Advanced Composites and Hybrid Materials最新文献

The exceptional properties of carbon nanoparticles, such as graphene, promise to expand the performance and functionality of many materials. The reinforcement of polymers is of keen interest due to their low density and flexible manufacturing methods. However, dispersing graphene in them has proven to be an enduring challenge due to the particles’ propensity to form performance-degrading agglomerations. Furthermore, effective solvents for nanoparticle dispersion are commonly harmful, non-renewable, petrochemicals. In this work, a bio-derived solvent, 1,4-cineole, is demonstrated as a renewable alternative to these solvents that can be used to form highly stable graphene nanoplatelet (GnP) suspensions and used to gel spin well-dispersed UHMWPE/GnP nanocomposite fibers. The GnP concentration in the fibers was varied across three orders of magnitude, 0.01 to 1 wt%, to examine its effect on fiber microstructure and properties. At low concentrations, the particles act as point defects without affecting the fiber microstructure, and poor particle/matrix interfacial adhesion results in significantly reduced mechanical properties. At 1 wt% GnPs, a network effect takes hold thereby reinforcing the fibers, but the particles also impede the growth and orientation of crucial load-carrying crystalline structures in the fiber. Unveiling the microstructural effects of GnPs on highly oriented and crystalline polymers in this study provides crucial insights for future work developing high-performance polymer nanocomposite fibers.

The development of stretchable bacterial cellulose (BC)–based nanocomposites with enhanced mechanical strength holds significant potential for biomedical applications. The study utilized the cost-effectively produced BC by using coconut waste as the carbon source and utilized an ex situ approach to synthesize BC-based composites by incorporating cactus gel (BC-C) and multiwalled carbon nanotubes (BC-MWCNT) alone and together (BC-C-MWCNT). Field emission scanning electron microscopy (FE-SEM) revealed porous and fibrous morphology of BC and successful impregnation of cactus gel and MWCNTs into its matrix. Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analyses confirmed successful additives integration, with thermogravimetric analysis (TGA) demonstrating improved thermal stability. Mechanical behavior analysis via tensile testing demonstrated significant improvements in both tensile strength and elongation properties with the addition of cactus gel and MWCNTs. While cactus gel enhanced elongation to 17.03%, MWCNTs primarily increased tensile strength to 146.30 MPa, resulting in a balanced enhancement in BC-C-MWCNT nanocomposite. Full-field strain analysis using the three-dimensional digital image correction (3D-DIC) method provided insights into the failure mechanisms and strain localization. BC-C-MWCNT nanocomposite exhibited a combination of ductile and brittle failure modes, with enhanced strength and elongation compared to pristine BC. The BC-C-MWCNT nanocomposites demonstrated notable antibacterial activity against Escherichia coli and Staphylococcus aureus. In vitro biocompatibility assessments with NIH 3T3 cells showed superior cell proliferation and spreading for BC-C and BC-C-MWCNT composites. In conclusion, the incorporation of cactus gel and MWCNTs into the BC matrix significantly enhanced its structural, mechanical, antibacterial, and biocompatible properties, making it a promising biomaterial for advanced biomedical applications.

In recent decades, the concentration of pharmaceutical residues and narcotics has increased in municipal wastewater. Decomposing these toxic organic chemicals is challenging and requires new techniques and advanced catalytic materials. Precursors of metal composites were prepared by calcining an aqueous suspension of natural clay–based kaolin with Mn and Cu, binding chemically the active metals to the aluminosilicate frame structure of the precursor. The specific surface area of Mn and Cu composite was 67 m²/g and 81 m²/g, respectively. The mechanical durability was determined in terms of compressive strength, and 3.3 MPa and 3.6 MPa were obtained, respectively. In the CWAO of pharmaceutical wastewater, Mn composite gave the highest conversions of 54% and 46% of the chemical oxygen demand (COD) and total organic carbon (TOC), respectively. Metal composites were mechanically and chemically highly durable, inducing only 1.2 wt.% and 1.4 wt.% mass loss. In CWAO, Mn and Cu composite increased the biodegradation of organic species in the wastewater by 65% and 75%, respectively.

Long-distance space missions encounter a significant hurdle in the form of space radiation, which calls for effective radiation shielding materials to protect astronauts and critical equipment. It is in response to this challenge that we developed the first-ever example of pure boron nitride nanotube (BNNT) woven textiles. For this, we prepared wet-spun aromatic amide polymer (AAP) and BNNT (AB) composite threads using the lyotropic molecular self-assembly (LMSA) method. The 1D AB threads provide the necessary continuity and pliability to easily fabricate macroscopic 2D woven textiles. Finally, we successfully developed 2D BNNT woven textiles by applying the soft domain selective degradation (SDSD) process, which selectively removes only the thermally labile organic domain of AAP. This process ensures the retention of the 1D fibrous structure of the thermally stable inorganic domain of BNNT. The resulting pure BNNT woven textile exhibits thermal neutron shielding performance (0.48 mm⁻¹) and outstanding thermal resistance (1350 °C), making it a promising material for space applications.

Graphical Abstract

The pure BNNT thread-based woven textiles, created using the lyotropic molecular self-assembly method and soft domain selective degradation process, offer an innovative solution to protect both astronauts and critical electronics from the hazards of space radiation at extreme temperature.

Three-dimensional (3D) printing is a prominent technology across various industrial sectors, and its increasing popularity urgently calls for sustainable 3D printing materials. However, the availability of such materials remains under exploit. Here, we present a low-cost strategy to harnesses waste papers as a feedstock to develop sustainable 3D printing inks. This approach offers a remarkable printability and circular utilisation of biodegradable paper wastes to produce 3D printed constructs, with desired mechanical properties and shape stability for high temperature applications. Our constructs can be efficiently recycled into inks for reprinting, and our method can be applied to various types of waste papers. By employing multi-material printing, our approach can be extended to produce multi-coloured constructs, security information printings, and mechanically appealing designs. This strategy offers an innovative and sustainable solution that addresses the need for repurposing paper wastes, which would otherwise end up in landfills, while concurrently reducing the reliance on virgin plastics for 3D printing.

Recently, there has been a noteworthy development in the realm of metal–organic frameworks (MOFs) showcasing their potential as efficient materials for triboelectric nanogenerators (TENGs) designed to harvest ambient mechanical energies. Hence, many researchers are trying to synthesize a new cubic metal–organic framework (MOF-5) applied composite for TENG. To address this challenge, a strong electron-donating surface functional group is introduced herein. This paper designs and synthesizes MOF-5 integrated with graphene quantum dots (GQDs) through a surface modification doping strategy. Here, the incorporation of oxygen-containing functional groups within GQDs into MOF-5 (GQDs@MOF-5) boasts strong electron positivity to lead to a significant enhancement in the electrical output of MOF-5-based TENG. In addition, these functional groups allow tailored interactions with metal ions and organic ligands in MOF-5, creating additional pores and channels within GQDs@MOF-5 and enhancing its overall performance. Since the GQDs@MOF-5 has improved surface properties and electron-donating capabilities, the proposed TENG is achieving a remarkable eight-fold increase (~378.51 μW/cm² to ~2971.80 μW/cm²), in power density compared with unmodified MOF-5 TENGs. Notably, the voltage and current outputs have reached record highs at ~885 V and ~84 µA, respectively. The proposed GQDs@MOF-5-based TENG can be applied to various applications such as energy harvesting, physiological motion monitoring, and vehicle speed recognition. The proposed work can also open a new gate enhancing oxygen vacancies and porosity in triboelectrification.

Heteroatom doping represents an innovative strategy for finely tuning a catalyst’s electronic structure and kinetics for efficient water splitting. We synthesized a novel electrocatalyst of copper-doped zinc cobalt sulfide nanosheets (Cu-ZnCoS/NF) via a hexamethylenetetramine-assisted hydrothermal process. The resulting catalyst exhibits exceptional performance, with minimal overpotentials for both the hydrogen evolution reaction (HER 119/217 mV) and the oxygen evolution reaction (OER 210/280 mV) at 20 and 50 mA cm⁻², respectively, in an alkaline environment. The water electrolyzer/anion–exchange membrane (AEM) electrolyzer containing Cu-ZnCoS/NF as both cathode and anode operate at a low voltage of 1.51 V/1.88 V, respectively, for several hours. The density functional theory (DFT) and electrochemical tests reveal that modulation of the electronic structure optimizes intermediate adsorption energy, enhances electroactive centers, and facilitates charge transfer of the water-splitting process. These findings pave the way for exploring similar catalysts as robust electrocatalysts for practical electrolyzer devices.

Due to their great potential in saving weight, carbon fiber–reinforced epoxy composites are receiving great interests for the liquid oxygen (LOX) cryotank as the largest component in the spacecraft propulsion system. However, the application of epoxy resins as matrices in LOX composite cryotanks is severely constrained by their LOX incompatibility and poor cryogenic mechanical properties. To address these issues, two-dimensional MXene nanosheets as multifunctional fillers are introduced into an epoxy resin, and the effects of MXene on the cryogenic mechanical properties and liquid oxygen compatibility of the epoxy resin are comprehensively examined. It is interestingly observed that the mechanical properties at both room temperature (RT) and cryogenic temperature (90 K) of the epoxy resin, including tensile strength, elastic modulus, and fracture toughness, are significantly enhanced with the addition of low content MXene; and the MXene/epoxy nanocomposite with 0.10 wt.% MXene exhibits the optimal mechanical performances. MXene is also effective in enhancing the LOX compatibility of the epoxy, and the MXene/epoxy nanocomposite with 0.20 wt.% MXene completely passes the LOX impact test. In overall, the MXene/epoxy nanocomposite with simultaneously enhanced cryogenic mechanical properties and LOX compatibility is promising for applications in LOX composite tanks.

Graphical Abstract

Luminescent gold nanoparticles (L-AuNPs) with diameters exceeding 2 nm hold great promise for biomedical imaging due to their unique optical properties and excellent biocompatibility. However, they typically exhibit weak photoluminescence (PL) because of surface plasmon resonance (SPR) effects. Moreover, conventional synthesis of L-AuNPs, often through thermal or chemical reduction, tends to be complex and labor-intensive. It is crucial, therefore, to develop more straightforward synthesis methods that enhance PL emission efficiency. Herein, we introduce a facile photochemical method for synthesizing highly luminescent AuNPs coated with 2-n-hexylthio-1,3,4-thiadiazole-5-thiol (L-AuNP@HTT). These nanoparticles, with a diameter of 3.19 nm, exhibit outstanding optical properties, including a high quantum yield (φ ~ 12%), an extremely long luminescence lifetime (~ 1 µs), a symmetric PL spectrum, and a narrow full width at half maximum (FWHM ≤ 49 nm). They also feature an exceptionally large two-photon absorption cross-section (σ), reaching up to 8.0 × 10⁴ GM (1 GM = 10⁻⁵⁰ cm⁴ s photon⁻¹). Upon encapsulation in a polymer matrix (p-AuNPs), the TPA cross-sections were further enhanced to 1.1 × 10⁸ GM. These p-AuNPs demonstrated high photostability and efficient targeting to mitochondria, making them highly effective for mitochondrial-targeted two-photon excited luminescence (TPEL) imaging. Deep-tissue time-gated TPEL imaging and in vivo computed tomography (CT) imaging have also been achieved with p-AuNPs. This work establishes a straightforward synthesis route for highly luminescent gold nanoparticles larger than 2 nm, significantly broadening their potential in various bioimaging applications.

The fabrication of nano-materials with delicate microstructure design and suitable multicomponent allocation is considered as a promising approach to meet the requirements of lightweight, high efficiency, and broadband absorption for electromagnetic wave (EMW) absorbers. Toward this end, nickel/carbon@zirconium dioxide core–shell nanofibers composited with polyurethane were successfully prepared through flexible electrospinning, carbonization, and a subsequent resin curing process. Profiting from the synergistic coactions of constituents and unique morphology, the ternary nanocomposites displayed the minimum reflection loss of − 61.7 dB at 17.1 GHz, and an ultra-broad bandwidth up to 8.3 GHz. In-depth investigation through electromagnetic parameters analysis and electric field distribution simulation indicated that the introduction of zirconium dioxide brought about the optimal impedance matching, while the existence of nickel and abundant heterogeneous interfaces contributed to diverse attenuation pathways, including interface polarization, dipoles polarization, conductivity loss, and magnetic loss. Thus, this study paved new research avenues for the design and synthesis of one-dimensional high-performance microwave absorbing materials, and enriched the application range of polyurethane matrix composites.