The adsorption of ethylene on silver(I) oxide. II. Adsorption equilibria

1967 ◽  
Vol 20 (3) ◽  
pp. 409
Author(s):  
JA Allen ◽  
PH Scaife
Keyword(s):  
Adsorption Process ◽  
Preceding Paper ◽  
Isosteric Heat ◽  
Kcal Mole ◽  
Reversible Adsorption ◽  
Temperature Range ◽  
Chromatographic Methods ◽  
Adsorption Equilibria

The adsorption of ethylene on silver(I) oxide in the temperature range 190-363�K has been studied by volumetric and gas chromatographic methods. A reversible adsorption process characterized by an isosteric heat of 8.4 kcal mole-1 extends over the whole range of temperature and coverage, and coexists at temperatures greater than 250�K with an activated adsorption process described in the preceding paper.

Thermoanalytical Methods in Vulcanizate Analysis II. Derivative Thermogravimetric Analysis

1975 ◽  
Vol 48 (4) ◽  
pp. 661-677 ◽  
Author(s):  
D. W. Brazier ◽  
G. H. Nickel
Keyword(s):  
Preceding Paper ◽  
Limiting Factor ◽  
Inorganic Pigments ◽  
Thermal Stabilities ◽  
Pyrolysis Products ◽  
Exothermic Reactions ◽  
Temperature Range ◽  
Black Oil ◽  
Scan Rate ◽  
Tg And Dtg

Abstract We have shown in this and the preceding paper that fully compounded stocks can be analyzed for all main constituents by use of a combination of DSC, TG, and DTG. Further, this can be achieved on a time scale consistent with routine quality control. DSC gives information on cure characteristics, sulfur, and accelerator levels in approximately five minutes. Elastomer, elastomer ratio, carbon black, oil/plasticizer, and inorganic pigments are determined in about 35 minutes by TG/DTG, at a scan rate of 10°C/min. This time can be reduced by increasing the scan rate, but interference from highly exothermic reactions can be a limiting factor. Each compound must be treated individually to determine the maximum scan rate that can be used without impairing reproducibility. Clearly limitations exist for identification of unknown blends by DTG. The main problem is that many commercial elastomers have very similar thermal stabilities, which results in DTG peaks in the same temperature range. Further work is being undertaken with the DTG—gas chromatography interface to identify not only the pyrolysis products, but the temperature range over which they are evolved. In this manner, the DTG acts essentially as a thermal fraetionation unit and GC analysis of products from a given component in a blend can be achieved.

Antiferromagnetic exchange in triclinic crystals of tetra-u-benzoato- bits (4-methylquinoline) dicobalt II

1978 ◽  
Vol 360 (1701) ◽  
pp. 191-210 ◽  
Keyword(s):  
Cobalt Complex ◽  
Preceding Paper ◽  
Transverse Magnetic ◽  
Antiferromagnetic Coupling ◽  
Temperature Range ◽  
General Terms ◽  
Carboxylate Groups ◽  
A New Technique ◽  
Unambiguous Conclusion ◽  
Good Agreement

The magnetic susceptibilities of tetra- u -benzoato- bis (4-methylquinoline) dicobalt ii have been measured and interpreted within the theoretical model described in the preceding paper. Crystals of the title complex are triclinic, a circumstance which has lead to the development of a new technique for the measurement of triclinic crystal susceptibilities using a Faraday balance. The technique is discussed in general terms and is applicable with Faraday equipment employing either longitudinal or, as here, transverse magnetic fields. The magnetic tensor for this binuclear cobalt complex has been determined throughout the temperature range 20- 300 K. Good agreement between these results and those calculated from the quantum mechanical model have been obtained in the temperature range 90-300 K. At lower temperatures, a probable small paramagnetic impurity prevents useful theoretical treatm ent. There emerges an unambiguous conclusion that the antiferromagnetic coupling between the cobalt atoms is almost completely determined by interaction between metal xy orbitals, presumably via a superexchange process involving the delocalized n bonding framework of the bridging carboxylate groups.

The dissolution of beryllia in molten alkali metal hydroxides

1965 ◽  
Vol 18 (11) ◽  
pp. 1719 ◽  
Author(s):  
ME Shying ◽  
RB Temple
Keyword(s):  
Alkali Metal ◽  
Water Vapour ◽  
Beryllium Oxide ◽  
Major Product ◽  
Kcal Mole ◽  
Metal Hydroxides ◽  
Temperature Range ◽  
Alkali Metal Hydroxides ◽  
Reversible Formation

Beryllium oxide shows a limited reversible solubility in molten alkali-metal hydroxides only when dissolved water vapour is present. The reaction taking place has been studied in detail. The results obtained are consistent with the reversible formation of the beryllate ion [Be(OH)4]2- as the major product, according to the overall equation BeO(solid) + H2O(dissolved) + 2OH- ↔ [Be(OH)4]2-(dissolved) The enthalpy of the reaction has been calculated to be 4.8 kcal/mole over the temperature range 240-510�.

scholarly journals Experimental studies on equilibrium adsorption isosteres and determination of the thermodynamic quantities of polar media on alumina Al2O3

2017 ◽  
Vol 4 (1) ◽  
pp. 34-45 ◽  
Author(s):  
Albena Yonova
Keyword(s):  
Active Sites ◽  
Adsorption Process ◽  
Surface Acidity ◽  
Experimental Studies ◽  
Isosteric Heat ◽  
Heat Of Adsorption ◽  
Equilibrium Adsorption ◽  
Thermodynamic Quantities ◽  
Isosteric Heat Of Adsorption ◽  
Adsorption Isosteres

Abstract The present work is a revieif of theoretical and experimental study on the adsorption performance of the adsorbent Alumina (Al2O3) used in the adsorption system. An experimental investigation on the equilibrium adsorption isosteres at low pressure (< 1 atm) of working pairs Al2O3/H2O and Al2O3/C2H6O2 is carried out. The isovolume measurement method is adopted in the test setup to directly measure the saturated vapor pressures of working pairs at vapor-liquid equilibrium (dG=0 and dμi=0). Quantity adsorbed is determined from pressure, volume and temperature using gas law. The isosteric heat of adsorption is calculated from the slope of the plot of lnP versus 1/T different amounts of adsorbate onto adsorbent as follows: 0,01 vol% Al2O3/H2O; 0,03 vol% Al2O3/H2O; 0,1 vol% Al2O3/H2O; 0,01 vol% Al2O3/C2H6O2; 0,03 vol% Al2O3/C2H6O2; 0,1 vol% Al2O3/C2H6O2. This study shows that adsorption working pair Al2O3 C2H6O2 has better adsorption performances than those of the A2O3/H2O. Surface acidity! is a most important property! far both adsorption and catalysis and therefore is examined structure of active sites of alumina surface. Thermodynamic parameters such as isosteric heat of adsorption, isosteric enthalpy and entropy of adsorption are critical design variables in estimating the performance and predicting the mechanism of an adsorption process and are also one of the basic requirements for the characterization and optimization of an adsorption process

Heterogeneity Analysis of Single-Walled Carbon Nanotubes from the Adsorption Equilibria of Nitrogen and Benzene

2006 ◽  
Vol 6 (11) ◽  
pp. 3583-3588
Author(s):  
Wang-Geun Shim ◽  
Hyun-Chul Kang ◽  
Chan Kim ◽  
Jae-Wook Lee ◽  
Sang-Chai Kim ◽  
...  
Keyword(s):  
Second Virial Coefficient ◽  
Nitrogen Adsorption ◽  
Isosteric Heat ◽  
Heat Of Adsorption ◽  
Isotherm Models ◽  
Type I ◽  
Isosteric Heat Of Adsorption ◽  
Adsorption Equilibria ◽  
Equilibrium Data ◽  
Different Temperatures

Nitrogen adsorption/desorption isotherms and gravimetric methods were employed to examine the structural and adsorption properties of selected adsorbent. The equilibrium data of benzene were also obtained at three different temperatures (303.15, 313.15, and 323.15 K) with pressures up to 7 kPa. The results of nitrogen and benzene sorption isotherm revealed that SWCNTs exhibit type II with the features of type I. The Toth and UNILAN models were found to provide a reasonable correlation between the adsorption isotherm data. In addition, the adsorption second virial coefficient and the isosteric heat of adsorption were determined by using these isotherm models. The isosteric heat of adsorption and adsorption energy distribution indicated that SWCNTs have energetically and structurally heterogeneous surfaces.

THE THERMAL DECOMPOSITION OF PERACETIC ACID IN THE VAPOR PHASE

1963 ◽  
Vol 41 (7) ◽  
pp. 1819-1825 ◽  
Author(s):  
C. Schmidt ◽  
A. H. Sehon
Keyword(s):  
Thermal Decomposition ◽  
Vapor Phase ◽  
Dissociation Energy ◽  
Peracetic Acid ◽  
Kcal Mole ◽  
Temperature Range ◽  
Primary Reactions

The thermal decomposition of peracetic acid in a stream of toluene was studied over the temperature range 127–360 °C. The main products of the reaction were CO2, CH3COOH, C2H6, CH4, HCHO, O2, and traces of CO. Dibenzyl was also formed.The overall decomposition of peracetic acid was partly heterogeneous and was represented by the two parallel primary reactions[Formula: see text] [Formula: see text]The dissociation energy of the O—O bond in peracetic acid was estimated to be 30–34 kcal/mole.

The thermal decomposition of RDX at temperatures below the melting point. II. Activation energy

1970 ◽  
Vol 23 (4) ◽  
pp. 749 ◽  
Author(s):  
JJ Batten ◽  
DC Murdie
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Melting Point ◽  
Kinetic Parameter ◽  
Arrhenius Equation ◽  
Kcal Mole ◽  
Decomposition Products ◽  
Sample Geometry ◽  
Temperature Range ◽  
Definition Of

The activation energy has been determined in the temperature range 170-198�. If the sample was spread the activation energy was independent of the definition of the kinetic parameter substituted in the Arrhenius equation and was 63 kcal mole-1. In the case of the unspread samples the activation energies of the induction, acceleration, and maximum rates were 49, 43, and 62 kcal mole-1 respectively. The effect that sample geometry has on the activation energy is attributed to gaseous decomposition products influencing the reaction.

THE PHOTOLYSIS OF MERCURY DIMETHYL WITH DEUTERIUM

1954 ◽  
Vol 32 (2) ◽  
pp. 113-116 ◽  
Author(s):  
Richard E. Rebbert ◽  
E. W. R. Steacie
Keyword(s):  
Activation Energy ◽  
Satisfactory Agreement ◽  
Kcal Mole ◽  
Temperature Range ◽  
Work Done

Mercury dimethyl was photolyzed in the presence of deuterium in the temperature range from 27 °C. to 253 °C. The activation energy for the reaction[Formula: see text]was found to be 12.7 ± 0.5 kcal./mole. This is in satisfactory agreement with the work done with acetone and deuterium.

Kinetic Process of Purple Cabbage Pigment on Macro Porous Absorbent Resin

2011 ◽  
Vol 236-238 ◽  
pp. 1987-1990
Author(s):  
Jian Hua Yi ◽  
Zhen Bao Zhu ◽  
Yuan Fang Wu
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Adsorption Kinetics ◽  
Temperature Increase ◽  
Adsorption Process ◽  
Adsorbent Resin ◽  
Temperature Range ◽  
Porous Adsorbent ◽  
Kinetics Of ◽  
Langmuir And Freundlich Models

The adsorption kinetics of purple cabbage pigment (PCP) on LSA-21 macro porous adsorbent resin were studied at different adsorbent resin concentrations (1, 2, 4, 8 g adsorbent resin per liter of purple cabbage extraction solution) for the temperature range of 20~50°C. The results showed that the adsorption of PCP in purple cabbage extraction solution onto LSA-21 macro porous adsorbent resin is highly in agreement with both Langmuir and Freundlich models. Heat of adsorption (ΔH) value of 11.976 kJ/mol indicates the endothermic adsorption process. A decrease of Gibbs free energy (ΔG) with temperature increase also indicates the spontaneous nature of the process.

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