Preparation Of Composite Materials Research Articles

Enhanced carbon dioxide capture through composite of polyamide 6 nanofibers and zeolites: Preparation and performance evaluation

The increasing concentration of atmospheric carbon dioxide (CO2) demands innovative solutions for its capture and sequestration. Composite and nanocomposite materials have gained attention for their high surface area, adjustable properties, and improved adsorption capabilities. This manuscript explores the preparation, characterization, and performance assessment of a novel composite material consisting of polyamide 6 nanofibers combined with two types of zeolites, designed for CO2 capture. We detail the fabrication process, as well as the structural, chemical, and morphological characterization of the composites. The results confirmed the successful modification of polyamide 6 nanofibers with both types of zeolites. CO2 sorption measurements revealed that the composite with zeolite Y exhibited a notably high sorption capacity, with a maximum of 35.8 cm³/g, significantly surpassing the performance of amine-modified nanofibers, which demonstrated sorption capacities approximately three times lower. These findings highlight the potential of this composite for efficient CO2 capture, providing valuable insights into its practical application for reducing greenhouse gas emissions. While the CO2 sorption capacities of the composite are lower than those of pure zeolites, the composite offers practical advantages, such as easier handling and simplified application.

Boron-Nitrogen Compounds in Luminescent Materials: A Review of Applications and Synthesis Methods

Boron-nitrogen compounds (B-N) have emerged as a promising material due to their unique electronic structure and excellent luminescent properties, showing great potential in organic light-emitting diodes (OLED) and electroluminescent devices. This paper systematically reviews the molecular structure, optical, and electronic properties of B-N compounds, discusses their applications in luminescent materials, and explores synthesis methods, including Friedel-Crafts-type reactions, borohydride reduction reactions, and olefin metathesis. Additionally, the paper analyzes key factors in controlling the performance of luminescent materials, investigating the impact of synthesis conditions, doping, and the preparation of composite materials on luminescent efficiency and stability. Despite significant progress in B-N compound research, challenges remain in synthesis precision, luminescent efficiency, and industrial production. Future research should focus on improving targeted synthesis capabilities, optimizing electronic structure and luminescent performance, and exploring more efficient, cost-effective production processes. With continued innovation, B-N compounds are poised to become a foundation for the next generation of high-efficiency luminescent materials, driving advancements in optoelectronic technology.

The Research About Anode Material for Sodium-Ion Batteries

Sodium-ion batteries are replacing lithium-ion batteries due to their lower cost and more abundant resources. The sodium-ion battery anode, including carbon-based materials, alloy materials, and organic materials, plays a key role in improving battery performance but also faces problems such as poor conductivity, which limits sodium storage capacity attenuation and irreversible volume expansion. To solve these problems, researchers have proposed a variety of solutions, such as chemical activation, element doping, micro-nanostructure design, composite material preparation, surface coating application, and buffer medium introduction. This article summarizes these strategies and points out the direction of future research, including the development of innovative anode materials with better conductivity and sodium storage capacity, and improved manufacturing processes. Further research and development of sodium-ion batteries anode is expected to make important contributions to the new energy field.

Preparation and properties of phosphogypsum-based calcined coal gangue composite cementitious materials

Phosphogypsum (PG) and coal gangue (CG), as the largest solid waste today, the effective utilization of this part of the resource can help to alleviate environmental pollution and resource waste. The aim of this study was to utilize the excellent thermal insulation properties of original PG and the regulation of hydration products by calcined coal gangue (CCG) to produce phosphogypsum-based calcined coal gangue composite cementitious materials (PBCM). The optimal ratio of PBCM was studied through a combination of mechanical properties and thermal insulation properties. Finally, the effect of the foam factor is further investigated. The results show that: CCG can be used as a silicon-rich material with gelling properties to regulate the hydration products generated. The test block with a foam content of 8% has the best performance, with a compressive strength of 2.53MPa and a thermal conductivity of 0.1427W/(m·K). The optimal experimental scheme obtained from the orthogonal test was as follows: The optimal experimental design obtained from orthogonal experiments was as follows: PG, quicklime (QL), sulfoaluminate cement (SAC) and foam contents were 45%, 8%, 8% and 8%, respectively. The CCG: cement and water-solid ratios (W/S) were 3:7 and 0.275, respectively. The development of high-performance composites presented in this study is conducive to enhancing waste utilization and provides a novel approach as well as a theoretical foundation for insulating building materials in practical engineering applications.

The influence of CuxS particles on the thermal decomposition of anion exchangers

AbstractDue to the versality, surface imperfections and diverse redox chemistry of CuxS, hybrid ion exchangers (HIXs) containing these particles are an interesting object of research, including thermal transformation. The composite materials used for testing were strongly basic anion exchangers, with macroreticular (M) and gel-type structure (G), containing in the poly (styrene/divinylbenzene) skeleton fine particles of covellite/brochantite (M1), covellite (M2), covellite/digenite/djurleite (G1) and covellite/digenite (G2). The prepared HIXs contained 12–16 mass% S + Cu. They were subjected to thermal analysis under air and N2 to identify the role of the inorganic phase in decomposition of the polymeric phase. The results were discussed on the basis of the TG/DTG curves and X-ray diffraction (XRD) patterns of the solid residues (CuO after combustion, carbon/Cu2S after pyrolysis). It was found that CuxS in the resin phase exhibited oxidative activity promoting the combustion process. The polymeric skeleton of HIXs decomposed in air at a much lower temperature compared to pure resins (400 vs 600 °C). The TG/DTG curves had a model shape, three separate conversions occurring in a narrow temperature range, which indicated sequential decomposition. The low consumption of hydrogen for the reduction of CuxS to Cu2S during pyrolysis was not conducive to condensation of alkyl radicals and increase of the mass of carbon matter. The results advance the understanding of the effect of copper/sulfur-containing fine particles on the thermal decomposition of anion exchanger and can be useful in preparation of multifunctional carbon-containing composite materials.

Evaluation of setting and hardening properties of accelerator and slag-silica fume-cements

Industrial solid waste is used as a supplementary cementitious material (SCM) to replace cement, promoting the recycling and improving resource and economic sustainability. In this study, an organic combination of SCMs was prepared, along with the preparation of composite cementitious materials (CCM) that can be tailored to the aluminum sulfate alkali-free liquid accelerators. The findings revealed that a combination of 30% SCMs, including 10% slag, 15% silica fume, and 5% treated hardened cement powder (T-HCP), was blended with cement to form a CCM. Under the influence of the accelerator, the initial setting time of CCM is 1 min 20 s and the final setting time of CCM is 3 min. The compressive strength at 1, 3, and 28 days reaches 17.2, 29.9, and 51.6 MPa, respectively. CCM can utilize SiO2 from silica fume and CaCO3 in T-HCP as the nucleus to facilitate the substantial generation of AFt and Ca(OH)2 in the initial stage. It can be seen that the use of SCM together with alkali-free liquid accelerators in shotcrete not only enables the utilization of solid waste but also greatly improves the performance of shotcrete.

Preparation of Porous Composite Materials through Silicon Component Foaming and Special Heat Treatment.

This study proposes a foaming method along with calcination to produce silica-based porous materials. The high-silicon-content waste residue reacts with sodium hydroxide for hydrogen evolution foaming reactions. Then, the foaming green bodies are embedded and calcined in the calcination powder consisting of silicon, silicon carbide, graphite, and activated carbon at 1200 °C. The calcination powder creates a reducing atmosphere and prevents adhesion of the foaming green bodies to the crucible during calcination. Furthermore, the addition of activated carbon and calcination improve the macroporosity issue of the prepared sample through a gas-liquid-solid transformation. The BET surface area measurement is 64.197 m2/g, and the mercury intrusion porosimetry measurement indicates a porosity of 56.48%, with an average pore diameter of 396.48 nm. The porous composite materials exhibit the capability to adsorb methylene blue in solution. The porous materials possessing functional groups suggest promising potential for future development and application prospects.

DNA-Based Complexes and Composites: A Review of Fabrication Methods, Properties, and Applications.

Deoxyribonucleic acid (DNA), a macromolecule that stores genetic information in organisms, has recently been gradually developed into a building block for new materials due to its stable chemical structure and excellent biocompatibility. The efficient preparation and functional integration of various molecular complexes and composite materials based on nucleic acid skeletons have been successfully achieved. These versatile materials possess excellent physical and chemical properties inherent to certain inorganic or organic molecules but are endowed with specific physiological functions by nucleic acids, demonstrating unique advantages and potential applications in materials science, nanotechnology, and biomedical engineering in recent years. However, issues such as the production cost, biological stability, and potential immunogenicity of DNA have presented some unprecedented challenges to the application of these materials in the field. This review summarizes the cutting-edge manufacturing techniques and unique properties of DNA-based complexes and composites and discusses the trends, challenges, and opportunities for the future development of nucleic acid-based materials.

A novel application of waste poplar sawdust biochar: preparation of a shape-stable composite phase-change material with excellent thermal energy-storage performance

ABSTRACT The practical application of phase-change materials (PCMs) is limited due to leakage and low thermal conductivity. In this study, waste poplar sawdust (PW) and its derived biochar (PWC) were used as encapsulation materials, with stearic acid (SA) as the phase-change material, to successfully prepare composite phase-change materials with no leakage and high thermal conductivity. The microstructure and pore structure of PW and PWC were studied through SEM and nitrogen adsorption–desorption curves. The analysis results of FTIR, XRD and TGA indicated SA/PW and SA/PWC had excellent chemical compatibility and thermal stability. Excitingly, compared to SA/PW, SA/PWC exhibited higher latent heat and thermal conductivity. DSC results showed that the phase-change latent heat of SA/PWC can reach 100 J/g, which was 21% higher than that of SA/PW and the thermal conductivity increased by 87% times compared to SA/PW . In addition, SA/PW and SA/PWC still exhibited good thermal energy storage capacity after 200 thermal cycles. This research not only effectively resolved the leakage and low thermal conductivity challenges associated with PCMs but also introduced a novel utilization strategy for waste poplar sawdust, thereby significantly expanding its application potential.

Improved Electromagnetic Interference Shielding Efficiency of PVDF/rGO/AgNW Composites via Low-Pressure Compression Molding and AgNW-Backfilling Strategy.

Silver nanowires (AgNWs) have excellent electrical conductivity and nano-sized effects and have been widely used as a high-performance electromagnetic shielding material. However, silver nanowires have poor mechanical properties and are prone to fracture during the preparation of composite materials. In this study, PVDF/rGO/AgNW composites with a segregated structure were prepared using low-pressure compression molding and the AgNW-backfilling process. The low-pressure compression of the composite significantly improves its electromagnetic shielding performance because the low-pressure process can maintain the AgNWs' integrity. The backfilled AgNWs played a vital role in increasing the path of electromagnetic wave propagation and the absorption of electromagnetic waves. The backfilled amount of AgNWs was only 1 wt%, which increased the composite material's conductivity by one order of magnitude. The total electromagnetic interference shielding (SET) of the composite materials increased by 23.3% from 24.88 dB to 30.67 dB. The absorption contribution (SEA/SET) increased from 84.2% to 92.8%, significantly improving the electromagnetic interference shielding and the absorption contribution of the AgNWs in the composites. This was attributed to the backfilling of the porous structure by the AgNWs, which promoted multiple reflections and enhanced the absorption contribution.

A Review of the Development of Titanium-Based and Magnesium-Based Metallic Glasses in the Field of Biomedical Materials.

This article reviews the research and development focus of metallic glasses in the field of biomedical applications. Metallic glasses exhibit a short-range ordered and long-range disordered glassy structure at the microscopic level, devoid of structural defects such as dislocations and grain boundaries. Therefore, they possess advantages such as high strength, toughness, and corrosion resistance, combining characteristics of both metals and glasses. This novel alloy system has found applications in the field of biomedical materials due to its excellent comprehensive performance. This review discusses the applications of Ti-based bulk metallic glasses in load-bearing implants such as bone plates and screws for long-term implantation. On the other hand, Mg-based metallic glasses, owing to their degradability, are primarily used in degradable bone nails, plates, and vascular stents. However, metallic glasses as biomaterials still face certain challenges. The Young's modulus value of Ti-based metallic glasses is higher than that of human bones, leading to stress-shielding effects. Meanwhile, Mg-based metallic glasses degrade too quickly, resulting in the premature loss of mechanical properties and the formation of numerous bubbles, which hinder tissue healing. To address these issues, we propose the following development directions: (1) Introducing porous structures into titanium-based metallic glasses is an important research direction for reducing Young's modulus; (2) To enhance the bioactivity of implant material surfaces, the surface modification of titanium-based metallic glasses is essential. (3) Developing antibacterial coatings and incorporating antibacterial metal elements into the alloys is essential to maintain the long-term effective antibacterial properties of metallic biomaterials. (4) Corrosion resistance must be further improved through the preparation of composite materials, while ensuring biocompatibility and safety, to achieve controllable degradation rates and degradation modes.

Preparation of ZIF-67 composite MBI-modified Co-MOF material and its corrosion resistance to epoxy resin coating

Metal corrosion causes a lot of waste of resources, and the protection of metals from corrosion is becoming increasingly important. In this study, zeolite-imidazole (ZIF-67) was grown on the surface of Co-MOF for the first time by a one-step (complexation) method. 2-Mercaptobenzimidazole (MBI) was then loaded into the inner cavity of ZIF-67, resulting in the formation of a new composite material, Co-MOF@ZIF-67@MBI. The modified Co-MOF exhibits excellent interfacial compatibility with the water-based epoxy resin, and the Co-MOF@ZIF-67@MBI composite coating demonstrates robust anti-corrosion properties. Following a 60-day immersion period, the electrochemical experiment demonstrated that the corrosion resistance modulus of the Co-MOF@ZIF-67@MBI composite coating reached 108 Ω cm², indicating that the coating effectively enhanced the corrosion resistance of the coating and significantly extended the service life of the coating.

Preparation and Characterization of Epoxy-Based Composite Materials Reinforced with Graphene Oxide

In this study, modified graphene oxide (GO) with γ-APS silane coupling agent before being dispersed into an epoxy/4,4’-diamino diphenyl methane matrix to prepare a composite material using the bar-coating technique. The modified GO materials with the γ-APS silane (GOS) were characterized by infrared spectrum, Zeta potential, and TG/DSC thermal analysis. The amount of silane grafted on the GO is ~ 3.3 wt.%; the Zeta potential value shifted from the negative to the positive region was observed on the surface potential distribution diagram. Scanning electron microscopy, DSC thermal analysis, and dielectric constant were used to characterize the obtained composite epoxy/GO material properties. The results show that graphene oxide, after modification with γ-APS silane agent, has good dispersion ability in the epoxy resin matrix. Composite material epoxy/GOS presented a high dielectric constant value (εaverage = 6.19, at 1 kHz), increasing thermal stability, which is a suitable material promising for future applications.

Preparation of dodecahydrate disodium hydrogen phosphate shape-stabilized composite phase change materials and their experimental investigation in solar thermal storage and exothermic systems

To alleviate the mismatch between energy supply and demand caused by the spatial and temporal distribution mismatch and weather uncertainty during solar energy utilization, solar energy is combined with phase change thermal storage technology to improve the performance of solar thermal storage systems. In this study, a shape-stabilized composite phase change material with a highly absorbent resin structure is proposed as thermal storage material. This material exhibits a latent heat of phase change of 246.5 J/g, a thermal conductivity of 1.968 W/(m·K), and maintains good stability after 200 thermal cycles. Subsequently, a detachable experimental setup integrating solar energy with a phase change thermal storage tank was designed and constructed. The effects of inlet and outlet hot water flow rates and heat source temperature on heat storage time and the amount of stored water were investigated separately. The experiments show that increasing the heat source temperature during storage effectively shortens the storage time, and that the largest effective amount of hot water is obtained when the exothermic flow rate is 300 L/h. The study's results are significant for broadening solar energy utilization, alleviating the mismatch between solar energy supply and demand, and evaluating the thermal performance of latent heat storage systems.

Lignin-Based Composite Film and Its Application for Agricultural Mulching.

Agricultural mulching is an important input for modern agricultural production and plays an important role in guaranteeing food security worldwide. At present, polyethylene (PE) mulching is still commonly used in agricultural production in most countries around the world, which is non-biodegradable, and years of mulching have caused serious agricultural white pollution. Lignin is one of the three major components of plant cell walls, and it is also the main renewable natural aromatic compounds in nature. Lignin-based composite film materials are green, biodegradable, and show good prospects for development in the field of agricultural mulch. This paper introduces the types, structure, and application status of lignin, summarizes the preparation of lignin-based composite film materials and its latest research progress, focuses on the types, preparation methods, and application examples of lignin-based agricultural mulching, and looks forward to the future development prospects of lignin-based agricultural mulching.

Study on the hydration characteristics, mechanical properties, and microstructure of thermally activated low-carbon recycled cement

Based on the thermal activation method, utilizing fine particles of waste concrete to prepare low-carbon recycled cement (RC) is currently one of the research hotspots. Based on existing literature research results, this paper identifies four calcination temperature conditions (120, 450, 750, 1000 ℃) and uses replacement rates of 10 %, 30 %, 50 %, 70 %, and 100 % of RC to replace ordinary Portland cement (OPC).The main physical properties, hydration characteristics, mechanical properties, and microstructure of RC are studied. The study elucidated the influence of RC thermal activation temperature, replacement rate, fineness, and age on its hydration characteristics, mechanical properties, and microstructure, establishing a macro-micro correlation for RC and revealing the mechanism of improvement in mechanical properties of thermal-activated RC. The research indicates that in the initial stage of hydration, RC exhibits a relatively fast hydration rate, with higher initial total heat release than OPC. Hydration products include internal hydration products (formation of C-(A)-S-H gel) and external hydration products (formation of plate-shaped AFm). Furthermore, RC exhibits a faster hydration rate at a hot activation temperature of 750°C, with CH and C-S-H gel transforming into the highly hydrated α´L-C2S, forming a denser microstructure at an early stage. Moreover, at a replacement rate of 30 %, the compressive strength of cement mortar reaches its optimum at 28 days, achieving 13.81 MPa, equivalent to 60.7 % of OPC cement mortar, with a 66.67 % reduction in carbon emissions. Microstructure analysis reveals that when the temperature reaches 1000°C, excessive combustion of RC leads to the formation of low-reactivity C2AS and β-C2S, resulting in a decrease in macroscopic mechanical properties. Additionally, increasing the fineness of RC significantly enhances its rehydration capability, especially as the age increases. This study is of great significance for the preparation of green cement-based composite cementitious materials.

Preparation and erosion resistance of SiC-based ceramic-PCM sensible-latent heat composite heat storage materials

Alloy phase change materials (PCM) are key materials in latent heat storage systems for solar thermal power generation, however, their application is limited by the high corrosion and oxidation problems of alloys. To reduce the erosion problem of alloy PCM, SiC-based ceramic encapsulated flake graphite (EG) modified Al-Cu28-Si6 alloy was used to successfully prepare composite PCM with high compatibility and oxidation resistance. Adopting static erosion test method, the composite PCM was subjected to 50 thermal cycles (25–1000 °C holding time of 10 h was recorded as 1 cycle). The results showed that SiC-based ceramics have excellent corrosion resistance to composite PCM with 10 wt% EG added, which due to the excellent reticulation and encapsulation of EG. Based on the Young-Laplace equation and the contact angle, the erosion resistance mechanism of silicon carbide ceramic alloys has been revealed. SiC-based ceramic-PCM sensible heat-latent heat composite heat storage material was expected to be used for high-temperature heat storage in solar thermal power generation.

Utilization of graphene nanoplatelets for friction coefficient reduction in NiCu/WC-12Ni composite materials

Graphene Nanoplates (GNPs), known for their outstanding performance, have found extensive applications in the preparation of metal composite carbon materials. In this investigation, a Directed Energy Deposition system was employed to effectively produce deposition specimens of NiCu/WC-12Ni + x wt% GNPs (x = 0, 0.5, 1.0, 1.5) composite material. The findings suggest that incorporating GNPs improved the microstructure of the NiCu/WC-12Ni deposited specimens, leading to a reduction in grain size with predominantly equiaxed and cellular grains. GNPs transformed into amorphous graphene spheres, uniformly distributed within the deposited structure. When 1 wt% GNPs were added, the average microhardness of the deposited specimens increased by approximately 15 %, the friction coefficient decreased from the original 0.318 to 0.257, and the wear rate decreased by 23.2 %. The primary wear mechanism observed was abrasive wear, demonstrating excellent wear resistance. Moreover, introducing a suitable quantity of graphene improved the electrochemical corrosion resistance of the deposited specimen.

Fabrication of Cross‐Linked Polyimide Hollow Microspheres With Lightweight, Thermal Resistance and Controllable Size

AbstractPolyimide (PI) hollow microspheres possess lightweight and excellent thermal resistance, which are widely used in microreactors, catalysis, adsorption separation, high‐temperature insulation, and so on. In this manuscript, PI hollow microspheres are fabricated by constructing a crosslinked structure combined with gradient heating. The formation of PI hollow microspheres includes gas nucleation, expansion, and imidization. The PI hollow microspheres size is controlled by adjusting polyester ammonium salts size, and microspheres size is distributed in 309–956 µm. PI hollow microspheres have lightweight, excellent heat resistance and carbonization performance, bulk density, initial decomposition temperature, and weight residue at 800 °C is 87.3–178.6 kg m−3, 533.6 °C and 59.8%. The PI hollow microspheres have potential applications in high‐temperature resistant and multifunctional composite materials preparation. Moreover, this method is simple, efficient, and highly operable, which can be used for large‐scale production of PI hollow microspheres.

Comparative study on preparation and hydration mechanism of composite cementitious materials containing copper slag

Copper slag (CS) is a kind of non-ferrous solid waste with low content of aluminosilicate and relatively high content of iron oxide. In this paper, the feasibility and mechanism of CS as the mineral admixture and precursor of alkali activated cementitious material were studied. The effects of CS on mechanical properties were studied and the hydration products were determined by several characterization methods. Scanning Electron Microscopy (SEM) and Mercury Injection Porosimetry (MIP) were performed to characterize the microstructure. The results show that CS composite fly ash (FA) has more advantages than CS alone, but its application as a mineral admixture is limited by the low activity. The alkali activated cementitious material prepared by CS and FA as precursor has excellent mechanical properties. The compressive strength of specimen at 28 days age can reach the maximum of 81.3 MPa when the dosage of CS is 30 %. The 3d and 28d compressive strength of the specimen contained 60 % CS obtained 57.7 MPa and 70.7 MPa, respectively. The research exhibits great potential for the future utilization of CS.