ABSTRACTS 529

covering carbons to only a few percent, this study produces monolayer coverage of surface by reacting PVDC carbons with atomic oxygen at 289°K. All surface carbon atoms therefore can be examined, The thermal stabilities and activation energies (26-40 kcat ma&*f of de~orn~si~on are measured. CO/CO, ratios vary between 2-2 and 3-O. Two regions of minimum stability of surface oxide are observed betow 6WK. Spectroscopic methods are being used to examine these complexes formed from atomic oxygen.

13. The reaction of ozone with adsorbent charcoal

J. L. Bitner and V. R. Deitz (Surface Chemistry Branch, Nad Research Laboratory, Washington, D.C.). The reaction of ozone with several kinds of charcoal have been followed in a flow system by continuously measuring the absorption spectra of the gaseous components. Changes in the weight of charcoal were f’ollowed and nitrogen adsorption measurements (at 77+X) were carried out for setected samples. The

experimental results suggest that entry into the porous carbon network of the charcoal is restricted by formation of et.her linkages across the narrolv openings that arc present in the surfaces of individual charcoal granules. Results of elemental chemical analyses of the treated charcoals, the outgassing behavior upon heating in a vacuum, and the density changes give support to this model.

14. Desorption from fixed bed columns containing activated carbon

1. Zwiebel and J. J. Schnitzer (Worcester Polytechnic Institute, Chcmicd ~n~~ne~i~~ ~e~~~~~rne~lt, Worcester, ~~~~~~s~~hz~~~et~). Resorption of gaseous adsrtrhates (CO,, C,H,, and C:,H, from hxed beds of act.is;tted carbon was studied. Isotherm non-linearity and adsorbent loading were the primary variables investi- gated experiment.ally. A simple mathematical model based upon the film type mechanism, utilizing the Langmuir type isotherm, was used to predict performance. increased isotherm non-linearity extended depletion points and broadened desorption curves, while increased adsorbent loadings reduced deple- tion times and sharpened mass transfer zones.

15. Carbon molecular sieve supports for metal catalysts J. I.. Schmitt, Jr.* and P. L. Walker, Jr. f P~~?zs?~~~ur~~ St&e ~ly~i~l~r,~~~?, ~~~~1~~~~~~ Park, ~e~~~s~~z~~rl~~~).

t’tx system p!atmum supported on a carbon molecular sieve has been prepared by carbonizing p&y- furfuryl alcohot containing chioroplatinic acid and an activated carbon fiIIer. Static adsorption results indicated that this mat.erial could be roughly classed as a 5.4 molecular sieve since its capacity for butane was six times that for isobutane. In addition, evidence was obtained for the presence of slit-shaped pores or pore constrictions. Using a continuous flow technique, shape selectivity was demonstrated for the competitive hydrogenations of 3-methyl-1-butene with both I-butene and cyclope. No such selectivity was observed in the I-butene: isobutene system, probably due to the planar structure of‘ isobutene and the significant dif%sivity of isobutane at the reaction temperature used.

16. Studies of porous carbon surfaces by high resolution nuclear magnetic resonance of adsorbed liquids

.J. Conard (Crntre National ~ech~~he S~~~?~t~~~z~e CRSOCI, 45 Ork~atzs, Fruncef and S. Gradsztajn (Chrmi- ccrl ~e~ff~?~erl~, ~ff~n~ta~}i~ I.~niv&ty, I,ruell. Acisorption produces shift and widenin of the H.N.M.K. line. The shift may reach SOif Hz with carbons and is attributed to diamagnetic amsotrop) and pctre flatness for spheron 6 and active charcoal. The widening arising f’rom distribution of preceding Iocaf field and partial avet-aging interaction, shows r)referei~t~ai attachment of formic acid OH group on car- kc&c with production of monomer. Extension to divided metals and oxides are evokated.

17, Forced spreading in four-phase systems: ~raphite/oi~~water/air systems

.M. C. Wilkinson, M. P. Aronson and A. C. Zettlemoper (Center ,& Surf&-r ~rnd Codrtg,~ KP,ww&, Lehigh Univev@ Bethdehem, Pennsylvania). The Factors governing the spreading tendencies of +r.tiu& submerged oil drops at graphite/water interfaces have been studied. To fullv describe the relativk distribution of the oil and water for the graphite surface. in these four-phase c&figurations. properties of all four phases need to be specified.