Composite Materials Research Articles

Enhanced charge transfer kinetics across the graphdiyne-metal sulfide ohmic interface for boosting photocatalytic hydrogen evolution

The design and construction of photocatalysts are the crucial step for solar-driven hydrogen evolution. Herein, a new type of graphdiyne (CnH2n-2)-based photocatalyst, which was prepared by one pot method, was used to promote hydrogen evolution reaction by constructing GDY/VS2 ohmic junction with S sites anchoring on the surface. Actually, the unique two-dimensional conjugated carbon network of GDY can maintain the structural stability. The uneven surface facilitates the flow of electrons, which makes GDY a good electron donor. In addition, the expanded interlayer spacing of VS2 exposes more hydrogen evolution active sites. The increase in surface electronegativity of composite catalysts enhances their redox ability and charge transfer kinetics. The band edge of the graphdiyne-metal sulfide Ohmic contact interface is bent, allowing electrons to flow into the co catalyst without resistance. These synergistic effects lead to the robust hydrogen production of GDY/VS2, which was increased by nearly 10.3 times compared with that of pure GDY. Finally, charge migration at the interface of graphdiyne-metal sulfide heterojunction was proposed and further verified combining in situ XPS and theory calculation. This research marks a significant stride for enhance the efficiency of photocatalytic hydrogen evolution by designing and constructing composite heterojunction materials.

New insights into the remediation of chromium-contaminated industrial electroplating wastewater by an innovative nano-modified biochar derived from spent mushroom substrate: Mechanisms, batch study, stability and application

To enhance the adsorption and detoxification capabilities of hexavalent chromium (Cr(VI)) using agricultural spent mushroom substrate (SMS), this study pioneered the preparation of biochar (NBC) from Lentinus edodes spent substrate. Subsequently, nano iron sulfide (FeS) particles were integrated onto NBC with carboxymethyl cellulose (CMC) as a stabilizer, resulting in a novel composite biosorption material, nFeS-BC. The adsorption and reduction potential of both NBC and nFeS-BC against Cr(VI) were evaluated through batch experiments, which identified pH as a critical factor influencing adsorption efficiency. Remarkably, nFeS-BC exhibited a superior maximum adsorption capacity (qmax) of 99.57 mg g−1 and a reduction efficiency of 68.65%, outperforming NBC by 277.73% and 211.76% under optimized conditions, respectively. Characterization techniques including Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX), Fourier Transform Infrared Spectroscopy (FT-IR), and X-ray Photoelectron Spectroscopy (XPS) elucidated the removal mechanisms, predominantly attributed to ion exchange, electrostatic attraction, functional group interaction, and redox reaction. The carbon-oxygen functional groups and nano particles were crucial in the adsorption and reduction processes. Compared with NBC, the incorporation of FeS particles increased the specific surface area and pore volume of nFeS-BC by 130.86% and 183.77%, respectively. nFeS-BC owned a shelf-life of up to ∼3 months of use and exhibited excellent performance in the processing of actual electroplating wastewater with q of 16.71 mg g−1 under 0.1 g L−1 dosage. These findings underscore the potential of nFeS-BC as an efficient material for Cr(VI) removal, presenting a novel adsorbent for the sustainable detoxification of contaminated water resources and the potential for using agricultural waste materials in environmental remediation.

New insights into sustainable in-situ fixation of heavy metals in disturbed seafloor sediments

To address the issues of plume formation and heavy metal ion release during deep-sea mining operations, this study employed multi-sourced mineral composite roasting materials (MMCCM) of varying sizes. An in-situ capping technique was applied within a simulated system to immobilize heavy metals in contaminated sediments. The results demonstrated that capping with MMCCM of different sizes significantly suppressed the upward migration of Cu, Co, and Ni from sediments into the overlying seawater following disturbance. Ion diffusion was identified as a key mechanism driving heavy metal migration. By calculating the release rates of heavy metals during both the disturbed and undisturbed phases, it was found that the application of MMCCM induced a negative diffusion of heavy metals, indicating that the MMCCM-sediment layer functioned as a "sink" for heavy metals. FTIR and XPS analysis showed that the primary mechanisms for heavy metal removal by MMCCM were electrostatic attraction and complexation-precipitation. Additionally, capping with MMCCM facilitated the transition of heavy metals from labile to stable forms within the sediments. Through comprehensive evaluation, the long-term effectiveness of the fixed effects was demonstrated as follows: large MMCCM (L@MCM) > medium MMCCM (M@MCM) > small MMCCM (S@MCM) > powder MMCCM (P@MCM). Finally, we proposed future research directions and introduced the DQSE framework for the sustainable application of MMCCM. Based on the above findings, this study provides new insights and research references for the in-situ immobilization of heavy metals and plume reduction during future deep-sea mining processes.

Glass-ceramic binder of cordierite composition for low-temperature sintering of high-strength ceramic materials based on oxygen-free silicon compounds

The mechanical properties of composite ceramic materials obtained based on oxygen-free silicon compounds are largely determined by the properties of the glass binder. This paper presents the results of studies aimed at determining the most fusible glass in the pseudo-binary system 2MgO2Al2O35SiO2–2MnO2Al2O35SiO2 with a high tendency to crystallize as a glass-ceramic binder for low-temperature sintering of high-strength ceramic materials based on oxygen-free silicon compounds. The crystallization tendency of the experimental melts decreases with an increase in in the content of manganese cordierite, as confirmed by X-ray and infrared spectroscopic studies. Based on experimental studies, a melting diagram was constructed, which was used to determine the ratio between magnesium cordierite and manganese cordierite (50:50 wt.%), ensuring a minimum melt temperature of 12750C. The melting point of the glass of the specified composition is 14500C. The synthesized glass is characterized by a softening point of 8000C and crystallizes intensively at 10300C. The The thermal coefficient of linear expansion of the crystallized glass samples is 20.810–7 0C–1. X-ray diffraction and electron microscopic studies have shown that the developed glass is almost completely crystallized during heat treatment for 2 hours, forming a cordierite solid solution 2(Mg,Mn)O2Al2O35SiO2. The size of the cordierite phase crystals ranges from 0.5 to 3.0 m. Due to its fusibility and high crystallization tendency, the developed glass, can be proposed as a promising glass-ceramic binder for the production of high-strength ceramic materials (wear and impact resistant) based on SiC and Si3N4 with reduced sintering temperatures.

Proposing Novel Biological Scaffolds for the Regeneration of the Dura Mater

ABSTRACTThe dura mater protects underlying tissues and cerebrospinal fluid, but dural abnormalities can cause leaking and meningitis and wound infections. This review emphasizes the relevance of dural repair and the progress of dural reconstruction materials, focusing on biological scaffolds. A comprehensive assessment of dural substitution literature focused on composite, acellular, natural, synthetic, and homologous materials. Decellularized dura scaffolds as viable natural biomaterials for tissue engineering are explored in this overview of these materials' properties, effectiveness, and therapeutic uses. The evaluation also compares materials and assesses host tissue response in preclinical and clinical studies. The review highlights various dural substitution findings. There is no gold standard for dural repair, despite the variety of materials used. Replicating natural dura mater's mechanical and structural qualities is difficult. Recent research suggests that decellularized dura scaffolds can regenerate tissue while reducing inflammation and transplant rejection. Furthermore, the movement toward personalized medicine in this sector suggests that bespoke alternatives might be chosen depending on patient characteristics, improving treatment effects. Synthesizing dural replacement research and clinical uses in this review adds to knowledge. It tackles standard materials' shortcomings and shows how biological scaffolds might improve dural repair. The analysis opens the door to personalized dural repair research that might enhance patient outcomes and advance neurosurgery. The insights presented herein highlight the intriguing prospects for appropriate dural restorative materials, seeking to improve dural defect treatment.

Hemp fibre reinforced natural rubber bio-macromolecule based biodegradable engineered leather

Out of the diverse industrial applications of hemp fibre, for the first time we report the development of a leather alternative (flexible composite) material by integrating hemp fibre, as a bio-reinforcement and natural rubber (latex) macromolecules, as a matrix. For developing such unique product, primarily, hemp fibre was extracted from the Canabinus sativa L., i.e., industrial hemp plant. The structure and physico-mechanical properties of extracted hemp fibre used for making leather alternative were thoroughly studied. Characterization analysis has underscored that the fibre has crystallinity of around 78 % and composed of mainly cellulose, hemicellulose and lignin. Physical properties of fibre denote that hemp is longer, finer, stronger, higher elongation%, than widely available ligno-cellulosic jute fibre. Natural rubber (latex) biomolecule-based formulation was used as matrices, allowing the hemp fibre content in the flexible composite approximately 38–40 %. Developed flexible composite was then hot-pressed and coloured for mimicking with natural leather. Natural fibre-reinforced-leather with areal density of 250–550 g/m2 were fabricated and were characterized in detail in terms of physical, structural, mechanical, and chemical properties. Tensile and tear strength of the developed leather material lies in between 8 and 9 N/mm2 and 90–110 N, respectively. Moreover, different integral parts of natural rubber based engineered leather were examined by Fourier-Transform-Infrared-Spectroscopy (FTIR), X-ray diffraction (XRD), surface roughness, chemical composition analysis and scanning-electron-microscopy (SEM) techniques to understand the mechanical of interaction among the different component and to suggest the possible chemical reaction among the different macro-molecules, responsible towards good stability of the natural fibre-reinforced-leather structure.

Reduced Graphene Oxide/Silica Based Electrode Material: Synthesis and Characterization

<span lang="EN-US">Developing a Reduced Graphene Oxide (rGO) synthesis method based on rice husk as a composite electrode material with silica has garnered particular attention for designing high-quality electrode materials. This research successfully synthesized rGO-Si material from rice husk-derived activated carbon through a one-step thermal reduction process at 200 °C. This method offers a simple, efficient, cost-effective, and environmentally friendly synthesis approach. The resulting samples' morphology, surface composition, crystal structure, surface area, and pore diameter size were characterized using FE-SEM, EDX, XRD, and SAA-BET. EDX characterization results confirmed the predominance of carbon content in the samples. At the same time, the natural emergence of Si without external addition due to thermal reduction at 200 °C was an intriguing initial finding. The spherical crystal structure of silica between the wrinkled rGO layers was confirmed through FE-SEM and XRD analysis. The synergistic effect between Si and rGO significantly increased the sample's surface area, with a value of 34.17 m<sup>2</sup>/g for the rGO sample before thermal reduction, which increased to 121.24 m<sup>2</sup>/g after the thermal reduction process at 200 °C. This process also positively impacted the reduction in pore size of rGO-Si, with a value decreasing from 9.33 nm before thermal reduction to 4.89 nm after the thermal reduction process. The results of this study demonstrate that rGO-Si synthesized from rice husk-derived activated carbon holds great potential as a high-performance electrode material, combining the advantages of thermal reduction, natural Si content, and increased surface area for diverse applications.</span>

Preparation and Performance Study of PEK‐C‐OH/MWCNT‐COOH/Graphite Composite Bipolar Plates for PEMFCs With Improved Interface Properties

ABSTRACTBipolar plates are an essential part of proton exchange membrane fuel cells, and due to the specificity of their functions, various properties are required. In this study, a composite bipolar plate with a “sandwich” structure was prepared to solve the problems of graphite/resin composite bipolar plate, which is challenging in balancing the electrical conductivity and mechanical properties, and the interface is not tightly bonded. Through the bidirectional modification between graphite‐carbon/nanotubes and resin, the graphite phase and resin phase are connected by chemical bonding, which enhances the direct interfacial bonding performance, effectively broadens the conductive pathway, and improves the mechanical properties. The prepared composite bipolar plate showed a conductivity of 244.01 S/cm, a hydrophobicity angle of 121.4°, a flexural strength of 53.38 MPa, a corrosion current density of 0.76 μA/cm2, and a corrosion voltage density of 0.354 V. The composite bipolar plate showed good performance, and it is expected to be one of the candidates for future graphite/resin composite bipolar plate materials.

Composite energetic materials constructed by metal nitrates and nitro-substituted polymers

Composite energetic materials constructed by metal nitrates and nitro-substituted polymers

Development of two-layer whisker-reinforced PcBN materials for cutting tool applications

This study investigates the polycrystalline cubic boron nitride (PcBN) tool materials with a TiN-Zr based binder without additives (BTZ base material) and with whisker additives (SiCw, Al2O3w, Mg2B2O5w) obtained via high-pressure high-temperature (HPHT) sintering at 7.7 GPa and 2000 °C. The whiskers reinforced composite compacts were produced both in one- and two-layer (sandwich-type) forms. The phase composition, microstructure, physical-mechanical properties and cutting performance of the composite compacts were analysed. The results demonstrate that reinforcing with SiCw leads to the formation of BTZ+SiCw composites with a homogeneous microstructure, high hardness, and Young's modulus, enabling the manufacture of one-layer cutting inserts with an extended tool life of up to 11 min when turning Inconel 718 alloy. Similarly, the BTZ+Al2O3w one-layer material, despite exhibiting slightly lower hardness compared to BTZ+SiCw, still displayed satisfactory wear resistance with a tool life of up to 7 min. Notably, the two-layer (sandwich type) s1: BTZ+SiCw/BTZ+Al2O3w composite cutting inserts exhibited the highest durability, with a tool life of up to 13 min when tested on the SiCw-reinforced side and 8 min on the Al2O3w-reinforced side. In contrast, the BTZ+Mg2B2O5w composite was found unsuitable as a working tool component but shows promise as a substrate layer in two-layer configurations. The study indicates the potential for further development of whisker-reinforced two-layer composite PcBN materials to enhance tool performance and longevity.

Advances in Aerogels Formulations for Pulmonary Targeted Delivery of Therapeutic Agents: Safety, Efficacy and Regulatory Aspects.

Aerogels are the 3D network of organic, inorganic, composite, layered, or hybrid-type materials that are used to increase the solubility of Class 1 (low solubility and high permeability) and Class 4 (poor solubility and low permeability) molecules. This approach improves systemic drug absorption due to the alveoli's broad surface area, thin epithelial layer, and high vascularization. Local therapies are more effective and have fewer side effects than systemic distribution because inhalation treatment targets the specific location and raises drug concentration in the lungs. The present manuscript aims to explore various aspects of aerogel formulations for pulmonary targeted delivery of active pharmaceutical agents. The manuscript also discusses the safety, efficacy, and regulatory aspects of aerogel formulations. According to projections, the global respiratory drug market is growing 4-6% annually, with short-term development potential. The proliferation of literature on pulmonary medicine delivery, especially in recent years, shows increased interest. Aerogels come in various technologies and compositions, but any aerogel used in a biological system must be constructed of a material that is biocompatible and, ideally, biodegradable. Aerogels are made via "supercritical processing". After many liquid phase iterations using organic solvents, supercritical extraction, and drying are performed. Moreover, the sol-gel polymerization process makes inorganic aerogels from TMOS or TEOS, the less hazardous silane. The resulting aerogels were shown to be mostly loaded with pharmaceutically active chemicals, such as furosemide-sodium, penbutolol-hemisulfate, and methylprednisolone. For biotechnology, pharmaceutical sciences, biosensors, and diagnostics, these aerogels have mostly been researched. Although aerogels are made of many different materials and methods, any aerogel utilized in a biological system needs to be made of a substance that is both biocompatible and, preferably, biodegradable. In conclusion, aerogel-based pulmonary drug delivery systems can be used in biomedicine and non-biomedicine applications for improved sustainability, mechanical properties, biodegradability, and biocompatibility. This covers scaffolds, aerogels, and nanoparticles. Furthermore, biopolymers have been described, including cellulose nanocrystals (CNC) and MXenes. A safety regulatory database is necessary to offer direction on the commercialization potential of aerogelbased formulations. After that, enormous efforts are discovered to be performed to synthesize an effective aerogel, particularly to shorten the drying period, which ultimately modifies the efficacy. As a result, there is an urgent need to enhance the performance going forward.

A straw-soy protein composite (SSPC) material: preparation, physical properties and wetting drying stability

The use of bio-based biomass construction materials has the advantage of helping to reduce fossil energy demand, protecting the environment from carbon dioxide emission and reducing the production of non-degradable waste. This paper used resin-modified soy protein (SP) adhesive to combine rice straw stalks, and made straw-soy protein composites (SSPC) material. The physical properties, compressive behavior and stability during wetting drying cycles of SSPC were measured. Due to water evaporation, the SP matrix is full of connected pores, resulting to its physical properties of small density, high shrinkage ratio and low thermal conductivity, which are 0.24 g/cm3, 16.2%, and 0.065 W/(m•K), respectively. Adding straw is helpful to the physical properties of SP matrix, leading to an obvious decrease in shrinkage ratio and thermal conductivity of SSPC, which are 8.51% and 0.075 W/m•K. Furthermore, the compressive load–displacement curves of SSPC groups divide into two types: divergent and convergent. The compressive strength of divergent samples is decided by the critical displacement determined according to the convergent specimens. It shows that straw stalk proves the positive effect on the compressive property of SP matrix. As to the mass of SSPC samples during the wetting drying cycles, it drops apparently in the initial three cycles, and becomes negligible from the fifth cycle, meaning that the stability of SSPC during wetting drying cyclic process is quite good. The research result would be helpful for using SSPC as building material, especially as thermal insulation material.

Expanded graphite encapsulation of nitrates for enhanced thermal transport: Mechanism insight and component screening

The efficient improvement of the heat transfer capability of high-temperature molten salts and the accurate measurement within the operating temperature range is vital for improving the efficiency of concentrating solar power devices. Through theoretical investigation, this paper explores different thermal properties including thermal conductivity, phase transition properties and interfacial interactions using a range of expanded graphite/nitrates (EG/nitrates). Molecular dynamics simulations reveal that the EG/eutectic salt (ES) exhibits optimal comprehensive properties. Experimentally prepared EG/ES composite phase change materials (PCMs), coupled with theoretical predictions, demonstrate exceptional thermal conductivity (2.2 W m−1 K−1) and a significant latent heat of phase change (>80 J g−1). The calculation results of the interaction energy between the host-guest indicate that the strong interaction of the EG to ES restricts the molecule movement, leading to a weak temperature dependence of the thermal conductivity of the EG/ES composite PCM. This contrasts with the conventional understanding of PCM thermal conductivity, which typically exhibits a sharp change during the phase transition from solid state to liquid state. Additionally, the thermal response of 15 wt% EG/ES is increased by 27.2 % compared to pure ES, which effectively helps alleviate local overheating in practical applications. The progress made so far sheds light on the mechanism behind the improved heat transfer and storage performance of nitrate from a microscopic view, offering valuable theoretical insight for developing high-efficient nitrate PCMs in solar thermal power generation systems.

Chemical looping gasification of vinegar residue with enhanced LD slag composite Ca-Fe oxygen carrier for syngas production

Biomass chemical looping gasification (BCLG) is an emerging technology that enables waste co-processing into clean energy. A laboratory-scale vertical fixed-bed reactor was used to conduct CLG experiments with vinegar residue (VR) as a biomass fuel, and the effect of enhanced LD slag composite Ca-Fe material as an oxygen carrier (OC) on the production of syngas from BCLG was investigated. This study analyzed the influence of LD slag proportion, kinds of OC, and operational conditions (temperature, oxygen carrier/biomass (OC/B) ratio, and steam/biomass (S/B) ratio) on gasification performance. Results indicate that the syngas yield under the gasification operating conditions at about 850 °C, OC/B = 1, and S/B = 2.5 obtained 1.36 Nm3/kg, the CCE and CGE achieved about 80.82% and 98.16%, respectively, and the H2/CO molar ratio was as high as 2.57. The OCs multi-redox cycle test revealed that after undergoing 10 redox cycles under the conditions mentioned above, the gas yield, CCE, and CGE were reduced to varying extents, but still maintained impressive reactivity. The mechanism analysis showed that the performance degradation of the LD slag composite Ca-Fe OC during the multi-cycle process was related to its agglomeration due to thermal stress and steam. This study provides a new perspective on the synthesis of low-cost OCs and the co-utilization of solid wastes.

Experimental investigation of a low-temperature packed-bed thermal storage system with graphite-based composite phase change material

Experimental investigation of a low-temperature packed-bed thermal storage system with graphite-based composite phase change material

Influence of Al2O3 - nano filler on the Vachellia Nilotica blended hybrid epoxy composites: a comprehensive analysis of mechanical, viscoelastic, and dielectric behavior

This work presents the influence of Alumina (Al2O3) Nano powder on the mechanical, dynamic, and dielectric properties of the hybrid epoxy resin composite material containing Vachellia nilotica (VN). The hand lay up method was used to make the composite specimens at different volume fractions of the alumina nano particle filler (3, 6, 9, 12, and 15 v/v%). The Vachellia nilotica content was kept at 12 v/v% in all the samples remaining being epoxy resin. The experimental results indicate that the composite with 9 v/v% Al2O3 showed better mechanical and dielectric properties when compared to other volume percentages. The epoxy composite with the highest glass transition temperature and storage modulus was also the one containing 9 v/v% nano filler. Furthermore, the dielectric test demonstrated that the addition of the nano filler strengthened the dielectric strength of the composite. The structural morphology of the composite's tensile fracture was investigated using scanning electron microscopy (SEM) to investigate the interaction between the epoxy matrix and the fillers in the hybrid composites.

Modification of polyurethane latexes of the Aquapol® brand with polymer-polymer complexes for the production of fibrous-porous polymer composite materials

Modification of polyurethane latexes of the Aquapol® brand with polymer-polymer complexes for the production of fibrous-porous polymer composite materials

Sizing modification enhances interfacial compatibility and improves PP/BF mechanical properties of foamed composite materials

Sizing modification enhances interfacial compatibility and improves PP/BF mechanical properties of foamed composite materials

Surface Wettability of Lignin Materials from Supercritical Water Hydrolysis of Wood

To meet the demands of the evolving circular economy, there is a growing need for renewable resources as base materials for innovative, easily recyclable products. Lignin, the second most abundant biopolymer, has emerged as a promising source of aromatics and reinforcing agent in polymer composites. For the successful manufacturing of homogeneous composite materials, good bonding between the coexisting phases is essential to prevent the formation of voids and agglomerates. Therefore, understanding the surface properties of these materials is crucial for designing optimal composite compounds. In this study, the wettability of lignin-cellulose composites and lignin samples obtained through supercritical water hydrolysis (SCWH) of birch wood is investigated. The contact angle (CA) technique, specifically the sessile drop method, was employed to assess and compare the wettability of SCWH lignin with commercially available lignin and raw birch wood. The results provide insights into their surface energy, adhesion, and hydrophilic or hydrophobic characteristics under processing conditions. All samples exhibited hydrophilicity, with an initial CA approximately 40 °, except for raw birch wood, which had a higher initial CA of ~ 64°. Notably, when lignin is accompanied by significant amounts of cellulose, different trends in CA changes over time were observed. The influence of pressure on the CA between water and these polymers was also analyzed, but no significant impact was detected. This research advances the development of lignin-based materials with tailored surface properties for various industrial applications.

The degradation of Sulfamethoxazole using a heterojunction photocatalytic membrane composed of Z-scheme LaFeO3/Ag3PO4@GO: Assessment of activity and degradation mechanisms

We synthesized La-deficient LaFeO3 through a simple hydrothermal method, enhancing the physicochemical properties and catalytic performance of the initial LaFeO3. Subsequently, Ag3PO4 was grown on 0.7 LaFeO3 using electrostatic deposition to obtain composite materials LA-1, LA-2, and LA-3 with different composite ratios, improving the transfer rate of photogenerated charge carriers and reducing impedance. By physically combining LA with GO, a photocatalytic membrane LAG was produced, effectively enhancing the stability and recyclability of the photocatalytic membrane. The photocatalytic membrane LAG-2 achieved an 80.4% SMX degradation efficiency under neutral conditions, with a degradation rate of 76.5% at pH=3. The retention rate for SMX was 82%, with a flux of 106.2L·m-2 h-1 bar-1. Additionally, the flux for CIP reached 530.8L·m-2 h-1 bar-1, with a retention rate of 65.5%. After six cycling experiments, the degradation rate of LAG-2 was 67.4%, and the leaching concentration of iron ions exhibited good performance. SEM analysis reveals that the morphology of the membrane remains intact before and after the cycle, with LAG retaining its integrity and exhibiting excellent mechanical properties. This indicates that the photocatalytic membrane demonstrates good stability and reusability. The excellent integration of the photocatalyst and membrane overcomes the challenge of difficult recovery of the photocatalyst, promising extensive applications and providing new insights for the practical application of photocatalytic degradation of antibiotics.