Functional Composite Materials最新文献

Large-towel carbon fiber (LCF) offers excellent cost-effectiveness and higher processing efficiency, and its development has been rapid. Understanding the engineering constants of large-towel carbon fiber monofilaments is crucial for designers. This paper proposes a method using an angled tensile test deviating from the axial direction to determine the engineering properties of LCF single filaments, including the axial tensile modulus E3 of 218 GPa, the transverse tensile modulus E1 of 67 GPa, and the shear modulus G13 of 42 GPa. Using the Cai-Wu failure criterion, the longitudinal strength X, transverse strength Y, and shear strength S of the carbon fiber filaments were determined to be 4063 MPa, 812 MPa, and 890 MPa, respectively. The ultimate strength values in all directions for the large-towel carbon fiber were also obtained. By processing the experimental data and applying the Weibull distribution, the corresponding parameter values were obtained, and the final parameters were solved using these values. Electron microscope testing was conducted on the large-towel carbon fiber to observe the fracture morphology of the single filaments. The results indicated that the structure of the large-towel carbon fiber, as observed macroscopically, consists of a shell-and-core structure.

Developing advanced polymeric composites is pivotal for enhancing the performance and sustainability of materials used across various industries, including the electrical sector. This study investigates isophthalic-polyester composites reinforced with clay feldspar, calcite, and glass fiber powder for their mechanical, electrical, thermal, and morphological properties. Compression tests showed that IsoFG50 (fiberglass power) exhibited the highest mechanical strength, with a 24% increase in compressive stress (140 MPa) and a 60% increase in modulus of elasticity. In contrast, IsoCF50 (clay feldspar) showed the lowest tensile strength, decreasing from 40 MPa (pure polymer) to 15 MPa. Electrical conductivity tests confirmed that all composites exhibited insulating behavior (conductivities in the range of 10^− 6 Ω⁻¹ m^− 1), ensuring suitability for electrical applications. SEM (scanning electron microscopy) analysis showed that IsoFG50 had a well-distributed glass fiber network, which improved mechanical integrity, while IsoCF50 had weak matrix adhesion with visible gaps. Contact angle measurements showed that IsoCF50 and IsoFG50 had a contact angle of over 90°, confirming hydrophobicity. Flammability tests classified all reinforced composites as non-flammable, underlining their applicability in the electrical sector. These results emphasize the potential of polyester composites with mineral fillers for insulating applications, protective components, and structural elements in electrical systems. The improved mechanical properties, electrical insulation, and resistance to environmental stresses indicate that they represent a sustainable alternative to conventional materials for electrical applications. Future research should focus on optimizing filler dispersion and improving interfacial adhesion to maximize the performance of the composites.

The glass fiber / polyether ether ketone (GF / PEEK) prepregs were successfully prepared using both conventional hot melt (G-PEEK-M) and proposed slurry processing (G-PEEK-S) methods. The mechanical responses of the GF / PEEK prepreg were significantly improved compared to pure PEEK. The tensile strength and modulus of G-PEEK-S has increased by 71% and 83%, respectively, as compared to pure PEEK. Cross-sectional (edge view) scanning electron microscope (SEM) images clearly show that the PEEK polymer has impregnated the woven glass fibers, forming a strong interpenetrating network structure in the G-PEEK-S prepreg, which is categorically absent in G-PEEK-M. UV-vis and FTIR spectroscopy were employed to estimate the chemical interaction between glass fiber and PEEK polymer, and the XRD measurements was used to analysed the microstructural changes after the incorporation of the glass fiber in polymer matrix. The glass transition temperature (T_g), measured using dynamic mechanical analysis (DMA) by assessing the material’s response to an oscillatory force across a range of temperatures, has increased to 157 °C in G-PEEK-S, significantly higher than the T_g of pure PEEK (135 °C). The storage (Gʹ) and loss modulus (Gʺ) of the G-PEEK-S prepregs are 2020 MPa and 57.5 MPa, respectively, showing a 137% rise in Gʹ and a ⁓218% increase in Gʺ as compared to pure PEEK (Gʹ = 854 MPa, Gʺ = 18.1 MPa) at the same temperature (30 °C). Rheological analysis involves in the measurements of flow and deformation characteristics of materials under various conditions, such as different shear rates, temperatures, times and frequencies. The viscosities of PEEK, G-PEEK-M, and G-PEEK-S are found to be 5.1 × 10³, 19.6 × 10³, and 30.4 × 10³ Pa.s, respectively, showing no significant change in viscosity for GF/PEEK prepregs over time, while a gradual reduction was observed in pure PEEK.

Graphical abstract

Wastewater treatment has become a trending environmental concern because the water crisis is a crucial concern. In this study, Graphene-iron composites were synthesized by different processes, and a comparative analysis was done for the best-optimized process; the efficacy of treating wastewater by adsorption and advanced oxidation (ozonation and Fenton oxidation) in removing polyaromatics was evaluated. The characteristics of the obtained iron nanocomposites were evaluated using different compositions and physicochemical and mechanical characteristics such as FTIR, SEM, TGA, DSC, and DTA. Various parameters like pH, the concentration of adsorbent, and adsorbent dosage were also assessed, which intimates that Graphene-iron composite using adsorption study has shown the removal using phenol and naphthalene of about 35% and 40% with optimum pH 8, adsorbent dosage 90 mg/ml, adsorbate concentration 180 mg/L; Fenton oxidation results depicted a removal of 50% and 60% with optimum pH 7–8, with concentration 5 mg/L at 15 min, and Ozonation intimated a removal of 40% and 45% with optimum pH 7–8 maintaining a concentration of 100 mg/L at 35 min which evaluated that the composites have been the potential adsorbents for current wastewater treatment and can be further used in the purification of drinking.

Graphical Abstract

Atomic-scale characterization is pivotal in elucidating structure–property relationships across quantum materials, energy systems, and biological nanostructures. This review critically examines recent advances in high-resolution imaging, aberration-corrected TEM/STEM, cryo-EM, scanning probe microscopy (SPM), and helium ion microscopy (HIM), alongside spectroscopies such as electron energy loss spectroscopy (EELS), tip-enhanced Raman spectroscopy (TERS), and atom probe tomography (APT). Particular focus is placed on their integration with in-situ/operando environments and AI-driven workflows, enabling real-time, multimodal analysis at sub-ångström resolutions. We propose a unified framework combining machine learning, unsupervised clustering, and automated data pipelines to accelerate insight extraction and materials design. Case studies highlight this convergence: perovskite solar cells reached 25.7% efficiency through defect passivation guided by TEM; silicon–carbon anodes retained over 80% capacity across 1,000 cycles via nanostructure-informed optimization; cryo-EM resolved biomolecular assemblies below 2 Å with direct electron detection; and 4D-STEM enabled atomic-scale 3D reconstructions in cathodes with 0.3 nm precision. These tools have revealed critical structure–function linkages, such as lithium heterogeneity in nickel-manganese-cobalt (NMC) cathodes driving capacity fade, and PbI₂ segregation at perovskite grain boundaries impairing photovoltaic performance. Persistent challenges-resolution-dose tradeoffs, dataset reproducibility, and global disparities in instrumentation access are also assessed. Future directions include quantum-enhanced metrology and cloud-based remote experimentation. This review presents an integrated, forward-looking perspective on the fusion of atomic-scale metrology and autonomous experimentation, outlining a strategic roadmap to accelerate materials discovery while foregrounding sustainability, equity, and open-access principles often overlooked in prior literature.

Graphite is considered a critical mineral by many countries due to its strategic importance, especially as an anode material in lithium-ion batteries. Natural graphite is preferred over synthetic forms for its lower carbon footprint. However, it typically occurs with aluminosilicate-based impurities (gangue) and requires beneficiation. With the shift from flake to microcrystalline graphite (MG) ores, traditional froth flotation becomes ineffective due to fine particle size and gangue entrapment, while chemical methods pose environmental and economic concerns. As a result, low-grade MG ores often remain unprocessed.

In this study, we present a novel, environmentally benign beneficiation method based on evaporation-assisted film flotation, which leverages the hydrophobicity of microcrystalline graphite and small size to form a thin film at the liquid–air interface, avoiding gangue entrapment. A low-grade MG ore was characterized, revealing a carbon content of 6.3 at% and natural graphitic flake size of 320 ± 200 nm. One gram of crushed raw ore powder was dispersed in 50 mL of 2.5 M NaOH and stirred at different temperatures (40 °C, 60 °C, and 80 °C) for 12 and 24 h. The optimal condition (60 °C for 24 h) for the current setup yielded a recoverable floating film of 3.01 wt%. Characterization of this film fraction showed a tenfold increase in carbon content (60.9 at%) and particle size of 643 ± 200 nm. These results demonstrate the effectiveness of the proposed film-flotation method for beneficiating low-grade microcrystalline graphite.

This study systematically evaluated the elastic recoverability of bitumen during laboratory ageing processes. Two types of unmodified (neat) bitumen and one type of SBS polymer modified bitumen (PMB) were employed in this study. The monotonic elastic recovery measured by a DSR at a consistent shear rate of 2.315 s-1, the binder yield energy, and the multiple stress creep and recovery (MSCR) tests were carried out. Based on the results, it was seen that the elastic recoverability of neat bitumen increased continuously with ageing degrees, while it increased then decreased for PMB due to the simultaneous physical hardening and polymer degradation. Different testing methods generally showed consistent trends and strong correlations. The MSCR test was identified to be inappropriate for characterising the elastic recoverability of PMB, as the nine-second recovery period was insufficient for PMB to fully recover.

Self-healing composites are innovative materials designed to autonomously repair damage and restore functionality, offering a sustainable alternative to traditional thermosetting materials. These materials enable self-repair without external intervention, extending service life and reducing maintenance costs. Recently, bio-based self-healing composites comprising matrices and fillers derived from renewable resources such as polysaccharides (e.g., cellulose), lignin, vegetable oils, and vanillin have emerged as a promising solution to reduce dependence on non-renewable petroleum-based materials. This review delves into the advancements in bio-based self-healing composites, with a focus on systems utilizing dynamic covalent bonds (e.g., hydroxyl ester, Schiff base, disulfide bonds) and dynamic non-covalent interactions. It explores diverse self-healing mechanisms, including supramolecular chemistry, covalent bond reformation, diffusion and flow, heterogeneous systems, and shape-memory effects, as well as their synergistic combinations. The discussion spans both physical and chemical approaches, highlighting integrated physico-chemical strategies. Furthermore, the review examines state-of-the-art fabrication techniques and the broad range of applications for these materials. Future perspectives and research directions underscore the pivotal role of bio-based self-healing composites in advancing sustainable and durable solutions across multiple industries.

Basalt fiber reinforced polymer composites (BFRP) are widely applied in sectors such as aerospace, rail transportation, construction, and energy. However, developing BFRP with effective damage self-sensing capabilities remains a major technical challenge. This study utilized basalt fiber (BF) as both a reinforcement and volume exclusion phase to improve the mechanical and electrical properties of BF/carbon nanotube (CNT)/polyarylene ether nitrile (PEN) composites, aiming to achieve damage self-sensing functionality. The CNT content in BF/CNT/PEN was fixed at only 0.5 wt%. As the BF content increased from 10 wt% to 50 wt%, the mechanical properties of the BF/CNT/PEN composites improved, with tensile strength, flexural strength, and flexural modulus increasing by 39.0%, 26.3%, and 167.7%, respectively. Additionally, the electrical conductivity of composites with 40 wt% BF increased by three orders of magnitude compared to that with 10 wt% BF. Combined with acoustic emission (AE) monitoring, it was confirmed that composites with 40 wt% BF demonstrated excellent damage self-sensing and fracture warning capabilities under tensile and bending stress. This study not only improved the mechanical properties but also enhanced the electrical conductivity of the BFRP without the need for additional conductive materials, thereby ensuring effective damage self-sensing functionality. These results offer valuable insights for developing high-performance, multifunctional BFRP.

This study investigates the effects of fiber concentration and the stacking sequence of laminae on the mechanical properties of a sisal-reinforced polyester composite. The mechanical properties, such as the tensile, flexural, and impact strength were characterized for laminated composite with different fiber concentrations and stacking sequences of lamina after they were processed using the hand layup weaved method. In addition to the mechanical properties, morphological analysis was done. Specimens with different fiber concentrations and stacking sequences were prepared using a manual compression molding technique that provides a flat plate with a thickness of 5 mm. The results showed that 40 wt% of sisal fiber-reinforced composites with 90/0/45 staking sequence have shown the maximum tensile (68.409 MPa), flexural (64.276 MPa), and impact (67.71 MPa) strength, and laminated composite with 90/0/45 staking sequence has shown superior tensile, flexural and impact properties as it compared with randomly oriented and non-woven fiber reinforced composite. The microstructure showed that a better interface adhesion was observed at 40 wt% of fiber and 90/0/45 staking sequence. Therefore, 90/0/45 laminated composite materials can be proposed for engineering applications that require equivalent properties, including automobile front-fender applications.