Conventional Materials Research Articles

A CO2-responsive Janus SiO2 nanofluid: Integration of enhanced oil recovery and demulsification

Aiming to address the issues of limited suitability of conventional chemical oil displacement materials for formation conditions and the serious emulsification of oil and water in the produced liquid, the innovative nano oil-displacing system with CO2-responsive behavior has been developed. This system integrates oil displacement and emulsion breaking. The efficacy of the CO2-response system in creating stable emulsions with a high capacity to decrease interfacial tension has been demonstrated. The interfacial responsive behavior of all active components, including Janus nanoparticles, sodium oleate, gums, and asphaltenes, in the emulsion system was analyzed in terms of interfacial rheology and adsorption. Additionally, the prepared system demonstrated a rapid response to CO2, effectively breaking the emulsion within 5 min. Furthermore, the oil recovery enhancing mechanism of the CO2-response system was investigated using a microscopic visualization model. The system was proved to be efficient in initiating the residual oil within pore channels. Considering the combined effectiveness of the CO2-response system in terms of efficient oil displacement and rapid response, it offers valuable insights for advancing the chemical flooding technology of in enhanced oil recovery.

Solar PV vacuum glazing (SVG) insulated building facades: Thermal and electrical performances

As fire emergencies and energy saving demand of buildings have grown around the globe, concerns have been raised about the flammability of conventional external insulation materials in cold weather areas. In this paper, solar PV vacuum glazing (SVG) was proposed as a promising alternative to traditional external insulation layers of buildings due to its incombustible nature and superior thermal insulation performance. To assess the thermal and electrical performances of SVG-insulated facades, a heat transfer model and an effective absorptance calculation model for SVG-insulated façades were developed and validated against experimental data. Results showed that SVG-insulated facades exhibited significantly lower U values, ranging from 44.1% to 47.5% less than those of traditional concrete walls (without insulation layer). Additionally, the application of Low-emissivity (Low-e) coatings on the glazing could further reduce the U value from 2.05 W/(m2·K) to 0.647 W/(m2·K), making SVG-insulated facades competitive with traditional insulation walls. The secondary heat transfer factor (SHTF), defined as the ratio of indoor heat gain from solar radiation absorbed by building facades to incident solar radiation, was also reported for SVG-insulated facades with different solar cells (C-si, A-si, and CdTe), along with their respective efficiencies. Parametric analyses of eight parameters subsequently highlighted that their influence on the thermal performance of SVG-insulated façades was much greater than on the solar cell efficiency. Furthermore, considering the combined effect of optimal value of key influencing parameters, the lowest U value of 0.153 W/(m2·K) could be achieved, which represents approximately 24.6% of the U value of traditional insulation walls. This study provides compelling evidence for the adoption of SVG-insulated facades as replacements for traditional insulation walls and offers insights into optimizing their thermal performance.

The enhanced antiferromagnetic interaction and tunable temperature coefficient of resistivity in antiperovskite compounds Mn3−xCoxAgN (0≤x≤0.2)

The magnetic and electric evolution with the substitution level of Co element has been investigated in Mn[Formula: see text]CoxAgN. The DC magnetic measurements demonstrate that the substitution of Co for Mn enhances the antiferromagnetic (AFM) interaction and weakens the magnetic irreversibility at low temperature. The strengthening of AFM order in Mn[Formula: see text]CoxAgN has been attributed to the enhanced Co–Mn AFM interaction and weakened Co–N–Mn ferromagnetic (FM) interaction. Additionally, with the gradual increase of Co content, the temperature coefficient of resistivity (TCR) in paramagnetic (PM) region changes from a positive one to a negative one gradually. When [Formula: see text], the TCR value is only [Formula: see text]5[Formula: see text]ppm/K, which is one magnitude smaller than that of conventional standard resistor materials. The negative TCR phenomenon is closely associated with the Co-element-induced lattice disorder, which leads to the weak localization of conduction electrons.

Design of Steel-Cu composites for enhancing thermal properties of plastic processing tools by using a numerical model of the microstructure

Limitationsof conventional materials used for plastic processing tools, particularly related to thermal conductivity, significantly influence production efficiency, with the cooling time of moulded parts appearing as one of the key factors. Therefore, this study focuses on designing Steel-Cu composites with the aid of a numerical model of the composite's microstructure for enhancing their overall thermal properties. We present a novel procedure for designing such composites, which facilitates the identification of the optimal shape for the phases to improve overall thermal conductivity. We have developed a data-driven homogenization model to aid the optimization process and ensure time-efficient solutions. The data has been generated through numerical homogenization based on the finite element method. The proposed shape optimization procedure has been applied to determine the optimal shape of the Cu phase across various volume fractions. We found out that the optimal shape of the Cu phase is not constant but depends on its volume fraction. Emphasizing the practical utility of the proposed procedure, it is noteworthy that once the data-driven model is established, it enables a time-efficient optimization of the Cu phase shape for arbitrary volume fractions of phases. Consequently, this may expedite the decision-making process for material manufacturers.

Optimization of Thermoelectric Properties and Physical Mechanisms of Cu2Se-Based Thin Films via Heat Treatment.

Cu2Se is an attractive thermoelectric material due to its layered structure, low cost, environmental compatibility, and non-toxicity. These traits make it a promising replacement for conventional thermoelectric materials in large-scale applications. This study focuses on preparing Cu2Se flexible thin films through in situ magnetron sputtering technology while carefully optimizing key preparation parameters, and explores the physical mechanism of thermoelectric property enhancement, especially the power factor. The films are deposited onto flexible polyimide substrates. Experimental findings demonstrate that films grown at a base temperature of 200 °C exhibit favorable performance. Furthermore, annealing heat treatment effectively regulates the Cu element content in the film samples, which reduces carrier concentration and enhances the Seebeck coefficient, ultimately improving the power factor of the materials. Compared to the unannealed samples, the sample annealed at 300 °C exhibited a significant increase in room temperature Seebeck coefficient, rising from 9.13 μVK-1 to 26.73 μVK-1. Concurrently, the power factor improved from 0.33 μWcm-1K-2 to 1.43 μWcm-1K-2.

Training on Making Street Light Poles Using Light Steel for the Community of Griya Permata Housing Complex, Handil Bakti Village, Alalak District, Barito Kuala Regency, South Kalimantan Province

Training on making street lighting poles using light steel can be an effective solution in improving the quality of lighting in public areas. Light steel has several advantages, such as lighter weight, resistance to corrosion, and ease of installation compared to conventional materials such as concrete or wood. The implementation of training activities on making street lighting poles using light steel was carried out on Saturday, May 25, 2024 at the Welding and Plumbing Workshop, Banjarmasin State Polytechnic. It is hoped that this training can contribute to community empowerment, where participants can apply the skills they have acquired to open small businesses in the manufacture and installation of lighting poles

Process optimization on kesterite-based ceramics for enhancing their thermoelectric performances assisted by active machine learning approach: A tool for metal-sulfide ceramics development

The thermal process parameters are crucial in metal-sulfides ceramics as they affect significantly the resulting physico-chemical properties. In the present work, we investigated the sintering effect in the kesterite Cu2.125Zn0.875SnS4 on its structural, microstructural, and thermoelectric (TE) properties to highlight the non-negligible contribution of the thermal process often ignored in metal-sulfide ceramics. For this purpose, we developed an approach combining data science with the conventional material experiment/theory approach which can be used as a tool to shortcut the time-consuming steps of TE material optimization. We confirmed that the optimization and control of the densification process is critical in unravelling the highest potential on metal sulfide TE ceramics with a non-negligible increase of its zT up to 60 %. We propose a scientific tool, the synergic combination of active machine learning with conventional chemistry/theory approaches, to either identify the most proficient sintering process as well as the process to avoid the degradation of the metal-sulfide ceramic properties and thus in a shorten number of experiments. This approach can be extended not only to other metal-sulfide ceramics for thermoelectricity but also to other research fields.

Aqueous benzene, toluene, ethylbenzene and xylene (BTEX) removal using core-shell structure activated carbon ball as a permeable reactive barrier material

Permeable reactive barriers (PRBs) are passive and sustainable treatment systems for remediating the diffusion of contaminant plumes in groundwater. Several conventional reactive materials such as activated carbon (AC) have long been used as reactive media for PRBs. AC, which is known for its high adsorption capability and cost-effectiveness, is commonly used to remove multiple pollutants from groundwater. Unfortunately, among the reactive materials, AC can fill in the barrier and pose practical problems, such as a pressure drop, solid losses during handling, and safe disposal of filled sorbents, because of its low particle strength. In this study, AC balls were prepared using zeolite as the core and powdered AC, quartz, and calcite as the shell. AC ball with excellent mechanical strength and high permeability properties in the form of a core–shell layer is a good alternative to conventional reactive materials. The adsorption characteristics of benzene, toluene, ethylbenzene, and p-xylene (BTEX) from solutions using AC balls were investigated. The adsorption equilibrium is in the order of X > E > T > B. The adsorption capacity for B (4.90 mg/g), T (3.37 mg/g), E (1.16 mg/g) and X (0.46 mg/g) were observed at solution pH = 7. To validate the proposed models, batch experiments indicated that the pseudo-2nd-order (11.61 and 10.54 mg/g) and Langmuir models (8.81 and 5.27 mg/g) were the most suitable for describing the kinetics and equilibrium of benzene and toluene, respectively. Regeneration experiments were performed using chemical extraction (methanol) and microwave (MW) heating. When the AC ball was reused six times, the removal efficiency for benzene was maintained above 81 % using methanol, whereas that for benzene was increased to 91 % using MW. A series of experiments revealed that AC balls have considerable reusability. The AC ball can be effectively used as a medium for the removal of benzene in a continuous flow system such as column and sandbox. Based on these results, AC balls are a potential reactive medium for field-scale PRB practical remediation applications.

Conductive, biodegradable multi-array smart bandage for gesture recognition and motion detection

Triboelectric nanogenerator (TENGs), which are capable of capturing high-entropy energy dispersed in the environment and converting it into electricity, have received significant attention for their potential as power sources for sensing networks and wearable portable electronics. Conventional triboelectric materials have serious limitations, which can be overcome by using nanostructured materials. Conductivity and semiconductor nanomaterials have been extensively studied as active components for this type of application, but need to be coupled to an elastic matrix, in order to be functional in flexible technologies. In this study, we prepared MWCNTs/PEO (MCP) films with conductive and biodegradable properties. MCP can be used as conductive ink printed on flexible substrates to fabricate flexible circuits. MCP is utilized as a high-performance positively charged material to construct a TENG (KMCP-TENG) with a maximum power density of 593 mW/m2. Furthermore, MCP can be degraded and recycled, and the output performance of the KMCP-TENG prepared using recycled MCP reaches 90 % of the original TENG. Additionally, the multi-array smart bandage (MASB) is designed and fabricated based on KMCP-TENG, which exhibits high sensitivity and stability. This MASB offers broad applications in health monitoring, motion tracking and human–computer interaction.

Developing hybrid C-sections from waste and recycled composite materials

This paper investigates the performance of hybrid composites made from mixed waste plastics (wMP), recycled carbon fibre (rCF), and waste glass fibre (wGF). Two lay-up configurations with varying wGF and rCF contents were considered: one with approximately 7 vol% rCF (25 vol% wGF) and another with approximately 15 vol% rCF (9.4 vol% wGF). The tensile, compressive, and flexural performance of standard coupon specimens for both configurations were assessed, revealing that specimens with increased rCF content exhibited superior performance. Additionally, three hybrid C-sections, containing 15 vol% rCF, were thermoformed and subjected to axial compression. All three C-sections failed due to bearing failure, accompanied by some interlaminar delamination and material crushing at the loading ends. Their weight-specific load capacity surpassed that of similar sections published in the literature, such as ultra-thin-walled steel C-sections, by almost 95 %. A finite element model (FEM) of the C-section was developed and was able to predict reasonably well the stress versus strain response. These findings demonstrate that waste and recycled composite materials could serve as sustainable alternatives to ultra-thin-walled steel C-sections and other conventional materials commonly used in construction.

Electroplating of zinc onto polyelectrolyte complex membranes as anode for aqueous zinc-ion batteries

Conventionally, the anode of a primary Aqueous zinc-ion batteries (ZIBs) is metallic and rigid, which made it difficult to integrate into flexible designs. In this research, a composite polyelectrolyte complex (PEC) with cationic poly(diallyldimethylammonium chloride), anionic poly(sodium-4-styrenesulfonate) and carbon black (CB) as conductive filler (PEC-CB) was developed as an anode substrate for zinc deposition via electroplating technique. The Zinc-electroplated PEC-CB (Zn-PEC-CB) anode was characterized using electron microscopy and X-Ray diffraction analysis to verify the successful zinc coating. The Zn-PEC-CB was then assembled with PEC-CB-MnO cathodes in an ZIB setup. The results demonstrated the potential of PEC-based electrodes as a promising alternative to conventional materials in ZIBs, encouraging further exploration in energy storage applications.

Design, Processing, Testing and Characterizing for Orthodontics Material of Palm-Fibres Based Bio-Nanocomposite

Current research is carried out for newly developed of Bio-CPNC biomaterial nanocomposite for dentistry applications. The developed Bio-CPNC is invented of clay-based polymer CPNC and palm-tree micro-fibers, where CPNC is composed by nanotechnology of HDPE and MMT nanoclay. The research contains the methodology of design, processing, testing and characterization mainly focusing on mechanical and fracture properties, microstructure morphology and testing of thermal effect changes due to surrounding temperature changes. The necessity for finding new biomaterials and new techniques for dental materials for restoration and orthodontics with high biocompatibility with human bones and tissue are the aim for developing this natural bio-nanocomposites to be instead of using ceramics and metals like titanium. The new developed bio-CPNC dental material have special mechanical, thermal and fracture properties to resist the effects of occlusal loads of mastication with sustainability without expecting bad effects with orofacial esthetics and normal lingual ability because it is green. It can be applied for different types of orthodontics like crowns, bridges and dental implants. The study included processing, design, testing and characterization of different properties. The testing included detailed fundamental experimental work for investigation of the changes of mechanical and fracture properties based on fracture mechanics science. The results and comparison are promising where they are showing large enhancement of the mechanical, fracture and thermal properties of Bio-CPNC in comparison to the polymer material which encourage the researchers, dentists, and dental-companies for extra research to stabilize these natural green Bio-CPNC nanocomposite for dental applications with reducing the cost where all materials components are available locally in comparison to use of conventional ceramics materials or expensive zirconia composites.

Unconventional charge density wave in a kagome lattice antiferromagnet FeGe

FeGe is a kagome material that exhibits both charge density wave (CDW) order and magnetic order. The CDW order is developed deep inside the A-type antiferromagnetic phase in FeGe, providing a unique platform to investigate the interplay between CDW and magnetism. However, the driving mechanism of the CDW phase remains controversial. In this work, we performed high-pressure electrical transport and x-ray diffraction measurements combined with density-functional theory calculations to investigate the evolution of the CDW of FeGe under pressure. In contrast to conventional CDW materials, the CDW transition temperature of FeGe increases with increasing pressure, indicating the unconventional mechanism of CDW in this material. More interestingly, another possible CDW with a 3×3×6 superlattice emerges above 20 GPa, which may be explained by the calculated metastable CDW states under high pressure. These observations exclude the possibility of Van Hove singularities nesting as a CDW driving force. Our results unveil versatile CDW states and broaden the study of intertwined electronic states in the magnetic kagome metal FeGe. Published by the American Physical Society 2024

One-Step fabrication of bioinspired Peptide-Functionalized ice surface for bioanalysis

Solid surfaces modified with functional biomolecules that can selectively capture specific molecules play a crucial role in physical science and biomedical research. However, convenient biomolecule-modified materials are still faced with problems such as harsh synthesis conditions and time-consuming functionalization processes. As an easy-to-prepare solid substance, ice, holds the potential to be developed as an excellent functional material, but its inert nature hampers efficient functionalization with biomolecules. In this study, drawing inspiration from anti-freeze organisms in nature, we endow ice with biorecognition ability by leveraging the natural non-covalent binding between peptides and ice. By exploiting ice as a substrate modified with functional biomolecules, we demonstrate advantages such as high accessibility, one-step modification, and cost-effectiveness compared to conventional biomolecule-modified materials. Additionally, the temperature-controlled melting of ice offers a facile way to release captured biomolecules while maintaining their activity for further studies. The feature is further applied in protein assays, exhibiting satisfactory selectivity and quantitative capabilities with a minimum detectable concentration of approximately 0.1 ng/mL. Overall, our strategy to endow ice with desired biological functions provides a new tool for investigation in physical science and broader applications in the field of biomedicine.

Graphene-PbS Quantum Dot Heterostructure for Broadband Photodetector with Enhanced Sensitivity.

Photodetectors converting light into electrical signals are crucial in various applications. The pursuit of high-performance photodetectors with high sensitivity and broad spectral range simultaneously has always been challenging in conventional semiconductor materials. Graphene, with its zero bandgap and high electron mobility, is an attractive candidate, but its low light absorption coefficient restricts its practical application in light detection. Integrating graphene with light-absorbing materials like PbS quantum dots (QDs) can potentially enhance its photodetection capabilities. Here, this work presents a broadband photodetector with enhanced sensitivity based on a graphene-PbS QD heterostructure. The device leverages the high carrier mobility of graphene and the strong light absorption of PbS QDs, achieving a wide detection range from ultraviolet to near-infrared. Employing a simple spinning method, the heterostructure demonstrates ultrahigh responsivity up to the order of 107 A/W and a specific detectivity on the order of 1013 Jones, showcasing significant potential for photoelectric applications.

Research Progress and Emerging Directions in Stimulus Electro-Responsive Polymer Materials.

Stimulus electro-responsive polymer materials can reversibly change their physical or chemical properties under various external stimuli such as temperature, light, force, humidity, pH, and magnetic fields. This review introduces typical conventional stimulus electro-responsive polymer materials and extensively explores novel directions in the field, including multi-stimuli electro-responsive polymer materials and humidity electro-responsive polymer materials pioneered by our research group. Despite significant advancements in stimulus electro-responsive polymer materials, ongoing research focuses on enhancing their efficiency, lifespan, and production costs. Interdisciplinary collaboration and advanced technologies promise to broaden the application scope of these materials, particularly in medical and environmental protection fields, ultimately benefiting society.

Combining linear and cyclic sulfones as a strategy for elaborating more efficient high-dielectric polymer materials: A second case of dipolar glass copolymers

Motivated by the excellent features exhibited by sulfone functional groups in the development of high-dielectric polymer materials, this work assesses the combination of linear and cyclic sulfone structures through copolymerization to prepare novel polymer materials exhibiting high dielectric constants (ԑr'), low dissipative behavior, and improved thermal properties. Five new polymethacrylate-based copolymers with varying compositions were synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization. The correct structure and macromolecular nature of the devised materials were confirmed by infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H/13C NMR), and gel permeation chromatography (GPC), while their thermal properties were evaluated using thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). All specimens exhibited adequate thermal properties for most capacitor applications in terms of onset degradation (Ti) and glass transition (Tg) temperatures. All materials degraded well above 250 °C, with increased Ti and Tg values depending on the final composition of the cyclic sulfone monomer in the material. The incorporation of cyclic sulfones not only increased the thermal robustness of the specimens but also raised their Tg values to as high as 189 °C, notably expanding the range of temperatures where these systems can operate without dissipative phenomena. More importantly, broadband dielectric spectroscopy (BDS) revealed that all samples exhibited dielectric properties notably superior to those of conventional polymer materials, with high ԑr' values between 6.0 and 8.9 (at 25 °C and 1 Hz) and low loss factors (Tan(δ) < 0.018). Overall, the present work successfully demonstrates the advantages of including cyclic structures with high dipole moments in polymeric backbones, offering a new strategy to enhance the thermal and dielectric properties of high-dielectric polymer materials.

Hierarchical nanolayered structures-enabled record-high fracture resistant zircaloy

As a widely used nuclear structural material, zirconium (Zr) alloys are susceptible to brittle hydride-induced cracking. The intrinsic inability to arrest this cracking tendency in Zr poses a significant threat to the service safety of Zr cladding tubes. Here, we propose a microstructural design strategy, by introducing a hierarchical nanolayered duplex-phase structure in the Zr-2.5Nb alloy, to effectively inhibit the propagation of cracks. An unprecedented fracture toughness of KJIc ∼ 165 MPa·m1/2, corresponding to JIc ∼ 256 kJ/m2, is achieved due to the uniform and dense plastic deformation that develops ahead of the crack tip, which is uncharacteristic of Zr-based materials. Our analysis reveals that the effective crack tip blunting occurs because the high density of multiply oriented α/β interfaces in the hierarchical Zr-2.5Nb alloy stimulates ample <c+a> dislocations and facilitates deformation twin nucleation, both of which are challenging to activate in conventional Zr-based materials at room temperature. The exceptional fracture toughness enabled by the hierarchical nanolayered structure provides a new pathway to designing damage-tolerant hexagonal metals for safety-critical applications.

A mechanically robust and optically transparent nanofiber-aerogel-reinforcing polymeric nanocomposite for passive cooling window

The development of mechanically robust, visibly transparent and infrared spectrally selective films is pivotal for enhancing the thermal insulation efficiency of transparent building envelopes such as skylights and windows. Herein, an aligned nanofiber-aerogel-reinforcing all-polymeric nanocomposite is prepared by impregnating and curing methacrylate monomers within an aligned cellulose nanofiber aerogel. The deliberately structured cellulose aerogel with an aligned porous structure perpendicular to the film plane facilitates the formation of a robust nanofiber-matrix interface within the nanocomposite. This design enhances the mechanical strength and impact resistance reaching values of 274.5 MPa and 51.1 kJ m−2, respectively. Utilized as spectrally selective transparent window materials, these nanocomposites demonstrate exceptional infrared spectral selectivity, with a visible light transmittance of up to 78.2 %, near-infrared transmittance as low as 32.3 %, and mid-infrared emissivity as high as 91.0 %. They can be directly utilized as high-strength and impact-resistant spectrally selective cooling windows for effective indoor solar energy management, offering both indoor illumination and spontaneous cooling, leading to a reduction in indoor temperatures by 3.2 °C compared to conventional glass window materials.

Gelatin-based ionic hydrogel for intelligent fire-alarm system with considerable toughness, flame retardancy, and thermoelectric performance

Temperature-responsive materials with excellent reliability, sensitivity, and flame-retardant properties have always been an urgent need in the field of intelligent fire protection. In this discourse, we introduce a novel thermosensitive ionic hydrogel coating (gelatin/poly(acrylamide-co-acrylic acid)/CaCl2/spindle-shaped aluminum hydroxide nanosheet/glycerol, HCA) synthesized via free radical polymerization. HCA not only demonstrates considerable mechanical properties with a fracture strain of up to 842.5 % and a maximum tensile strength of 0.77 MPa but also exhibits notable flame retardancy and adhesion. It effectively covers combustible surfaces, providing outstanding fire protection. Notably, HCA boasts a Seebeck coefficient of up to 10.1 mV/K, significantly surpassing conventional thermoelectric materials. The well-established linear relationship between the generated voltage and temperature variation enables HCA-based intelligent fire-alarm system to accurately emit continuous alerts during fire incidents and swiftly transmit alarm signals to terminal devices. The development of this intelligent fire-alarm system presents new avenues in intelligent fire-safety technologies.