Homogeneous Crystals Research Articles

Homogeneous nucleation and crystallization model of aluminum droplet based on isothermal DSC analysis

Homogeneous nucleation and crystallization model of aluminum droplet based on isothermal DSC analysis

Biomimetic Mineralization of Tooth Enamel Using Nanocrystalline Hydroxyapatite under Various Dental Surface Pretreatment Conditions.

In this report, we demonstrated the formation of a biomimetic mineralizing layer obtained on the surface of dental enamel (biotemplate) using bioinspired nanocrystalline carbonate-substituted calcium hydroxyapatite (ncHAp), whose physical and chemical properties are closest to the natural apatite dental matrix, together with a complex of polyfunctional organic and polar amino acids. Using a set of structural, spectroscopy, and advanced microscopy techniques, we confirmed the formation of a nanosized ncHAp-based mineralized layer, as well as studying its chemical, substructural, and morphological features by means of various methods for the pretreatment of dental enamel. The pretreatment of a biotemplate in an alkaline solution of Ca(OH)2 and an amino acid booster, together with the executed subsequent mineralization with ncHAp, led to the formation of a mineralized layer with homogeneous micromorphology and the preferential orientation of the ncHAp nanocrystals. It was shown that the homogeneous crystallization of hydroxyapatite on the biotemplate surface and binding of individual nanocrystals and agglomerates into a single complex by an amino acid booster resulted in an increase (~15%) in the nanohardness value in the enamel rods area, compared to that of healthy natural enamel. Obtaining a similar hierarchy and cleavage characteristics as natural enamel in the mineralized layer, taking into account the micromorphological features of dental tissue, is an urgent problem for future research.

Positional Isomerism-Mediated Copolymerization Realizing the Continuous Luminescence Color-Tuning of Liquid-Crystalline Polymers

Liquid crystals with color-tunable light emission are important for a variety of applications; however, achieving multicolor light-emitting liquid crystals whose emission colors can be fine-tuned remains challenging because the limited derivatization of mesogenic fluorophores disfavors the diversity of the emission. Here, we present a positional isomerism-mediated copolymerization strategy to obtain liquid-crystalline polymers with continuous luminescence color-tuning ability. The introduced α–/β-cyanostilbene positional isomers possess very similar molecular structures, thus reducing the risk of assembly heterogeneity and facilitating the formation of a homogeneous and consistent liquid crystal mesophase. Meanwhile, a significant electronic effect was caused for fluorophores with positional isomerization, allowing the efficient tuning of emission colors via copolymerization. Especially with a gradual change in the composition of the copolymers, the emission color shift behaved in a continuous manner from blue to green. These cyanostilbene-based liquid-crystalline polymers also showed reversible photochromic fluorescence switching ability. This approach highlights the value of positional isomers to prepare color-tunable solid-state light-emitting materials, allowing control and fine-tuning of the emission property while maintaining the ordered assembly ability.

Treatment of synthetic zinc and nickel wastewater and identification of its crystallization products by fluidized bed homogeneous crystallization technology

Heavy metals such as zinc and nickel can be found in wastewater from steel electroplating trace concentrations. These heavy metals harm the ecosystem and human health, which must be addressed. This study aimed to use fluidized bed homogeneous crystallization process (FBHCP) to recover nickel-zinc crystal from simulated electroplating wastewater. The best-operating conditions include a 10.2 initial pH of the crystallization reagent, variable nickel ion concentrations of 200 – 500 mg·L−1, and variable zinc ion concentrations of 100 – 400 mg·L−1. The nickel-zinc solution has a starting concentration of 300 mg L−1 of both nickel ions and zinc ions and a 1.75 molar ratio (MR) of [CO32-]/[Ni2++Zn2+]. The highest removal rate for zinc was 99.6 %, and for nickel was 88.7 %. According to SEM morphology, the crystals generated have a high-density smooth crystal with pores. According to XRD analysis, the crystals generated were layered hydroxide salts (LHS) of nickel-zinc with the structural formula. FBHCP was employed to successfully recover NiZn – LHS crystals from simulated wastewaters, which can now be utilized for future adsorption applications.

Halide perovskites enable polaritonic XY spin Hamiltonian at room temperature.

Exciton polaritons, the part-light and part-matter quasiparticles in semiconductor optical cavities, are promising for exploring Bose-Einstein condensation, non-equilibrium many-body physics and analogue simulation at elevated temperatures. However, a room-temperature polaritonic platform on par with the GaAs quantum wells grown by molecular beam epitaxy at low temperatures remains elusive. The operation of such a platform calls for long-lifetime, strongly interacting excitons in a stringent material system with large yet nanoscale-thin geometry and homogeneous properties. Here, we address this challenge by adopting a method based on the solution synthesis of excitonic halide perovskites grown under nanoconfinement. Such nanoconfinement growth facilitates the synthesis of smooth and homogeneous single-crystalline large crystals enabling the demonstration of XY Hamiltonian lattices with sizes up to 10 × 10. With this demonstration, we further establish perovskites as a promising platform for room temperature polaritonic physics and pave the way for the realization of robust mode-disorder-free polaritonic devices at room temperature.

Particle flow with a hybrid segmented crystal and fiber dual-readout calorimeter

In the reconstruction of physics events at future e+e- colliders the calorimeter design has a crucial role in the overall detector performance. The reconstruction of events with many jets in their final state sets stringent requirements on the jet energy and angular resolutions. The energy resolution for jets with energy of about 45 GeV is required to be at the 4–5% level to enable an efficient separation of the W and Z boson invariant masses. We demonstrate in this paper how such a performance can be achieved by exploiting a particle flow algorithm tailored for a hybrid dual-readout calorimeter made of segmented crystals and fibers. The excellent energy resolution and linearity of such calorimeter for both photons and neutral hadrons (3%/√E and 26%/√E, respectively), inherent to the homogeneous crystals and dual-readout technological choices, provides a powerful handle for the development of a new approach for particle identification and jet reconstruction. While the dual-readout particle flow algorithm (DR-PFA) presented in this paper is at its early stage of development, it already demonstrates the potential of a hybrid dual-readout calorimeter for jet reconstruction by improving the jet energy resolution with respect to a calorimeter-only reconstruction from 6.0% to about 4.5% for 45 GeV jets.

Predictions for the properties of water below its homogeneous crystallization temperature revisited

Properties of liquid water supercooled below its melting point have been thoroughly investigated. Experiments on bulk water become increasingly difficult as the temperature is lowered, and eventually impossible when the delay before ice nucleation becomes too short, around 230 K at ambient pressure. At low temperatures, amorphous ices and their glass transition may be studied only below the temperature of crystallization during heating, around 150 K. The temperature range from around 150 to 230 K at ambient pressure thus appears as a no man's land where the properties of bulk water are not accessible. Following Austen Angell's footsteps, I provide here physically acceptable predictions for thermodynamic properties (heat capacity, entropy) of liquid water down to its glass transition, and use the Adam-Gibbs approach to predict its dynamic properties (shear viscosity, self-diffusion coefficient, rotational correlation time). • The Adam-Gibbs relation between entropy and dynamic properties is applied to water. • The entropy of supercooled water is described with a modified two-state model. • We predict viscosity, diffusion, and rotational time down to the glass transition. • The results are consistent with a fragile-to-strong transition in supercooled water.

Programming DNA Self-Assembly by Geometry†.

This manuscript introduces geometry as a means to program the tile-based DNA self-assembly in two and three dimensions. This strategy complements the sequence-focused programmable assembly. DNA crystal assembly critically relies on intermotif, sticky-end cohesion, which requires complementarity not only in sequence but also in geometry. For DNA motifs to assemble into crystals, they must be associated with each other in the proper geometry and orientation to ensure that geometric hindrance does not prevent sticky ends from associating. For DNA motifs with exactly the same pair of sticky-end sequences, by adjusting the length (thus, helical twisting phase) of the motif branches, it is possible to program the assembly of these distinct motifs to either mix with one another, to self-sort and consequently separate from one another, or to be alternatingly arranged. We demonstrate the ability to program homogeneous crystals, DNA "alloy" crystals, and definable grain boundaries through self-assembly. We believe that the integration of this strategy and conventional sequence-focused assembly strategy could further expand the programming versatility of DNA self-assembly.

Development of an Automatic Ultrasonic Matrix Sprayer for Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) has emerged as a powerful tool for studying the spatial distribution of various types of molecules. Matrix deposition is a critical step for obtaining high-quality imaging data. An automatic device named SoniCoat was fabricated based on an ultrasonic nozzle driven by a pizeoelectric ceramic for matrix coating in the present study. Compared with the minihumidifier developed previously by our group for matrix deposition, SoniCoat realized automation, and the ultrasonic nozzle of this device is easy to clean and less likely to get clogged, indicating a longer life. Compared with commercial and homemade instruments such as the TM-Sprayer and electrospray matrix coating device, our newly developed device achieved a good nebulization effect without the need for high-pressure gas flow and high voltage. Matrix deposition by SoniCoat generated more homogeneous matrix crystals with diameters of about 10 μm and reduced the occurrence of molecular diffusion to a greater extent, compared with the results by TM-Sprayer. Repeatable high-spatial-resolution MS imaging data were obtained with the help of SoniCoat. Furthermore, the newly developed device can also be successfully applied for in situ derivatization.

Exploration and tuning of Al2O3/Mo composite for enhancement of anti-corrosion and tribological characteristics in zinc phosphate conversion coatings

Recently, phosphate conversion coatings have been modified by transition/non-transition metal oxide with distinguished characteristic features such as corrosion resistance, wear resistance, lubrication and adhesion. The present paper explores the development of Al2O3/Mo composite incorporated zinc phosphate coatings on galvanized steel for achieving higher corrosion-resistant characteristics with an added advantage of tribological performance. Incorporation of Mo leads to the phase transformation from γ to α-Al2O3, which ensures the subsequent crystallization of alumina particles by the anisotropic grain growth of Mo content. Particle size, elemental composition and morphology of the Al2O3/Mo composite are tuned for retaining the stable crystalline alpha phase of the composite. The optimum concentration of the tuned content of Al2O3/Mo composite in the phosphating solution can effectively perform as an active nucleating source for the establishment of more compact, homogeneous and dense zinc phosphate crystal growth and coverage in the galvanized steel surface by significantly reducing the activation energy during the phosphating process. The resultant composite phosphate coating ensures the formation of a large quantity of crystalline hopeite rich phase compared to other coatings, which effectively acts as an insulator during the electrochemical reaction by imparting a corrosion-resistant barrier between the substrate and corrosive media. Uniform distribution of composite particles at the grain boundaries and at the bulk grain composition is also achieved. Lower average surface roughness (Sa), root mean square surface roughness (Sq), maximum height (St), surface skewness (Ssk) and higher surface kurtosis (Sku) values are acquired for better anti-corrosion properties with excellent tribological performance. The higher Rp and Rct values with lower Cdl and corrosion rate values of the tuned composition of Al2O3/Mo composite based zinc phosphate coating confirms the better porosity and thereby enhances the corrosion-resistant performance due to the sealing action of the composite.

Influence of using low voltage electrostatic field during freezing and thawing processes on beef quality

This study examined the effects of LVEF-assisted freezing-thawing on beef loin (Longissimus dorsi) quality and texture. In this work, the quality of beef specimens at 15, 30, and 45 cm from the LVEF plate (test group) and without LVEF treatment (control group) was examined during freezing-thawing. LVEF aided freezing (LVEFF) sped up beef freezing and thawing by 32.46% and 32.60% at 30 cm layer spacing (LVEF-30). LVEF30 created the smallest, most homogeneous ice crystals and less injured muscle fibre tissue. SEM indicated that LVEF30 preserved muscle fibre and perimysium structure, and muscle fibre gaps did not expand. Z-line and M-line were generally intact, while A-band and I-band were distinct and readable, indicating that LVEF30 preserved myo􀂿 brillar structure efficiently. LVEF30’s L*, a*, and C values were substantially higher than the control group (P0.05) and fresh meat (P0.05). LVEF-30 reduced thawing loss, cooking loss, and drip protein content by 52.10%, 31.313%, and 15.97%. In conclusion, LVEF can improve the quality of thawed beef by reducing quality loss during freezing-thawing, and 30 cm is the best distance from the electrostatic field generation plate.

Starch crystal seed tailors starch recrystallization for slowing starch digestion

Crystal seed significantly affected polymers homogeneous or heterogeneous crystallization. However, how starch crystal seed affected recrystallization of gelatinized starch and in turn digestibility were not clearly understood. Herein, effects of endogenous crystal seed on starch recrystallization and digestibility were herein investigated. Structures of retrograded starches characterized by Fourier transform infrared spectroscopy and X-ray diffraction indicated that endogenous A-type crystal seed significantly promoted starch reassociation to form well-defined crystalline structure. Notably, starch crystal seed-mediated retrograded starch contained more compact structures after cooking in comparison with that of retrograded starch mediation without the crystal seed, and therefore the crystal seed-mediated retrograded starch exhibited a lower digestibility. This study preliminarily indicated starch endogenous crystal seed significantly modulate starch retrogradation and digestibility, nevertheless, how recrystallization temperature, the content and crystalline structure of the crystal seed affect recrystallization behaviors of crystal seed-containing starch are part of future work.

Olivine Melt Inclusion Constraints on Some Intensive Properties of Subvolcanic Crystal Mushes and Their Evolution through Boundary Layer Fractionation in Northern Japan

Abstract Magma differentiation in arc settings has usually been attributed to an interplay of processes (fractional crystallization, assimilation, and magma mixing). Homogeneous fractional crystallization has been widely used to model the magmatic evolution of volcanic systems in arc settings due to its simplicity, even though boundary layer fractionation (BLF) has been proposed as a preponderant process of differentiation in hydrous magmatic systems. Both models produce distinct compositional paths and the application of the wrong model yields erroneous estimates of parameters like pressure–temperature-H2O conditions and primary melt compositions. Melt inclusion (MI) populations corrected for post-entrapment processes have the potential to help discriminate between these two types of fractional crystallization, as their compositions are not affected by crystal accumulation and should capture the magmatic evolution as crystallization occurs. In this study, olivine-hosted MIs are used to assess the differentiation trends of basic arc magmas in northern Japan. Differentiation trends from five arc volcanic systems in northern Japan show that BLF is ubiquitous. Homogeneous fractionation models are unable to explain the liquid lines of descent of minor elements, like TiO2 and P2O5. To reproduce these differentiation trends, the presence of accessory phases like titanomagnetite or apatite are required, which in many cases are not equilibrated by the melt or need to be fractionated in amounts that are incompatible with homogeneous fractionation. The prevalence of BLF in all studied arc magmas of northern Japan indicates that solidification fronts are key environments in the crustal evolution of some hydrous subduction zone magmas.

In Situ Chemical Modification of Thermoplastic Starch with Poly(L-lactide) and Poly(butylene succinate) for an Effectively Miscible Ternary Blend

Thermoplastic starch (TPS) is in situ ring-opening polymerized with L-lactide (L-LA) and directly condensed with a poly(butylene succinate) (PBS) prepolymer in an extruder using two different production pathways to demonstrate the concept “like dissolves like” in a miscible poly(lactide)/TPS/PBS (PLA/TPS/PBS) ternary blend. The TPS crystalline pattern changes from a VH-type to an EH-type after TPS modification with a hydrophobic-PLLA segment. Heteronuclear multiple-bond correlation confirmed the successful formation of PLLA-TPS-PBS copolymers via two different in situ chemical modification pathways (i.e., (I) step-by-step modification and (II) one-pot reaction). All obtained PLLA-TPS-PBS copolymers functioned as the miscible phase, enhancing PLA/PLLA-TPS-PBS/PBS ternary blend miscibility, especially the random structural PLLA-TPS-PBS-II copolymers created in an in situ one-pot reaction. However, the PLLA-TPS-PBS-I copolymers can enhance PBS crystallization only. While the random PLLA-TPS-PBS-II copolymers exhibit a homogeneous multi-phase dispersion and crystallization acceleration in both the PLA and PBS chains. Moreover, the storage modulus level of the PLA/PLLA-TPS-PBS-II/PBS ternary blend remains high with a downward temperature shift in the glass transition region, indicating a stronger and more flexible system. The practical achievement of in situ modified TPS and, consequently, a miscible PLA/PLLA-TPS-PBS/PBS ternary blend with favorable physical properties, reveal its potential application in both compostable and food contact packaging.

Recovery of phosphate as hydroxyapatite by fluidized bed homogeneous crystallization technique.

Phosphorous recovery from aqueous solutions gained substantial attention and this not only secure the food demand but also curtail the pollution of freshwater courses. In the current study, authors employed novel fluidized bed homogeneous crystallization (FBHC) technique to granulate the phosphorous as hydroxyapatite (HAP). FBHC technique nurtures the formation of high pure HAP crystals without seed addition and potential technique to recover phosphorous compared to other techniques. The key operational parameters influencing the HAP crystallization were analyzed prior to FBHC by batch analysis. From the batch study results, the range of pH and calcium to phosphorous molar ratio fixed for FBHC studies. Maximum phosphate removal and granulation efficiencies obtained were 91.25% and 82.55%, respectively, at 500mg/L phosphate concentration, pH 12, and calcium to phosphorous molar ratio 1.65. Box-Behnken design of response surface methodology was employed for evaluating interaction impact of process parameters on granulation efficiency. Granulation efficiency of 79.74% was attained at pH 11.83, calcium to phosphorous molar ratio 1.637, and reaction time 70.73h.

Thermal expansion anisotropy of CuIn11Se17 single crystals

Homogeneous single crystals of CuIn11S17 with 14 mm in diameter and 40 mm in length were grown by directional crystallization of the melt (vertical Bridgman method). The composition and structure of the obtained single crystals were determined by the X-ray microanalysis and the X-ray diffraction analysis, respectively. It is shown that the obtained single crystals crystallize in a hexagonal structure. The anisotropy of thermal expansion was investigated for single crystals oriented parallel and perpendicular to the main crystal axis in the temperature range of 120–600 K. It was found that anomalies of thermal expansion are observed in the indicated single crystals oriented parallel to the main crystal axis.

Large CaFeAsF single crystals of high quality grown by the oscillating temperature technique

The oscillating temperature technique was successfully employed to grow large and composition homogeneous CaFeAsF single crystals due to the reduction of nuclei number by temperature oscillation. The largest as-grown CaFeAsF single crystal was nearly 8 mm in lateral size and 0.27 mm in thickness which is far larger than previously reported in all dimensions. The full-width-at-half maximum (FWHM) of x-ray rocking curve is as small as 0.163° indicating the high quality of CaFeAsF single crystals.

The recovery of sulfur as ZnS particles from sulfide-contained wastewater using fluidized bed homogeneous crystallization technology

Sulfide wastewater that is anthropogenically generated from industrial activities is highly corrosive, hazardous, and harms the natural ecosystem. This study uses a novel fluidized-bed homogeneous crystallization (FBHC) method to remove sulfide ions from an aqueous solution. Zinc is used as a precipitant to crystallize ZnS homogeneously in the FBHC reactor to reduce the sludge, which is commonly produced in a conventional chemical precipitation process. The optimal pH value, [Zn2+]0/[S2-]0 M ratio, sulfide cross-sectional surface loading (L, kg-S/m2.hr), and hydraulic retention time (HRT) for the system are established, to optimize the sulfur removal efficiency. The maximum crystallization ratio and the total removal efficiency for sulfur are 97.7% and 98.8%, respectively, at pH = 5.4, a [Zn2+]0/[S2-]0 M ratio of 1, a cross-sectional surface loading of 2.2 kg-S/m2.hr, and an HRT number of 6 with an initial sulfur concentration of 320 mg/L. The solid products are collected and identified as zinc sulfide (wurtzite) using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS).

Homogeneous linear ion crystal in a hybrid potential

We investigate the properties of a linear ion crystal in a combination of quadratic and quartic potentials. Both the discrete and the continuous models are employed to explore the homogeneity of a linear ion crystal by tuning the proportional parameter between the quadratic and quartic components. It is found that the size of the uniform region is significantly larger than that in either a purely quadratic or a quartic potential. The zigzag transition is also investigated in the hybrid potential, and its critical condition and phase diagram are determined numerically, which agrees well with previous theoretical and experimental results. Our results pave the way for experimental investigation of superlarge linear ion crystals in the combination of quadratic and quartic potentials.

Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging of Tissues via the Formation of Reproducible Matrix Crystals by the Fluorescence-Assisted Spraying Method: A Quantification Approach

The application of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) imaging to quantitative analyses is restricted by the variability of MS intensity of the analytes in nonreproducible matrix crystals of tissues. To overcome this challenge, a fluorescence-assisted spraying method was developed for a constant matrix amount employing an MS-detectable fluorescent reagent, rhodamine 6G (R6G), which was sprayed with the matrix. To form a homogeneous matrix crystal on the tissue section, a matrix solution, 1,5-diaminonaphthalene (10 mg/mL), containing R6G (40 μg/mL) and O-dinitrobenzene (O-DNB, 10 mg/mL) was sprayed until the desired constant fluorescence intensity was achieved. Compared with that obtained via conventional cycle-number-fixed spraying [relative standard deviation (RSD) = 31.1%], the reproducibility of the relative MS intensity of the analyte [ferulic acid (FA), RSD = 3.1%] to R6G was significantly improved by the fluorescence-assisted matrix spraying. This result indicated that R6G could be employed as an index of the matrix amount and an MS normalizing standard. The proposed matrix spraying successfully quantified nifedipine (0.5-40 pmol/mm2 in the positive mode, R2 = 0.965) and FA (0.5-75 pmol/mm2 in the negative mode, R2 = 0.9972) in the kidney section of a rat. Employing the quantitative MALDI-MS imaging assay, FA, which accumulated in the kidney of the rat after 50 mg/kg was orally administered, was visually determined to be 3.5, 3.0, and 0.2 μmol/g tissue at 15, 30, and 60 min, respectively.