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Influence of oxidation on the wettability of carbon blacks
551
Abstracts graphite were tested at room temperature. The ratio of bend strength to tensile strength was close to that predicted by the Weibull theory of strength, but the effect of sample volume was much less than predicted by Weibull theory. 80. A study of the determination of the dynamic Young’s modulus of various cokes D. Billyeald and J. W. Patrick (British Carbonisation Research
Association,
Chesterfield,
Derbyshire,
U.K.).
Young’s modulus and its temperature dependence up to 1200°C were determined for examples of industrial and laboratory-prepared cokes using the resonant-flexural vibration technique. The results obtained were compared with those obtained for graphite and non-graphitic carbon and considered in relation to previously published work. 81. Statistics of fracture of ATJ-S graphite in uniaxial and biaxial tension J. Jortner (McDonnell Douglas Astronautics Company, Huntington Beach, CA 92647). No abstract submitted. VI. ADSORPTION
82. The adsorption carbons
AND INTERCALATION
characteristics
of
polyphenylene
E. Fitzer and P. Laudenklos (Znstitut fur Chemische W. Germany). The paper describes the preparation of advanced carboneous molecular sieves. It is shown that chars made from poly-p -phenylene exhibit specific adsorption characteristics caused by their micro-pore volume and slit sized pore entrances. Superior molecular sieve properties are obtained however by using chlorinated poly p -phenylene as precursor. Such carbon residues show pore volumes up to 0.59 ml/g, and pore diameters of 6-8 A, and can be heat treated up to 1500°Cwithout influence on their adsorption behaviour. Technik, Universitat Karlsruhe,
83. Adsorption characteristics of polymer carbons R. C. Bansal and T. L. Dhami (Department Chemistry,
Panjab
University,
Chandigarh,
of India).
Polymer carbons are associated with appreciable amounts of chemisorbed oxygen and hydrogen, the amounts depending upon the polymer used and the history of their preparation. This associated oxygen imparts a certain amount of surface acidity, increases the adsorption of water vapours and decreases the adsorption of organic vapours. The adsorption of iodine on these carbons is partly physical and partly chemical. The carbons are fairly susceptible to chemisorption of oxygen indicating the presence of disordered, unstacked layers. 84. Acidic surface oxides on carbon B. H. Harrison and S. S. Barton (Department of
appear to be responsible for the acidity found on the surface of this carbon. 85. Adsorbents for removal of mercury vapor from air J. K. Thompson (Chemical Dynamics Branch, Chemistry Division, Naval Research Laboratory, Washington, D.C. 20375, U.S.A.). The performance of charcoal and
iodized charcoals as adsorbents for mercury vapor has been evaluated. Charcoal alone was ineffective. Charcoal impregnated with iodine or iodine and potassium iodide was effective in a bed 2.54cm deep. For an influent mercury concentration of 1 mg/m3 at 50 cmlsec face velocity a typical sample gave an effluent concentration of 0.015 mg/m3 after 100-300hr. Flow rate should be as low as practicable to assure best performance. Iodine evolution from the charcoal was not detected at room temperature, but occurred at higher temperatures. 86. Exfoliation of intercalated graphites-I.
Effect of graphite crystallinity M. B. Dowel1(Union Carbide Corporation, Parma, OH 44130, U.S.A.). Rapid heating of intercalated graphites
causes them all to expand, but only those having a high degree of crystal perfection remain expanded after intercalant is expelled. Structure studies of several graphites indicate that lattice spacing I 3.36 A and basal plane stock heights 2 100w are necessary conditions for exfoliation. 87. Exfoliation of intercalated graphites-II.
Structure of exfoliated graphite and mechanism of exfoliation M. B. Dowel1(Union Carbide Corporation, Parma, OH 44139, U.S.A.). Gravimetry and high-speed cinematog-
raphy show exfoliation to involve thermal decomposition of the graphite intercalation compound, diffusion of intercalant to grain boundary regions (primarily interlamellar voids), and pressure-induced expansion of grain boundary regions to form large pores. Vapor finally escapes to the outside through pre-existing channels. 88. Influence of oxidation on the wettabiity of carbon blacks
K. Kinoshita and J. A. S. Bett (Advanced Fuel Cell Research Laboratories, Power Utilities Division of United Aircraft Corporation, Middletown, CT06457, U.S.A.). A
technique developed by Studebaker and Snow was used to determine the contact angle of water (cos OH,,) on porous carbons which were electrochemically treated in phosphoric acid. Electrochemical oxidation resulted in a decrease in cos 0~~~whereas, electrochemical reduction resulted in an increase in cos &Q. These observations were correlated to the oxygen content of the porous carbon samples.
Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada).
89. Changes in the porous structure of a natural based
Changes in the concentration of functional groups on Spheron 6, determined by the reaction with methyl magnesium iodide, diazomethane, sodium hydroxide and sodium ethoxide, have been related quantitatively to the removal of surface oxides as CO,. Cyclic esters (lactones)
F. Rodriguez-Reinoso, J. de D. L6pez-GonzBlez and A. Linares-Solano (Departamento de Q&mica Inorgcinica, Facultad de Ciencias, Universidad de Granada, Spain). The surface and porous structure of a graphite based in a natural one has been studied by means of physical
graphite upon gasification
Abstracts graphite were tested at room temperature. The ratio of bend strength to tensile strength was close to that predicted by the Weibull theory of strength, but the effect of sample volume was much less than predicted by Weibull theory. 80. A study of the determination of the dynamic Young’s modulus of various cokes D. Billyeald and J. W. Patrick (British Carbonisation Research
Association,
Chesterfield,
Derbyshire,
U.K.).
Young’s modulus and its temperature dependence up to 1200°C were determined for examples of industrial and laboratory-prepared cokes using the resonant-flexural vibration technique. The results obtained were compared with those obtained for graphite and non-graphitic carbon and considered in relation to previously published work. 81. Statistics of fracture of ATJ-S graphite in uniaxial and biaxial tension J. Jortner (McDonnell Douglas Astronautics Company, Huntington Beach, CA 92647). No abstract submitted. VI. ADSORPTION
82. The adsorption carbons
AND INTERCALATION
characteristics
of
polyphenylene
E. Fitzer and P. Laudenklos (Znstitut fur Chemische W. Germany). The paper describes the preparation of advanced carboneous molecular sieves. It is shown that chars made from poly-p -phenylene exhibit specific adsorption characteristics caused by their micro-pore volume and slit sized pore entrances. Superior molecular sieve properties are obtained however by using chlorinated poly p -phenylene as precursor. Such carbon residues show pore volumes up to 0.59 ml/g, and pore diameters of 6-8 A, and can be heat treated up to 1500°Cwithout influence on their adsorption behaviour. Technik, Universitat Karlsruhe,
83. Adsorption characteristics of polymer carbons R. C. Bansal and T. L. Dhami (Department Chemistry,
Panjab
University,
Chandigarh,
of India).
Polymer carbons are associated with appreciable amounts of chemisorbed oxygen and hydrogen, the amounts depending upon the polymer used and the history of their preparation. This associated oxygen imparts a certain amount of surface acidity, increases the adsorption of water vapours and decreases the adsorption of organic vapours. The adsorption of iodine on these carbons is partly physical and partly chemical. The carbons are fairly susceptible to chemisorption of oxygen indicating the presence of disordered, unstacked layers. 84. Acidic surface oxides on carbon B. H. Harrison and S. S. Barton (Department of
appear to be responsible for the acidity found on the surface of this carbon. 85. Adsorbents for removal of mercury vapor from air J. K. Thompson (Chemical Dynamics Branch, Chemistry Division, Naval Research Laboratory, Washington, D.C. 20375, U.S.A.). The performance of charcoal and
iodized charcoals as adsorbents for mercury vapor has been evaluated. Charcoal alone was ineffective. Charcoal impregnated with iodine or iodine and potassium iodide was effective in a bed 2.54cm deep. For an influent mercury concentration of 1 mg/m3 at 50 cmlsec face velocity a typical sample gave an effluent concentration of 0.015 mg/m3 after 100-300hr. Flow rate should be as low as practicable to assure best performance. Iodine evolution from the charcoal was not detected at room temperature, but occurred at higher temperatures. 86. Exfoliation of intercalated graphites-I.
Effect of graphite crystallinity M. B. Dowel1(Union Carbide Corporation, Parma, OH 44130, U.S.A.). Rapid heating of intercalated graphites
causes them all to expand, but only those having a high degree of crystal perfection remain expanded after intercalant is expelled. Structure studies of several graphites indicate that lattice spacing I 3.36 A and basal plane stock heights 2 100w are necessary conditions for exfoliation. 87. Exfoliation of intercalated graphites-II.
Structure of exfoliated graphite and mechanism of exfoliation M. B. Dowel1(Union Carbide Corporation, Parma, OH 44139, U.S.A.). Gravimetry and high-speed cinematog-
raphy show exfoliation to involve thermal decomposition of the graphite intercalation compound, diffusion of intercalant to grain boundary regions (primarily interlamellar voids), and pressure-induced expansion of grain boundary regions to form large pores. Vapor finally escapes to the outside through pre-existing channels. 88. Influence of oxidation on the wettabiity of carbon blacks
K. Kinoshita and J. A. S. Bett (Advanced Fuel Cell Research Laboratories, Power Utilities Division of United Aircraft Corporation, Middletown, CT06457, U.S.A.). A
technique developed by Studebaker and Snow was used to determine the contact angle of water (cos OH,,) on porous carbons which were electrochemically treated in phosphoric acid. Electrochemical oxidation resulted in a decrease in cos 0~~~whereas, electrochemical reduction resulted in an increase in cos &Q. These observations were correlated to the oxygen content of the porous carbon samples.
Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, Ontario, Canada).
89. Changes in the porous structure of a natural based
Changes in the concentration of functional groups on Spheron 6, determined by the reaction with methyl magnesium iodide, diazomethane, sodium hydroxide and sodium ethoxide, have been related quantitatively to the removal of surface oxides as CO,. Cyclic esters (lactones)
F. Rodriguez-Reinoso, J. de D. L6pez-GonzBlez and A. Linares-Solano (Departamento de Q&mica Inorgcinica, Facultad de Ciencias, Universidad de Granada, Spain). The surface and porous structure of a graphite based in a natural one has been studied by means of physical
graphite upon gasification