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Lydéric Bocquet - One of the best experts on this subject based on the ideXlab platform.
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Giant osmotic energy conversion measured in a single transmembrane Boron Nitride Nanotube
Nature, 2013Co-Authors: Alessandro Siria, Philippe Poncharal, Xavier Blase, Stephen T. Purcell, Anne-laure Biance, Rémy Fulcrand, Lydéric BocquetAbstract:New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale^ 1 , 2 , with potential applications in ultrafiltration, desalination and energy conversion^ 3 . Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a Boron Nitride Nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single Nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the Nanotube’s internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that Boron Nitride Nanotubes could be used as membranes for osmotic power harvesting under salinity gradients. This paper describes the fabrication of a new type of nanopore membrane, in which a single Boron Nitride Nanotube traverses an ultrathin silicon Nitride membrane. The platform allows an exploration of the effects of pressure, chemical gradients and electric fields on fluidic transport at the nanoscale. In addition, it suggests a possible route to new technologies capable of producing large amounts of electric power from salinity gradients. Reservoirs on each side of the membrane contain different potassium chloride concentrations, generating a salinity gradient across the Nanotube. This gradient results in the generation of a large osmotically driven electric current that the authors attribute to a large surface charge carried by the internal walls of the Nanotube in water at high pH. A very large, osmotically induced electric current is generated by a salinity gradient between the ends of a single Boron Nitride transmembrane Nanotube, owing to the anomalously high surface charge carried by the Nanotube’s internal surface in water at large pH.
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Giant osmotic energy conversion measured in a single transmembrane Boron Nitride Nanotube
Nature, 2013Co-Authors: Alessandro Siria, Philippe Poncharal, Xavier Blase, Stephen T. Purcell, Anne-laure Biance, Rémy Fulcrand, Lydéric BocquetAbstract:New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale, with potential applications in ultrafiltration, desalination and energy conversion. Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a Boron Nitride Nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single Nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the Nanotube's internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that Boron Nitride Nanotubes could be used as membranes for osmotic power harvesting under salinity gradients.
Ying Chen - One of the best experts on this subject based on the ideXlab platform.
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Boron Nitride Nanotube reinforced titanium metal matrix composites with excellent high temperature performance
Journal of Materials Research, 2017Co-Authors: Mahedi Hasan Bhuiyan, Jiangting Wang, Peter Hodgson, Arvind Agarwal, Ma Qian, Ying ChenAbstract:Boron Nitride Nanotube (BNNT) reinforced titanium (Ti) matrix composites were prepared using the cold press-and-sinter method. In the composite sintered at 800 °C for 1 h, BNNTs were homogeneously distributed in the Ti matrix and restricted the growth of Ti grains. The compressive strength of the as-sintered Ti-4 vol% BNNT composite achieved 985 MPa at room temperature versus 678 MPa without the BNNT reinforcements. The highest compressive strength of 277 MPa at 500 °C was obtained from the Ti-5 vol% BNNT composite. When sintered at 1000 °C, chemical reactions occurred between Ti and BNNTs leading to the formation of the interfacial TiB phase, which serves as a strong binding between BNNTs and the Ti matrix. The reinforcements were attributed by a mixture of BNNTs and TiB after sintering at 1000 °C for 3 h. However, no BNNT was observed in the microstructure after sintering at 1100 °C for 3 h due to complete transformation into TiB whiskers.
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Boron Nitride Nanotube reinforced polyurethane composites
Progress in Natural Science: Materials International, 2013Co-Authors: Ying Chen, Zbigniew StachurskiAbstract:Abstract Bulk-sized Boron Nitride Nanotube (BNNT) reinforced polyurethane (PU) composites at different volume contents have been produced. A large quantity of BNNT fillers are synthesized by a Boron ink method. Compared to the neat PU, the 0.5 vol% and 2.0 vol% BNNT reinforced composites show 38.2% and 6.3% increases in compressive modulus, respectively. The relatively less enhanced compressive modulus of the 2.0 vol% composite may be due to the agglomerations of Nanotubes at high volume percentages. Contrary to normal behaviour, the composites show decreasing Rockwell (HRR) hardness values with an increasing volume fraction.
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insight into reactions and interface between Boron Nitride Nanotube and aluminum
Journal of Materials Research, 2012Co-Authors: Debrupa Lahiri, Ying Chen, Virendra Singh, Sudipta Seal, Tan Xing, Arvind AgarwalAbstract:Nature and mechanism of interfacial reactions between Boron Nitride Nanotubes (BNNTs) andaluminum matrix at high temperature (650 °C) are studied using high-resolution transmissionelectron microscopy (HRTEM). This study analyzes the feasibility of the use of BNNTs asreinforcement in aluminum matrix composites for structural application, for which interface playsa critical role. Thermodynamic comparison of aluminum (Al)-BNNT with analogous Al-carbonNanotube (Al-CNT) system reveals lesser amount of reaction in the former. Experimentalobservation also reveals thin (;7 nm) reaction-product formation at Al-BNNT interface even after120 min of exposure at 650 °C. The spatial distribution of the reaction-product species at theinterface is governed by the competitive diffusion of N, Al, and B. Morphology of the reactionproducts are influenced by their orientation relationship with BNNT walls. A theoretical predictionon Al-BNNT interface in macroscale composite suggests the formation of strong bond between thematrix and reinforcement phase.I. INTRODUCTIONBoron Nitride Nanotubes (BNNTs), the seamless cylin-drical structures made of hexagonal Boron Nitride sheetspossess excellent elastic modulus (;750–1200GPa
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controlling wettability of Boron Nitride Nanotube films and improved cell proliferation
Journal of Physical Chemistry C, 2012Co-Authors: Sugeetha Ramakrishnan, Ying Chen, Xiujuan J Dai, Kevin R Nicholas, Zhiqiang Chen, Xiaowei LiuAbstract:Desired wettability has been achieved on highly hydrophobic Boron Nitride Nanotube (BNNT) films using nitrogen/hydrogen (N2/H2) gas plasma treatments under controlled input energies and modes. Both hydrophilicity (contact angle (CA) ∼60°) and superhydrophilicity (CA < 5°) are demonstrated on BNNT films with little change of the surface morphology or the structure of individual BNNTs. The combination of continuous wave and pulse mode (CW+P) plasma shows more effective wettability modification and introduces more amine functional groups than the continuous wave (CW) plasma alone at a given input energy. (Super)hydrophilic/hydrophobic patterns have been created on BNNT films using masked plasma methods. The cell response to BNNT films is investigated for the first time. The proliferation of human primary mammary fibroblasts and a transformed mammary cell line (TXP RFP3) shows that the untreated hydrophobic BNNT films can support the growth of both cell lines, but the plasma treatments greatly enhance (up to ...
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mechanically activated catalyst mixing for high yield Boron Nitride Nanotube growth
Nanoscale Research Letters, 2012Co-Authors: Ying Chen, Xiujuan J Dai, Tan Xing, Mladen Petravic, Xiaowei LiuAbstract:Boron Nitride Nanotubes (BNNTs) have many fascinating properties and a wide range of applications. An improved ball milling method has been developed for high-yield BNNT synthesis, in which metal nitrate, such as Fe(NO3)3, and amorphous Boron powder are milled together to prepare a more effective precursor. The heating of the precursor in nitrogen-containing gas produces a high density of BNNTs with controlled structures. The chemical bonding and structure of the synthesized BNNTs are precisely probed by near-edge X-ray absorption fine structure spectroscopy. The higher efficiency of the precursor containing milling-activated catalyst is revealed by thermogravimetric analyses. Detailed X-ray diffraction and X-ray photoelectron spectroscopy investigations disclose that during ball milling the Fe(NO3)3 decomposes to Fe which greatly accelerates the nitriding reaction and therefore increases the yield of BNNTs. This improved synthesis method brings the large-scale production and application of BNNTs one step closer.
Dmitri Golberg - One of the best experts on this subject based on the ideXlab platform.
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Boron Nitride Nanotube enhanced osteogenic differentiation of mesenchymal stem cells
Journal of Biomedical Materials Research Part B, 2016Co-Authors: Xiupeng Wang, Yoshio Bando, Maho Yamaguchi, Xiangfen Jiang, Atsuo Ito, Dmitri GolbergAbstract:The interaction between Boron Nitride Nanotubes (BNNTs) layer and mesenchymal stem cells (MSCs) is evaluated for the first time in this study. BNNTs layer supports the attachment and growth of MSCs and exhibits good biocompatibility with MSCs. BNNTs show high protein adsorption ability, promote the proliferation of MSCs and increase the secretion of total protein by MSCs. Especially, BNNTs enhance the alkaline phosphatase (ALP) activity as an early marker of osteoblasts, ALP/total protein and osteocalcin (OCN) as a late marker of osteogenic differentiation, which shows that BNNTs can enhance osteogenesis of MSCs. The release of trace Boron and the stress on cells exerted by BNNTs with a fiber structure may account for the enhanced differentiation of MSCs into osteoblasts. Therefore BNNTs are potentially useful for bone regeneration in orthopedic applications. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 323–329, 2016.
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Boron Nitride Nanotube enhanced osteogenic differentiation of mesenchymal stem cells
Science & Engineering Faculty, 2016Co-Authors: Xiupeng Wang, Yoshio Bando, Maho Yamaguchi, Xiangfen Jiang, Atsuo Ito, Dmitri GolbergAbstract:Free to read The interaction between Boron Nitride Nanotubes (BNNTs) layer and mesenchymal stem cells (MSCs) is evaluated for the first time in this study. BNNTs layer supports the attachment and growth of MSCs and exhibits good biocompatibility with MSCs. BNNTs show high protein adsorption ability, promote the proliferation of MSCs and increase the secretion of total protein by MSCs. Especially, BNNTs enhance the alkaline phosphatase (ALP) activity as an early marker of osteoblasts, ALP/total protein and osteocalcin (OCN) as a late marker of osteogenic differentiation, which shows that BNNTs can enhance osteogenesis of MSCs. The release of trace Boron and the stress on cells exerted by BNNTs with a fiber structure may account for the enhanced differentiation of MSCs into osteoblasts. Therefore BNNTs are potentially useful for bone regeneration in orthopedic applications.
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powder metallurgy routes toward aluminum Boron Nitride Nanotube composites their morphologies structures and mechanical properties
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Dmitri Golberg, Maho Yamaguchi, Fanqiang Meng, Konstantin L Firestein, Koichi TsuchiyaAbstract:Abstract Aluminum/Boron Nitride Nanotube (BNNT) composites with up to 5 wt% (i.e., 9.7 vol%) Nanotube fractions were prepared via spark plasma sintering (SPS) and high-pressure torsion (HPT) methods. Various microscopy techniques, X-ray diffraction, and energy dispersive X-ray analysis confirmed the integration of the two phases into decently dense and compact composites. No other phases, like Al borides or Nitrides, formed in the Al–BNNTs macrocomposites of the two series. The BNNTs were found to be preferentially located along Al grain boundaries in SPS samples (grain size was 10–20 μm) creating micro-discontinuities and pores which were found to be detrimental for the sample hardness, whereas in HPT samples, the tubes were rather evenly distributed within a fine-grained Al matrix (grain size of several hundred nm). Therefore, the hardness of HPT samples was drastically increased with increasing BNNTs content in Al pellets. The value for Al–BNNT 3.0 wt% sample was more than doubled (190 MPa) compared to a pure Al–HPT compact (90 MPa). And the room temperature ultimate tensile strength of Al–BNNTs HPT samples containing 3.0 wt% BNNT (~300 MPa) became ~1.5 times larger than that of a BNNT-free HPT–Al compact (~200 MPa).
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synthesis structural analysis and in situ transmission electron microscopy mechanical tests on individual aluminum matrix Boron Nitride Nanotube nanohybrids
Acta Materialia, 2012Co-Authors: Yoshio Bando, Chunyi Zhi, Dmitri Golberg, Maho Yamaguchi, Daiming Tang, D V ShtanskyAbstract:Boron Nitride Nanotube (BNNT)/aluminum matrix composite nanohybrids were fabricated through magnetron sputtering of Al onto dispersed multiwalled BNNTs with average external diameters of 40-50 nm. Aluminum phase coating tightly wrapped the BNNTs after the deposition. The coating thickness in the range of 5-200 nm was controlled by changing sputtering time. Using imaging techniques and electron diffraction analysis in a transmission electron microscope, the Al phase was found to create nanocrystalline shields around individual BNNTs. The chemical states of the hybrid nanomaterials during the initial stages of sputtering were analyzed by X-ray photoelectron spectroscopy. Direct in situ bending and tensile tests on individual BNNT-Al nanocomposites were carried out by using a dedicated transmission electron microscope-atomic force microscope holder. In parallel, high-resolution TEM images and video recordings were taken for the analysis of deformation kinetics and fracture mechanisms. The nanohybrids with a suitably thick aluminum coating (similar to 40 nm) withstood at least nine times higher stresses compared to a pure non-armed Al metal. This pioneering work opens up a prospective pathway for making ultralight and superstrong "dream" structural materials for future automotive and aerospace applications. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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dielectric and thermal properties of epoxy Boron Nitride Nanotube composites
Pure and Applied Chemistry, 2010Co-Authors: Chunyi Zhi, Yoshio Bando, Chengchun Tang, Takeshi Terao, Dmitri GolbergAbstract:We report the fabrication of and investigations into the dielectric and thermal prop- erties of epoxy/Boron Nitride Nanotube (BNNT) composites. It was found that BNNT fillers can effectively adjust the dielectric constant of epoxy. Moreover, the thermal conductivity of epoxy was improved by up to 69 % with 5 wt % BNNTs. Our studies indicate that BNNTs are promising nanofillers for polymers, to obtain and control an adjustable dielectric prop- erty and improved thermal conductivity.
Alessandro Siria - One of the best experts on this subject based on the ideXlab platform.
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Giant osmotic energy conversion measured in a single transmembrane Boron Nitride Nanotube
Nature, 2013Co-Authors: Alessandro Siria, Philippe Poncharal, Xavier Blase, Stephen T. Purcell, Anne-laure Biance, Rémy Fulcrand, Lydéric BocquetAbstract:New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale^ 1 , 2 , with potential applications in ultrafiltration, desalination and energy conversion^ 3 . Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a Boron Nitride Nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single Nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the Nanotube’s internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that Boron Nitride Nanotubes could be used as membranes for osmotic power harvesting under salinity gradients. This paper describes the fabrication of a new type of nanopore membrane, in which a single Boron Nitride Nanotube traverses an ultrathin silicon Nitride membrane. The platform allows an exploration of the effects of pressure, chemical gradients and electric fields on fluidic transport at the nanoscale. In addition, it suggests a possible route to new technologies capable of producing large amounts of electric power from salinity gradients. Reservoirs on each side of the membrane contain different potassium chloride concentrations, generating a salinity gradient across the Nanotube. This gradient results in the generation of a large osmotically driven electric current that the authors attribute to a large surface charge carried by the internal walls of the Nanotube in water at high pH. A very large, osmotically induced electric current is generated by a salinity gradient between the ends of a single Boron Nitride transmembrane Nanotube, owing to the anomalously high surface charge carried by the Nanotube’s internal surface in water at large pH.
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Giant osmotic energy conversion measured in a single transmembrane Boron Nitride Nanotube
Nature, 2013Co-Authors: Alessandro Siria, Philippe Poncharal, Xavier Blase, Stephen T. Purcell, Anne-laure Biance, Rémy Fulcrand, Lydéric BocquetAbstract:New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale, with potential applications in ultrafiltration, desalination and energy conversion. Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a Boron Nitride Nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single Nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the Nanotube's internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that Boron Nitride Nanotubes could be used as membranes for osmotic power harvesting under salinity gradients.
Ruhong Zhou - One of the best experts on this subject based on the ideXlab platform.
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a unique feature of chiral transition of a difluorobenzo c phenanthrene molecule confined in a Boron Nitride Nanotube based on molecular dynamics simulations
Chemical Physics Letters, 2014Co-Authors: Yan Meng, Peng Xiu, Bolong Huang, Zhigang Wang, Ruiqin Zhang, Ruhong ZhouAbstract:Abstract Reliable structural information of extremal points in a reaction is important but difficult to achieve in molecular chiral transitions under confinement due to the complex molecular interactions. In this Letter, based on statistical results of a number of classical molecular dynamics simulations, we found that a complete chiral transition process of a difluorobenzo[c]phenanthrene molecule (C18H12F2, called D molecule) within a single-walled Boron-Nitride Nanotube involves at least five extremal point structures, showing a unique feature of chiral transition in the confined environment and suggesting an alternative to conventional first-principles calculations to determine the complex potential energy surface of intermolecular interactions.