Multi-walled carbon/IF-WS2 nanoparticles with improved thermal properties

Chemically activated core–shell structured IF-WS2@C nanoparticles enhance sugarcane-based carbon/epoxy nanocomposites

Ternary composites have demonstrated better capability than binary composites in enhancing the mechanical properties of the modified epoxy resins and are, therefore, currently under intensive investigation. Herein, we report a novel ternary nanocomposite prepared by filling a binary BPF (bisphenol F epoxy resin)/SCPs (sugarcane-based carbon powders) matrix with C-coated inorganic fullerene-like tungsten disulfide (IF-WS₂@C) nanoparticles, and the analysis of its interface synergetic effect using XPS/FTIR. This activated nano-carbon core–shell structure filler is considered an ideal nanofiller and shows the excellent mechanical performance of the ternary composites. XRD, IR, XPS, SEM, and TEM characterizations were applied in investigating this nanocomposite. The improvement of the thermal and mechanical properties demonstrated the enhancement effects of this nanofiller. The results show that the great improvement of the bending modulus of 39.4% increased with the addition of 0.5 wt% IF-WS₂@C nanoparticles, while 34.1% enhancement of bending strength was obtained with the addition of 0.2 wt% IF-WS₂@C nanoparticles. The hardness and thermal conductivity were also boosted up to 5.2% and 33.1% with 0.5 wt% addition, respectively. The incorporation of a chemically activated coating may provide a novel means for improving graphite crystallization, which could somehow expand the potential application of IF-WS₂@C nanoparticles.

Schematic diagram and typical curing mechanism of epoxy resins and the unique interactions of the IF-WS₂@C nanoparticles introduced into the matrix.

Laser-Directed Assembly of Nanorods of 2D Materials

Herein, the previously unrealized ability to grow nanorods and nanotubes of 2D materials using femtosecond laser irradiation is demonstrated. In as short as 20 min, nanorods of tungsten disulfide, molybdenum disulfide, graphene, and boron nitride are grown in solutions. The technique fragments nanoparticles of the 2D materials from bulk flakes and leverages molecular scale alignment by nonresonant intense laser pulses to direct their assembly into nanorods up to several micrometers in length. The laser treatment process is found to induce phase transformations in some of the materials, and also results in the modification of the nanorods with functional groups from the solvent atoms. Notably, the WS₂ nanoparticles, which are ablated from semiconducting 2H WS₂ crystallographic phase flakes, reassemble into nanorods consisting of the 1T metallic phase. Due to this transition, and the 1D nature of the fabricated nanorods, the WS₂ nanorods display substantial improvements in electrical conductivity and optical transparency when employed as transparent conductors.

Oxidation of 2D-WS2 nanosheets for generation of 2D-WS2/WO3 heterostructure and 2D and nanospherical WO3

Evolution of 2D-WS₂/WO₃ heterostructures as well as 2D and nanospherical WO₃ during the oxidation of WS₂ nanosheets in air.

A generic method to synthesise graphitic carbon coated nanoparticles in large scale and their derivative polymer nanocomposites

A versatile Rotary Chemical Vapour Deposition (RCVD) technique for the in-situ synthesis of large scale carbon-coated non-magnetic metal oxide nanoparticles (NPs) is presented, and a controllable coating thickness varying between 1–5 nm has been achieved. The technique has significantly up-scaled the traditional chemical vapour deposition (CVD) production for NPs from mg level to 10 s of grams per batch, with the potential for continuous manufacturing. The resulting smooth and uniform C-coatings sheathing the inner core metal oxide NPs are made of well-crystallised graphitic layers, as confirmed by electron microscopy imaging, electron dispersive spectrum elemental line scan, X-ray powder diffractions and Raman spectroscopy. Using nylon 12 as an example matrix, we further demonstrate that the inclusion of C-coated composite NPs into the matrix improves the thermal conductivity, from 0.205 W∙m⁻¹∙K⁻¹ for neat nylon 12 to 0.305 W∙m⁻¹∙K⁻¹ for a 4 wt% C-coated ZnO composite, in addition to a 27% improvement in tensile strength at 2 wt% addition.

Novel graphitic carbon coated IF-WS2reinforced poly(ether ether ketone) nanocomposites

Unique high performance thermoplastic PEEK ternary nanocomposites reinforced by nano graphitic carbon coated IF (inorganic fullerene-like)-WS₂have been prepared and their structures have been characterised by XRD, EDX and HR-TEM.

Ultra-toughened nylon 12 nanocomposites reinforced with IF-WS2

Inorganic fullerene-like WS2 nanoparticle- (IF-WS2) reinforced nylon 12 nanocomposites have been prepared through effective ultrasonic mixing without using any surfactant, followed by molding at 220 °C. Morphological characterizations using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and microcomputed tomography (micro-CT) have revealed the excellent dispersion of IF-WS2 nanoparticles in the nylon 12 matrix. X-ray diffraction (XRD) analyses have confirmed that a phase transition from α'-phase to a more stable γ-phase took place during the sintering of nylon 12, regardless of the amount of IF-WS2 added to the matrix. At a very low IF-WS2 content of 2 wt%, the tensile strength and bending strength of the composites increased slightly by 27% and 28%, respectively. However, the toughness dramatically improved by 185% and 148% at IF-WS2 additions of 0.25 and 0.5 wt%, respectively, when compared to the neat nylon 12. It is believed that such improvements should mainly be attributed to the well-dispersed IF-WS2 within the matrix. The vastly improved toughness suggests that the resulting polymer nanocomposites could be promising for structural and high-performance impact applications.