Fabrication Of Core Research Articles

Research progress of regulation of physical properties of two-dimensional materials based on thermal scanning probe lithography

With the continuous development of micro-scale exploration, micro/nano fabrication technologies, represented by photolithography and various etching processes, have been widely used for fabricating micro- and nanoscale structures and devices. These developments have driven innovation in fields such as integrated circuits, micro-nano optoelectronic devices, and micro-electromechanical systems, while also bringing new opportunities to fundamental scientific research, including the study of microscopic property regulation mechanisms. In recent years, as an emerging micro-nano fabrication technology, thermal scanning probe lithography (t-SPL) has shown promise and unique advantages in applications related to the fabrication and property regulation of two-dimensional materials, as well as the creation of nanoscale grayscale structures. By employing the fabrication methods such as material removal and modification, t-SPL can be used as an advanced technology for regulating two-dimensional material properties, or directly effectively regulating various properties of two-dimensional materials, thereby significantly improving the performance of two-dimensional material devices, or advancing fundamental scientific research on the micro/nano scale. This paper starts with the principles and characteristics of t-SPL, analyzes the recent research progress of the micro-nano fabrication and property modulation of two-dimensional materials, including several researches achieved by using t-SPL as the core fabrication methods, such as direct patterning, strain engineering, and reaction kinetics research of two-dimensional materials. Finally, the challenges in t-SPL technology are summarized, the corresponding possible solutions are proposed, and the promising applications of this technology are explored.

Recent Research Progresses and Challenges for Practical Application of Large-Scale Solar Hydrogen Production.

Solar hydrogen production is a promising pathway for sustainable CO2-free hydrogen production. It is mainly classified into three systems: photovoltaic electrolysis (PV-EC), photoelectrochemical (PEC) system, and particulate photocatalytic (PC) system. However, it still has trouble in commercialization due to the limitation of performance and economic feasibility in the large-scale system. In this review, the challenges of each large-scale system are, respectively, summarized. Based on this summary, recent approaches to solving these challenges are introduced, focusing on core components, fabrication processes, and systematic designs. In addition, several demonstrations of large-scale systems under outdoor conditions and performances of upscaled systems are introduced to understand the current technical level of solar-driven hydrogen production systems for commercialization. Finally, the future outlooks and perspectives on the practical application of large-scale solar-driven hydrogen production are discussed.

Robust Multifunctional Films with Excellent EMI Shielding, Anti-Peeling, and Joule Heating Performances Enabled by an Encapsulated Highly Conductive Fabric Strategy.

Recently, the issue of electromagnetic pollution has become increasingly prominent. Flexible polymer films with various conductive fillers are preferred to address this problem due to their highly efficient and durable electromagnetic interference (EMI) shielding performance. However, their applications are restricted by the unbalanced and insufficient electromagnetic wave absorption and shielding capabilities, as well as the weak interlayer bonding force. In this work, robust flexible multifunctional AgNW/MXene/NiCo-C (AMN) films are fabricated by hierarchical casting assembly and an encapsulated conductive fabric strategy. The synergistic effect of the conductive-absorption integrated sandwich core fabric and the conductive encapsulation layer collaborate to provide excellent absorption-dominated EMI shielding (EMI SEmax = 89.12dB with an ultralow reflectivityvalue of 0.19) and Joule heating (a high temperature of 103.5°C at 4.5V) performances. Besides, AMN films with embedded fabrics as a reinforcement structure achieved enhanced peel (1.97Nmm-1) and tensile (7.85MPa) strengths through an interface enhancement process (plasma and pre-immersion treatments). In conclusion, this paper proposes a feasible paradigm to prepare flexible multifunctional conductive films, which demonstrate tremendous potential for applications in the wearable electronics and aerospace fields.

Multi-core anti-resonant hollow core optical fiber

We report the fabrication and characterization of a multi-core anti-resonant hollow core fiber with low inter-core coupling. The optical losses were 0.03 and 0.08 dB/m at 620 and 1000 nm, respectively, while the novel structure provides new insights into hollow core fiber design and fabrication.

Fabrication of LTA zeolite core and UiO-66 shell structures via surface zeta potential modulation and sequential seeded growth for zeolite/polymer composite membranes

Zeolite-based polymer composites have garnered significant attention for their applications in separation, catalysis, and energy storage, owing to the unique properties of zeolites. The development of core–shell structures provides a promising strategy to enhance these properties, enabling the fine-tuning of zeolite characteristics within composite films. In this study, we present an innovative approach that leverages surface zeta potential differences to facilitate the growth of an organophilic metal–organic framework (MOF) on hydrophilic zeolite surfaces. Specifically, UiO-66 was successfully attached and grown on Linde Type A (LTA) zeolite particles, resulting in the formation of a robust core–shell structure (LTA@UiO-66). This core–shell architecture significantly minimized interfacial voids when embedded into a polyimide (PI, Matrimid® 5218) matrix, yielding composite films (LTA@UiO-66/PI) with superior mechanical integrity and enhanced gas-separation performance. The LTA@UiO-66/PI films demonstrated remarkable ideal selectivity for O2/N2 (10.7) and CO2/CH4 (47), outperforming traditional LTA/PI composites. These enhancements are attributed to the synergistic effects between the LTA core and the UiO-66 shell, which preserve the molecular sieving capability of the zeolite while ensuring strong adhesion and a void-free interface with the polymer matrix. The findings underscore the significant potential of zeolite-based core–shell structures in advancing industrial applications, particularly in the domains of sustainable gas separation and purification technologies.

Fabrication of core–shell nanostructure via novel ligand-defect reassembly strategy for efficient photocatalytic hydrogen evolution and NO removal

The core–shell structure often exhibits unique properties, resulting in superior physical and chemical performance distinct from individual component in the field of photocatalysis. However, traditional prepared methods such as template synthesis and layer-by-layer self-assembly are relatively complex. Therefore, it is necessary to explore an efficient and expedient approach. Here, we have proposed a convenient method to gradually destroy the terephthalic acid (BDC) of MIL-125 from the outer to inner layers through hydrothermal stirring, followed by reassembling with photosensitive 2-amino-terephthalic acid (BDC-NH2) into the exposed Ti-oxo clusters left by the BDC to create photocatalysts featuring a core–shell configuration. The special core–shell sample with the analogous mixture of MIL-125 and MIL-125-NH2 function as a high-performance dual-functional photocatalyst for hydrogen generation and NO elimination. The optimal core–shell material (M-125-45-N) exhibits an outstanding photocatalytic hydrogen production rate of 3.74 mmol·g−1·h−1 and an excellent photocatalytic NO removal rate of 70.15 %. The apparent quantum yield (AQY) value and solar-to-hydrogen energy conversion efficiency (STH) at specific wavelengths are also investigated. The Density functional theory (DFT) calculation, In-situ Fourier transform infrared (In-situ FT-IR) and Electron spin resonance (ESR) have suggested that the enhanced photocatalytic activity of optimal core–shell material arised from its stronger adsorption capacity towards reactants, promoting the production of reactive oxygen species (ROS) conducive to photocatalytic reactions. This study represents the first investigation of a dual functional core–shell MOFs formed via ligand-defect reassembly, showcasing the excellent efficacy in photocatalytic hydrogen evolution and NO removal, which contributes to the feasible development of novel dual-functional photocatalysts with core–shell structures.

Effect of Al2O3-SiO2 mass ratio and sintering temperature on the properties of water-soluble salt-based ceramic cores formed by binder jetting

Binder Jetting (BJ) technology, known for its cost-effectiveness and efficiency, is widely used for the rapid fabrication of complex ceramic cores. However, fabricating high-strength and water-soluble ceramic cores via BJ technology is particularly challenging due to the balance between mechanical properties and water solubility. In this work, BJ technology was employed to fabricate high-strength and water-soluble salt-based ceramic cores (SCC) regulated synergistically by Al2O3 and SiO2. The effects of the mass ratio of Al2O3 to SiO2 (A/S) and sintering temperature on the properties of Na2CO3-based samples were investigated, with detailed analyses of the regulation mechanism through thermodynamic, kinetic, and microstructural examinations. The results indicated that when A/S was 1:4, the bending strength of samples sintered at 760 °C for 60 min reached up to 62.38 MPa with good water collapsibility. Thermodynamic and kinetic analyses revealed that the formation of Na2SiO3 was prioritized over NaAlO2, and the content of Na2SiO3 as well as the proportion of liquid phase increased with the decrease of A/S and the increase of sintering temperature, resulting in the increase of sample density, as confirmed by microstructure analyses, which was the main strengthening mechanism of samples. Ultimately, complex-structure SCC samples were successfully fabricated. This study provides an insightful method for fabricating high-strength and water-soluble ceramic cores, with significant potential applications in the casting industry.

Fabrication of core–shell nickel ferrite@polypyrrole composite for broadband and efficient electromagnetic wave absorption

Herein, nickel ferrite@polypyrrole (NiFe2O4@PPy) composite was prepared by a simple two-step route of solvothermal synthesis and in-situ oxidation polymerization reaction. The results of micromorphology analysis showed that the obtained NiFe2O4@PPy composite had a unique core–shell structure, good magnetic performance and electrical conductivity. Furthermore, the as-prepared magnetic/conductive NiFe2O4@PPy composite exhibited notably enhanced electromagnetic wave (EMW) absorption performance than pure NiFe2O4 and PPy. When the filling ratio was 17.5 wt% and the matching thickness was 2.24 mm, the optimal minimum reflection loss (RLmin) of −56.25 dB and a broad effective absorption bandwidth (EAB) of 5.2 GHz were achieved for NiFe2O4@PPy composite. With slightly increasing the matching thickness to 2.6 mm, the maximum EAB of 7.12 GHz could be reached. Additionally, the probable EMW absorption mechanism was elucidated. Therefore, this work could provide a valuable reference for the preparation of magnetic ferrite/conductive polymer composites as broadband and high-efficiency EMW absorbers.

Fabrication of a new core–shell structured magnetic abrasive particles with good performance

The traditional Fe-based magnetic abrasive powders (MAPs) are prone to degrade by corrosion and oxidation. The extremely low stability to some extent limits the development of magnetic finishing. In this study, a new kind of 410 stainless steel-based spherical MAPs with core–shell structure was synthesized by gas nitriding. The nitride layer shows the dendrite structure containing (Fe, Cr)4N phase and lath-like CrN phase. The Zirconium tube roughness can be reduced from 0.280 to 0.153 μm. The origin of the good finishing performance was investigated through the Vickers hardness and nanoindentation tests.

Fabrication of core–shell Fe3O4@SiO2/graphite catalyst to improve the charge separation for enhanced photocatalytic toluene oxidation

Magnetite (Fe3O4) has been regarded as a potential photocatalyst for VOCs degradation. Nevertheless, the magnetism of Fe3O4 always leads to the aggregation of particles, which is adverse for gaseous VOCs degradation. Meanwhile, the fast charge recombination of Fe3O4 seriously limits the photocatalytic activity. Herein, a layer of SiO2 was coated on the surface of Fe3O4, and Fe3O4@SiO2 particles were combined with graphite to prepare the core–shell catalyst for photocatalytic toluene oxidation. Fe3O4@SiO2/G catalyst showed the toluene degradation efficiency of 85.09%, which was 3.2 and 1.3 times than those of Fe3O4 and Fe3O4/G. The coating of SiO2 prevented the aggregation of Fe3O4 and greatly enhanced the specific surface area. Experimental and theoretical calculation proved that the existence of SiO2 promoted the spatial charge separation and inhibited the charge recombination, resulting in the generation of abundant reactive oxygen species. These findings offered an insight into the catalyst design for photocatalytic VOCs oxidation.

Polyetheretherketone split post and core for restoration of multirooted molar with insufficient dental tissue remnants by digital techniques: a case report and 3-year follow up

BackgroundMulti-rooted teeth with extensive dental defects often face challenges in stability and biomechanical failure. High-performance polymer PEEK materials, with properties closer to dentin, show promise in reducing stress concentration and preserving tooth structure. This report aimed to explore the use of a highly retentive polyetheretherketone (PEEK) for manufacturing custom-made split post and core for the restoration of grossly destroyed endodontically treated molars.Clinical considerationsA 40-year-old female patient presented with complaints of loss of tooth substance in the posterior mandibular tooth. This case involved the digital design and fabrication of PEEK split post and core to restore multirooted molar with insufficient dental tissue remnants. The restorations were evaluated over a 3-year follow-up using the World Federation criteria (FDI). The restoration was clinically evaluated through intraoral examination, radiographic assessment, and subjective patient satisfaction, and was deemed clinically good according to FDI criteria.ConclusionThe outstanding mechanical properties of PEEK, coupled with the structure of the split post, provide an effective treatment option for weakened multirooted teeth. Simultaneously, the restoration configuration effectively addressed the challenge of varying postinsertion directions, and the interlocking mechanism between the primary and auxiliary posts enhanced the stability of the post and core.

Electric field-induced modulation of electronic and optical properties in doped CdTe/CdS core/shell quantum dots embedded in an oxide matrix

This work presents a theoretical analysis of a CdTe/CdS core/shell quantum dots embedded in a dielectric oxide matrix under the influence of hydrogenic impurity and the applied electric field intensity. The eigenstates and their corresponding eigenfunctions are computed by solving the Schrodinger equation using the finite element method within the effective mass approximation. The first-order linear and third-order nonlinear optical absorption coefficients as well as the refractive index changes are computed based on the compact density matrix approach. The obtained result shows that the first-order linear and third-order nonlinear optical properties are more pronounced with the electric field, surrounding oxide matrix and the donor impurity effects. However, the first-order linear and third-order nonlinear optical absorption coefficients and refractive index changes can experience a red or blue shift under the influence of electric field, oxide matrix and hydrogenic impurity. In addition, under all conditions, the height peaks of these optical properties can be raised (fall). Our findings demonstrate the critical importance of considering the roles of electric field, the presence of donor impurity, and the capped dielectric oxide matrix in the design and fabrication of core–shell-based optoelectronic devices.

Low‐Volume Cores for Fabrication of Compact, Versatile, and Intelligent Soft Systems

AbstractThis study introduces the low‐volume core (LVC) fabrication method, which enables the monolithic molding of compact, complex, versatile, and intelligent soft robotic systems. This method uses thin and flexible thermoplastic sheets to mold internal chambers in soft fluidic actuators, valves, and circuits. The LVC fabrication method creates low‐volume networks in soft actuators (LV‐net actuators) that can be made with compact and complex geometries, enabling both low actuation volume input and multi‐degree‐of‐freedom actuators. LVC fabrication can also be used for compact, completely soft, and monolithic logic components (valves with low‐volume core, also called as LV valves) to provide directional resistance as well as a switching mechanism that enables fluidic logic in soft systems. The compatibility of the fabrication methods for both soft actuators and valves facilitates the creation of compact, integrated, and versatile soft robotic systems with embodied intelligence. This study introduces two examples of such intelligent soft robotic systems that integrate both LV‐net actuators and LV valves to demonstrate capability for complex system fabrication.

Fabrication, characterization, and optimization of core–shell electrospun nanofibers for simultaneous sustained delivery of metformin and glibenclamide in type II diabetes treatment

Fabrication, characterization, and optimization of core–shell electrospun nanofibers for simultaneous sustained delivery of metformin and glibenclamide in type II diabetes treatment

Fabrication of Fe-based Nanocrystalline Spherical and Flake Powder Composite Magnetic Cores for Tens of MHz and their Application to Planar Power Inductor

Fabrication of Fe-based Nanocrystalline Spherical and Flake Powder Composite Magnetic Cores for Tens of MHz and their Application to Planar Power Inductor

Fabrication of Core–Shell Nanohybrid-Structured Hydrogel Sensors with Desirable Mechanical and Antibacterial Properties by Quaternary Ammonium Ionic Liquids with Different Chain Lengths

Fabrication of Core–Shell Nanohybrid-Structured Hydrogel Sensors with Desirable Mechanical and Antibacterial Properties by Quaternary Ammonium Ionic Liquids with Different Chain Lengths

ZSM-5@Zn/ZSM-5 core@shell nanocrystals as integrated catalysts for efficient methanol conversion into aromatics

The use of ZSM-5@Zn/ZSM-5 core@shell nanocrystals as integrated catalyst for efficient aromatic production from methanol aromatization is demonstrated. By combining the attributes associated with core@shell structural and acidic features, ZSM-5@Zn/ZSM-5 exhibited synergistic and improved catalytic performance toward methanol aromatization. The effect of Zn/ZSM-5 shell thickness and the acid density of the ZSM-5 core on synergistic performance was systematically investigated. Results showed that aromatic selectivity could be increased with shell thickness and the acid density of the ZSM-5 core, while catalytic stability was subject to the optimization on both shell thickness and core acid density. The strengthening of dehydroaromatization on the shell catalyst after Zn introduction and the hydrogen transfer for aromatization with increasing core acid density was confirmed. A double boost on catalytic stability from methanol conversion along with 40.7% increase on aromatic selectivity could be achieved for core@shell catalyst with a coating ratio of 0.3 compared with that on single core catalyst. The fabrication of ZSM-5 core with low SiO2/Al2O3 ratio for Zn/ZSM-5 not only provided more acid sites to promote the aromatization, but also promoted the dealkylation of the formed aromatics, which could enhance the selectivity of light aromatics and catalytic lifetime. The findings in the work not only enrich the family of core@shell composite zeolite catalysts, but also provide the fundamental understanding on the aromatization process over core@shell structural features.

Towards the authentication of urban pattern through fractal analysis: the case of Blida, Algeria

This paper discusses the use of fractals to identify and analyze the historical values of an urban fabric. The proposed fractal analysis is a novel contribution to valorize a historical fabric as urban heritage. The research focuses on the historical core of Blida, Algeria, and concerns the development of its built fabric over three centuries. The aim is to compare morphological parameters, frequently used to evaluate the fractal dimension of built surfaces, to determine the fabric’s authenticity based on the calculated spatial variations. The findings indicate that the fractal dimension effectively distinguishes Blida’s historical core fabric. Fractal analysis is demonstrated to be a promising tool in this study for describing the form of historical fabrics as well as studying intra- urban genesis and simulation for use as an urban identification tool.

Fabrication of cisplatin-loaded core–shell Fe3O4@UiO-66-NH2 magnetic nanocomposite for potential drug delivery

In this study, we developed a biocompatible core–shell magnetic Fe3O4@UiO-66-NH2@CisPt nanocomposite loaded with cisplatin as a therapeutic agent for drug delivery and cancer treatment. The nanocomposite was synthesized using a step-by-step method resulting in the formation of two phases within the core–shell structure. Advanced analytical techniques, such as XRD, HR TEM, TEM, FTIR, and VSM, were used to thoroughly analyze the structural properties, morphology, magnetic characteristics, and atomic structure of the core–shell nanocomposite. Fe3O4@UiO-66-NH2@CisPt nanocomposite exhibits superparamagnetic behavior, which is advantageous for controlled drug delivery and release by applying an external magnetic field. This study presents a significant contribution to the development of effective drug delivery systems for cancer treatment.

Additive manufacturing of Fe-6.5 wt.%Si transformer steel toroidal cores: Process optimization, design aspects, and performance

Fe-Si electrical steels are conventionally popular materials for transformer application. Although higher Si (4wt.%<) content is favorable for increasing the resistivity and improving the soft magnetic properties, fabrication of transformer core with higher Si containing electrical steels is difficult by conventional wrought processes due to an increase in its brittleness. Additive manufacturing provides a novel alternative plausible way to fabricate transformer cores with higher Si content and unique design features. The current work focused on process optimization and design aspects of laser powder bed fusion additive manufacturing of Fe-6.5wt.% electrical steel. Additively manufactured components with 99.5% relative density were produced. The optimally fabricated component contained columnar grains of α-FeSi phase morphologically oriented in the build direction. The optimally fabricated Fe-6.5wt.% component was also subjected to annealing treatment at 1150∘C for 1 h in Ar resulting in multi-fold grain growth and improved soft magnetic response. Based on optimal laser processing parameters, 3 different designs for toroidal cores with slit patterns for varying degree of cross-sectional areas were additively fabricated. The toroidal cores were subjected to same annealing treatment as that of the additively fabricated component. Core with least cross-sectional area exhibited improved magnetic performance compared to the other designs.