scispace - formally typeset
Search or ask a question

Showing papers in "The Journal of Physical Chemistry in 1958"











Journal ArticleDOI
TL;DR: For Teflon, the total surface energy is estimated to be between 56 and 69 ergs/cm/sup 2/, and the surface entropy, 0.17 erg/deg/m cm/m/s 2/n/n 2.
Abstract: A theory previously proposed for the estimation of interfacial energies is extended to cover the calculation of the surface energy of solids from heats of immersion. For Teflon, the total surface energy is estimated to be between 56 and 69 ergs/cm/sup 2/, and the surface entropy, 0.17 erg/deg/cm/sup 2/. For graphite, the total surface energy is estimated to be 119 ergs/cm/sup 2/, the surface free energy 70 ergs/cm/sup 2/, and the surface entropy 0.16 erg/cm/sup 2// deg. (auth)

167 citations


Journal ArticleDOI
TL;DR: The interaction of the intermetallic compound ZrNi with hydrogen was studied in this article, and pressure-composition isotherms were obtained at 100, 200, and 250 deg.
Abstract: The interaction of the intermetallic compound ZrNi with hydrogen was studied, and pressure --composition isotherms were obtained at 100, 200, and 250 deg . There was no resemblance to the zirconium--hydrogen system. The alloy formed a definite hydride at a limiting composition ZrNiH/sub 3/, and possibly a second hydride at ZrNiH. X-ray and density measurements on both the alloy and the hydrides indicated a distorted cubic structure for all phases. Hysteresis was observed on the isotherms and a possible explanation for this phenomenon is given on the assumption of lattice defects. (auth)



Journal ArticleDOI
TL;DR: In this paper, a mass spectrometric search has been made for gaseous metallic carbides in equilibrium with the corresponding metal vapor and graphite, for the systems Al-C, Be--C, Ga-C and LaC/sub 2/
Abstract: A mass spectrometric search has been made for gaseous metallic carbides in equilibrium with the corresponding metal vapor and graphite, for the systems Al-C, Be--C, Ga-C, La-C, and Ti-C. The molecules Al/sub 2/C/sub 2/, Ga/sub 2/C/ sub 2/, and LaC/sub 2/ have been identified in the se studies, as well as Ga/sub 2/ and probably Al/sub 2/. A thermodynamic treatment of the data has yielded heats of formation for these molecules, which provides evidence for the similarity of M-C/sub 2/ bonding to M-0 bonding, and hence indicates strong ionic contributions. (auth)

Journal ArticleDOI
TL;DR: In this article, the authors compared the solvents of organophosphorus compounds with uranyl nitrate and showed that an electronegative group greatly reduces the solvent strength.
Abstract: Organic phosphates, phosphonates, phosphinates, and phosphine oxides are compared as solvents for uranium and plutonium nitrates Distribution coefficients for U(VI) and Pu(IV) and (V) indicate a large difference in solvent strength among these groups of compounds The introduction of an electronegative group greatly reduces the solvent strength The P --- 0 stretching frequency can be correlated with solvent strength for these compounds Some solid complexes of the organophosphorus compounds with uranyl nitrate have been isolated (auth)


Journal ArticleDOI
TL;DR: In this paper, the free energies of 64 fluorocarbon solutions were compared with the predictions of Hildebrand's solubility parameter theory, and the results showed that some solutions show very much larger positive deviations from ideal behavior than can be accounted for by the difference of thermodynamic'' solubilities parameters.
Abstract: Existing data on 64 fluorocarbon solutions (vapor pressures, solubilities, heats of mixing and volume changes) are summarized, and the free energies deduced are compared in a consistent way with the predictions of Hildebrand's solubility parameter theory. Many solutions, notably fluorocarbon-- hydrocarbon mixtures, show very much larger positive deviations from ideal behavior than can be accounted for by the difference of thermodynamic'' solubility parameters. However, other solutions (e.g., C7F16 with CCl4 and with I2) are entirely normal. Variou s explanations of this anomalous behavior are reviewed and criticized: (1) the interpenetration of hydrocarbon molecules, (2) an empirical shift in 6 for hydrocarbons, (3) volume changes, (4) corresponding states theories, (5) polarity of C-- F bonds, (6) differences in ionization potential, and (7) non-central force fields. Of these, only the last two appear promising and they do not account for the behavior of all of the anomalous systems. Additional experimental and theoretical studies are needed; some directions for future research are suggested.


Journal ArticleDOI
TL;DR: In this article, the existence of quinone groups and aromatic hydroxyl groups on the surface of carbon black particles was shown based on polarographic analyses of slurries of carbon blacks.
Abstract: Evidence is presented for the existence of quinone groups and aromatic hydroxyl groups on the surface of carbon black particles. This evidence is based largely upon polarographic analyses of slurries of carbon blacks. A mechanism for the chemical interaction of carbon blacks with elastomers is proposed on the basis of these functional groups.






Journal ArticleDOI
TL;DR: In this article, the physical and chemical properties of transition metal carbides were determined and it was concluded that for a given temperature range, the linear thermal expansion of titanium, zircorium, niobium carbide, and tantalum carbide decreases with increasing weight.
Abstract: The physical and chemical properties of some transition metal carbides were determined, and it is concluded that for a given temperature range, the linear thermal expansion of titanium carbide, zircorium carbide, niobium carbide, and tantalum carbide decreases with increasing weight, and for a given temperature range the melting point is almost constant (JRD)