Solute diffesion in polymers is studied at infinite dilution of solute by inverse gas chromatgraphy. The diffesion model proposed by Romdhane and Danner is applied in thes study. and the thickness of polymer film in packed colunm is evaluated using the method proposed by Braun and Guillet. The diffusion coefficients at infinite dilution for CH2Cl2, CHCl3, C2H4Cl2 and CCl4 in polyethylene are determined.It shows that: 1) The smaller is the molecular volume of the solute, the larger is the diffusion coefficient. 2 )The diffesion coefficien increases with temperature.
Based on Onsager and Onsager-Fuoss-Chen equations of conductance,a new prediction equation is proposed for dilute electrolyte solution. It is used to predict and calculate the conductance of some single strong electrolyte solutions and their mixtures at 298.15 K. The results show good agreements with those data from literatureand they are better than those calculated with Onsager limiting equation and two-parameter Onsager-Fuoss-Chen equation. In addition,the new equation can also be used to determine the limiting molar conductivityof strong electrolyte by one-point experimental data of the molar conductivityat a certain concentration.The calculation deviation of the new equation shows a minimum value when the strength of ion in solution approaches 0.001 mol·dm^-3,hence,so long as the molar conductivity near this point is measured,the limitingmolar conductivity can be calculated conveniently and reliably by the new equation.
