Preparation Of Composites Research Articles

A biomass phosphonamide enables biodegradable polylactide with favorable flame retardancy and rapid crystallization

PLA is widely known as biodegradable plastics whose further application in fields such as automotive and architectural is still constrained by its flammability and unsatisfactory crystallization properties. To address the aforementioned concerns, a novel biomass phosphonamide PDPA was synthesized with chemical structure confirmed by FTIR, NMR and elemental analysis tests. Immediately thereafter, PLA/PDPA composites were prepared by melting blending, with a focus on flame retardancy, crystallization properties and flame-retardant mechanism. As expected, PDPA efficiently enhanced both the flame retardancy and crystallization properties of PLA. Specifically, the PLA/4.0PDPA obtained UL-94 V-0 grade and the LOI value increased to 28.6 % with only 4 wt% PDPA added, which comes down to the superior free radical capture and dilution effect of PDPA in the vapor phase and the melting droplet effect. More appealingly, the crystallinity of PLA/4.0PDPA was significantly enhanced to 43.4 % from 2.5 % of PLA, and the shortest t1/2 was 4 mins in the isothermal crystallization process due to the excellent heterogeneous nucleation of PDPA. Moreover, PLA/PDPA composites maintain almost the same mechanical performance as pure PLA. In brief, this work provides a green strategy for the preparation of PLA composites with excellent comprehensive performance and shows great potential in engineering materials.

Factor analysis on property enhancement of electrically/thermally conductive composites by continuous forced assembly

AbstractCurrently, with the development of many important fields such as aerospace and automotive industries, polymer composites have become an indispensable part of these fields. As for preparation methods, common methods like hot pressing make composites difficult to achieve continuous production. This paper proposed the continuous forced assembly (CFA) and designed continuous production facility, which can achieve the continuous preparation of low filler content (30 wt%) composites with high electrical/thermal conductivity. Besides, we structurally designed roll pressing device and explored its effect on the machining process. Here, short cut carbon fiber (SCF) and solid silica gel (MVQ) are used as electrically/thermally conductive filler and polymer matrix respectively, and continuous preparation of functional composites is completed by CFA method. Compared to the thermal conductivity (1.186 W/(m·K)) of SCF/MVQ composites prepared with lower viscosity matrix (MVQ‐A), the thermal conductivity of composites prepared with high viscosity matrix (MVQ‐D) reached 2.230 W/(m·K). Meanwhile, the process is optimized to explore the effects of the “accordion folding” and “pre‐stretch” methods on the thermal conductivity of composites, the thermal conductivity is converted from in‐plane to vertical direction. In addition, under the same filler content, 2 wt% rGO is beneficial in enhancing the electrical/thermal conductivity of prepared composites. The electrical conductivity and thermal conductivity of SCF28/rGO2/MVQ composite reach 663 S/m and 2.82 W/(m·K), which is higher than that of the properties of SCF/MVQ composite with the same filler content. To sum up, CFA facilitates continuous production of composites, which can be used in thermal management materials (TMMs).Highlights Compared with the “pre‐stretch” method, the thermal conductivity of SCF/MVQ composites prepared by “accordion folding” has a significant improvement. The SCF/rGO/MVQ composites prepared by CFA method show superior thermal conductivity and electrical conductivity. Composites prepared by CFA method can realize the continuous preparation of functional materials.

Enhancing dye/salt separation efficiency through polysulfobetaine-modified poly (triazine imide)/polyethersulfone (PTI-PSBMA/PES) composite membrane fabrication

Membrane technology stands as a vital solution for efficient dye/salt separation in various industrial processes. For the first time in this study, polysulfobetaine-modified poly (triazine imide) (PTI-PSBMA) was simply prepared by reversible addition-fragmentation chain-transfer (RAFT) polymerization as an additive for PTI-PSBMA/PES composite membrane preparation using the phase inversion strategy. The SEM, AFM pictures, and WCA analysis results exhibited that the modified membranes with PTI-PSBMA possess smoother surfaces and are more hydrophilic. After conducting an investigation using a dead-end filtration setup, it has been determined that the PTIZ-1 membrane, containing 1.0 wt% of PTI-PSBMA, emerged as the most effective membrane. This membrane exhibited a remarkable water flux of 46.0 L. m−2 h−1 bar−1 and demonstrated the highest rejections for various dyes, such as Reactive Red 120 (92.3 %), Direct Yellow 29 (79.3 %), and Methyl Green (85.0 %). Additionally, the PTIZ-1 membrane displayed impressive antifouling properties, with protein adsorption decreasing by over 96.0 %. With exceptional rejection rates for dyes and high permeability for salts, this composite membrane presents a promising solution for practical applications in wastewater treatment and dye removal processes. This research contributes to advancing membrane technology by introducing a highly efficient composite membrane with enhanced separation properties, addressing critical challenges in industrial dye/salt separation processes.

The influence of sintering additives on densification and phase composition of ZrB2 – HfB2 composite

This work deals with the preparation of composites from the ZrB2-HfB2-MeX system (where: MeX = SiC, B4C, WC, MoSi2 and CrSi2). Three pressure-assisted sintering techniques were used to obtain the composites, i.e. hot-pressing (HP), spark-plasma sintering (SPS) and high pressure-high temperature (HPHT) sintering. Hot-pressing was selected as the most favourable sintering technique. The composites obtained via hot-pressing were characterized by high density and homogeneous microstructure. The work did not undermine or justify the need to reduce passivating oxide layers on boride grains. In the case of silicides, especially chromium silicide, there was a significant reduction in the sintering temperature of the ZrB2-HfB2 composites by about 500–600°C. In composites with the addition of silicides, there is a tendency to create complex solid solutions, which is visible as core-shell microstructures.

Homogeneous Adsorption of Multiple Potassiation Products of Red Phosphorus Anode toward Stable Potassium Storage.

Potassium ion batteries (PIBs) are a viable alternative to lithium-ion batteries for energy storage. Red phosphorus (RP) has attracted a great deal of interest as an anode for PIBs owing to its cheapness, ideal electrode potential, and high theoretical specific capacity. However, the direct preparation of phosphorus-carbon composites usually results in exposure of the RP to the exterior of the carbon layer, which can lead to the deactivation of the active material and the production of "dead phosphorus". Here, the advantage of the π-π bond conjugated structure and high catalytic activity of metal phthalocyanine (MPc) is used to prepare MPc@RP/C composites as a highly stable anode for PIBs. It is shown that the introduction of MPc greatly improves the uneven distribution of the carbon layer on RP, and thus improves the initial Coulombic efficiency (ICE) of PIBs (the ICE of FePc@RP/C is 75.5% relative to 62.9% of RP/C). The addition of MPc promotes the growth of solid electrolyte interphase with high mechanical strength, improving the cycle stability of PIBs (the discharge-specific capacity of FePc@RP/C is 411.9 mAh g-1 after 100 cycles at 0.05 A g-1). Besides, density functional theory theoretical calculations show that MPc exhibits homogeneous adsorption energies for multiple potassiation products, thereby improving the electrochemical reactivity of RP. The use of organic molecules with high electrocatalytic activity provides a universal approach for designing superior high-capacity, large-volume expansion anodes for PIBs.

Enhancing strength and toughness of GNS/Al nanocomposites via a hybridization strategy

Good strength-ductility balance in graphene nanosheet (GNS)-reinforced aluminum nanocomposites can be achieved through tailorable and facile agglomeration control. Our previous study showed that pre-modulating the Al powder morphology by adding hard silicon carbide nanoparticles (SiCnp) during the two-step ball milling process effectively promotes the uniform dispersion of GNSs. However, excess SiCnp content causes SiCnp aggregate and premature cracking of composites. Here, GNS-reinforced aluminum nanocomposites with different SiCnp content (0.3–1.5 vol%) were prepared, and the optimal SiCnp-to-GNS ratio was determined after optimizing the SiCnp content in a pre-studied composite preparation process. The effect of SiCnp on the microstructure and mechanical properties of the composites was systematically investigated. The cold welding deformation of Al flakes increased with the SiCnp content. Nonetheless, inadequate or excessive SiC content caused insufficient lamination or excessive cold-weld stacking of Al flakes, respectively. Al-0.9vol.%SiCnp powders possessed the highest specific surface area which resulted in high homogeneous dispersion of 3.0 vol% GNS during the second ball-milling stage. Consequently, the resulting hybrid reinforced (GNS + SiCnp)/Al composites showed simultaneous improvement in strength and plasticity, unlike Al-3.0vol.%GNS composites. This showed that introducing hard nanoparticles (i.e., the hybridization strategy) is a promising method to simultaneously enhance strength and plasticity of aluminum nanocomposites.

Development of accumulative roll bonding for metallic composite material preparation and mechanical/functional applications

Development of accumulative roll bonding for metallic composite material preparation and mechanical/functional applications

Preparation of multifunctional flame-retardant wood composites by crosslinking chitosan-based polymers with phytic acid functionalized UiO-66-NH2

Bio-based composites can mitigate the pollution issues linked to petroleum-based materials due to their eco-friendly properties. On the other hand, bio-based functionalized metal-organic frameworks have gained attention in the field of flame retardants due to their multi-pathway flame retardant mechanism and environmentally friendly synthesis process. However, its application in wood industry is less. In this work, a novel functional adhesive and coating (ACS-MACS/PA-UiO66-NH2) was developed by using phosphorus-rich biomass phytate functionalized metal-organic framework (MOF) PA-UiO66-NH2 as a flame retardant and mixed with modified chitosan. Furthermore, using ACS-MACS/PA-UiO66-NH2 and three-layer wooden boards, a tight cross-linked network was formed through hot pressing dehydration and condensation reactions to prepare multifunctional wood composites. The experimental results indicated that the mechanical properties of the multifunctional wood composites are excellent. Additionally, these wood composites exhibit high levels of charring and graphitization, leading to excellent flame retardancy. The preparation process of these multifunctional wood composites is straightforward, and their excellent properties provide a foundation for the development of high-performance green composite materials.

Preparation and Characterization of Graphite-SiO2 Composites for Thermal Storage Cement-Based Materials.

Thermal storage cement-based materials, formed by integrating phase change materials into cementitious materials, exhibit significant potential as energy storage materials. However, poor thermal conductivity severely limits the development and application of these materials. In this study, an amorphous SiO2 shell is encapsulated on a graphite surface to create a novel thermally modified admixture (C@SiO2). This material exhibits excellent thermal conductivity, and the surface-encapsulated amorphous SiO2 enhances its bond with cement. Further, C@SiO2 was added to the thermal storage cement-based materials at different volume ratios. The effects of C@SiO2 were evaluated by measuring the fluidity, thermal conductivity, phase change properties, temperature change, and compressive strength of various thermal storage cement-based materials. The results indicate that the newly designed thermal storage cement-based material with 10 vol% C@SiO2 increases the thermal conductivity coefficient by 63.6% and the latent heat of phase transition by 11.2% compared to common thermal storage cement-based materials. Moreover, C@SiO2 does not significantly impact the fluidity and compressive strength of the thermal storage cement-based material. This study suggests that C@SiO2 is a promising additive for enhancing thermal conductivity in thermal storage cement-based materials. The newly designed thermal storage cement-based material with 10 vol% C@SiO2 is a promising candidate for energy storage applications.

A fast method to prepare highly isotropic and optically adjustable transparent wood-based composites based on interface optimization

The production design of transparent materials using wood flour as the substrate aims to improve the value-added utilization rate of waste wood, and explore the preparation process of energy-saving building materials. This paper reports a rapid method for the preparation of transparent wood-based composites (TW-OTS) with high isotropy and optical adjustability, which changes the high energy consumption of bleaching wood flour in the past. Using the fluffy and porous structure of wood flour, the wood flour was bleached by hydrogen peroxide drop coating method assisted with ultraviolet light, and then hydrophobicized and impregnated with epoxy resin. The interfacial bonding and optimization mechanism of organic polymer Octadecyl trichlorosilane (OTS), wood fiber and resin at the micro scale were systematically studied in order to improve the optical parameters, mechanical strength and thermal properties of the composites, so as to balance the relationship between the structure and properties. TW-OTS based on interface optimization has excellent transmittance (80.1 %), thermal insulation performance, mechanical strength, and biocompatibility. If 1 % chitosan is added to the resin, the antibacterial properties of the sample can be added. This material can be used in energy-saving building windows, medical equipment, ecological home products, and other fields.

Design Principles of Quinone Redox Systems for Advanced Sulfide Solid-State Organic Lithium Metal Batteries.

The emergence of solid-state battery technology presents a potential solution to the dissolution challenges of high-capacity small molecule quinone redox systems. Nonetheless, the successful integration of argyrodite-type Li6PS5Cl, the most promising solid-state electrolyte system,and quinone redox systems remains elusive due to their inherent reactivity. Here, a library of quinone derivatives is selected as model electrode materials to ascertain the critical descriptors governing the (electro)chemical compatibility and subsequently the performances of Li6PS5Cl-based solid-state organic lithium metal batteries (LMBs). Compatibility is attained if the lowest unoccupied molecular orbital level of the quinone derivative is sufficiently higher than the highest occupied molecular orbital level of Li6PS5Cl. The energy difference is demonstrated to be critical in ensuring chemical compatibility during composite electrode preparation and enable high-efficiency operation of solid-state organic LMBs. Considering these findings, a general principle is proposed for the selection of quinone derivatives to be integrated with Li6PS5Cl, and two solid-state organic LMBs, based on 2,5-diamino-1,4-benzoquinone and 2,3,5,6-tetraamino-1,4-benzoquinone, are successfully developed and tested for the first time. Validating critical factors for the design of organic battery electrode materials is expected to pave the way for advancing the development of high-efficiency and long cycle life solid-state organic batteries based on sulfides electrolytes.

Mechanically robust and electrically conductive nanofiber composites with enhanced interfacial interaction for strain sensing

Electrically conductive fiberfibre/fabric composites (ECFCs) are competitive candidates for use in wearable electronics. Therefore, it is essential to develop mechanically robust ECFC strain sensors with sensing performance. In this study, MXene assembly and hot-pressing were combined to prepare strong yet breathable ECFCs for strain and temperature sensing. Hydrogen bonding between MXene and polyurethane (PU) and ultrasonication-induced interfacial sintering were responsible for MXene nanosheets assembly on the PU nanofibers. MXene decoration made PU nanofibers electrically conductive, resulting in a conductive network. Hot-pressing improved interface adhesion among the conductive nanofibers. Thus, the mechanical properties of the nanofiber composites, including tensile strength, toughness and fracture energy, were enhanced. The nanofiber composites exhibited surface stability and durability. When the nanofiber composites were used as strain sensors, they showed breathability with a linear resistance response ranging from 1 % to 100 % and cycling stability. In addition, they produced stable sensing signals over 1000 cycles when a notch was present. They could also monitor temperature variations with a negative temperature coefficient (−0.146 %/°C). This study provides an interfacial regulation method for the preparation of multi-functional nanofiber composites with potential applications in flexible and wearable electronics.

Preparation of composites with MgAl-LDH-modified commercial activated carbon for the quick removal of Cr(VI) from aqueous solutions.

The problem of soil and water contamination caused by Cr(VI) discharged from the dyeing, electroplating, and metallurgical industries is becoming increasingly serious, posing a potentially great threat to the environment and public health. Therefore, it is crucial to develop a fast, efficient, and cost-effective adsorbent for remediating Cr-contaminated wastewater. In this work, MgAl-LDH/commercial-activated carbon nanocomposites (LDH-CACs) are prepared with hydrothermal. The effects of preparation and reaction conditions on the composite properties are first investigated, and then its adsorption behavior is thoroughly explored. Finally, a potential adsorption mechanism is proposed by several characterizations like SEM-EDS, XRD, FTIR, and XPS. The removal of Cr(VI) reaches 72.47% at optimal conditions, and the adsorption study demonstrates that LDH-CAC@1 has an extremely rapid adsorption rate and a maximum adsorption capacity of 116.7 mg/g. The primary removal mechanisms include adsorption-coupled reduction, ion exchange, surface precipitation, and electrostatic attraction. The reusability experiment illustrates that LDH-CAC@1 exhibits promising reusability. This study provides an effective adsorbent with a remarkably fast reaction, which has positive environmental significance for the treatment of Cr(VI) wastewater.

Hollow TiO2@Fe2O3 nanofiber additives using template based approach for capture-conversion of polysulfides in Lithium-sulfur batteries

High theoretical capacity (1675 mA h g−1) and energy density (2600 Wh kg−1) in addition to low cost, non-toxicity and natural abundance stimulates the exploration of sulfur as a potential cathode material. However, serious capacity fade and poor reaction kinetics leads to untimely failure which prevents the practical commodification of these batteries. Here, a simple and versatile electrospinning technique has been employed to prepare a polymeric template to fabricate hollow metal oxide@metal oxide nanofibers. The hollow fibrous shell with large specific surface area is incorporated as an anchoring material comprising of distinct crystalline phases separated by amorphous domains. Meanwhile, the encapsulated metal oxide nanoparticles ensure efficient conversion of soluble polysulfides thereby, promoting the reaction kinetics and avoiding any surface passivation of anchoring material. The LSB cell with 5 % TiO2@Fe2O3 nanofiber additives delivers impressively in the rate capability test with stable capacities of 620 and 480 mA h g−1 at 1C and 2C rate, respectively. Moreover, an excellent cycling performance is attained with a fade rate of 0.092 % per cycle over 500 cycles at 0.5C-rate. The findings of this work shall provide a pathway for facile preparation of functional metal oxide composites for simultaneous trapping and conversion of polysulfide species in sulfur batteries.

Advances in 3D printing for polymer composites: A review

AbstractThe potential of three‐dimensional (3D) printing technology in the fabrication of advanced polymer composites is becoming increasingly evident. This review discusses the latest research developments and applications of 3D printing in polymer composites. First, it focuses on the optimization of 3D printing technology, that is, by upgrading the equipment or components or adjusting the printing parameters, to make them more adaptable to the processing characteristics of polymer composites and to improve the comprehensive performance of the products. Second, it focuses on the 3D printable novel consumables for polymer composites, which mainly include the new printing filaments, printing inks, photosensitive resins, and printing powders, introducing the unique properties of the new consumables and different ways to apply them to 3D printing. Finally, the applications of 3D printing technology in the preparation of functional polymer composites (such as thermal conductivity, electromagnetic interference shielding, biomedicine, self‐healing, and environmental responsiveness) are explored, with a focus on the distribution of the functional fillers and the influence of the topological shapes on the properties and functional characteristics of the 3D printed products. The aim of this review is to deepen the understanding of the convergence between 3D printing technology and polymer composites and to anticipate future trends and applications.image

A Ni-doped coral-like three-dimensional Mo2C nanorod for sensitive electrochemical monitoring of environmentally polluting nitrobenzene

This paper reports the synthesis of a Ni-doped coral-like three-dimensional Mo2C nanorod via the pyrolysis of polypyrrole (PPy)-loaded NiMoO4·xH2O nanorods for nitrobenzene (NB) detection. The incorporation of Ni species into Mo2C enhances dual-atom synergistic catalysis, while the inclusion of PPy as a preferred carbon source improves the composite's active area. The coral-like three-dimensional rod structure not only provides various types of sites for adsorbing reactants but also offers more channels for ion migration and electron transfer, promoting charge transfer and further enhancing its electrical conductivity. The resulting composite demonstrates a wide linear detection range (2.11–1053.61 μM), high sensitivity, low limit of detection (0.64 μM, S/N = 3), and excellent stability and anti-interference performance in NB detection. This novel composite preparation approach offers promising prospects for practical NB detection applications.

Effect of Dynamic Recrystallization Mode on Texture Components and Hardness for Nano-SiC Particles Reinforced Aluminum Matrix Composites Prepared Via Friction Stir Processing

Effect of Dynamic Recrystallization Mode on Texture Components and Hardness for Nano-SiC Particles Reinforced Aluminum Matrix Composites Prepared Via Friction Stir Processing

Recent Advances in Porous Bio-Polymer Composites for the Remediation of Organic Pollutants.

The increasing awareness of the importance of a clean and sustainable environment, coupled with the rapid growth of both population and technology, has instilled in people a strong inclination to address the issue of wastewater treatment. This global concern has prompted individuals to prioritize the proper management and purification of wastewater. Organic pollutants are very persistent and due to their destructive effects, it is necessary to remove them from wastewater. In the last decade, porous organic polymers (POPs) have garnered interest among researchers due to their effectiveness in removing various types of pollutants. Porous biopolymers seem to be suitable candidates among POPs. Sustainable consumption and environmental protection, as well as reducing the consumption of toxic chemicals, are the advantages of using biopolymers in the preparation of effective composites to remove pollutants. Composites containing porous biopolymers, like other POPs, can remove various pollutants through absorption, membrane filtration, or oxidative and photocatalytic effects. Although composites based on porous biopolymers shown relatively good performance in removing pollutants, their insufficient strength limits their performance. On the other hand, in comparison with other POPs, including covalent organic frameworks, they have weaker performance. Therefore, porous organic biopolymers are generally used in composites with other compounds. Therefore, it seems necessary to research the performance of these composites and investigate the reasons for using composite components. This review exhaustively investigates the recent progress in the use of composites containing porous biopolymers in the removal of organic pollutants in the form of adsorbents, membranes, catalysts, etc. Information regarding the mechanism, composite functionality, and the reasons for using each component in the construction of composites are discussed. The following provides a vision of future opportunities for the preparation of porous composites from biopolymers.

Preparation of Ni Nanowires Covalent Organic Framework Composites with High Electrochemical Stability and Supercapacitor Performance

Preparation of Ni Nanowires Covalent Organic Framework Composites with High Electrochemical Stability and Supercapacitor Performance

Novel MAXPOWER biological antibacterial liquid for eradicating oral Helicobacter pylori

BackgroundEradication of oral Helicobacter pylori (H. pylori) not only reduces the infection rate from the transmission route but also improves the success rate of intragastric eradication. MAXPOWER Biological Bacteriostatic Liquid, developed in our previous work, is a composite biological preparation with strong antibacterial ability and unique antibacterial mechanism. The present study evaluated the efficacy of the MAXPOWER biocontrol solution on H. pylori and its success rate in eradicating oral H. pylori in clinical patients.MethodsLive-dead cell staining and hemolysis test were used to evaluate the cellular safety of MAXPOWER biocontrol solution; plate spreading, live-dead bacterial staining, and scanning electron microscopy methods were used to evaluate its antimicrobial effect against H. pylori. Transcriptomics was used to analyze the changes in H. pylori genes before and after treatment. After seven days of gavage treatment, H&E staining and mice feces were collected for 16SrDNA sequencing to evaluate the animals’ safety. Oral H. pylori-positive patients were randomized to be given a placebo and MAXPOWER Bio-Bacteriostatic Liquid gargle for seven days to evaluate the effect on oral H. pylori eradication.ResultsIn vitro tests demonstrated that this product has excellent biocompatibility and hemocompatibility and can effectively eradicate oral H. pylori. In vivo tests further showed that it has good biosafety and virtually no adverse effect on intestinal microflora. Transcriptomics analysis revealed that it kills H. pylori cells mainly by disrupting their cell membranes and metabolism. Additionally, the results of randomized controlled trials on humans disclosed that the oral H. pylori eradication rates achieved by MAXPOWER Biological Antibacterial Liquid were 71.4% and 78.9% according to the intention-to-treat and the per-protocol analysis, respectively.ConclusionMAXPOWER Biological Antibacterial Liquid is both safe and efficacious in the eradication of oral H. pylori.Trial registrationThis study was retrospectively registered in the ClinicalTrials.gov Trial Registry on 21/09/2023 (NCT06045832).