Initiation of Carbon Nanofiber Growth on Polycrystalline Nickel Foam under Low Ethylene Pressure

ChemCatChem ◽  
2018 ◽  
Vol 10 (14) ◽  
pp. 3107-3114 ◽  
Author(s):  
Joline M. Roemers-van Beek ◽  
Zhu-Jun Wang ◽  
Ali Rinaldi ◽  
Marc G. Willinger ◽  
Leon Lefferts
2018 ◽  
Vol 81 ◽  
pp. 70-76 ◽  
Author(s):  
Deepak Sridhar ◽  
Sasha Omanovic ◽  
Jean-Luc Meunier

2021 ◽  
pp. 004051752110371
Author(s):  
Hong Wu ◽  
Chengkun Liu ◽  
Zhiwei Jiang ◽  
Zhi Yang ◽  
Xue Mao ◽  
...  

In this study, a lignin/polyacrylonitrile (PAN) composite nanofiber membrane is prepared by electrospinning and used as the precursor to prepare flexible carbon nanofibers (CNFs) through pre-oxidation and carbonization. The micromorphology, crystal structure, pore size distribution and specific surface area of the CNFs are characterized by field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy and specific surface adsorption analysis, respectively. The electrochemical properties of the CNF membrane are also investigated by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy due to its potential application in binder-free electrode materials for supercapacitors. We successfully prepared flexible CNFs with an average diameter of about 539 nm and a specific surface area of 1053.78 m2/g when the mass ratio of lignin to PAN was 9:1 in a solution concentration of 28 wt%. The CNFs are loaded onto nickel foam to prepare the electrode materials for supercapacitors without a binder. When the current density is 0.5 A/g, the specific capacitance could be up to 201.27 F/g and the equivalent series resistance is only 0.57 Ω, which shows an excellent electrochemical performance. This study not only provides a theoretical basis for the high-value utilization of lignin and the preparation of flexible lignin/PAN-based CNFs, but also provides a new type of environmentally friendly raw material for the electrodes of supercapacitors and could be helpful to alleviate the energy crisis and environmental pollution.


Author(s):  
J. J. Laidler

The presence of three-dimensional voids in quenched metals has long been suspected, and voids have indeed been observed directly in a number of metals. These include aluminum, platinum, and copper, silver and gold. Attempts at the production of observable quenched-in defects in nickel have been generally unsuccessful, so the present work was initiated in order to establish the conditions under which such defects may be formed.Electron beam zone-melted polycrystalline nickel foils, 99.997% pure, were quenched from 1420°C in an evacuated chamber into a bath containing a silicone diffusion pump fluid . The pressure in the chamber at the quenching temperature was less than 10-5 Torr . With an oil quench such as this, the cooling rate is approximately 5,000°C/second above 400°C; below 400°C, the cooling curve has a long tail. Therefore, the quenched specimens are aged in place for several seconds at a temperature which continuously approaches the ambient temperature of the system.


2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster

AbstractSince the cytocompatibility of carbon nanofibers with respect to neural applications remains largely uninvestigated, the objective of the present in vitro study was to determine cytocompatibility properties of formulations containing carbon nanofibers. Carbon fiber substrates were prepared from four different types of carbon fibers, two with nanoscale diameters (nanophase, or less than or equal to 100 nm) and two with conventional diameters (or greater than 200 nm). Within these two categories, both a high and a low surface energy fiber were investigated and tested. Astrocytes (glial scar tissue-forming cells) and pheochromocytoma cells (PC-12; neuronal-like cells) were seeded separately onto the substrates. Results provided the first evidence that astrocytes preferentially adhered on the carbon fiber that had the largest diameter and the lowest surface energy. PC-12 cells exhibited the most neurites on the carbon fiber with nanodimensions and low surface energy. These results may indicate that PC-12 cells prefer nanoscale carbon fibers while astrocytes prefer conventional scale fibers. A composite was formed from poly-carbonate urethane and the 60 nm carbon fiber. Composite substrates were thus formed using different weight percentages of this fiber in the polymer matrix. Increased astrocyte adherence and PC-12 neurite density corresponded to decreasing amounts of the carbon nanofibers in the poly-carbonate urethane matrices. Controlling carbon fiber diameter may be an approach for increasing implant contact with neurons and decreasing scar tissue formation.


2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster

AbstractCarbon nanofibers possess excellent conductivity properties, which may be beneficial in the design of more effective neural prostheses, however, limited evidence on their cytocompatibility properties exists. The objective of the present in vitro study was to determine cytocompatibility and material properties of formulations containing carbon nanofibers to predict the gliotic scar tissue response. Poly-carbonate urethane was combined with carbon nanofibers in varying weight percentages to provide a supportive matrix with beneficial bulk electrical and mechanical properties. The substrates were tested for mechanical properties and conductivity. Astrocytes (glial scar tissue-forming cells) were seeded onto the substrates for adhesion. Results provided the first evidence that astrocytes preferentially adhered to the composite material that contained the lowest weight percentage of carbon nanofibers. Positive interactions with neurons, and, at the same time, limited astrocyte functions leading to decreased gliotic scar tissue formation are essential for increased neuronal implant efficacy.


Author(s):  
А. Г. Басов ◽  
Ю. О. Шкурдода ◽  
Л. В. Дехтярук

2017 ◽  
Vol 16 (4) ◽  
pp. 829-836
Author(s):  
Florica Manea ◽  
Magdalena Ardelean ◽  
Aniela Pop ◽  
Rodica Pode ◽  
Joop Schoonman

2011 ◽  
Vol 1 (1) ◽  
pp. 16-26
Author(s):  
Likun Pan ◽  
Haibo Li ◽  
Yankun Zhan ◽  
Yanping Zhang ◽  
Zhuo Sun

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