Han Buxing

Solubility of CO2 in a mixed solvent of n-octane and i-octane at elevated pressures

Abstract The solubility of CO2 in binary mixtures of n-octane and i-octane have been measured at 30.0, 45.0, 60.0, and 73.2° C and at pressures up to 70 atm. Some thermodynamic properties have been calaulated using the experimental results.

EFFECT OF HYDRATION ANDpH ON THE THERMAL STABILITY OF PROTEINASE K

The effect of hydration andpH on the thermal stability of proteinase K was studied in the temperature range 310–450 K by differential scanning calorimetry. The dependences of the denaturation temperatureTd, the specific enthalpy of denaturation ΔHd and the maximum of excess apparent specific heat capacityCexmax upon the degree of hydrationh and thepH of the buffers used are presented. The relation betweenTd andh is of the Flory-Garretts type. By means of Oois model, the two components of the denaturation enthalpy arising from hydration and conformational change, respectively, were estimated. The fact that the specific denaturation enthalpy of proteinase K is very low may be attributed to its very low enthalpy of conformational change per heavy atom.

Ionic Association in Binary Ionic Liquids by Conductivity

In this study,the conductivity of 13 ionic liquids(ILs) and 25 related binary mixtures were determined at temperatures ranging from 293.15-323.15 K.The conductivity data of the pure ILs and their mixtures were fitted using the Vogel-Tammann-Fulcher(VTF) equation.The ionic association in the ILs and IL mixtures was discussed using the parameters of the VTF equation.It was demonstrated that at the same temperature,the ILs with short side chain cations,low charge density anions,and weak hydrogen bonding force between cations and anions usually exhibited high conductivity.Anions had a more obvious effect on conductivity than cations.The ionic association in the mixtures was affected not only by the species but also by the composition of the mixture.