufacturing of superior SiC single crystal is of significant importance. One popular way of growing large-diameter SiC single crystal is to leverage physical vapor transport (PVT) method. However, this method admits a common challenge in thermal design and flow control. To tackle this problem, a numerical simulation study of the complete process of growing 150 mm SiC single crystal by resistive heating PVT method was proposed in this paper. A mathematical model to capture the growing process, which comprises the pyrolysis and recrystallization of source materials, the porous structure evolution, the heat-mass transport in the system, and the morphology changes of crystal growth front was established. In order to validate our developed model, the numerical simulations were implemented to study the interaction among the crystal growth, the consumption of source materials, and the thermal field changes. The results show that the high temperature on the side of the source area leads to uneven gas flow, and the high temperature at the bottom results in a uniform airflow and a slightly convex crystal surface. Meanwhile, the growth interface adjusts the equilibrium pressure of the gas species through the radial temperature distribution, therefore, the crystal surface grows into an isotherm shape. In addition, the crystal growth rate is positively correlated with the temperature of the source area and the amount of remaining raw materials. The simulation results are consistent with the reported experimental results inherently, which lay a solid foundation for the optimal growth of large-scale and high-quality SiC single crystals. [ABSTRACT FROM AUTHOR]

Crystallization of polyamide 12 (PA12) is an essential process requiring thorough investigation for evaluating the mechanical properties after the polymer parts are manufactured. The change in crystallization temperature results in different crystallization behaviors for PA12. Hence, the crystal morphology of PA12 achieved provides important information about crystallization behavior, especially for those produced through additive manufacturing due to its heterogenous cooling rate in a single print bed. Considering the need of investigating PA12 crystallization using phase‐field modeling, this paper aims to simulate the spherulite morphology of PA12 undergoing isothermal crystallization. This model is compared with the spherulite morphologies obtained from the optical microscopy test. The model shows that PA12 spherulites have thicker dendrites when the isothermal temperature is higher. The present phase‐field model can determine the spherulite morphologies of bulk printed PA12 based on the crystallization condition and be used to evaluate the properties of the printed part. [ABSTRACT FROM AUTHOR]

In this paper, the process for obtaining non-encapsulated Thermochromic Liquid Crystal (TLC) micro-particles from commercial bulk material (UN R25C10W) is described. The bulk material is analyzed in terms of morphology and rheological properties (i.e. viscosity, maximum shear rate). An experimental evaluation of surface tension values and contact angle measurements is made to complement the rheological data. On the basis of the obtained thermophysical values, an emulsification procedure is proposed and non-encapsulated TLC droplets with a dimension lower than 10 µm were acquired. Further, attention has been focused on the calibration process of TLC bulk material before and after the emulsification. A relation between the local temperature value, RGB and colour intensities (HSI) is obtained by analyzing the digital images with MATLAB Image Processing Toolbox. The obtained results indicate that the commercial bulk material UN R25C10W TLC can be used to obtain stable oil-in-water emulsion by proposed emulsification procedure in this paper. [ABSTRACT FROM AUTHOR]

Compared with jagged and rod-like raw products, the spherulitic 3-nitro-1,2,4-triazol-5-one (NTO) crystalline powder is generally superior in the formulation. However, the growth mechanism and corresponding influential factors for NTO spherulites remain to be deeply explored. Herein, the morphological evolutions of NTO crystals in alcohol solvents under a range of maximum supersaturation (Smax) are systematically investigated. It was found that differences in solvent-crystal interface interactions determine the primary morphology of the growing crystals while the magnitude of Smax determines the subsequent polycrystalline evolution. The cooling rate, initial concentration and stirring rate all could affect the crystal morphology by changing the Smax. It is demonstrated that there exists a critical Smax range (1.75–1.88) above which the formation of spherulites is kinetically favorable. Face indexing tests suggest that the (0 0 1) plane of NTO is mostly prone to twinning at low supersaturation, which is because that the molecular layers on the (0 0 1) surface are prone to twisting and the energy difference before and after is only 8.77 kJ mol−1. Then, the interfacial growth theory is employed to explain how a growing crystal plane develops from smooth to rough with non-crystallographic sub-individuals as the crystallization driving force increases. The change of morphology has a positive consequence in improving the safety performance of NTO crystalline powder under drop-weight impact. These findings would forward the understanding of the spherulitic crystallization process for energetic crystals. [ABSTRACT FROM AUTHOR]

The boron (B)-sulfur (S) co-doped single crystal diamond was prepared by diffusion device using high purity boron powder and sulfur powder at 1 300 ° under a high temperature vacuum. In this paper, scanning electron microscopy, X-ray energy spectroscopy, Raman spectroscopy, and other tests show that the morphology and crystal quality of diamond change with doping of the two elements. The co-doping diamond crystal surface morphology is complex, and the internal morphology of etch pits and gully is stepped. With the doping amount increases, the steps appear to fracture, and high content of boron and sulfur atoms is detected at the etch pits. The diamond with B-S mass fraction of 0.5 have the highest content of boron and sulfur atoms at the etch pits. With the impurity atoms infiltration, full width at half maximum of Raman increases, and crystal quality of the diamond decreases. Hall testing at room temperature reveals that the diamond resistivity decreases after doping. The samples with the B-S mass fraction of 1 and 2 exhibit p-type conductivity. While the sample with the B-S mass fraction of 0.5, the Hall coefficient is negative and shows n-type conductivity. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, we conducted a fundamental study concerning the effect of thermal treatment on the structure and morphology of 2 mol% vanadium doped ZnO nanopowders obtained by microwave assisted sol–gel method (MW). The samples were analyzed by DTA, FTIR, XRD, SEM, and UV–Vis spectroscopy. The DTA results showed that above 500 °C, there was no mass loss in the TG curves, and ZnO crystallization occurred. The XRD patterns of the thermally treated powders at 500 °C and 650 °C showed the crystallization of ZnO (zincite) belonging to the wurtzite-type structure. It was found that in the 650 °C thermally treated powder, aside from ZnO, traces of Zn3(VO4)2 existed. FTIR spectra of the annealed samples confirmed the formation of the ZnO crystalline phase and V–O bands. The micrographs revealed that the temperature influenced the morphology. The increase in the annealing temperature led to the grain growth. The SEM images of the MW powder thermally treated at 650 °C showed two types of grains: hexagonal grains and cylindrical nanorods. UV–Vis spectra showed that the absorption band also increased with the increasing temperature of thermal treatment. The MW sample annealed at 650 °C had the highest absorption in ultraviolet domain. [ABSTRACT FROM AUTHOR]

Coal-based graphene sheets (GS) and coal-based graphene quantum dots (GQDs) are usually prepared separately. In this paper, symbiosis of coal-based GS and coal-based GQDs was successfully prepared with our proposed preparation method by using three raw coals with different reflectance (collected from Qinshui coalfield, Shanxi Province) as carbon sources. The results showed that coal-based GS and coal-based GQDs can exist stably in the symbiosis and are distributed in different layers, and the GQDs are freely distributed between layers of GS. The average number of GS (N ave) in the three symbiosis is about 7 and the average interlayer spacing (d 002) is about 0.3887 nm. The average diameter of GQDs in the three symbiosis is about 4.255 nm and the average d 002 is about 0.230 nm. The average N ave of the three symbiosis was about 3 and the average d 002 is about 0.361 nm. The morphology and crystal parameters of symbiosis is more similar to that of graphene, the elements are only carbon and oxygen. In the prepared symbiosis, the higher the reflectance of raw coal, the smoother the lattice skeleton and the less vortex-layer structure of GS, and the larger the diameter and the denser the six membered ring of GQDs. The C and O functional groups of the prepared symbionts are similar. The higher the reflectance of coal, the higher the content of Câ€"C/C=C. Under ultraviolet light, the prepared products all emit blue, and the higher the reflectance of coal, the higher the ultraviolet absorption, and the stronger the fluorescence intensity. [ABSTRACT FROM AUTHOR]

Recently, microbially induced carbonate precipitation (MICP) has shown potent potential in the field of civil engineering. The calcium carbonate crystals produced by bacteria during the MICP process play a central role in sticking the soil. However, the morphological changes of calcium carbonate crystals in this process and the mechanical performance of soil in the corresponding stages have not been clearly explored. In this paper, the alterations in the morphology of calcium carbonate crystals were continuously observed via scanning electron microscopy during the MICP process in one week, and the mechanical changes of the samples were monitored every day, so as to reveal the relationship between the morphology of calcium carbonate crystals and the mechanical performance of the samples. The results show that the calcium carbonate crystals undergo a gradual change from ellipsoid to rhombic at the 72nd hour. The mechanical properties of both were greatly improved, among which the compressive strength was increased by 2.78 times compared with the previous time point, and the flexure strength was increased by 2.57 times; this time point was also the time when calcite appears. In addition, we found direct evidence on the first day that bacteria act as the nucleation site of calcium carbonate formation. The above findings have certain guiding significance for the in-depth understanding of the internal microscopic changes of MICP and the influence of calcium carbonate morphology on sample mechanics. [ABSTRACT FROM AUTHOR]

Yttrium aluminum garnet powders of good morphology are composed of tiny single crystals of regular faces. However, the growth mechanism of those ploy single crystals remains unknown. This paper provides morphology images of particles uncrushed, and it is found that those tiny crystals grow from large clusters in a pomegranate-like manner. The morphology change occurs after phase transition, and is driven by flux, which provides a semi-liquid environment around the crystals. This paper is beneficial for understanding growth mechanism of poly tiny single crystals of yttrium aluminum garnet powders. [ABSTRACT FROM AUTHOR]

Polyethylene vinyl acetate (EVA) has been widely investigated and employed as polymeric wax inhibitor (PWI). In this paper, the wax deposition characteristics of synthetic oils with different concentrations of EVA PWI were investigated. The obtained surface and bottom wax deposits were analyzed through differential scanning calorimeter (DSC), polarizing microscope, Fourier transform-infrared spectroscopy (FT-IR) and high-temperature gas chromatography (HTGC). It is found that the EVA PWI could obviously decrease the wax deposition rate and accelerate the aging of wax deposits. Adding the EVA PWI can trigger a novel heterogeneous wax deposit structure, in which the wax appearance temperature and wax content increases continuously from the bottom to the surface layer. Compared to the bottom wax deposit, the surface wax deposit has higher concentrations of both EVA and high carbon number wax molecules (Cn > C25). The formation mechanism of the novel heterogeneous wax deposit structure was explained from two aspects. Firstly, the wax crystal morphology of surface layer is significantly changed from needlelike to diamond-like due to higher temperature and the accumulation of EVA and high carbon number wax molecules in the surface wax deposit, therefore, higher solid wax content is needed for the building of a continuous three-dimensional network structure to resist shearing of pipe flow. Secondly, the lower temperature and larger aspect ratio of wax crystals in the bottom wax deposit are adverse for the diffusion of wax molecules into the bottom wax deposit, thus the aging rate of bottom wax deposit is lower than that of surface layer. [ABSTRACT FROM AUTHOR]

Human health has been seriously endangered by arsenic pollution in drinking water. In this paper, iron hydroxide nanopetalines were synthesized through a precipitation method using KBH4 and their performance and mechanism of As(V) and As(III) removal were investigated. The prepared material was characterized by SEM–EDX, XRD, BET, zeta potential and FTIR analyses. Batch experiments indicated that the iron hydroxide nanopetalines exhibited more excellent performance for As(V) and As(III) removal than ferrihydrite. The adsorption processes were very fast in the first stage, followed a relatively slower adsorption rate and reached equilibria after 24 h, and the reaction could be fitted best by the pseudo-second order model, followed by the Elovich model. The adsorption isotherm data followed to the Freundlich model, and the maximal adsorption capacities of As(V) and As(III) calculated by the Langmuir model were 217.76 and 91.74 mg/g at pH 4.0, respectively, whereas these values were 187.84 and 147.06 mg/g at pH 8.0, respectively. Thermodynamic studies indicated that the adsorption process was endothermic and spontaneous. The removal efficiencies of As(V) and As(III) were significantly affected by the solution pH and presence of PO43– and citrate. The reusability experiments showed that more than 67% of the removal efficiency of As(V) could be easily recovered after four cycles. The SEM and XRD analyses indicated that the surface morphology and crystal structure before and after arsenic removal were stable. Based on the analyses of FTIR, XRD and XPS, the predominant adsorption mechanism was the formation of inner-sphere surface complexes by the surface hydroxyl exchange reactions of Fe–OH groups with arsenic species. This research provides a new strategy for the development of arsenic immobilization materials and the results confirm that iron hydroxide nanopetalines could be considered as a promising material for removing arsenic from As-contaminated water for their highly efficient performance and stability. [ABSTRACT FROM AUTHOR]

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Copyright of Chinese Journal of Liquid Crystal & Displays is the property of Chinese Journal of Liquid Crystal & Displays and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper aims to explore the influence of solvent effects on the crystal habit of venlafaxine hydrochloride using the modified attachment energy (MAE) model by molecular dynamics (MD) simulation. Solvent effects were investigated based on the different morphologies of venlafaxine hydrochloride acquired by simulation and experimental technology from the solvents of isopropanol, dimethyl sulfoxide, and acetonitrile. Firstly, morphologically dominant crystal faces were obtained through the prediction of crystal habit in vacuum by the attachment energy (AE) model. Subsequently, the MAEs were calculated by the MD simulation to modify the crystal shapes in a real solvent environment, and the simulation results were in agreement with the experimental ones. Meanwhile, in order to have a better understanding of the solvent effects, the surface structure was introduced to analyze the solvent adsorption behaviors. The results show that the crystal habits of venlafaxine hydrochloride are affected by the combination of the AE and surface structures. Finally, the flowability of the obtained crystal powders from different solvents was investigated by measurement and analysis of the angle of repose and compressibility. The above results verify that the physical properties are closely related to the morphologies of the crystals. [ABSTRACT FROM AUTHOR]

In this paper, the polyketone (POK) extrusion cast film is manufactured by melt stretching method, and the evolution process of the crystal morphology and mechanical properties with the increase of melt drawing ratio (MDR) are followed. The results show that the melt stretching process produces many micro shish‐kebab crystals in the POK. The length of the shish crystal and the thickness of the kebab crystal hardly increase with MDR, but the lateral length of the kebab crystal shows linear growth when MDR exceeds 40. The crystalline morphology of POK is mainly affected by melt relaxation. The molecular chain has sufficient relaxation during cooling at a low MDR (20–40). At this time, micro shish‐kebab crystals are mainly randomly arranged. When MDR exceeds 40, the rapid melt stretching shortens the relaxation time of the tie chain between the neighborhood shish crystal, and the atomic force microscopy image shows a typical shish‐kebab structure. This experimental result indicates that the formation of the oriented lamella structure may be related to the relaxation of the molecular chains between the micro‐shish. When the length of the shish axis and the thickness of the kebab lamellae are similar, it is difficult to distinguish the two. [ABSTRACT FROM AUTHOR]

Today, an actual task of photovoltaics is the search for new light-absorbing materials for solar cells, which will make them more efficient and economically affordable. Semiconductor Cu2NiSn(S,Se)4 (CNTSSe) thin films are promising materials due to suitable optical and electrical properties. This compound consists of abundant, inexpensive, and low-toxicity elements. However, few results of studying the properties of CNTSSe films have been presented in the literature. This paper presents the results of studying the morphology, phase composition, and crystal structure of the CNTSSe films, which were first obtained by high-temperature annealing of electrodeposited Ni/Cu/Sn/Ni precursors on glass/Mo substrates in chalcogen vapor. The films were studied using X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. It has been found that sequential electrochemical deposition makes it possible to obtain the Ni/Cu/Sn/Ni precursors of the required quality for further synthesis of the films. It is shown that high-temperature annealing in chalcogen vapor in air makes it possible to synthesize stable polycrystalline CNTSSe films. The obtained results confirm that the production of CNTSSe films is suitable for use in solar cells by the proposed method, which can be improved by more precise control of the precursor composition and annealing conditions. [ABSTRACT FROM AUTHOR]

Perovskite-structured ABX3 halides are one of the most promising families of materials with many potential applications. However, the controllable growth methods of their crystal facets and the corresponding synthetic chemistry have not yet been resolved. In this paper, we report a ligand substitution strategy for the facet-tunable growth of perovskite structure KMF3 (M = Mg, Mn, Co, Ni and Zn) fluorides under mild hydrothermal conditions. The competition of the strong ligand of NH3 and weak ligand of F− in the octahedral crystal fields of M2+ results in different facet evolution routes for KMF3 samples with the M-site of empty-, partially- or fully-filled 3d orbitals. Although X-ray diffraction results indicated that all five KMF3 compounds are crystalized into the same space group (Pm3m, no. 221), the crystal shape of KMF3 with M = Mg, Mn, Co and Ni evolved from cubic shape to edge-truncated chamfer box shape, while KZnF3 evolved from cubic shape to corner-truncated cubic shape under the same set of synthetic conditions. The cubic shape habitat morphology of KMF3 crystals is enclosed by {100} facets, chamfer box {100} and {110} facets, and corner-truncated cube {100} and {111} facets. The crystal shape formation mechanism was analysed based on ligand field theory and the Bravais–Friedel–Donnay–Harker (BFDH) theory. We expect that the shape controllable synthetic method can benefit the growth of other halide material crystals, and the shape tunable crystals can find more important applications. [ABSTRACT FROM AUTHOR]

In this paper, we report on the effect of sulfur additives (as FeS2 in the Fe90Ni10–C system) on the growth processes, morphology, and defect-and-impurity content of diamond crystals at 6 GPa and 1400 °C. It has been established that the sulfide component plays an inhibitory role in diamond crystallization processes. As the concentration of the sulfur additive (XS) in the system increases from 0 to 20 wt%, the degree of graphite-to-diamond transformation decreases from 100% to zero and the solubility of carbon in the melt decreases from 6.6 to 0.4 wt%. Addition of sulfur to the growth system leads to the appearance of metastable graphite and its amount increases with increasing sulfur content. It is found that the concentration of nitrogen impurities in the synthesized diamonds decreases from 50–100 ppm at XS = 0 to 5–10 ppm at XS = 10–15 wt%. Sulfide additives lead to the transformation of flat-faced octahedral diamond crystals to specific crystals with the elements of antiskeletal growth and fragmentation of their vertices. It is suggested that the main reason for the change in the morphology of diamond crystals is the selective adsorption of sulfide clusters on planar defects located mainly near the vertices of the octahedron. Inhibition of the propagation of growth layers on the {111} faces of diamond crystals leads to the formation of faceted macrosteps, the fragmentation of the crystal vertices and the polycentric structure of the faces. [ABSTRACT FROM AUTHOR]

In this paper, we consider the interaction of components during high-temperature annealing of compressed magnesium and boron powders during the production of superconducting compound MgB2 in studies using standard synthesis technology and hot gas-static pressing technology. In a computer model of crystallization of a binary alloy, the effect of the diffusion of components in the region of the interphase boundary during crystal growth on the morphology of dissipative structures formed during phase transformation was studied. The conditions and mechanism of the formation of a "layered" structure that appears during the crystallization of MgB2 from a magnesium melt in the (Mg–B) system are analyzed. [ABSTRACT FROM AUTHOR]

ZIF-67 is a representative type of metal–organic framework (MOF) developed for the oxygen reduction reaction (ORR) owing to its robust structure in alkaline electrolytes and the presence of the redox-active Co2+ species in the structure. In this work, the improvement of the ORR electrolytic performance of ZIF-67 in its pure phase by optimization of its crystal morphology and crystal facets has been presented. ZIF-67 nanocubes exhibit higher ORR activity than their bulk crystals. The enriched (100) facet in the nanocube crystals provides a higher number of exposed Co2+ sites resulting in improved ORR performances. Moreover, DFT study suggests a distinguished mechanism in the (100) facet highlighting the importance of crystal facets in electrochemical performances. [ABSTRACT FROM AUTHOR]

Filamentous crystals such as whisker crystals are often seen not only in metallic liquids, but also in organic liquids and solutions. They are interesting as reinforce materials. However, it remains challenging to induce filamentous crystals due to an incomplete understanding of the mechanisms behind their formation. In this paper, we investigate filamentous crystal growth in viscous organic liquids. It is found that filamentous crystals grow via an extraordinary dynamical path, where the molecules locally evaporate to bubbles and then redeposite to the tip of growing crystalline filaments. We also succeeded in controlling whether filamentous or faceted crystal growth is selected by inducing or suppressing the bubbles. [ABSTRACT FROM AUTHOR]

Monocrystalline silicon slicing is the first step in making chips, and the surface quality of silicon wafers directly affects the quality of later processing and accounts for a large proportion in the chip manufacturing cost. Ultrasonic vibration assisted wire saw (UAWS) is an effective sawing process for cutting hard and brittle materials such as monocrystalline Si, which can significantly improve the surface quality of silicon wafers. In order to further study the formation mechanism of the surface morphology of single crystal silicon sliced by UAWS, a new model for prediction of wafer surface morphology in UAWS slicing single crystal silicon based on mixed material removal mode is presented and verified by experiments in this paper. Firstly, the surface model of diamond wire saw tool is established by equal probability method. Then, the trajectory equation of arbitrary abrasive particles on the surface of wire saw is derived and analyzed. Thirdly, a new model for prediction of the wafer surface morphology based on mixed material removal mode is presented. Finally, the prediction model is verified by UAWS slicing experiment, and the effects of slicing parameters such as wire saw speed, feed speed, and workpiece rotate speed on the surface quality of silicon wafer were studied. It shows that the predicted wafer surface morphology and the experimental wafer surface morphology are similar in some characteristics, and the average error between the experimental and the theoretical values of the wafer surface roughness is 11.9%, which verifies the validity of the prediction model. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the continuous growth of the population and the improvement of production, the shortage of freshwater has plagued many countries. The use of novel technologies such as desalination to produce fresh water on a large scale has become inevitable in the world. Hydrate-based desalination (HBD) technology has drawn an increasing amount of attention due to its mild operation condition and environmental friendliness. In this paper, literature on hydrate-based desalination is comprehensively analyzed and critically evaluated, focuses on experimental progress in different hydrate formers that have an impact on thermodynamics and dynamics in hydrate formation. Besides, various porous media promotion is investigated. Besides, the hydrate formation morphology and hydrate crystal structure with different hydrate formers are analyzed and compared. Moreover, molecular dynamic simulation is discussed to further understand microscopic information of hydrate formation. Furthermore, simulations of the HBD process by considering the energy consumption are also investigated. In conclusion, the hydrated based desalination is a potential technology to get fresh water in a sustainable way. [ABSTRACT FROM AUTHOR]

The composite gelling system of chlorine and magnesium thioxide was prepared by mixing different mass fractions of magnesium sulfate solution into MOC. Detailed studies regarding the influences of magnesium sulfate replacing magnesium chloride on the setting time, compressive strength, and water resistance of magnesium oxychloride cement (MOC) have been carried out in this paper. The phase composition and micro morphology of the hydration products in the mixed system were analyzed by XRD and SEM. The results show that the addition of magnesium sulfate prolongs the setting time and reduces the compressive strength of the mixed MOC. Compared with the primordial MOC system, the water resistance of the mixed system improved, with the mixed system exhibiting optimal water resistance when the mass fraction of magnesium sulfate was 30%. The phases of the mixed system were composed of 5Mg(OH)2·MgCl2·8H2O and 5Mg(OH)2·MgSO4·7H2O phases. The microscopic morphology shows that the interior of air-cured MOC was composed of a large number of needle-like crystals, and continuous crystal structures have close contact and a strong bonding force. Cracks and pores appear on the surface after submerging in water, and the crystallization state of the internal crystals becomes worse. The compressive strength and water stability of MOC were closely related to the crystal morphology. [ABSTRACT FROM AUTHOR]

Microfluidics is a new experimental approach that investigates the processes related to fluids flowing through small channels or porous media. Microfluidic chips, the core elements of the microfluidic technique, consist of quasi-2-dimensional pore structures etched and sealed in transparent materials. Fluids are allowed to flow through the chips, and real-time observations can be made about the transport and reactions of fluids at the pore scale. In this study, we test the feasibility of using the microfluidic technique to visualise the microbially induced carbonate precipitation (MICP) process. The experimental results obtained in this study show that the generation, evolution, and morphology of calcium carbonate, the effective product in MICP, can be clearly observed during the entire spatial and temporal range of the tests. Comparative tests with different testing variables, including the concentration of treatment solutions, activity of bacterial suspensions, and particle size, were also carried out. The results show that the influence of these variables on the treatment effects, such as the production rate of the reaction, spatial distribution of calcium carbonate, type and morphology of crystals, amount of ammonia gas produced, and presence/absence of clogging issues, can be visualised in microfluidic chips. The results presented in this paper prove that the microfluidic technique could be a helpful tool for unravelling the mechanisms of the MICP process at the pore scale and understanding the factors influencing the MICP process. [ABSTRACT FROM AUTHOR]

The influence of organic additives on crystallization of polyolefins has not been paid enough attention due to the low dosage, but it may have a significant impact on the properties of polyolefins. In the paper, the organic amphiphilic molecules were introduced into high-density polyethylene (HDPE) through melt blending, and compared with neat HDPE. It is mainly discussed for the following aspects including analysis of crystal structure and morphology using wide-angle X-ray diffraction (WAXD) and polarized optical microscopy (POM), respectively; analysis of crystallinity, crystal rate, crystal growth and crystallization enthalpy, using the differential scanning calorimetry (DSC). The research indicates that the organic amphiphilic molecules may act as an internal lubricant. On the one hand, HDPE molecular chains are easy to fall off from crystal lattices, resulting in lagging crystallization peak, simultaneously reducing the interaction between HDPE molecules should induce the lower activation energy (ΔEm) to increase the crystallinity of HDPE. On the other hand, the amphiphilic molecules should be exclude from HDPE crystal to the amorphous area due to poor compatibility; thus, the HDPE/amphiphilic molecules blends, similar to neat HDPE, conduct homogeneous nucleation, and the growth of monocrystal performs the tendency of the zero-dimension to the two-dimension with increase in temperature of isothermal crystallization and decreasing cooling rate of non-isothermal crystallization. It is hoped that through these studies, people will pay more attention to the impact of organic additives on the performance of HDPE. [ABSTRACT FROM AUTHOR]

Revealing the internal structure of diamonds is key to understanding the general regularities of crystal growth and dissolution. This paper presents and summarizes data on the internal structure of diamonds of different morphological types, colors and defect-impurity composition. In order to provide a comprehensive explanation of the stages of diamond growth, crystals and plates were observed, and panchromatic cathodoluminescence and photoluminescence techniques were applied. This article considers the mechanism of tangential growth from existing surfaces (regeneration growth) as an intermediate stage between normal and tangential crystal growth. The regeneration growth is very fast due to the absence of the limiting stage-nucleation of a new atomic layer. Cuboid diamonds were refaceted to stepped octahedrons by the regeneration growth mechanism. A schematic model of crystal habit transformation due to regeneration growth explains the internal structure of crystals in connection with their morphology and thermal history. The main variants of regeneration stage and its morphological manifestations were demonstrated. Most diamonds pass through the regeneration stage, and in many cases, it was a stage of growth termination. [ABSTRACT FROM AUTHOR]

An aluminosilicate zeolite has a porous structure with openings comparable to the molecular size, which endows it with unique adsorptive and catalytic properties that are highly dependent on its chemical composition and crystal morphology. Thus, the precise control or rational design of zeolite's particle morphology has attracted much attention as it can greatly improve the adsorptive separation and catalytic properties by effectively adjusting the diffusion path of adsorbates, reactants and products. This paper reviews the recent progress made in the synthesis and application of zeolites with a specific crystal/particle morphology with emphasis on the control of the crystal size and facet exposure degree, oriented assembly of crystals, creation of hierarchical porous structures and synthesis of core–shell structures. It is shown that an appropriate decrease of the crystal size and/or an increase of the exposure degree of certain facets by adding seeds and optimizing the synthesis conditions enhances the catalytic stability and product selectivity in some reactions. This can also be achieved by introducing plenty of mesopores and/or macropores in zeolites as a result of significant alleviation of diffusion limitation. Assembly of zeolite crystals into membranes on porous substrates improves the adsorptive separation performance of zeolites, for e.g. alcohol/water mixture and xylene and butane isomers. Core–shell-structured composites with metal nanoparticles or subnanoparticles as the core and the zeolite, including its modified counterpart, as the shell show excellent catalytic performance in some hydrogenation, dehydrogenation and oxidation reactions. In addition, attempts to illustrate the relationship between zeolite's particle morphology and its catalytic performance are discussed and strategies for the rational design of zeolite's particle size and behavior are envisioned. [ABSTRACT FROM AUTHOR]

Summary: In this paper, a type of high‐performance nanostructure Fe2O3 (Fe2O3‐arc) is synthesized via a novel direct current electric arc method and employed as a sulfur‐wrapping matrix for lithium‐sulfur batteries. Scanning electron microscopy reveals Fe2O3‐arc has a granular morphology and the crystal size can be controlled below 100 nm. X‐ray diffraction patterns and Raman spectrums show that Fe2O3‐arc displays obvious confusion, but continues to have a typical Fe2O3 crystal structure with preferentially growing on the (110) crystal plane. After sulfur loading, stable physical entrapment and chemical interaction can be established between sulfur and Fe2O3‐arc matrix. The electrochemical test indicates the sulfur composite cathode with Fe2O3‐arc as matrix at the loading mass ratio to 1:3 has a stable and conventional sulfur electrochemical process. The initial discharge specific capacities can achieve 720.59, 653.79 and 540.32 mAh.g−1 at 0.1, 0.2 and 0.5 C current rates, respectively. And after 200 cycles, the capacity retention rate can be at 62.23%. [ABSTRACT FROM AUTHOR]