The Experts below are selected from a list of 1695 Experts worldwide ranked by ideXlab platform
Debra R. Rolison - One of the best experts on this subject based on the ideXlab platform.
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Redesigning air cathodes for metal–air batteries using MnOx-functionalized carbon nanofoam architectures☆
Journal of Power Sources, 2012Co-Authors: Christopher N Chervin, Jean Marie Wallace, Natalie L. Brandell, Nathan W Kucko, Jeffrey W. Long, Debra R. RolisonAbstract:a b s t r a c t We have redesigned the air cathode for metal–air batteries by adapting fiber-paper-supported carbon nanofoams as the base electrode architecture. Electrocatalytic functionality for the oxygen reduction reaction (ORR) is added into the conductive, ultraporous nanofoam paper by electroless deposition at the carbon walls of conformal nanoscopic coatings of birnessite-like manganese oxide (10–20-nm thick MnOx) via redox reaction with aqueous permanganate (MnO4 −). We report the ORR activity measured using an air-breathing electroanalytical cell for a series of native and MnOx-functionalized carbon nanofoams in which the size of the pore network is varied from tens to hundreds of nanometers, the thickness of the air cathode is varied, and the degree of hydrophilicity/hydrophobicity of the electrode structure is altered. Technologically relevant ORR activity is obtained at 0.9 V vs. Zn for MnOx-functionalized carbon nanofoams that are ≥180-m thick, have pores on the order of 100–200 nm, and are modified with hydrophobic poly(vinylidene difluoride). © 2012 Elsevier B.V. All rights reserved.
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redesigning air cathodes for metal air batteries using mnox functionalized carbon nanofoam architectures
Journal of Power Sources, 2012Co-Authors: Christopher N Chervin, Jean Marie Wallace, Natalie L. Brandell, Nathan W Kucko, Jeffrey W. Long, Debra R. RolisonAbstract:a b s t r a c t We have redesigned the air cathode for metal–air batteries by adapting fiber-paper-supported carbon nanofoams as the base electrode architecture. Electrocatalytic functionality for the oxygen reduction reaction (ORR) is added into the conductive, ultraporous nanofoam paper by electroless deposition at the carbon walls of conformal nanoscopic coatings of birnessite-like manganese oxide (10–20-nm thick MnOx) via redox reaction with aqueous permanganate (MnO4 −). We report the ORR activity measured using an air-breathing electroanalytical cell for a series of native and MnOx-functionalized carbon nanofoams in which the size of the pore network is varied from tens to hundreds of nanometers, the thickness of the air cathode is varied, and the degree of hydrophilicity/hydrophobicity of the electrode structure is altered. Technologically relevant ORR activity is obtained at 0.9 V vs. Zn for MnOx-functionalized carbon nanofoams that are ≥180-m thick, have pores on the order of 100–200 nm, and are modified with hydrophobic poly(vinylidene difluoride). © 2012 Elsevier B.V. All rights reserved.
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carbon nanofoam based cathodes for li o2 batteries correlation of pore solid architecture and electrochemical performance
219th ECS Meeting, 2011Co-Authors: Christopher N Chervin, Natalie L. Brandell, Jeffrey W. Long, Debra R. RolisonAbstract:Freestanding, binder-free carbon nanofoam papers afford the opportunity to gauge the influence of pore size on the discharge capacity of Li–O2 cells. Four sets of carbon nanofoam papers were synthesized from resorcinol–formaldehyde sols, with pore size distributions in pyrolyzed forms ranging from mesopores (5–50 nm) to a size regime not represented in the literature for Li-O2 cathodes—small macropores (50–200 nm). The first-cycle discharge capacity in cells containing 0.1 M LiClO4 in dipropylene glycol dimethyl ether tracks the average pore size distribution in the carbon nanofoam cathode, rather than the specific surface area of the nanoscale carbon network or its total pore volume. The macroporous nanofoams yield cathode specific capacity of 1000–1250 mA h g−1 at –0.1 mA cm−2 discharge rate, approximately twice that of the mesoporous nanofoams (∼580–670 mA h g−1), even though the macroporous foams have lower specific surface areas (270 and 375 vs. >400 m2 g−1). The specific capacity of the cathode decreases as the thickness of macroporous carbon nanofoam paper is increased from 180to 530-μm, which indicates that the interior pore volume is underutilized, particularly with thicker nanofoams. For the four pore–solid nanofoam architectures studied, the specific capacity is limited by pore occlusion arising from solid Li2O2 product that is electrogenerated near the outer boundaries of the nanofoams. © 2013 The Electrochemical Society. [DOI: 10.1149/2.070309jes] All rights reserved.
Christopher N Chervin - One of the best experts on this subject based on the ideXlab platform.
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Redesigning air cathodes for metal–air batteries using MnOx-functionalized carbon nanofoam architectures☆
Journal of Power Sources, 2012Co-Authors: Christopher N Chervin, Jean Marie Wallace, Natalie L. Brandell, Nathan W Kucko, Jeffrey W. Long, Debra R. RolisonAbstract:a b s t r a c t We have redesigned the air cathode for metal–air batteries by adapting fiber-paper-supported carbon nanofoams as the base electrode architecture. Electrocatalytic functionality for the oxygen reduction reaction (ORR) is added into the conductive, ultraporous nanofoam paper by electroless deposition at the carbon walls of conformal nanoscopic coatings of birnessite-like manganese oxide (10–20-nm thick MnOx) via redox reaction with aqueous permanganate (MnO4 −). We report the ORR activity measured using an air-breathing electroanalytical cell for a series of native and MnOx-functionalized carbon nanofoams in which the size of the pore network is varied from tens to hundreds of nanometers, the thickness of the air cathode is varied, and the degree of hydrophilicity/hydrophobicity of the electrode structure is altered. Technologically relevant ORR activity is obtained at 0.9 V vs. Zn for MnOx-functionalized carbon nanofoams that are ≥180-m thick, have pores on the order of 100–200 nm, and are modified with hydrophobic poly(vinylidene difluoride). © 2012 Elsevier B.V. All rights reserved.
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redesigning air cathodes for metal air batteries using mnox functionalized carbon nanofoam architectures
Journal of Power Sources, 2012Co-Authors: Christopher N Chervin, Jean Marie Wallace, Natalie L. Brandell, Nathan W Kucko, Jeffrey W. Long, Debra R. RolisonAbstract:a b s t r a c t We have redesigned the air cathode for metal–air batteries by adapting fiber-paper-supported carbon nanofoams as the base electrode architecture. Electrocatalytic functionality for the oxygen reduction reaction (ORR) is added into the conductive, ultraporous nanofoam paper by electroless deposition at the carbon walls of conformal nanoscopic coatings of birnessite-like manganese oxide (10–20-nm thick MnOx) via redox reaction with aqueous permanganate (MnO4 −). We report the ORR activity measured using an air-breathing electroanalytical cell for a series of native and MnOx-functionalized carbon nanofoams in which the size of the pore network is varied from tens to hundreds of nanometers, the thickness of the air cathode is varied, and the degree of hydrophilicity/hydrophobicity of the electrode structure is altered. Technologically relevant ORR activity is obtained at 0.9 V vs. Zn for MnOx-functionalized carbon nanofoams that are ≥180-m thick, have pores on the order of 100–200 nm, and are modified with hydrophobic poly(vinylidene difluoride). © 2012 Elsevier B.V. All rights reserved.
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carbon nanofoam based cathodes for li o2 batteries correlation of pore solid architecture and electrochemical performance
219th ECS Meeting, 2011Co-Authors: Christopher N Chervin, Natalie L. Brandell, Jeffrey W. Long, Debra R. RolisonAbstract:Freestanding, binder-free carbon nanofoam papers afford the opportunity to gauge the influence of pore size on the discharge capacity of Li–O2 cells. Four sets of carbon nanofoam papers were synthesized from resorcinol–formaldehyde sols, with pore size distributions in pyrolyzed forms ranging from mesopores (5–50 nm) to a size regime not represented in the literature for Li-O2 cathodes—small macropores (50–200 nm). The first-cycle discharge capacity in cells containing 0.1 M LiClO4 in dipropylene glycol dimethyl ether tracks the average pore size distribution in the carbon nanofoam cathode, rather than the specific surface area of the nanoscale carbon network or its total pore volume. The macroporous nanofoams yield cathode specific capacity of 1000–1250 mA h g−1 at –0.1 mA cm−2 discharge rate, approximately twice that of the mesoporous nanofoams (∼580–670 mA h g−1), even though the macroporous foams have lower specific surface areas (270 and 375 vs. >400 m2 g−1). The specific capacity of the cathode decreases as the thickness of macroporous carbon nanofoam paper is increased from 180to 530-μm, which indicates that the interior pore volume is underutilized, particularly with thicker nanofoams. For the four pore–solid nanofoam architectures studied, the specific capacity is limited by pore occlusion arising from solid Li2O2 product that is electrogenerated near the outer boundaries of the nanofoams. © 2013 The Electrochemical Society. [DOI: 10.1149/2.070309jes] All rights reserved.
Susana C. M. Fernandes - One of the best experts on this subject based on the ideXlab platform.
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Functional Chitosan Derivative and Chitin as Decolorization Materials for Methylene Blue and Methyl Orange from Aqueous Solution
Materials, 2019Co-Authors: Abdelkader Labidi, Asier M. Salaberria, Jalel Labidi, Susana C. M. Fernandes, Manef AbderrabbaAbstract:The precise role and value of incorporating Nanoforms in biologically active matrices for medical applications is not known. In our current work, we incorporate two chitin Nanoforms (i.e., nanocrystals or nanofibers) into Genipin-chitosan crosslinked matrices. These materials were studied as 2D films and 3D porous scaffolds to assess their potential as primary support and guidance for stem cells in tissue engineering and regenerative medicine applications. The incorporation of either Nanoforms in these 2D and 3D materials reveals significantly better swelling properties and robust mechanical performance in contrast to nanoform-free chitosan matrices. Furthermore, our data shows that these materials, in particular, incorporation of low concentration chitin Nanoforms provide specific topological cues to guide the survival, adhesion, and proliferation of human adipose-derived stem cells. These findings demonstrate the potential of Genipin-chitosan crosslinked matrices impregnated with chitin Nanoforms as value added materials for stem cell-based biomedical applications.
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Chitin Nanoforms Provide Mechanical and Topological Cues to Support Growth of Human Adipose Stem Cells in Chitosan Matrices
Biomacromolecules, 2018Co-Authors: Verónica Zubillaga, Asier M. Salaberria, Teodoro Palomares, Ana Alonso-varona, Sujit Kootala, Jalel Labidi, Susana C. M. FernandesAbstract:The precise role and value of incorporating Nanoforms in biologically active matrices for medical applications is not known. In our current work, we incorporate two chitin Nanoforms (i.e., nanocrystals or nanofibers) into Genipin-chitosan crosslinked matrices. These materials were studied as 2D films and 3D porous scaffolds to assess their potential as primary support and guidance for stem cells in tissue engineering and regenerative medicine applications. The incorporation of either Nanoforms in these 2D and 3D materials reveals significantly better swelling properties and robust mechanical performance in contrast to nanoform-free chitosan matrices. Furthermore, our data shows that these materials, in particular, incorporation of low concentration chitin Nanoforms provide specific topological cues to guide the survival, adhesion, and proliferation of human adipose-derived stem cells. These findings demonstrate the potential of Genipin-chitosan crosslinked matrices impregnated with chitin Nanoforms as val...
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Chitin Nanoforms Provide Mechanical and Topological Cues to Support Growth of Human Adipose Stem Cells in Chitosan Matrices
Biomacromolecules, 2018Co-Authors: Verónica Zubillaga, Asier M. Salaberria, Teodoro Palomares, Ana Alonso-varona, Sujit Kootala, Jalel Labidi, Susana C. M. FernandesAbstract:The precise role and value of incorporating Nanoforms in biologically active matrices for medical applications is not known. In our current work, we incorporate two chitin Nanoforms (i.e., nanocrystals or nanofibers) into Genipin-chitosan crosslinked matrices. These materials were studied as 2D films and 3D porous scaffolds to assess their potential as primary support and guidance for stem cells in tissue engineering and regenerative medicine applications. The incorporation of either Nanoforms in these 2D and 3D materials reveals significantly better swelling properties and robust mechanical performance in contrast to nanoform-free chitosan matrices. Furthermore, our data shows that these materials, in particular, incorporation of low concentration chitin Nanoforms provide specific topological cues to guide the survival, adhesion, and proliferation of human adipose-derived stem cells. These findings demonstrate the potential of Genipin-chitosan crosslinked matrices impregnated with chitin Nanoforms as value added materials for stem cell-based biomedical applications.
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Chitin Nanoforms Provide Mechanical and Topological Cues to Support Growth of Human Adipose Stem Cells in Chitosan Matrices
2018Co-Authors: Verónica Zubillaga, Asier M. Salaberria, Teodoro Palomares, Ana Alonso-varona, Sujit Kootala, Jalel Labidi, Susana C. M. FernandesAbstract:The precise role and value of incorporating Nanoforms in biologically active matrices for medical applications is not known. In our current work, we incorporate two chitin Nanoforms (i.e., nanocrystals or nanofibers) into Genipin-chitosan crosslinked matrices. These materials were studied as 2D films and 3D porous scaffolds to assess their potential as primary support and guidance for stem cells in tissue engineering and regenerative medicine applications. The incorporation of either Nanoforms in these 2D and 3D materials reveals significantly better swelling properties and robust mechanical performance in contrast to nanoform-free chitosan matrices. Furthermore, our data shows that these materials, in particular, incorporation of low concentration chitin Nanoforms provide specific topological cues to guide the survival, adhesion, and proliferation of human adipose-derived stem cells. These findings demonstrate the potential of Genipin-chitosan crosslinked matrices impregnated with chitin Nanoforms as value added materials for stem cell-based biomedical applications
Yong Zhao - One of the best experts on this subject based on the ideXlab platform.
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Low-dielectric polyimide nanofoams derived from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride and 2,2′-bis(trifluoromethyl)benzidine
RSC Advances, 2017Co-Authors: Pengxia Lv, Zhixin Dong, Yong ZhaoAbstract:Low-dielectric polyimide (PI) nanofoams were prepared by introducing nanopores into the PI matrix containing fluorine groups. The nanopores were formed by thermolysis of the thermally labile content, namely, polyethylene glycol (PEG) oligomers, in air. The prepared PI nanofoams were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and broadband dielectric spectroscopy. Results indicated that the PI nanofoams showed nanosized closed pores, excellent thermal stability, and a low dielectric constant of 2.12. The dielectric constant of the as-prepared nanofoams was stable within −150 °C to 150 °C. The thermal decomposition process of PEG in the PI matrix was designed and optimized to control the decomposition rate of PEG and the diffusion rate of the decomposition products of PEG. The dielectric constant of the nanofoams significantly decreased from 2.45 to 2.12 as the heating rate decreased from 5 °C min−1 to 1 °C min−1. The as-prepared PI nanofoams exhibited excellent properties and thus could be used in the microelectronics industry as a dielectric layer, multi-chip modules, or integrated circuit chips.
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low dielectric polyimide nanofoams derived from 4 4 hexafluoroisopropylidene diphthalic anhydride and 2 2 bis trifluoromethyl benzidine
RSC Advances, 2017Co-Authors: Zhixin Dong, Yong Zhao, Xuemin Dai, Xuepeng QiuAbstract:Low-dielectric polyimide (PI) nanofoams were prepared by introducing nanopores into the PI matrix containing fluorine groups. The nanopores were formed by thermolysis of the thermally labile content, namely, polyethylene glycol (PEG) oligomers, in air. The prepared PI nanofoams were characterized by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and broadband dielectric spectroscopy. Results indicated that the PI nanofoams showed nanosized closed pores, excellent thermal stability, and a low dielectric constant of 2.12. The dielectric constant of the as-prepared nanofoams was stable within −150 °C to 150 °C. The thermal decomposition process of PEG in the PI matrix was designed and optimized to control the decomposition rate of PEG and the diffusion rate of the decomposition products of PEG. The dielectric constant of the nanofoams significantly decreased from 2.45 to 2.12 as the heating rate decreased from 5 °C min−1 to 1 °C min−1. The as-prepared PI nanofoams exhibited excellent properties and thus could be used in the microelectronics industry as a dielectric layer, multi-chip modules, or integrated circuit chips.
Natalie L. Brandell - One of the best experts on this subject based on the ideXlab platform.
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Redesigning air cathodes for metal–air batteries using MnOx-functionalized carbon nanofoam architectures☆
Journal of Power Sources, 2012Co-Authors: Christopher N Chervin, Jean Marie Wallace, Natalie L. Brandell, Nathan W Kucko, Jeffrey W. Long, Debra R. RolisonAbstract:a b s t r a c t We have redesigned the air cathode for metal–air batteries by adapting fiber-paper-supported carbon nanofoams as the base electrode architecture. Electrocatalytic functionality for the oxygen reduction reaction (ORR) is added into the conductive, ultraporous nanofoam paper by electroless deposition at the carbon walls of conformal nanoscopic coatings of birnessite-like manganese oxide (10–20-nm thick MnOx) via redox reaction with aqueous permanganate (MnO4 −). We report the ORR activity measured using an air-breathing electroanalytical cell for a series of native and MnOx-functionalized carbon nanofoams in which the size of the pore network is varied from tens to hundreds of nanometers, the thickness of the air cathode is varied, and the degree of hydrophilicity/hydrophobicity of the electrode structure is altered. Technologically relevant ORR activity is obtained at 0.9 V vs. Zn for MnOx-functionalized carbon nanofoams that are ≥180-m thick, have pores on the order of 100–200 nm, and are modified with hydrophobic poly(vinylidene difluoride). © 2012 Elsevier B.V. All rights reserved.
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redesigning air cathodes for metal air batteries using mnox functionalized carbon nanofoam architectures
Journal of Power Sources, 2012Co-Authors: Christopher N Chervin, Jean Marie Wallace, Natalie L. Brandell, Nathan W Kucko, Jeffrey W. Long, Debra R. RolisonAbstract:a b s t r a c t We have redesigned the air cathode for metal–air batteries by adapting fiber-paper-supported carbon nanofoams as the base electrode architecture. Electrocatalytic functionality for the oxygen reduction reaction (ORR) is added into the conductive, ultraporous nanofoam paper by electroless deposition at the carbon walls of conformal nanoscopic coatings of birnessite-like manganese oxide (10–20-nm thick MnOx) via redox reaction with aqueous permanganate (MnO4 −). We report the ORR activity measured using an air-breathing electroanalytical cell for a series of native and MnOx-functionalized carbon nanofoams in which the size of the pore network is varied from tens to hundreds of nanometers, the thickness of the air cathode is varied, and the degree of hydrophilicity/hydrophobicity of the electrode structure is altered. Technologically relevant ORR activity is obtained at 0.9 V vs. Zn for MnOx-functionalized carbon nanofoams that are ≥180-m thick, have pores on the order of 100–200 nm, and are modified with hydrophobic poly(vinylidene difluoride). © 2012 Elsevier B.V. All rights reserved.
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carbon nanofoam based cathodes for li o2 batteries correlation of pore solid architecture and electrochemical performance
219th ECS Meeting, 2011Co-Authors: Christopher N Chervin, Natalie L. Brandell, Jeffrey W. Long, Debra R. RolisonAbstract:Freestanding, binder-free carbon nanofoam papers afford the opportunity to gauge the influence of pore size on the discharge capacity of Li–O2 cells. Four sets of carbon nanofoam papers were synthesized from resorcinol–formaldehyde sols, with pore size distributions in pyrolyzed forms ranging from mesopores (5–50 nm) to a size regime not represented in the literature for Li-O2 cathodes—small macropores (50–200 nm). The first-cycle discharge capacity in cells containing 0.1 M LiClO4 in dipropylene glycol dimethyl ether tracks the average pore size distribution in the carbon nanofoam cathode, rather than the specific surface area of the nanoscale carbon network or its total pore volume. The macroporous nanofoams yield cathode specific capacity of 1000–1250 mA h g−1 at –0.1 mA cm−2 discharge rate, approximately twice that of the mesoporous nanofoams (∼580–670 mA h g−1), even though the macroporous foams have lower specific surface areas (270 and 375 vs. >400 m2 g−1). The specific capacity of the cathode decreases as the thickness of macroporous carbon nanofoam paper is increased from 180to 530-μm, which indicates that the interior pore volume is underutilized, particularly with thicker nanofoams. For the four pore–solid nanofoam architectures studied, the specific capacity is limited by pore occlusion arising from solid Li2O2 product that is electrogenerated near the outer boundaries of the nanofoams. © 2013 The Electrochemical Society. [DOI: 10.1149/2.070309jes] All rights reserved.
