Crystal Morphology Research Articles

Innovative application of green surfactants as eco-friendly scale inhibitors in industrial water systems.

Scale deposition poses significant challenges in various industrial utilities, necessitating the development of eco-friendly scale inhibitors in line with environmental regulations. This study investigates the potential of two natural surfactants, Casein and Rhamnolipid, as innovative inhibitors for calcium carbonate (CaCO3) scale formation, offering an alternative to traditional water treatment chemicals. The anti-scaling characteristics of these two green surfactants were performed using conductivity and electrochemical impedance spectroscopy (EIS) techniques. Additionally, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to analyze the morphology of CaCO3 crystals and understand the structural changes induced by surfactant interaction. The results revealed that Rhamnolipids significantly outperform Casein in suppressing scale formation, attributed to the adsorption of their multiple functional groups onto scale microcrystals. This adsorption modifies the crystal structure and inhibits further growth. Computational studies were employed to investigate the inhibition mechanism of these surfactants. The spatial and electrical configurations of optimal molecular structures are also analyzed using the Density Functional Theory (DFT) approach. Monte Carlo simulations on the CaCO3 (104) surface demonstrated that Rhamnolipids exhibit superior inhibition compared to Casein, as evidenced by their higher adsorption energy, indicating a more stable binding to the surface. Overall, this research highlights the potential of these natural surfactants as sustainable scale inhibitors, particularly in industries such as food and pharmaceuticals, thereby contributing to environmentally friendly water treatment solutions.

Water desalination using atmospheric pressure plasma combined with thermal treatment

AbstractHerein, a novel method is presented for enhancing the thermal desalination process of saline water and seawater using atmospheric pressure plasma (APP). The effect of APP treatment combined with thermal heating (APP-TH) on the energy consumption, conductivity, and pH of seawater and saline water is investigated. Utilizing scanning electron microscopy and X-ray diffractometry, the evolution of the morphology, structure, and chemical composition of precipitated crystals is characterized. The APP-TH method reduces the energy consumption for desalination by 40.5% for saline water and by 52.82% for seawater when compared to the TH-only method. The pH value remains approximately unchanged, decreasing slightly for the saline water from 7.1 for untreated saline water to 7.05 after APP-TH treatment. However, after APP-TH treatment, the pH value of the seawater increased slightly, from 7 to 7.8. The total dissolved salts decreased after APP-TH treatment, lowering the conductivity of the saline water from 65,000 µS/cm to 160 µS/cm and the conductivity of the seawater from 58,200 µS/cm to 243 µS/cm. Moreover, the size of precipitated crystals from saline water is 31.47 nm after APP-TH treatment, compared to 55.59 nm after TH-only treatment. They also dropped from 41 nm to 39.5 nm for seawater. Compared with traditional approaches, this research proposes an optimistic solution to address global potable water scarcity issues.

The Modification of Waste Polystyrene and Its Application as a Heavy Oil Flow Improver

The widespread use of polystyrene has brought great convenience to people's lives, but inappropriate recycling practices can also have a significant negative impact on the environment and public health. In this work, waste polystyrene was refined using maleic acid anhydride to produce flow improvers. The effect of the modified polystyrene perception of viscosity reduction and pour point depression of Henan oil was evaluated. The results show that modified polystyrene reduces the viscosity of Henan oil by 96.5% at most and depresses the pour point by 6.1 °C at most. Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1HH NMR) were used to investigate the modified polystyrene. The mechanism of modified polystyrene that improves the fluidity of heavy oil was proposed and analyzed through the study of wax crystal morphology (at 20 °C below the pour point).

Use of a humidity adsorbent derived from cockleshell waste in Thai fried fish crackers (Keropok)

Abstract In this research, cockleshell waste from food processing is developed into a humidity adsorbent using a simple technique. Cockleshells were first heated at 1,000°C. The crystal structure, functional group, and morphology of cockleshells before and after heat treatment were investigated. Cockleshells before heat treatment had the aragonite phase of CaCO3 compound, but it transformed into the CaO phase after heat treatment. Next, fried fish crackers, Keropok, were selected for humidity testing. The behavior of the humidity adsorbent and fried fish crackers was investigated for 0–180 days. After humidity testing, the CaO phase of the humidity adsorbent reacted with the humidity or water molecules and transformed into the Ca(OH)2 phase. The amount of crack and roughness on the humidity adsorbent surface increased with the increase in humidity testing time. The humidity adsorbent underwent a high humidity reaction and transformed into Ca(OH)2 after 30 days. The water activity, crispness, and thiobarbituric acid-reactive substances (TBARS) of fried fish crackers were analyzed. The water activity of fried fish crackers rapidly decreased, whereas the crispness slowly decreased in the range of 0–30 days. The humidity adsorbent controlled the TBARS value by increasing slowly. Based on these results, cockleshell waste can be developed as a humidity adsorbent and used to prolong the shelf-life of local food products to at least 90 days.

Study on the Effect of Cations on Morphology in the Preparation of Vaterite Calcium Carbonate from Dolomite

AbstractIn this paper, the effect of trace components in dolomite on the morphology of vaterite calcium carbonate is studied in the CaCl2‐NH3‐CO2 system, with a focus on the effect of cations (Mg2+, Fe3+, Si4+, and Al3+) in the solution. Ca2+, NH4+, Mg2+, Fe3+, Si4+, and Al3+ in the digestion solution are proportionally prepared into a solution by analyzing the calcium rich digestion solution which is obtained by digesting dolomite with ammonium chloride solution. Under the optimal conditions, NH3 is introduced at a rate of 0.5 L min−1 for 1 h, CO2 is introduced at a rate of 0.5 L min−1 for 1 h and rotation speed of 500 r min−1 to prepare the vaterite calcium carbonate. The results show that the addition of Mg2+, Fe3+, Si4+, and Al3+ can promote the growth of vaterite calcium carbonate. Among them, adding Mg2+ and Si4+ can promote the dispersion of vaterite, Fe3+ and Al3+ can cause agglomeration of vaterite. Material Studio software is used to predict the crystal morphology of vaterite calcium carbonate under ideal conditions, and the calculation results are basically consistent with the experimental results.

Crystallization and crystal morphology of polymers: A multiphase-field study

In this paper, we introduce a coarse-grained model of polymer crystallization using a multiphase-field approach. The model combines a multiphase-field method, Nakamura’s kinetic equation, and the equation of heat conduction for studying microstructural evolution of crystallization under isothermal and non-isothermal conditions. The multiphase-field method provides flexibility in adding any number of phases with different properties making the model effective in studying blends or composite materials. We apply our model to systems of neat PA6 and study the impact of initial distribution of crystalline grains and cooling rate on the morphology of the system. The relative crystallinity (conversion) curves show qualitative agreement with experimental data. We also investigate the impact of including carbon fibers on the crystallization and grain morphology. We observe a more homogeneous crystal morphology around fibers. This is associated with the higher initial volume fraction of crystal grains and higher heat conductivity of the fiber (compared to the polymer matrix). Additionally, we observe that the crystalline grains at the fiber surface grow perpendicular to the surface. This indicates that the vertical growth observed in experiments is merely due to geometrical constraints imposed by the fiber surface and neighbouring crystalline regions.

Tuning Molten-Salt-Mediated Calcination in Promoting Single-Crystal Synthesis of Ni-Rich LiNixMnyCozO2 Cathode Materials

High Ni-content LiNixMnyCozO2 (NMC) cathodes (with x ≥ 0.8, x + y + z = 1) have gained attention recently for their high energy density in electric vehicle (EV) Li-ion batteries. However, Ni-rich cathodes pose challenges in capacity retention due to inherent structural and surface redox instabilities. One promising strategy is to make the Ni-rich NMC material in the form of single-crystal micron-sized particles, as they resist intergranular and surface degradation during cycling. Among various methods to synthesize single-crystal NMC (SC-NMC) particles, molten-salt-assisted calcination offers distinct processing advantages but at present, is not yet optimized or mechanistically clarified to yield the desired control over crystal growth and morphology. In this project, molten-salt-mediated transformation of Ni0.85Mn0.05Co0.15(OH)2 precursor (P-NMC) particles to LiNi0.85Mn0.05Co0.15O2 particles is investigated in terms of the crystal growth mechanism and its electrochemical response. Unlike previous studies that involved large volumes of molten salt, using a smaller volume of molten KCl is found to result in larger primary particles with improved cycling performance achieved via partial reactive dissolution and heterogeneous nucleation growth, suggesting that the ratio of molten salt volume to NMC mass is an important parameter in the synthesis of single-crystal Ni-rich NMC materials.

Effect of trehalose dehydration on crystal morphology and food caking during post-treatment

Effect of trehalose dehydration on crystal morphology and food caking during post-treatment

Hardness properties of calcium and magnesium ions in drinking water

The drinking water parameter - water hardness - is defined as the sum of calcium and magnesium ion concentrations. In this study, their precipitation during boiling was investigated, using water of different hardnesses, calcium to magnesium ratios, natural tap and bottled waters. During boiling, pH value, conductivity, and calcium and magnesium concentrations were measured. Further, the morphology and composition of precipitates were analyzed. Boiling tests with durations of 30 min showed only a decrease of calcium concentration by precipitation. Longer boiling of water with a high proportion of magnesium showed decreasing magnesium concentrations once the calcium precipitation was completed. Calcium carbonate precipitated as calcite and aragonite crystals with aragonite needles occurring in the presence of high magnesium concentrations. Magnesium hydroxide formed during precipitation was identified as hydromagnesite crystals with different crystallization morphologies. Unexpectedly, for a water with low and equimolar concentrations of calcium and magnesium only magnesium precipitated at the relatively low pH 8.7. In summary, calcium ions in drinking water are evaluated as being of considerably higher relevance for the hardness properties than the magnesium ions. However, the precipitation of both minerals depends on their concentrations and ratio as well as on the pH value and the water matrix.

Degradation of hemihydrate phosphogypsum-based backfill in underground mining: Mechanical and microstructural insights on the effects of pH and temperature of mine water

The mechanical properties of hemihydrate phosphogypsum-based backfill (HPG-backfill) are significantly influenced by the temperature and pH of mine water (MW), impacting the stability of underground mining operations. This study evaluates the effects of MW at different temperatures (20°C, 30°C, and 40°C) and pH levels (3, 5, and 7) on HPG-backfill’s mechanical strength. A comprehensive analysis, including uniaxial compressive strength (UCS) testing, scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric and differential thermogravimetric (TG-DTG), and nuclear magnetic resonance (NMR), was employed to explore degradation mechanisms. The results indicate a significant decline in the mechanical performance of HPG-backfill when exposed to MW. This degradation becomes particularly pronounced under more acidic conditions and at elevated temperatures. A polynomial relationship between strength and pH, and a linear correlation with temperature, were identified. Interaction effects between temperature and pH on 28-day strength degradation were observed, diminishing with increased temperature or decreased pH. Gray relational analysis highlights pH as a more critical factor than temperature in degradation. Strength degradation is primarily attributed to gypsum dissolution and the pressure induced by recrystallization, which leads to the formation of fatigue cracks. Additionally, acidic conditions accelerate premature crystallization, altering both the crystal morphology and the pore structure. These insights advance the understanding of HPG-backfill degradation, guiding the developing of more resilient backfill materials for extreme mining environments.

Influence of starch on freeze-thaw stability of Hypophthalmichthys molitrix surimi gel observed via ice crystal distribution and gel properties

Starch has been recognized as a vital ingredient in surimi products due to its ability to absorb water, which reduces the deterioration of gels and water loss during freezing and thawing. However, it is essential to ascertain the role of starch in the formation of ice crystals and the texture of surimi gels. The impact of freeze-thaw cycles on the morphology and distribution of ice crystals, as well as the textural characteristics of gelatinized and ungelatinized starch-surimi gels was investigated. The results of light microscopy revealed that the presence of starch, irrespective of whether it was gelatinized, resulted in a reduction in the size of ice crystals within the surimi gel network during the freeze-thaw process. In addition, starch in surimi gels was subjected to freeze-thaw cycles, resulting in the emergence of two distinct states of bound water (0.1–1 ms and 1–10 ms). The higher relative content of immobile water indicated that the gelatinized starch had improved water holding properties. Furthermore, the incorporation of gelatinized starch into surimi enhanced its freeze-thaw stability and retarded the loss of gel strength, hardness, and whiteness. The addition of starch had a synergistic impact, enhancing the gel properties by affecting the formation of ice crystals and water absorption.

The Influence of Carbon Fiber on Crystallization and Morphology of Poly(Ether Ketone Ketone) Composites Towards High Rate Thermoplastic Manufacturing Processes

Recent interest in thermoplastic composites for aerospace applications is driven by the need for high-volume manufacturing of materials that display excellent mechanical, thermal, and solvent resistive properties. Specifically, a large component of the composite properties of thermoplastic composites are highly dependent on the crystalline fraction of the semi-crystalline polymer matrix of the reinforced system. This work investigates the melting behavior of poly (ether ketone ketone) (PEKK) and the influence of temperature and fiber on crystallization kinetics and morphology of (PEKK) composites utilizing, differential scanning calorimetry, Velaris-Sefaris modelling, and polarized optical microscopy (POM). Annealing temperatures of 380°C and above were required to fully erase crystalline ordering in the PEKK matrix. Furthermore, carbon fibers accelerated crystallization kinetics in PEKK at a range of temperatures observed via DSC, and Velaris-Sefaris modelling implied a shift from bulk to surface induced nucleation by the addition carbon fiber to the PEKK matrix, reducing activation energy of crystallization events. This nucleation behavior was visually confirmed through POM with observation of transcrystalline domains nucleated from the surface of a single carbon fiber.

Enhanced Toughness of KZr2(PO4)3 ceramics via hydrothermal Incorporation of multi-walled carbon nanotubes

The multi-walled carbon nanotubes/KZr₂(PO₄)₃ (MWCNTs/KZP) composite ceramics were successfully prepared by introducing MWCNTs during the hydrothermal process. The impact of MWCNTs addition on the crystal structure, morphology, mechanical strength, and thermal expansion properties of KZP ceramics was investigated. XRD and SEM analyses revealed that the introduction of MWCNTs did not alter the phase and crystal structure of KZP. It was observed that the MWCNTs formed a strong interfacial bond with the KZP matrix and were uniformly dispersed. Mechanical testing showed that the composite ceramic with 0.3 wt% MWCNTs exhibited significantly improved flexural strength and fracture toughness, measuring 125.08 MPa and 2.57 MPa·m1/2, respectively, compared to the KZP ceramic. This enhancement was attributed to the refinement of KZP grain size and the formation of a high-strength bonding interface between MWCNTs and the KZP matrix. Moreover, the incorporation of MWCNTs not only improved the toughness of KZP ceramics but also imparted exceptional thermal properties, with a thermal expansion coefficient (TEC) ranging from -0.30 to 0.49×10-6/K, demonstrating outstanding near-zero low thermal expansion characteristics.

Multicolor luminescence and high efficient optical thermometric performance of Eu3+ and Sm3+ in self-activated Na2LuMg2V3O12 garnet

To develop efficient luminescence and optical thermometry materials for color display and non-contact temperature measurement, novel RE3+ (RE = Eu, Sm) doped self-activated Na2LuMg2V3O12 phosphors were prepared by a typical solid-state reaction method. Their crystal structure, morphology, multi-color luminescence and temperature sensing properties were elaborately investigated. Under UV light excitation, an intense and broad green-yellow emission band from VO43– group is observed in the Na2LuMg2V3O12 matrix, indicating its potential application in solid state lighting. After the incorporation of Eu3+ and Sm3+ ions, efficient energy transfer (ET) from VO43– group to Eu3+/Sm3+ ions occurs and the emission color of the samples can be readily tuned among different color ranges. Besides, based on the change of luminescence intensity and lifetimes of VO43– group in Na2LuMg2V3O12:Eu3+ and Na2LuMg2V3O12:Sm3+, the ET efficiency was analyzed and the mechanism is illustrated. Finally, large discrepancy between the thermal stability of VO43– group and Eu3+/Sm3+ ions are observed in the temperature-dependent emission spectra of Na2LuMg2V3O12:Eu3+ and Na2LuMg2V3O12:Sm3+. By taking advantage of the luminescence intensity ratio (LIR) between VO43– group and Eu3+/Sm3+ ions in Na2LuMg2V3O12:0.01Eu3+ and Na2LuMg2V3O12:0.07Sm3+, two new types of optical thermometry mediums were designed and their basic temperature sensing parameters were calculated.

The Influence of Carbon Fiber on Crystallization and Morphology of Poly(Ether Ketone Ketone) Composites Towards High Rate Thermoplastic Manufacturing Processes

Recent interest in thermoplastic composites for aerospace applications is driven by the need for high-volume manufacturing of materials that display excellent mechanical, thermal, and solvent resistive properties. Specifically, a large component of the composite properties of thermoplastic composites are highly dependent on the crystalline fraction of the semi-crystalline polymer matrix of the reinforced system. This work investigates the melting behavior of poly (ether ketone ketone) (PEKK) and the influence of temperature and fiber on crystallization kinetics and morphology of (PEKK) composites utilizing, differential scanning calorimetry, Velaris-Sefaris modelling, and polarized optical microscopy (POM). Annealing temperatures of 380°C and above were required to fully erase crystalline ordering in the PEKK matrix. Furthermore, carbon fibers accelerated crystallization kinetics in PEKK at a range of temperatures observed via DSC, and Velaris-Sefaris modelling implied a shift from bulk to surface induced nucleation by the addition carbon fiber to the PEKK matrix, reducing activation energy of crystallization events. This nucleation behavior was visually confirmed through POM with observation of transcrystalline domains nucleated from the surface of a single carbon fiber.

Growth and spectroscopy characteristics of Er, Ce:BGSO crystal: A promising material for eye-safe laser applications

Er, Ce co-doped BGSO single crystals were successfully grown by the Bridgman method. The growth parameters, including temperature gradient and growth rate, were optimized to achieve high-quality crystals. The crystal structure and morphology were characterized using X-ray diffraction and scanning electron microscopy. The optical absorption properties of Er, Ce co-doped BGSO single crystals were studied using UV–Vis absorption spectroscopy. The absorption spectrum revealed the absorption edge and the presence of absorption bands related to the presence of Ce dopant, providing valuable insights into the energy transfer processes occurring within the crystal lattice. Furthermore, the luminescence mechanism of BGSO crystals was analyzed using the Judd-Ofelt (J-O) theory, with detailed investigation into the role of ligands in spectral parameters. The photoluminescence spectra and emission decay time of Er, Ce co-doped BGSO single crystals were characterized. A comparative analysis with Er, Ce:BGSO crystals was conducted to investigate the sensitization mechanism of Ce ions on Er emission at 1.5 μm, demonstrating their potential for use as eye-safe laser materials in various applications.

Influence of reaction aging time on the crystal structure, morphology, and photoluminescence properties of Sm3+-doped CdMoO4 phosphor

Influence of reaction aging time on the crystal structure, morphology, and photoluminescence properties of Sm3+-doped CdMoO4 phosphor

Modification mechanism of Te and morphology evolution of primary Mg2Si in an Al-20Mg2Si alloy

In the present work, the modification effect of Te and the corresponding growth process of Mg2Si were clarified. With 0.5 wt.% Te addition, the dendritic primary Mg2Si transformed to polygons, accompanied by a reduction in size from over ∼165 μm to ∼18 μm. However, 2.0 wt.% Te addition resulted in degradation of modification effect, and the morphology of Mg2Si changed to dendrite. Three-dimensional morphology of primary Mg2Si indicated that Te altered the morphology of primary Mg2Si from dendrites to polyhedrons surrounded by {111} and {100}. The modification mechanism of Te can be attributed to the heterogeneous nucleation and the doping of Te during the growth process of primary Mg2Si, which greatly contributed to dimension decrease and morphology evolution of primary Mg2Si respectively. With Te corporation, the relative surface energy between the {100} and {111} (r) drops, contributing to the exposure of {100}. Our work shows that the solute concentration under non-equilibrium solidification plays an important role in determining the final morphology of Mg2Si. The local segregation of Mg and Si solutes results in the degradation of dendrite arms along certain directions during the initial stage of crystal growth. Combined with the modifying effect of Te, which alters the surface energy of the crystal, the final crystal morphology deviates from its equilibrium state. Our study demonstrates that ultimate morphology and dimensions of primary Mg2Si can be determined simultaneously with the addition of certain modifiers, which can be achieved by regulating the growth and nucleation of Mg2Si at the same time.

Morphological control for hollow rod crystals of a photochromic diarylethene on spherulites by surface properties of substrates.

Sublimation methods utilizing the surface properties of substrates can address the challenge of controlling hollow morphologies in rod crystals. Spherulites were formed on the hydrophilic surface of the (0001) planes of α-quartz and sapphire substrates by sublimation of 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1a). Various types of hollow morphologies, distinguished by the size and shape of their cross sections and by the presence or absence of branching structures, were formed separately on α-quartz and sapphire substrates. Such precise control of the hollow morphologies was attributed to the wettability of each substrate, leading to the formation of spherulites of 1a. In addition, it was indicated that the formation process of the surface morphologies of spherulites was associated with the hollow morphologies of rod crystals of 1a.

Harvesting Zr-based metal-organic frameworks by continuous-flow synthesis as efficient adsorbents for eliminating nitrogen-containing compounds in liquid fuel

This work designed a continuous-flow tubular reactor for rapidly and scalably harvesting the metal-organic framework (MOF) of UiO-66(Zr)-NH2. The experimental conditions, including temperature (110–140 °C), holding time (10–30 min), and CH3COOH/H2N-BDC molar ratio (100–250), were carried out to survey their impacts on the product yield and quality. The highest yield and production rate of ∼72% and ∼1.55 g h−1 were obtained at 130 °C, 20 min, and CH3COOH/H2N-BDC ratio 200. The temperature and modulator content significantly influenced MOFs’ crystal morphology, crystallinity, and porosity. Besides, the adopted method also successfully produced UiO-66 and UiO-67 MOFs with high production rates. The adsorptive denitrogenation (ADN) performances were carried out using liquid fuel models containing quinoline (QU) and 2-methyl pyrrole (MP). In batch mode adsorption, the UiO-66-NH2-130-200 sample showed the highest adsorbing quantities of ∼199 and ∼163 mg g−1 for QU and MP, respectively. Furthermore, the prepared MOFs efficiently removed NCCs from liquid fuel under a continuous fixed-bed column process. These demonstrate that modulator-assisted continuous-flow synthesis can be a potential strategy for the scalable harvest of Zr-MOFs with good qualities and high performance in getting rid of NCCs from liquid fuel.