Thermodynamic Properties of the Azeotropic Mixture of Acetone, Cyclohexane and Methanol

Wang, Xiurong; Nan, Zhaodong; Tan, Zhi‐Cheng

doi:10.1002/cjoc.200690242

Cited by 9 publications

(12 citation statements)

References 16 publications

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“…[10][11][12] The calorimeter was established by Thermochemistry Laboratory of Dalian Institute of Chemical Physics, Chinese Academy of Sciences, which mainly consists of a sample cell, a miniature platinum resistance thermometer, an electric heater, an inner and outer adiabatic shield, two sets of chromel-copel thermocouples and a high vacuum system. Its working temperature is from 80 to 400 K 13 with liquid nitrogen as cooling medium.…”

Section: Adiabatic Calorimetrymentioning

confidence: 99%

Low Temperature Heat Capacities and Thermodynamic Properties of 2‐Methyl‐2‐butanol

2008

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The low-temperature heat capacity C p,m of 2-methyl-2-butanol was precisely measured in the temperature range from 80 to 305 K by means of a small sample automated adiabatic calorimeter. Three solid-solid phase transitions and one solid-liquid phase transition were found at T＝146. 355, 149.929, 214.395 and 262.706 K from the experimental C p -T curve, respectively. The dependence of heat capacity on temperature was fitted to the following polynomial equations with a least square method. In the temperature range of 80 to 140 K, C p,m ＝39.208＋8.0724X-X＝(T-110)/30; in the temperature range of 155 to 210 K, C p,m ＝70.701＋10.631X＋12.767X 2 ＋0.3583X 3 -22.272X 4 -0.417X 5 ＋12.055X 6 , X＝(T-182.5)/27.5; in the temperature range of 220 to 250 K, C p,m ＝99.176＋7.7199X-26.138X 2 ＋28.949X 3 ＋0.7599X 4 -25.823X 5 ＋21.131X 6 , X＝(T-235)/15; and in the temperature range of 270 to 305 K, C p,m ＝121.73＋16.53X-1.0732X 2 -34.937X 3 -19.865X 4 ＋24.324X 5 ＋18.544X 6 , X＝(T-287.5)/17.5. The molar enthalpies of these transitions were determined to be 0.9392, 1.541, 0.6646 and 2.239 kJ•mol -1 , respectively. The molar entropies of these transitions were determined to be 6.417, 10.28, 3.100 and 8.527 J•K -1 •mol -1 , respectively. The thermodynamic functions [H T -H 298.15 ] and [S T -S 298.15 ], were derived from the heat capacity data in the temperature range of 80 to 305 K with an interval of 5 K.

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Section: Adiabatic Calorimetrymentioning

confidence: 99%

Low Temperature Heat Capacities and Thermodynamic Properties of 2‐Methyl‐2‐butanol

2008

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“…13 shown in Figure 9. In the temperature range from 288.000 to 303.700 K, solid state, the heat capacity data (J•K -1 •mol -1 ) were fitted to the following polynomial in reduced temperature (X) by means of the least squre fitting: according to the energy provided for the sample cell.…”

Section: Heat Capacities Of Na 2 Hpo 4 •12h 2 Omentioning

confidence: 94%

“…In the temperature range from 288.000 to 303.700 K, solid state, the heat capacity data (J•K -1 •mol -1 ) were fitted to the following polynomial in reduced temperature (X) by means of the least squre fitting: according to the energy provided for the sample cell. 13,15 In conclusion, pure disodium hydrogen phosphate dodecahydrate cannot be directly applied as phase change material for its incongruent fusion behavior. Thickening agent sodium alginate may restrain phase separation of it.…”

Section: Heat Capacities Of Na 2 Hpo 4 •12h 2 Omentioning

confidence: 99%

“…The experimental heat capacities were measured with an adiabatic calorimeter described previously, [13][14][15] which was calibrated with standard material α-Al 2 O 3 (1.6382 g, 0.016 mol). Deviations of the measured heat capacity of the α-Al 2 O 3 from the recommended values by the former National Bureau of Standards (NBS) are within ±0.2% in the range from 80 to 400 K.…”

Section: Heat Capacity and Ft-ir Measurementmentioning

confidence: 99%

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Heat Storage Performance of Disodium Hydrogen Phosphate Dodecahydrate: Prevention of Phase Separation by Thickening and Gelling Methods

Lan¹,

Tan²,

Yue³

et al. 2007

Chin. J. Chem.

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Disodium hydrogen phosphate dodecahydrate (Na 2 HPO 4 •12H 2 O) is an attractive candidate for phase change materials. The main problem for its practical use comes from incongruent melting character during thermal cycling. Experimentally, heat of fusion of the pure salt decreased from 200 to 25 J•g -1 in a four-run freeze-thaw cycling.Additives such as thickening agent or in-situ synthesized polyacrylate sodium in the molten salt can prevent its phase separation to some extent. In the test, sodium alginate 3.0%-5.0% (w/w) thickened mixture containing Na 2 HPO 4 •12H 2 O and some water showed constant heat storage capacities. Polyacrylate sodium gelled salt was synthesized through polymerizing sodium acrylate in the melt of Na 2 HPO 4 •12H 2 O and some extra water at 50 ℃. Optimum conditions composed of sodium acrylate 3.0%-5.0% (w/w), cross-linking agent N,N-methylenebisacrylamide 0.10%-0.20% (w/w), K 2 S 2 O 8 and Na 2 SO 3 (mass ratio 1∶1) 0.06%-0.12% (w/w). As opposed to normal large crystals of pure Na 2 HPO 4 •12H 2 O in solid state, the gelled salt existed in a large number of tiny particles dispersed in the gel network at room temperature, commonly less than 2 mm. But only those sample particles with sizes less than 0.2 mm may have relatively stable thermal storage property. A problem encountered was the poor reproducibility of the synthesis method: heat storage capacity of the product was often very different even though the synthesis was carried out in the same conditions. An alternative gelling method by sodium alginate grafted sodium acrylate was tried and it showed a fairly good effect. Heat capacities and heat of fusion of Na 2 HPO 4 •12H 2 O were measured by an adiabatic calorimeter.

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“…In the classical P-N theory, the Peierls barrier and stress are obtained by calculating the misfit energy only. However, it has been shown that the contribution from strain energy is as important as that from the misfit energy 21,32 . Therefore, the total energy including contribution from both misfit and strain energies should be evaluated to obtain correct result.…”

Section: And Ref 20 the Dislocation Equation For An Arbitrary Mixedmentioning

confidence: 99%

On the Properties of Shuffle Dislocation in BC5: Core Structure and Peierls Barrier and Stress

Zhang¹,

Wu²,

Yuan³

2014

Asian J. Chem.

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The dislocation widths for shuffle 60º and screw dislocations in diamond like BC5 have been calculated by the improved Peierls-Nabarro theory in which the discrete effect has been taken into account. For the dislocations with same angles, the width of dislocation located between B-C layers is about 1.2 times wider than that located between CC layers. For the dislocations located between same layers, the width of 60º dislocation is about 1.4 times wider than that of the screw dislocation. Peierls barriers and stresses have been evaluated with considering the contribution from both misfit and strain energies. The Peierls barriers for shuffle 60º and screw dislocations in BC5 are, respectively about 0.059 and 0.167 eV/Å, Peierls stresses are, respectively about 5 and 15 GPa. The results calculated in this paper are useful for data analysis of experiments.

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Thermodynamic Properties of the Azeotropic Mixture of Acetone, Cyclohexane and Methanol

Cited by 9 publications

References 16 publications

Low Temperature Heat Capacities and Thermodynamic Properties of 2‐Methyl‐2‐butanol

Low Temperature Heat Capacities and Thermodynamic Properties of 2‐Methyl‐2‐butanol

Heat Storage Performance of Disodium Hydrogen Phosphate Dodecahydrate: Prevention of Phase Separation by Thickening and Gelling Methods

On the Properties of Shuffle Dislocation in BC5: Core Structure and Peierls Barrier and Stress

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