The Experts below are selected from a list of 3627 Experts worldwide ranked by ideXlab platform
Jean-paul Lellouche - One of the best experts on this subject based on the ideXlab platform.
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Tungsten Disulfide-based nanocomposites for photothermal therapy
Beilstein journal of nanotechnology, 2019Co-Authors: Tzuriel Levin, Hagit Sade, Rina Ben-shabbat Binyamini, Maayan Pour, Iftach Nachman, Jean-paul LelloucheAbstract:Nanostructures of transition-metal dichalcogenides (TMDC) have raised scientific interest in the last few decades. Tungsten Disulfide (WS2) nanotubes and nanoparticles are among the most extensively studied members in this group, and are used for, e.g., polymer reinforcement, lubrication and electronic devices. Their biocompatibility and low toxicity make them suitable for medical and biological applications. One potential application is photothermal therapy (PTT), a method for the targeted treatment of cancer, in which a light-responsive material is irradiated with a laser in the near-infrared range. In the current article we present WS2 nanotubes functionalized with previously reported ceric ammonium nitrate-maghemite (CAN-mag) nanoparticles, used for PTT. Functionalization of the nanotubes with CAN-mag nanoparticles resulted in a magnetic nanocomposite. When tested in vitro with two types of cancer cells, the functionalized nanotubes showed a better PTT activity compared to non-functionalized nanotubes, as well as reduced aggregation and the ability to add a second-step functionality. This ability is demonstrated here with two polymers grafted onto the nanocomposite surface, and other functionalities could be additional cancer therapy agents for achieving increased therapeutic activity.
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Covalent functionalization/polycarboxylation of Tungsten Disulfide inorganic nanotubes (INTs-WS_2)
Nano Research, 2015Co-Authors: Daniel Raichman, David A. Strawser, Jean-paul LelloucheAbstract:Inorganic nanotubes of Tungsten Disulfide (INTs-WS_2) are insoluble in common solvents and practically inert, hindering their usefulness in both research and commercial applications. The covalent attachment of functional species onto the surface of INT-WS_2 is a critical first step in realizing the potential that INT-WS_2 offer for high-performance materials and products. Although a few attempts have been reported regarding preparing modified nanotubes, only a limited range of surface functionalities is possible with these methods. We have developed a versatile method, based on a modified, highly electrophilic acidic Vilsmeier-Haack reagent, to produce covalently bonded, polycarboxylated functional WS_2 nanotubes that are dispersible in polar liquids, including water. The surface polycarboxylated shell provides a means for additional derivatization, enabling matching compatibility of derivatized nanotubes to both hydrophobic and hydrophilic materials. Nanocomposites incorporating derivatized INT-WS_2 are expected to show improved properties as a result of enhanced interfacial compatibility, made possible by the large number of classes of functionalization available through the initial polycarboxylation step.
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Covalent functionalization/polycarboxylation of Tungsten Disulfide inorganic nanotubes (INTs-WS2)
Nano Research, 2014Co-Authors: Daniel Raichman, David A. Strawser, Jean-paul LelloucheAbstract:Inorganic nanotubes of Tungsten Disulfide (INTs-WS2) are insoluble in common solvents and practically inert, hindering their usefulness in both research and commercial applications. The covalent attachment of functional species onto the surface of INT-WS2 is a critical first step in realizing the potential that INT-WS2 offer for high-performance materials and products. Although a few attempts have been reported regarding preparing modified nanotubes, only a limited range of surface functionalities is possible with these methods. We have developed a versatile method, based on a modified, highly electrophilic acidic Vilsmeier-Haack reagent, to produce covalently bonded, polycarboxylated functional WS2 nanotubes that are dispersible in polar liquids, including water. The surface polycarboxylated shell provides a means for additional derivatization, enabling matching compatibility of derivatized nanotubes to both hydrophobic and hydrophilic materials. Nanocomposites incorporating derivatized INT-WS2 are expected to show improved properties as a result of enhanced interfacial compatibility, made possible by the large number of classes of functionalization available through the initial polycarboxylation step.
Reshef Tenne - One of the best experts on this subject based on the ideXlab platform.
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Strong light-matter interaction in Tungsten Disulfide nanotubes.
Physical chemistry chemical physics : PCCP, 2018Co-Authors: Lena Yadgarov, Reshef Tenne, Bojana Višić, Tsafrir Abir, Alexander Yu. Polyakov, Roi Levi, Tatyana V. Dolgova, Varvara V. Zubyuk, Andrey A. Fedyanin, Eugene A. GoodilinAbstract:Transition metal dichalcogenide materials have recently been shown to exhibit a variety of intriguing optical and electronic phenomena. Focusing on the optical properties of semiconducting WS2 nanotubes, we show here that these nanostructures exhibit strong light–matter interaction and form exciton–polaritons. Namely, these nanotubes act as quasi 1-D polaritonic nano-systems and sustain both excitonic features and cavity modes in the visible-near infrared range. This ability to confine light to subwavelength dimensions under ambient conditions is induced by the high refractive index of Tungsten Disulfide. Using “finite-difference time-domain” (FDTD) simulations we investigate the interactions between the excitons and the cavity mode and their effect on the extinction spectrum of these nanostructures. The results of FDTD simulations agree well with the experimental findings as well as with a phenomenological coupled oscillator model which suggests a high Rabi splitting of ∼280 meV. These findings open up possibilities for developing new concepts in nanotube-based photonic devices.
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Diameter-dependent wetting of Tungsten Disulfide nanotubes.
Proceedings of the National Academy of Sciences of the United States of America, 2016Co-Authors: Ohad Goldbart, Ifat Kaplan-ashiri, Sidney R. Cohen, Polina Glazyrina, H. Daniel Wagner, Andrey N. Enyashin, Reshef TenneAbstract:The simple process of a liquid wetting a solid surface is controlled by a plethora of factors—surface texture, liquid droplet size and shape, energetics of both liquid and solid surfaces, as well as their interface. Studying these events at the nanoscale provides insights into the molecular basis of wetting. Nanotube wetting studies are particularly challenging due to their unique shape and small size. Nonetheless, the success of nanotubes, particularly inorganic ones, as fillers in composite materials makes it essential to understand how common liquids wet them. Here, we present a comprehensive wetting study of individual Tungsten Disulfide nanotubes by water. We reveal the nature of interaction at the inert outer wall and show that remarkably high wetting forces are attained on small, open-ended nanotubes due to capillary aspiration into the hollow core. This study provides a theoretical and experimental paradigm for this intricate problem.
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The effect of Tungsten Disulfide nanotubes on the properties of silicone adhesives
International Journal of Adhesion and Adhesives, 2014Co-Authors: G. Goldberg, Hanna Dodiuk, S. Kenig, R. Cohen, Reshef TenneAbstract:Abstract The effects of Tungsten Disulfide inorganic nanotubes (INT-WS 2 ) on the bulk and adhesion properties of silicone nanocomposites were investigated. The nanocomposites were prepared using solvent mixing which enhanced the distribution and dispersion of the nanotubes in the high viscosity silicone matrix. The quality of dispersion was evaluated using scanning electron microscopy (SEM) which indicated good dispersion state. It was found that the optimal concentration of INT-WS 2 in the nanocomposites was 2 wt%, exhibiting 33% higher storage modulus, 6% improvement in tensile strength, 17% reduction in the coefficient of linear thermal expansion and 13% improvement in shear strength, compared to the neat polymer. Above this threshold value the nanocomposites adhesion properties were reduced.
Shibin Sun - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and structural characterization of Tungsten Disulfide nanomaterials
Materials Letters, 2011Co-Authors: Shibin Sun, Xueting ChangAbstract:Abstract In this study, Tungsten Disulfide nanoparticles with different structure have been generated via a solid–gas reaction with Tungsten oxide nanobundles as precursors. The structural features of the as-prepared Tungsten Disulfide nanomaterials were investigated via electron microscopy and selected area electron patterns (SAED) in detail. SAED pattern obtained from the Tungsten Disulfide particles with sheet-texture structure is discrete speckled rings consisting of numbers of diffraction spots, differing dramatically from those of Tungsten Disulfide nanorods and nanotubes. The formation of the unique Tungsten Disulfide sheet-texture particles should be attributed to both the morphological evolution of the Tungsten oxide bundles and the sulphur diffusion during the oxide-to-Disulfide conversion. This study may be helpful to investigate structurally other layered materials with different morphology.
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Synthesis of Tungsten Disulfide nanotubes from different precursor
Materials Chemistry and Physics, 2008Co-Authors: Shibin Sun, Zengda Zou, Guanghui MinAbstract:Differently structured Tungsten Disulfide nanomaterials were generated by using corresponding Tungsten oxides prepared by solvothermal method and subsequent thermal treatment. The morphology, structure and phase compositional feature of the resulting nanomaterials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The final morphologies of the sulphide were controlled by the initial morphology of the oxide precursors.
Eugene A. Goodilin - One of the best experts on this subject based on the ideXlab platform.
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Strong light-matter interaction in Tungsten Disulfide nanotubes.
Physical chemistry chemical physics : PCCP, 2018Co-Authors: Lena Yadgarov, Reshef Tenne, Bojana Višić, Tsafrir Abir, Alexander Yu. Polyakov, Roi Levi, Tatyana V. Dolgova, Varvara V. Zubyuk, Andrey A. Fedyanin, Eugene A. GoodilinAbstract:Transition metal dichalcogenide materials have recently been shown to exhibit a variety of intriguing optical and electronic phenomena. Focusing on the optical properties of semiconducting WS2 nanotubes, we show here that these nanostructures exhibit strong light–matter interaction and form exciton–polaritons. Namely, these nanotubes act as quasi 1-D polaritonic nano-systems and sustain both excitonic features and cavity modes in the visible-near infrared range. This ability to confine light to subwavelength dimensions under ambient conditions is induced by the high refractive index of Tungsten Disulfide. Using “finite-difference time-domain” (FDTD) simulations we investigate the interactions between the excitons and the cavity mode and their effect on the extinction spectrum of these nanostructures. The results of FDTD simulations agree well with the experimental findings as well as with a phenomenological coupled oscillator model which suggests a high Rabi splitting of ∼280 meV. These findings open up possibilities for developing new concepts in nanotube-based photonic devices.
Zhendong Chen - One of the best experts on this subject based on the ideXlab platform.
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Tungsten Disulfide saturable absorber for passively Q-Switched YVO4/Nd:YVO4/YVO4 laser at 1342.2 nm
Optical Materials, 2019Co-Authors: Gang Zhang, Yonggang Wang, Zhiyong Jiao, Jiang Wang, Zhendong ChenAbstract:Abstract By using both Tungsten Disulfide saturable absorber (WS2-SA) and YVO4/Nd:YVO4(0.3 at.%)/YVO4 crystal, a passively Q-switched laser centered at 1342.2 nm is first reported. Stable Q-switched pulses can be obtained. At the pump power of 12 W, a shortest pulse width of 550 ns and a pulse repetition rate of 97 kHz can be observed by a digital oscilloscope, corresponding to maximum pulse energy of 5.55 μJ and pulse peak power of 10.1 W. The results promote the promising applications of WS2-SA in all-solid-state laser at 1.3 μm.
