The Organic Nature of Carbon Black Surfaces

Hallum, Jules V.; Drushel, Harry V.

doi:10.1021/j150559a031

Cited by 129 publications

(34 citation statements)

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“…Up to 18% of the oxygen found on carbon blacks has been reported to be present in the form of a 1,4-quinone. 58 Figure 5 also shows that only carefully selected topologies satisfy the criterion of vinylogous resonances for two carbonyl groups usually attached to different annellated benzene rings. In contrast, there is no restriction on topology when dealing with the hydroquinone structure.…”

Section: Mechanistic Considerationsmentioning

confidence: 99%

Quantitative Aspects of the Interfacial Catalytic Oxidation of Dithiothreitol by Dissolved Oxygen in the Presence of Carbon Nanoparticles

Sauvain

Rossi

2016

Environ. Sci. Technol.

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The catalytic nature of particulate matter is often advocated to explain its ability to generate reactive oxygen species, but quantitative data are lacking. We have performed molecular characterization of three different carbonaceous nanoparticles (NP) by: 1. identifying and quantifying their surface functional groups based on probe gas-particle titration; 2. studying the kinetics of dissolved oxygen consumption in the presence of suspended NP's and dithiothreitol (DTT). We show that these NP's can reversibly change their oxidation state between oxidized and reduced functional groups present on the NP surface. By comparing the amount of O 2 consumed and the number of strongly reducing sites on the NP, its average turnover ranged from 35 to 600 depending on the type of NP. The observed quadratic rate law for O 2 disappearance points to a Langmuir-Hinshelwood surface-based reaction mechanism possibly involving semiquinone radical. In the proposed model, the strongly reducing surface site is assumed to be a polycyclic aromatic conjugated hydroquinone whose oxidation to the corresponding quinone is rate-limiting in the catalytic chain reaction. The presence and strength of the reducing surface functional groups are important for explaining the catalytic activity of NP in the presence of oxygen and a reducing agent like DTT.

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Section: Mechanistic Considerationsmentioning

confidence: 99%

Quantitative Aspects of the Interfacial Catalytic Oxidation of Dithiothreitol by Dissolved Oxygen in the Presence of Carbon Nanoparticles

Sauvain

Rossi

2016

Environ. Sci. Technol.

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“…Such structures produce redox properties similar to the quinone/hydroquinone system. The presence of such structures has been inferred from the electrochemical reduction/oxida-tion behavior of carbon-containing surface oxygen [521][522][523][524][525]. There is also chemical evidence for the existence of quinone structures [452,526,527].…”

Section: Surface Oxides On Carbonmentioning

confidence: 99%

Nature and Estimation of Functional Groups on Solid Surfaces

Boehm

Knözinger

1983

Catalysis

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“…However it was observed (Garten and Weiss 1957) that the acidity of these carbons did not change on reduction, from which it was concluded " that either quinone groups are reduced beyond the hydroquinone stage or that a group other than quinone must be responsible for the oxidation of the borohydride ". It has recently been realized, however, that this conclusion is not necessarily valid and that the following mechanism for the oxidation of a carbon by air at about 400 "0 would reconcile Studebaker's work with our own and also with Hallum and Drushel's (1958) polarographic evidence for quinones. It is now postulated that the primary step in the oxidation of the carbon black during its production by the channel or roller processes is the formation of carbonyl and carboxyl groups as in (I).…”

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confidence: 60%

The Reaction of Carbon Blacks with Sodium Borohydride

Garten¹,

Weiss²

1961

Aust. J. Chem.

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It has been shown (Garten, Weiss, and Willis 1957) that the acidity of carbon blacks is due to phenolic hydroxyls and two types of lactones. Those lactones which can be methylated by diazomethane were termed F lactones, whilst those that are not were termed N lactones.It was also shown (Garten and Weiss 1955) that the acidity of a carbon that had been activated in air at 800 "C and cooled in nitrogen increased after reduction, and this was taken as evidence for quinones in these carbons. Studebaker. et al. (1956) on the other hand suggested that since many carbon blacks are reduced b y sodium borohydride they also contain quinones. However it was observed (Garten and Weiss 1957) that the acidity of these carbons did not change on reduction, from which it was concluded " that either quinone groups are reduced beyond the hydroquinone stage or that a group other than quinone must be responsible for the oxidation of the borohydride ". It has recently been realized, however, that this conclusion is not necessarily valid and that the following mechanism for the oxidation of a carbon by air at about 400 "0 would reconcile Studebaker's work with our own and also with Hallum and Drushel's (1958) polarographic evidence for quinones. It is now postulated that the primary step in the oxidation of the carbon black during its production by the channel or roller processes is the formation of carbonyl and carboxyl groups as in (I). These groups are unstable when interconnected by conjugated double bonds and, as in the phthalein dyestuffs, revert to the more stable F lactone tautomer (11). IF' lactones have been shown to be

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The Organic Nature of Carbon Black Surfaces

Abstract: for use of data on which temperature calculations of EVis were based, and to Wladimir Philippoff for helpful advice and suggestions. This work was conducted under contract between the Chemical Corps, U. S. Army, and Rensselaer Polytechnic Institute.

Cited by 129 publications

References 0 publications

Quantitative Aspects of the Interfacial Catalytic Oxidation of Dithiothreitol by Dissolved Oxygen in the Presence of Carbon Nanoparticles

Quantitative Aspects of the Interfacial Catalytic Oxidation of Dithiothreitol by Dissolved Oxygen in the Presence of Carbon Nanoparticles

Nature and Estimation of Functional Groups on Solid Surfaces

The Reaction of Carbon Blacks with Sodium Borohydride

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