X-Ray Photoelectron Spectroscopy and Tribology Studies of Annealed Fullerene-like WS2 Nanoparticles

Kopnov, F.; Tenne, R.; Späth, B.; Jägermann, Wolfram; Cohen, Hagai; Feldman, Yishay; Zak, Alla; Moshkovich, A.; Rapoport, L.

doi:10.1007/978-1-4020-8903-9_3

Cited by 3 publications

(3 citation statements)

References 15 publications

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“…This shift shows that the interlayer spacing in the NTs is larger than that of WS 2 flakes, which was attributed in the past to relaxation of the bending strain in the NTs . Peaks occurring at higher angles, such as those corresponding to (006) and (112) planes, are related to the elongated periodic layered structure of the NT, therefore generating broader and less intense peaks in the spectra. , …”

Section: Resultsmentioning

confidence: 88%

“…3 Peaks occurring at higher angles, such as those corresponding to (006) and (112) planes, are related to the elongated periodic layered structure of the NT, therefore generating broader and less intense peaks in the spectra. 49,50 Basal planes such as (101) and (103) have higher intensities and broadened peaks, which identify with the 3D atomic structure of cylindrical NTs, analogous with their carbon NT counterparts, due to the similarity in the nanostructure. 51 Figure 5b shows the XRD profile of the WS 2 NTs post-TGA− MS analysis, clearly identifying a significant change in crystallographic plane alignment.…”

Section: Resultsmentioning

confidence: 99%

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WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Magee

Tang

Ozdemir

et al. 2022

ACS Appl. Nano Mater.

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Multi-walled WS 2 nanotubes (NTs) with lengths ranging from 2 to 65 μm and widths from 50 to 110 nm were synthesized in a horizontal quartz-made reactor by a process yielding NTs with aspect ratios (ARs) between ∼40 and >1000. The NTs obtained were thermally stable in air up to 400 °C but were oxidized within the temperature range 400−550 °C to produce yellow WO 3 particles. Critically, 400 °C is well above the temperature used to mix additives with the majority of meltprocessable polymers. The hydrophilic WS 2 NTs were easily dispersed in poly(lactic) acid (PLA) using a twin-screw extruder, but the shear stresses applied during melt mixing resulted in chopping of the NTs such that the AR decreased by >95% and the tensile mechanical properties of the PLA were unchanged. Although the as-extruded unfilled PLA was >99% amorphous, the much-shortened WS 2 NTs had a significant effect on the crystallization behavior of PLA, inducing heterogeneous nucleation, increasing the crystallization temperature (T c ) by ∼3 °C and the crystalline content by 15%, and significantly increasing the rate of PLA crystallization, producing smaller and more densely packed spherulites. The reduction in the AR and the nucleating effect of WS 2 NTs for PLA are critical considerations in the preparation, by melt mixing, of composites of rigid 1D NTs and polymers, irrespective of the target application, including bone tissue engineering and bioresorbable vascular scaffolds.

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Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Magee

Tang

Ozdemir

et al. 2022

ACS Appl. Nano Mater.

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“…Also, similar to graphite, the layers are held together by weak Van der Waal forces, which allow the sulfides to be used as a solid state lubricant. 44 Fundamental investigations have afforded a deep understanding of the factors that govern the activity of these layered metal sulfide catalysts, enabling the improvement of their performance in large scale applications. 32,34,35,37,[45][46][47][48] Several studies have reported that the basal plane of these structures is inert, whereas the catalytically sites are located on the edge planes.…”

mentioning

confidence: 99%

Correlating Microstructure and Activity for Polysulfide Reduction and Oxidation at WS₂Electrocatalysts

Stephens

Ducati

Fray

2013

J. Electrochem. Soc.

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The polysulfide reduction and oxidation activity of WS2 electrocatalysts was studied. This was undertaken with a specific view to improve the efficiency of the polysulfide-bromine redox flow battery, for large scale energy storage. Using data from the literature, it is estimated that the catalysts would require exchange current densities of ∼0.7 to 1 mA cm−2 true microscopic surface area to enable them to become economically viable. The experiments were performed upon three different forms of WS2: platelet like particles of the 2H polytype of WS2 (2H-WS2), ball milled WS2 and inorganic fullerene-like WS2 (IF-WS2). The catalysts were characterized ex-situ using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray analysis and N2 gas adsorption methods. Electrochemical measurements were performed at 35°C, in aqueous solutions of 1.8 M Na2S2.47 and 1 M NaOH, simulating the operating conditions of a half-charged polysulfide-bromine redox flow battery. The catalyst activity increased in the following order: IF-WS2 < 2H-WS2 < ball milled WS2. We attempt to rationalize this trend on the basis of the morphological features observed ex-situ. The exchange current density of the ball milled WS2, at ∼0.012 mA cm−2, falls short of the estimated target by a factor of ∼60 to 70.

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Experimental Methodologies for the Characterization of Nanoparticles

Singh

2016

Engineered Nanoparticles

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X-Ray Photoelectron Spectroscopy and Tribology Studies of Annealed Fullerene-like WS2 Nanoparticles

Cited by 3 publications

References 15 publications

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Correlating Microstructure and Activity for Polysulfide Reduction and Oxidation at WS₂Electrocatalysts

Experimental Methodologies for the Characterization of Nanoparticles

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X-Ray Photoelectron Spectroscopy and Tribology Studies of Annealed Fullerene-like WS2 Nanoparticles

Cited by 3 publications

References 15 publications

WS2 Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

WS2 Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Correlating Microstructure and Activity for Polysulfide Reduction and Oxidation at WS2Electrocatalysts

Experimental Methodologies for the Characterization of Nanoparticles

Contact Info

Product

Resources

About

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

WS₂ Nanotubes as a 1D Functional Filler for Melt Mixing with Poly(lactic acid):Implications for Composites Manufacture

Correlating Microstructure and Activity for Polysulfide Reduction and Oxidation at WS₂Electrocatalysts