Wettability of Nitric Acid Oxidized Carbon Fibers

The surface reaction of tetraethylenepentamine (TEPA) with nitric acid-oxidized type II PAN-based carbon fibers has been investigated by using X-ray photoelectron spectroscopy (XPS), ion scattering spectroscopy (ISS), and acid/base surface titrations. Initially, nitric acid treatments of varying intensity impart different quantities of oxygenated functional groups onto the fibers, and surface roughening due to formation of pits and crevasses occurs. Subsequent treatment with TEPA at 190 °C introduces significant amounts of surface-bound TEPA via reaction with carboxyl groups on the oxidized carbon fiber surfaces. Angle-resolved XPS (ARXPS) spectra are consistent with a TEPA surface concentration that varies as a function of depth (into crevasses and pits) and remains greatest primarily within the outermost 15 Å. The extent of the TEPA surface reaction is proportional (but not linearly) to the fibers' initial oxygen content. Nonlinearity may be due to several factors including (1) decomposition of a portion of the carbon fibers' carboxyl groups under the TEPA reaction conditions and (2) a nonuniform reaction with the commercial TEPA mixture, which contains several different pentamine molecular structures together with small amounts of tetra- and hexamine impurities. An accurate determination of the TEPA bonding configuration is difficult to achieve; however, the data suggest that at least 70% of the TEPA molecules form two (or more) bonds to the carbon fiber surfaces.

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A Study of Surface Modification on Adsorption Behaviors of Nanoporous Carbon

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.119.211 ◽

2007 ◽

Vol 119 ◽

pp. 211-214 ◽

Cited By ~ 1

Author(s):

Byeoung Ku Kim ◽

Young Seak Lee ◽

Seung Kon Ryu ◽

Byung Joo Kim ◽

Soo Jin Park

Keyword(s):

Nitric Acid ◽

Functional Groups ◽

Carbon Fibers ◽

Acid Treatment ◽

Surface Acidity ◽

Activated Carbon Fibers ◽

Adsorption Behaviors ◽

Toxic Gases ◽

Adsorption Amount ◽

Polar Functional Groups

In this work, to introduce polar functional groups on carbon surfaces, activated carbon fibers (ACFs) were treated by nitric acid in order to enhance the adsorption capacity of propylamine which was one of toxic gases in cigarette smoke. It was found that the polar functional groups were predominantly increased up to 2.0 M of nitric acid, resulting in the increase of total surface acidity. It was found that the adsorption amount of propylamine of the modified ACFs was increased around 17% after a nitric acid treatment. From the XPS results, it was observed that propylamine was reacted with strong or weak polar (acidic) groups, such as COOH, -COO or OH existed on the ACF surfaces.

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A small temperature difference concentration cell of carbon fibers and nitric acid

Synthetic Metals ◽

10.1016/0379-6779(83)90176-5 ◽

1983 ◽

Vol 6 ◽

pp. 239-240

Author(s):

Michio Inagaki ◽

Akira Matsumoto ◽

Mototsugu Sakai

Keyword(s):

Nitric Acid ◽

Carbon Fibers ◽

Temperature Difference ◽

Small Temperature ◽

Concentration Cell ◽

Small Temperature Difference

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Oxidized BPL Carbons

Adsorption Science & Technology ◽

10.1177/0263617499010001-407 ◽

1993 ◽

Vol 10 (1-4) ◽

pp. 75-84 ◽

Cited By ~ 15

Author(s):

S.S. Barton ◽

M.J.B. Evans ◽

J.A.F. Macdonald

Keyword(s):

Nitric Acid ◽

Surface Area ◽

Water Adsorption ◽

Adsorption Properties ◽

Bet Surface Area ◽

Adsorption Sites ◽

A Value ◽

Nitrogen Desorption ◽

Oxidized Carbon ◽

Increasing Temperature

A series of oxidized carbons has been prepared by treatment of the carbon with concentrated nitric acid at various temperatures, and the surface and adsorption properties of the prepared carbons studied. Water adsorption was modelled using a recently derived equation capable of predicting a value for the primary adsorption sites on the surface of a microporous carbon while fitting the experimentally determined isotherm at high relative pressures. The concentration of primary sites was seen to increase with increasing temperature of oxidation. The very highly oxidized carbon samples were found to have a significantly lower BET surface area determined from nitrogen desorption at 77 K and higher apparent density measured from mercury displacement.

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Organocatalytic vs. Ru-based electrochemical hydrogenation of nitrobenzene in competition with the hydrogen evolution reaction

Dalton Transactions ◽

10.1039/d0dt01075h ◽

2020 ◽

Vol 49 (19) ◽

pp. 6446-6456

Author(s):

Alicia Moya ◽

Jordi Creus ◽

Nuria Romero ◽

José Alemán ◽

Xavier Solans-Monfort ◽

...

Keyword(s):

Hydrogen Evolution ◽

Carbon Fibers ◽

Hydrogen Evolution Reaction ◽

Electrochemical Hydrogenation ◽

Ruthenium Nanoparticles ◽

Catalytic Systems ◽

Inorganic P ◽

Nitrobenzene Hydrogenation ◽

Oxidized Carbon

Electrocatalytic Nitrobenzene Hydrogenation and competitive Hydrogen Evolution Reaction (HER) have been studied, using two catalytic systems: oxidized carbon fibers (organic) and Ruthenium nanoparticles supported on unaltered carbon fibers (inorganic).

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Liquid-Phase Oxidation Modification of Carbon Fiber Surface

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.430-432.2008 ◽

2012 ◽

Vol 430-432 ◽

pp. 2008-2012 ◽

Cited By ~ 3

Author(s):

Wen Bo Lu ◽

Cheng Guo Wang ◽

Hua Yuan ◽

Xiu Ying Hu

Keyword(s):

Nitric Acid ◽

Liquid Phase ◽

Carbon Fiber ◽

Carbon Fibers ◽

Fiber Surface ◽

Oxidation Time ◽

Liquid Phase Oxidation ◽

Acid Oxidation ◽

Oxidation Treatment ◽

Phase Oxidation

The carbon fibers were subjected to liquid–phase oxidation treatment in 65% nitric acid solution. The relation between liquid-phase oxidation time and structure of carbon fibers had been assessed by LRS, XRD, SEM, and FTIR. The results indicate that smaller surface crystallites obtained by etching and more unsaturated carbon created after treatment, and corrosion enhanced with the increase of oxidation time. But nitric acid oxidation treatment does not change the bulk structure of carbon fibers. After nitric acid treated, the grooves of surface is wider and deeper compared to the original carbon fiber, When the oxidation times reach 12 hours, the surface of carbon fibers is severely damage. When the oxidation times reach 6 hours, there is not any characteristic peek in the FTIR. But after oxidation treatment for 9 hours, -COOH, -OH can be found from FTIR. So the best time for liquid-phase oxidation process is 9 hours.

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