Journal Description
Crystals
Crystals
is an international, peer-reviewed, open access journal on Crystallography published monthly online by MDPI. The Professional Committee of Key Materials and Technology for Electronic Components (PC-KMTEC) is affiliated with Crystals and its members receive discounts on the article processing charges.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), Inspec, CAPlus / SciFinder, and other databases.
- Journal Rank: JCR - Q2 (Crystallography) / CiteScore - Q2 (Condensed Matter Physics)
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 10.6 days after submission; acceptance to publication is undertaken in 2.7 days (median values for papers published in this journal in the second half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
2.7 (2022);
5-Year Impact Factor:
2.6 (2022)
Latest Articles
Structural and Optical Characterization of a New Tetra- and Hexa-Coordinated Cd-Based Hybrid Compound with White Light Emission
Crystals 2024, 14(5), 459; https://doi.org/10.3390/cryst14050459 (registering DOI) - 12 May 2024
Abstract
The present paper deals with a new two-in-one zero-dimensional (0D) organic–inorganic hybrid compound namely (C6H10N2)4[CdBr6][CdBr4]2. This molecular crystal structure contains isolated CdBr4 tetrahedra and CdBr6 octahedra. The
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The present paper deals with a new two-in-one zero-dimensional (0D) organic–inorganic hybrid compound namely (C6H10N2)4[CdBr6][CdBr4]2. This molecular crystal structure contains isolated CdBr4 tetrahedra and CdBr6 octahedra. The optical characterization by UV–Vis–NIR spectroscopy shows that the (C6H10N2)4[CdBr6][CdBr4]2 exhibits a large gap energy of 4.97 eV. Under UV excitation, this hybrid material shows a bright cold white light emission (WLE) at room temperature. The photoluminescence (PL) analysis suggests that the WLE originates from the organic molecules. Density of states (DOS) analysis using the density functional theory (DFT) demonstrates that the calculated HOMO(Br)→LUMO(organic) absorption transition (4.1 eV) does not have significant intensity, while, the transition involving the valence band (VB) and the second and third conduction bands (CB) around 5 eV are allowed, which is in good agreement with the experimental gap value. The interesting theoretical result is that the LUMO(organic)→HOMO(Br) emission is allowed, which confirms the important role of the organic molecule in the emission mechanism, in good agreement with the experimental PL analysis.
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(This article belongs to the Special Issue Advances in Organic Semiconductors)
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Two Consecutive Negative Electrocaloric Peaks in <001>-Oriented PMN-30PT Single Crystals
by
Yu Zhang, Weiping Gong, Zhen Li, Jianting Li, Changyu Li, Jun Chen, Yaodong Yang, Yang Bai and Wei-Feng Rao
Crystals 2024, 14(5), 458; https://doi.org/10.3390/cryst14050458 (registering DOI) - 12 May 2024
Abstract
The versatile electrocaloric (EC) behaviors of the (1-x)Pb(Mg1/3Nb2/3)O3-xPT (PMN-100xPT) single crystal are closely related to the multiple phase transitions under the multiple fields of electric field and temperature. In this work, the EC effect of
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The versatile electrocaloric (EC) behaviors of the (1-x)Pb(Mg1/3Nb2/3)O3-xPT (PMN-100xPT) single crystal are closely related to the multiple phase transitions under the multiple fields of electric field and temperature. In this work, the EC effect of <001>-oriented PMN-30PT single crystals with chemical composition at morphotropic phase boundary has been studied during the phase transformation process from the ferroelectric rhombohedral (R) phase to the tetragonal (T) phase. Two consecutive negative EC peaks have been achieved for the first time. Based on the projection of the EC effect in the electric field-temperature phase diagram, the relationship between the EC behaviors and the phase transitions is further established. It was found that the monoclinic (M) phase actually existed during the transformation from the R phase to the T phase, and the related R-M phase transition and M-T phase transition could both induce negative EC peaks. Under the electric field of E = 10 kV/cm, the first negative EC peaks induced by the R-M phase transition is at 57 °C with ΔTmax = −0.11 K. And the M-T phase transition can produce a higher negative EC peak, and its value can reach −0.22 K at 68 °C. Based on thermodynamic calculations, the relationship between the entropy change in different phase transitions and the EC behaviors has been further elucidated. The negative EC effect originates from the structural entropy increase in the electric field-induced phase transition process. This work not only advances the research on the electrical properties of relaxor ferroelectric single crystals but also provides a new insight into high-performance ferroelectric materials design.
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(This article belongs to the Special Issue Advanced Ferroelectric, Piezoelectric and Dielectric Ceramics)
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Open AccessArticle
Hierarchically Porous Carbon Cloth–Polyaniline (CC–PANI) Composite Supercapacitor Electrodes with Enhanced Stability
by
Svetlana V. Stakhanova, Ilya S. Krechetov, Kristina E. Shafigullina, Tatiana L. Lepkova, Valentine V. Berestov, Eugene S. Statnik, Zlatotsveta E. Zyryanova, Elena A. Novikova and Alexander M. Korsunsky
Crystals 2024, 14(5), 457; https://doi.org/10.3390/cryst14050457 (registering DOI) - 12 May 2024
Abstract
In this work, hierarchically porous composites were prepared in the form of activated carbon cloth (CC) Busofit T–1–055 filled with an electrically conductive polymer, polyaniline (PANI), for use as pseudocapacitive electrodes of electrochemical supercapacitors (SCs). CC fibers have high nanoporosity and specific surface
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In this work, hierarchically porous composites were prepared in the form of activated carbon cloth (CC) Busofit T–1–055 filled with an electrically conductive polymer, polyaniline (PANI), for use as pseudocapacitive electrodes of electrochemical supercapacitors (SCs). CC fibers have high nanoporosity and specific surface area, so it was possible to deposit (via the chemical oxidative polymerization of aniline) a significant amount of PANI on them in the form of a thin layer mainly located on the inner surface of the pores. Such morphology of the composite made allowed the combining of the high capacitive characteristics of PANI with the reversibility of electrochemical processes, high columbic efficiency and cyclic stability rather typical for carbon materials of double-layer SCs. The highest capacitance of composite electrodes of about 4.54 F/cm2 with high cyclic stability (no more than 8% of capacity loss after 2000 charge–discharge cycles with a current density of 10 A/cm2) and columbic efficiency (up to 98%) was achieved in 3 M H2SO4 electrolyte solution when PANI was synthesized from an aniline hydrochloride solution with a concentration of 0.25 M. Trasatti analysis revealed that 27% of specific capacitance corresponded to pseudocapacitance, and 73% to the double-layer capacitance.
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(This article belongs to the Special Issue Synthesis, Characterization and Applications of Crystalline Electroconductive Polymers)
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Open AccessArticle
Impact of Zinc Oxide on the Structure and Surface Properties of Magnesium–Potassium Glass–Crystalline Glazes
by
Katarzyna Pasiut, Janusz Partyka, Dawid Kozień and Piotr Pańtak
Crystals 2024, 14(5), 456; https://doi.org/10.3390/cryst14050456 (registering DOI) - 11 May 2024
Abstract
The present work describes test results for glass crystal materials based on the SiO2-Al2O3-MgO-K2O system after 5, 10, 15, and 20 wt.% zinc oxide was added. The glazing analysis involved determining the effect of the
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The present work describes test results for glass crystal materials based on the SiO2-Al2O3-MgO-K2O system after 5, 10, 15, and 20 wt.% zinc oxide was added. The glazing analysis involved determining the effect of the additive on the characteristic temperatures and properties of the surface obtained, such as color, gloss, and roughness, as expressed by a Ra parameter. The obtained glazes were also analyzed for changes in phase composition (quantitative and qualitative XRD tests), changes in microstructure (based on images obtained with a scanning electron microscope), and structure (based on analyses and decomposition of spectra obtained using mid-infrared spectroscopy). As a result, the maximum addition of zinc oxide provided the best results.
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(This article belongs to the Special Issue Porous Ceramics and Their Composite Materials)
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Open AccessArticle
Aluminium-Silicon Lightweight Thermal Management Alloys with Controlled Thermal Expansion
by
Peter Lewis, Andrew Tarrant, Andreas Frehn, Fritz Grensing, James Nicholson, Nick Farrah and Martyn Acreman
Crystals 2024, 14(5), 455; https://doi.org/10.3390/cryst14050455 (registering DOI) - 11 May 2024
Abstract
With the ever-growing emphasis on global decarbonization and rapid increases in the power densities of electronics equipment in recent years, new methods and lightweight materials have been developed to manage heat load as well as interfacial stresses associated with coefficient of thermal expansion
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With the ever-growing emphasis on global decarbonization and rapid increases in the power densities of electronics equipment in recent years, new methods and lightweight materials have been developed to manage heat load as well as interfacial stresses associated with coefficient of thermal expansion (CTE) mismatches between components. The Al–Si system provides an attractive combination of CTE performance and high thermal conductivity whilst being a very lightweight option. Such materials are of interest to industries where thermal management is a key design criterion, such as the aerospace, automotive, consumer electronics, defense, EV, and space sectors. This paper will describe the development and manufacture of a family of high-performance hypereutectic Al–Si alloys (AyontEX™) by a powder metallurgy method. These alloys are of particular interest for structural heat sink applications that require high reliability under thermal cycling (CTE of 17 μm/(m·°C)), as well as reflective optics and instrument assemblies that require good thermal and mechanical stability (CTE of 13 μm/(m·°C)). Critical performance relationships are presented, coupled with the microstructural, physical, and mechanical properties of these Al–Si alloys.
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(This article belongs to the Special Issue Advances in Metal Matrix Composites: Structure, Properties and Applications)
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Manufacturing of TiO2, Al2O3 and Y2O3 Ceramic Nanotubes for Application as Electrodes for Printable Electrochemical Sensors
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Alexandru Florentin Trandabat, Romeo Cristian Ciobanu, Oliver Daniel Schreiner, Mihaela Aradoaei and Sebastian Teodor Aradoaei
Crystals 2024, 14(5), 454; https://doi.org/10.3390/cryst14050454 (registering DOI) - 11 May 2024
Abstract
This paper describes the process to obtain ceramic nanotubes from titanium dioxide, alumina and yttrium oxide by a feasible, replicable and reliable technology, including three stages, starting from an electrospinning process of poly(methyl methacrylate) solutions. A minimum diameter of 0.3 μm was considered
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This paper describes the process to obtain ceramic nanotubes from titanium dioxide, alumina and yttrium oxide by a feasible, replicable and reliable technology, including three stages, starting from an electrospinning process of poly(methyl methacrylate) solutions. A minimum diameter of 0.3 μm was considered optimal for PMMA nanofibers in order to maintain the structural stability of covered fibers, which, after ceramic film deposition, leads to a fiber diameter of 0.5–0.6 μm. After a chemical and physical analysis of the stages of obtaining ceramic nanotubes, in all cases, uniform deposition of a ceramic film on PMMA fibers and, finally, a uniform structure of ceramic nanotubes were noted. The technological purpose was to use such nanotubes as ingredients in screen-printing inks for electrochemical sensors, because no study directly targeted the subject of ceramic nanotube applications for printed electronics to date. The printing technology was analyzed in terms of the ink deposition process, printed electrode roughness vs. type of ceramic nanotubes, derived inks, thermal curing of the electrodes and the conductivity of electrodes on different support (rigid and flexible) at different curing temperatures. The experimental inks containing ceramic nanotubes can be considered feasible for printed electronics, because they offer fast curing at low temperatures, reasonable conductivity vs. electrode length, good printability on both ceramic or plastic (flexible) supports and good adhesion to surface after curing.
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(This article belongs to the Special Issue Metal Oxide Thin Films, Nanomaterials and Nanostructures)
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The Influence of Variations in Synthesis Conditions on the Phase Composition, Strength and Shielding Characteristics of CuBi2O4 Films
by
Dauren B. Kadyrzhanov, Medet T. Idinov, Dmitriy I. Shlimas and Artem L. Kozlovskiy
Crystals 2024, 14(5), 453; https://doi.org/10.3390/cryst14050453 (registering DOI) - 10 May 2024
Abstract
This paper presents the results of the influence of variation of the synthesis conditions of CuBi/CuBi2O4 films with a change in the applied potential difference, as well as a change in electrolyte solutions (in the case of adding cobalt or
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This paper presents the results of the influence of variation of the synthesis conditions of CuBi/CuBi2O4 films with a change in the applied potential difference, as well as a change in electrolyte solutions (in the case of adding cobalt or nickel sulfates to the electrolyte solution) on changes in the phase composition, structural parameters and strength characteristics of films obtained using the electrochemical deposition method. During the experiments, it was found that, in the case of the addition of cobalt or nickel to the electrolyte solutions, the formation of films with a spinel-type tetragonal CuBi2O4 phase is observed. In this case, a growth in the applied potential difference leads to the substitution of copper with cobalt (nickel), which in turn leads to an increase in the structural ordering degree. It should be noted that, during the formation of CuBi/CuBi2O4 films from solution–electrolyte №1, the formation of the CuBi2O4 phase is observed only with an applied potential difference of 4.0 V, while the addition of cobalt or nickel sulfates to the electrolyte solution results in the formation of the tetragonal CuBi2O4 phase over the entire range of the applied potential difference (from 2.0 to 4.0 V). Studies have been carried out on the strength and tribological characteristics of synthesized films depending on the conditions of their production. It has been established that the addition of cobalt or nickel sulfates to electrolyte solutions leads to an increase in the strength of the resulting films from 20 to 80%, depending on the production conditions (with variations in the applied potential difference). During the studies, it was established that substitution of copper with cobalt or nickel in the composition of CuBi2O4 films results in a rise in the shielding efficiency of low-energy gamma radiation by 3.0–4.0 times in comparison with copper films, and 1.5–2.0 times for high-energy gamma rays, in which case the decrease in efficiency is due to differences in the mechanisms of interaction of gamma quanta, as well as the occurrence of secondary radiation as a result of the formation of electron–positron pairs and the Compton effect.
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(This article belongs to the Special Issue Advances in Synthesis, Characterization, and Application of Thin Films)
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Modification of LaB6 with ZrO2-Al2O3-TiO2 for Improvement of Density and Mechanical and Electrical Properties
by
Sen Yang, Ruiqing Ba, Jingnan Hong, Jing Li, Jingdong Guo, Xinghui He, Hongwei Zhang, Naihe Yi and Weibing Ma
Crystals 2024, 14(5), 452; https://doi.org/10.3390/cryst14050452 - 9 May 2024
Abstract
Pure lanthanum hexaboride (LaB6) ceramics were prepared using powders of different grain sizes. The ceramics could reach a relative density of 98.2% at high temperatures and pressures, but had a low flexural strength (136.9 MPa). LaB6 ceramics were synthesized using
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Pure lanthanum hexaboride (LaB6) ceramics were prepared using powders of different grain sizes. The ceramics could reach a relative density of 98.2% at high temperatures and pressures, but had a low flexural strength (136.9 MPa). LaB6 ceramics were synthesized using ZrO2-Al2O3-TiO2 (ZAT) as sintering additives. The ceramics demonstrate high density and excellent mechanical properties. The hot pressure sintering (HPS) method was utilized in the synthesis of the ceramics. Investigations were conducted on the effects of ZAT content, as well as the effects of the sintering temperature and pressure on the sintering behavior, microstructure, and mechanical and electrical properties of LaB6 ceramics. LaB6 ceramics fabricated with a ZAT addition of 6 wt.%, at a sintering temperature of 1700 °C, and under a pressure of 50 MPa, exhibited superior sintering and electrical properties, including a relative density of 97%, a conductivity of 7.2 MS/m, a flexural strength of 281.5 MPa, and a Vickers hardness of 21.2 GPa. The LaB6 ceramics synthesized in this research exhibit promising potential as electron-emitting cathodes for field emission applications.
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(This article belongs to the Section Polycrystalline Ceramics)
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A Modern Approach to HEAs: From Structure to Properties and Potential Applications
by
Radu Nartita, Daniela Ionita and Ioana Demetrescu
Crystals 2024, 14(5), 451; https://doi.org/10.3390/cryst14050451 - 9 May 2024
Abstract
High-entropy alloys (HEAs) are advanced materials characterized by their unique and complex compositions. Characterized by a mixture of five or more elements in roughly equal atomic ratios, these alloys diverge from traditional alloy formulations that typically focus on one or two principal elements.
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High-entropy alloys (HEAs) are advanced materials characterized by their unique and complex compositions. Characterized by a mixture of five or more elements in roughly equal atomic ratios, these alloys diverge from traditional alloy formulations that typically focus on one or two principal elements. This innovation has paved the way for subsequent studies that have expanded our understanding of HEAs, highlighting the role of high mixing entropy in stabilizing fewer phases than expected by traditional phase prediction methods like Gibbs’s rule. In this review article, we trace the evolution of HEAs, discussing their synthesis, stability, and the influence of crystallographic structures on their properties. Additionally, we highlight the strength–ductility trade-off in HEAs and explore strategies to overcome this challenge. Moreover, we examine the diverse applications of HEAs in extreme conditions and their promise for future advancements in materials science.
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(This article belongs to the Section Crystalline Metals and Alloys)
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Heat Treatment of Calcite to Enhance Its Removal of Color Dye Alizarin Red S
by
Zhaohui Li, Anna Bowman, Angie Rayniak, Jadyn Strommen, Lori Allen and Shangping Xu
Crystals 2024, 14(5), 450; https://doi.org/10.3390/cryst14050450 - 8 May 2024
Abstract
The use of color dyes in modern society presents a great challenge to the environment. Thus, extensive studies have been conducted in the last 30 years on the removal of color dyes from aqueous solutions such industrial wastewater. In this study, the removal
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The use of color dyes in modern society presents a great challenge to the environment. Thus, extensive studies have been conducted in the last 30 years on the removal of color dyes from aqueous solutions such industrial wastewater. In this study, the removal of alizarin red S (ARS), an anionic dye, from solution by raw calcite (Cal) and heat-treated calcite (HCal) was conducted and compared under different physico-chemical conditions. Based on the isotherm study, the ARS removal capacities increased from 167 to 251 mmol/kg after the Cal was heated to 1000 °C for 3 h. The X-ray diffraction analyses showed no difference in the calcite phase between Cal and HCal after ARS sorption. Fourier-transform infrared results also showed no change in the calcite phase after ARS sorption, except a slightly increase in wavenumber from 713 to 727 cm−1 for the OCO bending of HCal at high ARS sorption levels. SEM observations showed about the same particle size and morphology before and after ARS sorption. The TGA data showed the formation of CaO after Cal was heated, and CaO converted back into calcite after being in contact with water or ARS solution for 24 h and then being air-dried. Thus, the high ARS removal could be due to CaO produced after Cal being heated. The findings from this research proved that there is great potential in the use of calcite, a low-cost and readily available Earth material, after heat treatment for the removal of contaminants from water.
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(This article belongs to the Special Issue Porous Materials and Their Adsorption Behaviors)
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Open AccessCommunication
The Influence and Mechanism Analysis of the Longitudinal Magnetic Field on the Microstructure Evolution and Properties of AZ40 Welds
by
Jianghui Wang
Crystals 2024, 14(5), 449; https://doi.org/10.3390/cryst14050449 (registering DOI) - 8 May 2024
Abstract
This paper studied the effect of the longitudinal magnetic field (LMF) on the microstructure evolution and mechanical properties of AZ40 argon tungsten arc welding joints. Magnetic field-assisted argon tungsten arc welding technology was used to achieve butt welding of an AZ40 Mg alloy
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This paper studied the effect of the longitudinal magnetic field (LMF) on the microstructure evolution and mechanical properties of AZ40 argon tungsten arc welding joints. Magnetic field-assisted argon tungsten arc welding technology was used to achieve butt welding of an AZ40 Mg alloy sheet with a thickness of 1.5 mm. The microstructure of the Mg alloy weld was studied by using metallographic microscopy and scanning electron microscopy. Mechanical performance of the Mg alloy weld was evaluated by using a hardness tester and universal tensile machine. The experimental results revealed that the average crystallite dimension of the weld zone of the Mg alloy joint reached 43 μm without an LMF. By introducing LMF-assisted technology, the weld structure was significantly refined and the average crystallite dimension of the weld seam was reduced by 39.5% to 26 μm with a coil current of 1.2 A. For the joint without magnetic field assistance, the optimum tensile strength of the AZ40 weldment was 225 MPa under a welding current of 80 A, and fracture occurred in the center of joint welding seam. Under an LMF coil current of 1.2 A, the joint strength increased from the initial 225 MPa to 254 MPa, and fracture occurred at the weld edge with obvious plastic fracture characteristics. It can be confirmed that the LMF-assisted welding process effectively improved the microstructure characteristics of the weld seam and strengthened the microhardness and mechanical performance of the AZ40 joint.
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(This article belongs to the Section Crystalline Metals and Alloys)
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Open AccessReview
The “Forgotten” Hydroxyapatite Crystals in Regenerative Bone Tissue Engineering: A Critical Review
by
Anastasios-Nektarios Tzavellas, Chrysoula Katrilaka, Niki Karipidou, Magdalini Kanari, Maria Pitou, Georgios Koliakos, Angeliki Cheva, Theodora Choli-Papadopoulou, Amalia Aggeli and Eleftherios Tsiridis
Crystals 2024, 14(5), 448; https://doi.org/10.3390/cryst14050448 - 8 May 2024
Abstract
Bone regeneration using Bone Morphogenetic Proteins (BMPs) alongside various engineered scaffolds has attracted considerable attention over the years. The field has seen extensive research in preclinical animal models, leading to the approval of two products and guiding the quest for new materials. Natural
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Bone regeneration using Bone Morphogenetic Proteins (BMPs) alongside various engineered scaffolds has attracted considerable attention over the years. The field has seen extensive research in preclinical animal models, leading to the approval of two products and guiding the quest for new materials. Natural and synthetic polymers, ceramics, and composites have been used to fabricate the necessary porous 3D scaffolds and delivery systems for BMPs. Interestingly, all reported applications in the literature are triumphant. Evaluation of the results is typically based on histologic assessment after appropriate staining and radiological modalities, providing morphological identification of the newly formed bone and describing cells and the organic compound. Remarkably, while these evaluation methods illustrate mineralization, they are not capable of identifying hydroxyapatite crystals, the mineral component of the bone, which are crucial for its mechanical properties, structure, integrity, and long-term stability of regenerated bone tissue. This review aims to focus on the different scaffolds used in bone tissue engineering applications and underline the pressing need for techniques that could recognize the presence of hydroxyapatite crystals as well as their characteristics in bone tissue engineering, which will provide a more complete and comprehensive assessment of the successful results.
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(This article belongs to the Section Mineralogical Crystallography and Biomineralization)
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Synthesis and Characterization of Zinc Oxide Nanoparticle Anchored Carbon as Hybrid Adsorbent Materials for Effective Heavy Metals Uptake from Wastewater
by
Abdullah G. Alanazi, Mohamed A. Habila, Zeid A. ALOthman and Ahmed-Yacine Badjah-Hadj-Ahmed
Crystals 2024, 14(5), 447; https://doi.org/10.3390/cryst14050447 - 8 May 2024
Abstract
Hybrid material-derived adsorbents have shown a great applicable efficiency in various fields, including industrial uses and environmental remediation. Herein, zinc oxide nanoparticle modified with carbon (ZnO-C) was fabricated and utilized for wastewater treatment through the adsorption of Zn(II), Cd(II), Co(II), and Mn(II). The
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Hybrid material-derived adsorbents have shown a great applicable efficiency in various fields, including industrial uses and environmental remediation. Herein, zinc oxide nanoparticle modified with carbon (ZnO-C) was fabricated and utilized for wastewater treatment through the adsorption of Zn(II), Cd(II), Co(II), and Mn(II). The surface and structural characteristics were examined using TEM, SEM, XRD, FTIR spectroscopy, EDS, and the BET surface area. Kinetics and equilibrium investigations were applied to optimize the adsorptive removal of Zn(II), Cd(II), Co(II), and Mn(II) onto ZnO-C. The results indicated that the formation of ZnO-C in crystalline sphere-like granules with a nano-size between 16 and 68 nm together with carbon matrix. In addition, the spherical granules of zinc oxide were gathered to form clusters. FTIR spectroscopy indicated that the ZnO-C surface was rich with OH groups and ZnO. The adsorption capacity 215, 213, 206, and 231 mg/g for Zn(II), Cd(II), Co(II), and Mn(II), respectively, at the optimal conditions pH between 5 and 6, a contact time of 180 min, and an adsorbent dose of 0.1 g/L. The adsorptive removal data modeling for the uptake of Zn(II), Cd(II), Co(II), and Mn(II) onto ZnO-C showed agreement with the assumption of the pseudo-second-order kinetic model and the Freundlich isotherm, suggesting a fast adsorption rate and a multilayered mechanism. The achieved adsorption capacity using the prepared ZnO-C was more effective compared to ZnO, carbon, Fe3O4, and Fe3O4-C. Real wastewater samples were applied, including valley water, industrial wastewater, and rain wastewater, and evaluated for the applicable uptake of Zn(II), Cd(II), Co(II), and Mn(II) using ZnO-C and Fe3O4-C with effective removal efficiency.
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(This article belongs to the Special Issue Porous Materials and Their Adsorption Properties)
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Structural Analysis of Xylose Isomerase from Streptomyces avermitilis
by
Ki Hyun Nam
Crystals 2024, 14(5), 446; https://doi.org/10.3390/cryst14050446 - 7 May 2024
Abstract
Xylose isomerase (XI, also known as glucose isomerase) is an oxidoreductase that interconverts aldoses and ketoses. XI catalyzes the reversible isomerization of D-glucose and D-xylose into D-fructose and D-xylulose, respectively. The molecular function of XI is widely applied in producing high-fructose corn syrup
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Xylose isomerase (XI, also known as glucose isomerase) is an oxidoreductase that interconverts aldoses and ketoses. XI catalyzes the reversible isomerization of D-glucose and D-xylose into D-fructose and D-xylulose, respectively. The molecular function of XI is widely applied in producing high-fructose corn syrup (HFCS) in the food industry and bioethanol from hemicellulose in the biofuel industry. The structural information of XI from diverse strains is important for understanding molecular properties that can provide insights into protein engineering to improve enzyme efficiency. To extend the knowledge of the structural information on XI, the crystal structure of XI from Streptomyces avermitilis (SavXI) was determined at a 2.81 Å resolution. SavXI containing TIM barrel and extended α-helix domains formed the tetrameric assembly. The two metal-binding sites and their coordinating residues showed diverse conformations, providing the structural flexibility of the active site of SavXI. The structural comparison of SavXI and XI homologs exhibited unique metal-binding sites and conformations of the C-terminal α-helix domain. These structural results extend our knowledge of the molecular flexibility and mechanism of the XI family.
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(This article belongs to the Section Biomolecular Crystals)
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Open AccessArticle
Structural, Dielectric, Electrical, and Magnetic Characteristics of Bi0.8Ba0.1Er0.1Fe0.96Cr0.02Mn0.02O3 Nanoparticles
by
A. Bougoffa, E. M. Benali, A. Benali, A. Tozri, E. Dhahri, M. P. Graça, M. A. Valente and B. F. O. Costa
Crystals 2024, 14(5), 445; https://doi.org/10.3390/cryst14050445 - 7 May 2024
Abstract
Bi0.8Ba0.1Er0.1Fe0.96Cr0.02Mn0.02O3 (BBEFCMO) multiferroic ceramic was synthesized through the sol-gel route. The impact of incorporating various dopants into both A and B sites of the BiFeO3 was investigated, and structural,
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Bi0.8Ba0.1Er0.1Fe0.96Cr0.02Mn0.02O3 (BBEFCMO) multiferroic ceramic was synthesized through the sol-gel route. The impact of incorporating various dopants into both A and B sites of the BiFeO3 was investigated, and structural, Raman, dielectric, electric, and magnetic properties were studied. X-ray diffraction analysis and Raman spectroscopy revealed a rhombohedral structure with the R3c space group for the doped material (BBEFCMO). Dielectric properties were examined across a frequency range of 102–106 Hz. The present multiferroic material exhibits a colossal dielectric constant and minimal dielectric loss tangent, making it suitable for applications in energy storage. Furthermore, the Cole-Cole type of relaxation was deduced from the imaginary part of the modulus for both grain and boundary-grain contributions. Overall, this study indicates that substituting ions in both A and B sites of BiFeO3 significantly enhances its multiferroic properties, as evidenced by dielectric and magnetic measurements.
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(This article belongs to the Special Issue Structure, Thermal and Magnetic Properties of Nanocrystalline Materials)
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Open AccessEditorial
Advanced Aerospace Materials: Processing, Microstructure, Mechanical Properties and Applications
by
Yufei Zu, Huifang Pang and Fan Wu
Crystals 2024, 14(5), 444; https://doi.org/10.3390/cryst14050444 - 7 May 2024
Abstract
Advanced aerospace alloy deformation processing (contribution 1–3) is investigated in this collection [...]
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(This article belongs to the Special Issue Advanced Aerospace Materials: Processing, Microstructure, Mechanical Properties and Applications)
Open AccessReview
B-Factor Rescaling for Protein Crystal Structure Analyses
by
Georg Mlynek, Kristina Djinović-Carugo and Oliviero Carugo
Crystals 2024, 14(5), 443; https://doi.org/10.3390/cryst14050443 - 7 May 2024
Abstract
The B-factor, also known as the atomic displacement parameter, is a fundamental metric in crystallography for quantifying the positional flexibility of atoms within crystal lattices. In structural biology, various developments have expanded the use of B-factors beyond conventional crystallographic analysis, allowing for a
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The B-factor, also known as the atomic displacement parameter, is a fundamental metric in crystallography for quantifying the positional flexibility of atoms within crystal lattices. In structural biology, various developments have expanded the use of B-factors beyond conventional crystallographic analysis, allowing for a deeper understanding of protein flexibility, enzyme manipulation, and an improved understanding of molecular dynamics. However, the interpretation of B-factors is complicated by their sensitivity to various experimental and computational factors, necessitating rigorous rescaling methods to ensure meaningful comparisons across different structures. This article provides an in-depth description of rescaling approaches used for B-factors. It includes an examination of several methods for managing conformational disorder and selecting the atom types required for the analysis.
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(This article belongs to the Special Issue Intermolecular Interactions in Macromolecular Complexes)
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Open AccessArticle
Elemental Uptake by Different Calcite Crystal Faces: An In Situ Study
by
Mustafa Rezaei, Rinat Gabitov, Aleksey Sadekov, Alberto Perez-Huerta, Chiara Borrelli and Andrea Stiles
Crystals 2024, 14(5), 442; https://doi.org/10.3390/cryst14050442 - 7 May 2024
Abstract
This study aims to evaluate relationships between elemental signatures in calcite and the crystallographic orientation of its planes. The ability of calcite (a widespread calcium carbonate mineral) to entrap various trace and minor elements in its structure is the foundation of multiple methods
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This study aims to evaluate relationships between elemental signatures in calcite and the crystallographic orientation of its planes. The ability of calcite (a widespread calcium carbonate mineral) to entrap various trace and minor elements in its structure is the foundation of multiple methods (also called proxies) to reconstruct paleoenvironment conditions (e.g., temperature, pH, and marine chemistry). Although several element-to-calcium ratios (E/Ca) are routinely measured in marine carbonates and are widely used in paleoclimate studies, some of the controls on the incorporation of these elements are still unclear. Here, we examine the effect of crystallography on (E/Ca)calcite by growing thin layers of calcite on differently oriented Iceland Spar substrates immersed in modified seawater solution. Newly grown calcite layers were examined with Laser Ablation Inductivity–Coupled Plasma Mass Spectrometry (LA-ICP-MS), Backscattered Electron Imaging (BSE), and Energy Dispersive X-ray Spectroscopy (EDS). We propose that the crystallographic orientation might slightly influence the incorporation of lithium (Li), sodium (Na), magnesium (Mg), sulfur (S), and barium (Ba) into the studied calcite faces and have no impact on the incorporation of boron (B), potassium (K), and strontium (Sr) at least under the conditions of our experiment.
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(This article belongs to the Special Issue Crystallization Process and Simulation Calculation, Second Edition)
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Open AccessArticle
High Resolution Crystal Structure of the Pyruvate Kinase Tetramer in Complex with the Allosteric Activator Mitapivat/AG-348
by
Xiao Han, Tatyana Sandalova, Cheng Zhang, Adil Mardinoglu, Adnane Achour and Renhua Sun
Crystals 2024, 14(5), 441; https://doi.org/10.3390/cryst14050441 - 5 May 2024
Abstract
Pyruvate kinase (PK) deficiency is a rare genetic disorder that affects this critical enzyme within the glycolysis pathway. In recent years, Mitapivat (MTPV, AG-348) has emerged as a notable allosteric activator for treating PK deficiency. However, the allosteric regulatory effects exerted on PK
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Pyruvate kinase (PK) deficiency is a rare genetic disorder that affects this critical enzyme within the glycolysis pathway. In recent years, Mitapivat (MTPV, AG-348) has emerged as a notable allosteric activator for treating PK deficiency. However, the allosteric regulatory effects exerted on PK by MTPV are yet to be comprehensively elucidated. To shed light on the molecular mechanisms of the allosteric effects, we employed crystallography and biophysical methods. Our efforts yielded a high-resolution crystal structure of the PK tetramer complexed with MTPV at 2.1 Å resolution. Isothermal titration calorimetry measurements revealed that MTPV binds to human PK with an affinity of 1 μM. The enhanced structural details now allow for unambiguous analysis of the MTPV-filled cavity intricately embedded within the enzyme. Finally, the structure suggests that MTPV binding induces an allosteric effect on the B-domain situated proximal to the active site. In summary, our study provides valuable insights into the allosteric regulation of PK by MTPV and paves the way for further structure-based drug optimization for therapeutic interventions in PK deficiency.
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(This article belongs to the Special Issue X-ray Crystallography and Drug Discovery)
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Open AccessReview
Advancements in The Cross-Linking and Morphology of Liquid Crystals
by
Weronika Zając, Maciej Kisiel and Beata Mossety-Leszczak
Crystals 2024, 14(5), 440; https://doi.org/10.3390/cryst14050440 - 5 May 2024
Abstract
The liquid crystal state (LC) in polymer chemistry is a topic discussed in varied materials research. The anisotropic properties typical of these compounds are mostly the result of the presence of mesogens in the structure of liquid crystals. This article traces the development
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The liquid crystal state (LC) in polymer chemistry is a topic discussed in varied materials research. The anisotropic properties typical of these compounds are mostly the result of the presence of mesogens in the structure of liquid crystals. This article traces the development of liquid crystal science, focusing on liquid crystal epoxy resins (LCERs) and emphasizing the crucial role of mesogens and their diverse effect on the materials. It also highlights the importance of understanding the morphology of LC polymers, explaining their profound impact on material properties and performance. It explores the cross-linking process of liquid crystal resins and composites, describing how changes in structural factors affect material structure. The article also provides information about hardeners and their influence on the cross-linked structure. Various nanofillers were also discussed, elucidating their impact on the resulting composites.
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(This article belongs to the Collection Reviews in Liquid Crystals)
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