Crystal Technology Research Articles

Simultaneous Improvements of Physicochemical Properties and Anti‐Microbial Activity of Berberine via Forming Salt with Gallic Acid

AbstractImplementing combination medication through crystal engineering technology receives increasing attention from researchers due to improvements in the clinical treatment effects as well as the physicochemical properties of the drug. Berberine (BER) is commonly used to treat gastroenteritis and bacterial diarrhea, with the problems of poor solubility and low oral bioavailability. Recently, it is found that gallic acid (GA) also has anti‐inflammatory and anti‐bacterial activities. Therefore, if the above‐mentioned two ingredients can be combined, it is possible to enhance the therapeutic effects and physicochemical properties of BER. Inspired by this, 8‐hydroxy‐7,8‐dihydroberberine (8H‐HBER) in this study is employed to react with gallic acid to yield BER gallate dihydrate (2BER‐2GA‐2 W). Furthermore, dissolution experiments demonstrate that the maximum apparent solubility (MAS) of 2BER‐2GA‐2 W in dilute hydrochloric acid solution medium (pH 1.2) has increased by 7 times compared to the commercial form of BER, because of avoiding the common‐ion effect. Moreover, 2BER‐2GA‐2 W has also obviously enhanced stability relative to the commercial form of BER. In addition, 2BER‐2GA‐2 W has a better inhibitory effect on Staphylococcus aureus (S. aureus) relative to the commercial form of BER. Hence, 2BER‐2GA‐2 W will be a promising solid‐state form of BER for its further development.

Seeded membrane distillation crystallization for hypersaline brine treatment

Abstract Brine evaporation and crystallization are energy- and equipment-intensive technologies commonly used in industries. Alternatively, membrane distillation (MD) has shown ability for concentrating different saline solutions. However, there is a limited understanding of the impact of these solutions on the scaling and wetting behavior. To address this knowledge gap and reduce costs and energy consumption, we investigated a novel method called ‘seeded near-zero liquid discharge membrane crystallization’ (NZLDMC). This approach combines MD and crystallization in a single apparatus, reducing capital and operating costs while improving sustainability. Our study focused on applying seeding processes at NZLDMC for concentrating synthetic mono- and multi-salt solutions with a salinity of 300 g/L and a real salt solution. We investigated the effects of salt crystals and seeds on membrane performance under different operating conditions. Our findings indicate that seeding crystal technology leads to high yield and long-term stability, thereby offering the potential in industries and municipal water treatment to fractionate salt in multi-salt solutions and obtain purified water simultaneously.

Study on the vertical Bridgman method of melt-grown CsPbBr3 single crystals for nuclear radiation detection.

As an excellent representative of all-inorganic perovskite materials, CsPbBr3 has been widely used in high-energy rays or high-energy particles detection for its outstanding high carrier mobility and long diffusion length. The great challenges and opportunities in these fields are crystal growth technology, especially the high-quality and large-sized CsPbBr3 single crystals. In this work, the influences of growth parameters (temperature gradient, growth rate, cooling rate) and thermal stress by the vertical Bridgman method on the quality and performance of CsPbBr3 crystals are systematically studied. The final results show that 10°C cm-1 is the optimized temperature gradient and 0.5 mm h-1 is the suitable growth rate for CsPbBr3 crystal growth. The study also shows that a cooling rate of 10°C h-1 for the general temperature interval and 1°C h-1 for the phase transition temperature interval is helpful to balance crystal growth efficiency as well as crystal quality. Crystal cracks caused by thermal stress as well as crystal adhesion on the ampoule can be effectively solved by depositing a uniform carbon film on the ampoule in advance. The optical, electrical and detection performance are also investigated. The optical characterization in the wavelength region ranging from ultraviolet to infrared indicates the crystal has a low density of deep-level defects and good crystal quality. The resistivity over 109 Ω cm and μτ of electrons over 10-2 cm-2 V-1 proves that the electrical performance of the crystal has met the basic requirement for nuclear radiation detection. The metal-semiconductor-metal structure Ti/Ni/CsPbBr3/Ni/Ti detector fabricated from the optimized CsPbBr3 single crystal has an energy resolution of 12.85% (137Cs, 662 keV). The purpose of this work is to provide a useful guide and reference for the future exploration of repeatable and improvable CsPbBr3 crystal growth technology.

Spherical Crystallization Based on Liquid-Liquid Phase Separation in a Reverse Antisolvent Crystallization Process

Vanillin crystals undergo needle-like morphology that results in poor flowability, crystal breakage, and low packing density. The spherical crystallization technology can produce particles with improved flowability and stability. A reverse antisolvent crystallization based on liquid-liquid phase separation is proposed in this work to produce vanillin spherical agglomerates. Hansen Solubility Parameters are applied to explain the liquid-liquid phase separation (LLPS) phenomenon. The Pixact Crystallization Monitoring system is applied to in-situ monitor the whole process. A six-step spherical crystallization mechanism is revealed based on the recorded photos, including the generation of oil droplets, nucleation inside oil droplets, the coalescence and split of oil droplets, crystal growth and agglomeration, breakage of oil droplets, and attrition of agglomerates. Different working conditions are tested to explore the best operation parameters and a frequency-conversion stirring strategy is proposed to improve the production of spherical crystals.

Thermoelectric properties of half-Heusler alloys

Half-Heusler alloys (HHs) as medium- and high-temperature thermoelectric materials have attracted increasing considerable attention, owing to their excellent mechanical properties and thermal stability. Nonetheless, the intercoupling between the Seebeck coefficient and electrical conductivity, and their high thermal conductivity limit the furthermore enhancement of their thermoelectric properties. This review systemically summarizes and analyses the various current strategies for improving thermoelectric properties, such as manipulating band structure, optimizing electron and phonon transports, and constructing high configurational entropy, etc. Moreover, the possible deficiencies of the existing electric-phonon transport mechanisms are highlighted and discussed, which aiming to provide a meaningful guide for future efforts to accelerate the development of HHs. Finally, based on current research, a new potential future for the integration of single crystal technology and high-entropy effect is introduced for HHs.

Continuous supercritical hydrothermal synthesis of stabilized ZrO2 nanocomposites: Doping mechanism of typical metals and transition elements

In this study, Mg, Ce, Y and La-doped nano-zirconia particles were successfully obtained by continuous supercritical hydrothermal synthesis combined with nanotechnology and crystal stabilization technology. Through detailed characterization and analysis of the structure, crystal form, grain size of the particles and by-products, the doping amount of different element dopants was optimized, and the stable pathway of tetragonal and cubic phases was proposed. Moreover, the doping mechanisms of different elements and phase diagram of doped nano-zirconia were revealed. The results show that the crystal form is determined by the doping amount, ionic radius and intrinsic properties of ions. Y and Ce doping can completely stabilize the tetragonal or cubic phase without the formation of by-products. Mg and La doping produce by-products of Mg(OH)2 and La2O2CO3. As the ionic radius increases, the radius mismatch with Zr4+ leads to a stronger ability to stabilize the tetragonal or cubic phase. At the same time, minimum dopant for stable tetragonal or cubic phases will decrease.

Exploring the interplay of liquid crystal orientation and spherical elastic shell deformation in spatial confinement.

The application of liquid crystal technology typically relies on the precise control of molecular orientation at a surface or interface. This control can be achieved through a combination of morphological and chemical methods. Consequently, variations in constrained boundary flexibility can result in a diverse range of phase behaviors. In this study, we delve into the self-assembly of liquid crystals within elastic spatial confinement by using the Gay-Berne model with the aid of molecular dynamics simulations. Our findings reveal that a spherical elastic shell promotes a more regular and orderly alignment of liquid crystals compared to a hard shell. Moreover, during the cooling process, the hard-shell confined system undergoes an isotropic-smectic phase transition. In contrast, the phase behavior within the spherical elastic shell closely mirrors the isotropic-nematic-smectic phase transition observed in bulk systems. This indicates that the orientational arrangement of liquid crystals and the deformations induced by a flexible interface engage in a competitive interplay during the self-assembly process. Importantly, we found that phase behavior could be manipulated by altering the flexibility of the confined boundaries. This insight offers a fresh perspective for the design of innovative materials, particularly in the realm of liquid crystal/polymer composites.

Copper recovery from treatment of simulated copper-iron wastewater using fluidized-bed homogeneous crystallization technology

Electroless plating wastewater contains highly soluble Cu-EDTA complex which poses challenges for copper recovery using conventional methods. These complexes are destroyed first using Fenton process producing treated solutions with iron concentrations that may interfere copper recovery. The purpose of this study was to confirm the influence of trace amount of iron on copper removal, crystallization, and copper salt recovery using fluidized-bed homogeneous crystallization (FBHC) process. By varying several parameters like pH, initial copper and iron concentrations, and metal and precipitant inlet flowrate and molar ratio, the optimized conditions include pHe of 6.5–7.0, inlet flowrate of 15 mL min−1, and MR of 1.5. The effects of variable copper (3.15–9.44 mM) and iron concentrations (0.36–1.08 mM) were examined. The addition of iron had no significant impact on copper removal mainly due to its minimal presence in the solution, but a trend of decreasing, then increasing, copper crystallization ratio was observed at higher iron concentrations. The study recorded copper removal and crystallization rates from 88% to 96% and 75% to 95%, respectively, with varying iron concentrations. Characterization analyses of precipitates confirmed predominant presence of malachite and azurite. The FBHC's ability to obtain high purity spheroidal solid salts enables resource recovery and catalyzes strategies for circular economy practices.

Structure and thermodynamics of supported lipid membranes on hydrophobic van der Waals surfaces.

Understanding the adsorption and physical characteristics of supported lipid membranes is crucial for their effective use as model cell membranes. Their morphological and thermodynamic properties at the nanoscale have traditionally been studied on hydrophilic substrates, such as mica and silicon oxide, which have proved to facilitate the reconstruction of biomembranes. However, in more recent years, with the advent of the van der Waals crystals technology, two-dimensional crystals such as graphene have been proposed as potential substrates in biosensing devices. Membranes formed on these crystals are expected to behave differently owing to their intrinsic hydrophobicity, however thus far knowledge of their morphological and thermodynamic properties is lacking. Here we present a comprehensive nanoscale analysis of the adsorption of phosphatidylcholine lipid monolayers on two of the most commonly used van der Waals crystals, graphite and hexagonal boron nitride. Both morphological and thermodynamic properties of the lipid membranes were investigated using temperature-controlled atomic force microscopy. Our experiments show that the lipids adsorb onto the crystals, forming monolayers with their orientation dependent upon their concentration. Furthermore, we found that the hydrophobicity of van der Waals crystals determines a strong increase in the transition temperature of the lipid monolayer compared to that observed on hydrophilic substrates. These results are important for understanding the properties of lipid membranes at solid surfaces and extending their use to novel drug delivery and biosensing devices made of van der Waals crystals.

Probing and controlling oxygen impurity diffusion in h-BN semi-bulk crystals

Combining its unique features of ultrawide bandgap (UWBG) and two-dimensional nature, h-BN has been explored for emerging applications such as deep ultraviolet optoelectronic devices and single photon emitters. One of the unusual applications of h-BN is for solid-state neutron detectors by utilizing the property of high thermal neutron capture cross section of B-10 as well as its UWBG properties. Although a record high detection efficiency of 59% has been attained by h-BN detectors, the understanding/minimization of defects and impurities is still needed to further advance the h-BN material and detector technologies. We report metal organic chemical vapor deposition growth and oxygen (O) impurity diffusion in thick h-BN. The diffusion coefficient (D) of O impurities has been measured via the evolution of an oxygen related emission with the etching depth, providing a value of D of ∼ 2 × 10−13 cm2/s at 1450 °C and supporting the interpretation that oxygen in h-BN is a substitutional donor. A multiple-buffer-layer approach was employed to mitigate to a certain degree the issue of oxygen diffusion from sapphire substrate during growth. It was demonstrated that the performance of h-BN neutron detectors fabricated from the wafer incorporating multiple buffer layers was significantly improved, as manifested by the enhanced thermal neutron detection efficiency. The advancement of the crystal growth technology of h-BN semi-bulk crystals creates applications in optoelectronic and power electronic devices utilizing the UWBG semiconductor properties of h-BN, while high efficiency h-BN neutron detectors have the potential to supplant the traditional He-3 gas detectors in various application areas by offering the obvious advantages of UWBG semiconductor technologies.

Selective granulation of trivalent iron into ferric hydroxide from bi-metal containing wastewater using Fluidized-Bed Homogeneous Crystallization technology

The traditional method that is used to treat the bi-metal-contained wastewater involves simultaneous chemical precipitation for the removal of both metals. However, recent trends in wastewater treatment emphasize the importance of recovery, recycling, and reuse. This study uses Fluidized-Bed Homogeneous Crystallization (FBHC) technology to selectively recover Fe(III) as granulated Fe(OH)3 from electroplating wastewater that contains iron and copper. For the treatment of a pure iron solution ([Fe(III)]0 = 650 mg/L), the optimal conditions include a pH value of 3.8, a reflux ratio (R) of 17.5, an up-flow velocity (U) of 35.9 m/h and a hydraulic retention time (HRT) of 17.9 min to give the maximum total removal efficiency (TR) for iron of more than 99.5%, and a crystallization ratio (CR) for iron of 93.6%. To treat real electroplating wastewater that contains iron and copper ([Fe(III)]0 = 1000 mg/L and [Cu(II)]0 = 500 mg/L), Fe(III) is effectively recovered as granules with a TR of 99% and a CR of 90%, and more than 90% of copper ions remain in the solution. SEM analysis observes that the product is an unseeded core-shell spherical particle. Additionally, XRD, FT-IR, and TGA results confirm that the product is an amorphous ferric hydroxide (Fe(OH)3) compound. A FBHC system has a high potential to separate iron and copper in a solution via a selective granulation process.

An innovative biosensor harnessing the potential of photonic crystal technology to identify a multitude of cancer cells, distinguished by heightened quality factor and sensitivity

An innovative biosensor harnessing the potential of photonic crystal technology to identify a multitude of cancer cells, distinguished by heightened quality factor and sensitivity

A novel sulfhydryl-modified superparamagnetic photonic crystal sensing material for the simultaneous heavy metal ions detection and adsorption treatment

A novel superparamagnetic photonic crystal (Fe3O4@SiO2@Sulfhydryl SPC) was successfully created for simultaneous visual detection and absorption of harmful heavy metal ions. This SPC was made by combining photonic crystal and superparamagnetic nanosphere technologies. During detection, Fe3O4@SiO2@Sulfhydryl nanospheres can move in the liquid sample and fully absorb the target substances. The detection range is from 1 μg/L to 5 mg/L, which corresponds to the critical concentration range for heavy metal ions in drinking water and sewage. The detection limit is 1 μg/L. In the detection process, the signal responded rapidly and remained stable when analyzed with a fiber optic spectrometer. Notably, the signal intensity decreased significantly, with a reduction of 62.22 a.u. for Hg2+ and 124.31 a.u. for Ag+. Simultaneously, the visual results were striking. The SPC changed color from orange (PC structural color) to the original reddish-brown color of the solution with the formation of magnetic aggregates (PC structural color disappeared). This SPC exhibits excellent sensitivity, offers a clear visual display, possesses strong absorption detection capabilities, is easy to use, cost-effective, and, importantly, does not cause secondary pollution. Furthermore, the harmful heavy metal ions absorbed by the SPC can be easily removed from the water sample using an external magnetic field, overcoming challenges related to efficient separation of the adsorbent material from wastewater. As a result, this SPC holds great promise for real-time visual monitoring and practical sewage purification processes.

Recent progress in liquid crystal devices and materials of TFT-LCDs

Thin-film-transistor-liquid crystal displays (TFT-LCDs) still dominate most of the display markets due to a big leap in image quality while keeping low cost and superior reliability, and its evolution is continuing to compete with emerging emissive displays. In this paper, recent progress in liquid crystal technologies mainly focusing on fringe-field switching (FFS) and polymer-stabilized vertical alignment (PS-VA) modes and materials for improving electro-optic performances is reviewed.

Exploration of PVC@SiO2 nanostructure for adsorption of methylene blue via using quartz crystal microbalance technology

Methylene blue (MB) dye is considered a well-known dye in many industries and the low concentration of MB is considered very polluted for all environment if it discharged without any treatment. For that reason, many researchers used advanced technologies for removing MB such as the electrochemical methods that considered very simple and give rapid response. Considering these aspects, a novel quartz crystal microbalance nanosensors based on different concentrations of PVC@SiO2 were designed for real-time adsorption of MB dye in the aqueous streams at different pHs and different temperatures. The characterization results of PVC@SiO2 showed that the PVC@SiO2 have synthesized in spherical shape. The performance of the designed QCM-Based PVC@SiO2 nanosensors were examined by the QCM technique. The sensitivity of designed nanosensors was evaluated at constant concentration of MB (10 mg/L) at different pHs (2, 7 and 11) and temperatures (20 °C, 25 °C, and 30 °C). From the experimental, the best concentration of PVC@SiO2 was 3% for adsorbed 9.99 mg of cationic methylene blue at pH 11 and temperature 20 °C in only 5.6 min.

Advancements and trends in GaN HEMT

Gallium Nitride based High Electron Mobility Transistors (GaN HEMTs) technology has made significant advancements, revolutionizing the field of power electronics. With their unique properties such as high breakdown voltage, high frequency, and high electron mobility and high-power capabilities, GaN HEMTs offer significant advantages over traditional silicon-based devices, such as improved power density, higher operating temperature, and enhanced reliability. GaN HEMTs have shown great potential in sensing applications, such as gas and biosensors. This thesis explores the advancements and trends in GaN HEMT technology, including crystal growth technology, sensing applications, packaging technology, and performance optimization. Despite significant progress, challenges such as heat dissipation, production costs, and yield and reliability issues need to be addressed. Future research directions may focus on improving integration with other technologies, exploring potential applications in emerging fields such as 5G communication, and addressing these challenges. Overall, GaN HEMT technology has made significant advancements and is set to play a pivotal role in various industries.

Process engineering of semi-continuous boiling of massecuites based on Digital Twin of sucrose crystallization

The purpose of the study is to simulate the process of isobaric evaporative crystallization of sucrose to substantiate new ways of its industrial implementation. Using computer simulation, a three-stage crystallization technology for semi-continuous boiling of massecuites on a prepared crystalline base of a seed suspension (first stage) and a crystalline base of the preceding massecuite (second and third stages) was designed. A computer computational model of the express method for determining the molasses saturation coefficient has been created. By heating to a temperature of 50–55 °C, the molasses is transferred to an unsaturated state, then oscillating white sugar crystals are partially dissolved until saturation is reached while under conductometric control. The method makes it possible to determine the optimal parameters of standard molasses, taking into account the technical characteristics of crystallization equipment and centrifuges. On the basis of simulation modeling in the VisSim software environment, tests were carried out, and a justification was given for the technology of semi-continuous boiling of massecuite massecuites to increase the efficiency of crystallization in batch vacuum pans.

Twenty years crystal growth of solar silicon: My serendipity journey

The past two decades have been a transformative era for solar silicon crystal growth, especially in the competition between multi-crystalline silicon (Multi-Si) and mono-crystalline silicon (Mono-Si). As a critical sector of the solar photovoltaic (PV) industry, the demand for this crucial material has surged exponentially, expanding over a thousand-fold. This remarkable increase has led to an accumulative deployment of silicon solar panels, which now approach a striking terawatt (TW), capturing over 95 % of the global PV market share. Furthermore, the rapid advancements in crystal growth technology during this period have set an unprecedented historical benchmark. This paper reviewed our early effort in the hot-zone design of Czochralski (CZ) solar silicon and then discussed its recent advancements. In between, the small-grain high-performance multi-crystalline silicon (HPM-Si), which we proposed, and the mono-like silicon (ML-Si) were briefly introduced. Because of the much better ingot quality and growth yield, HPM-Si became the mainstream until 2018. Its market share peaked at more than 70 % in 2017 but slid down quickly and was replaced by CZ silicon due to the emergence of diamond wire sawing (DWS); the CZ silicon was easier to cut, and its kerf loss was much less. Since then, the CZ ingot size has also started to increase quickly. The wafer size increased from 156 mm × 156 mm (M0) to 217 mm × 217 mm (M12+) in a few recent years; the increase in wafer area was almost doubled. Nowadays, the market share of CZ mono-Si is over 80 %.

Bioaugmentation treatment of coal chemical reverse osmosis concentrate in biological contact oxidation system coupled with ozone pretreatment

With the zero discharge requirements of coal chemical industry in China, reverse osmosis technology and fractional crystallization technology have been applied to recover water and valuable salts. Organic matter significantly inhibits salt crystallization, therefore it is urgent to remove organic matter from coal chemical reverse osmosis concentrate (CCROC) efficiently and economically. Common biological systems have the bottlenecks of long start-up period and poor pollutants removal efficiency due to the inhibition of toxic compounds and high salinity to the microorganisms. In this work, a self-prepared halotolerant bacteria preparation (HBP, mixture of screened Bacillus, Pseudomonas, and Halomonas with strong degrading capacity of CCROC) was inoculated into different biochemical systems (activated sludge and biological contact oxidation in sequencing batch reactor) to try to enhance the pollutants removal of extremely refractory CCROC (BOD5/COD of 0.05). The results showed that HBP increased the total organic carbon (TOC) removal efficiency from 8% to 15% in activated sludge system. In addition, biological contact oxidation reactor (BCOR) could better retain the HBP, leading to a higher TOC removal efficiency (20%). Typically, the inoculation of HBP without activated sludge in BCOR contributed to the highest TOC removal (28%). The class Bacilli (genus Bacillus) was dominant during the start-up and stable period of this bioaugmented treatment process. To further increase the pollutants removal, ozone oxidation pretreatment was conducted prior to biological treatment to break the ring structures. The total TOC removal increased to 42% under the combined treatment, while the dominant classes in biofilms shifted to Actinobacteria, Gammaproteobacteria, Alphaproteobacteria, and Bacteroidia. This study provided an effective approach for CCROC treatment with industrial application potentials.

Leaching Performance of Nanotechnology-Induced High-Arsenic-Bearing Tooeleite-like Mineral Nanowaste

For arsenic decontamination from groundwater, arsenic crystallization is becoming adopted due to its sustainability and economic benefits. However, arsenic crystallization technology is a two-step process, which makes it complex and generates hazardous waste. Successful efforts toward making it a single-step process are presented here. The addition of nanorods and ball-milled zinc sulfide nanoparticles to arsenic-contaminated water result in highly monodispersed and high-arsenic-containing mineralized nanowaste with a crystalline structure similar to the mineral Tooeleite ((Fe3+6(As3+O3)4SO4(OH)4·4H2O)). This study reports the results of a short-term stability test based on a toxicity characteristic leaching procedure and a long-term stability test of the mineralized synthetic nanowaste produced from water treatment. The Tooeleite-like mineralized nanowaste passed short-term stability tests. Arsenic in the leachate were found to be 1.1 ± 0.2 mg L−1 and 4.8 ± 0.3 mg L−1 from waste generated by the nanorod and ball-milled nanoparticles, respectively. The crystallinity was well preserved, as observed from the post-stability-test diffraction patterns, consequently proving that the waste product can be non-hazardous and therefore would not require any secondary treatment before final disposal.