Han Shi-Jun

Prediction of Vapor-Liquid Equilibrium Data from C H Band Shift of IR Spectra in Some Binary Systems *

Abstract Prediction of vapor-liquid equilibrium (VLE) is extremely necessary to separate liquid mixture in chemical production, especially when the required experimental data are difficult to measure, or the measurement is not economical. The infinite dilution activities can be used to predict VLE. However, it needs both the ends of the activities that are difficult to obtain for many systems. In the present study, a new model is proposed for correlating the frequency shift of C—H stretching band of IR spectra over the whole concentration. Investigated mixtures include water/2-propanol, water/ N, N -dimethylformamide (DMF), water/methanol, water/ethanol, water/1,4-dioxane, and water/dimethylsulfoxide (DMSO) systems. Simultaneous correlations of C—H frequency shift and VLE data are made. Furthermore, the VLE data were predicted with satisfactory results by the parameters obtained from IR spectra coupled with one of the infinite dilution activity coefficients.

Dynamic Monte Carlo simulation of linear SAW polymer chain near a flat surface

Investigation of the conformational properties of a SAW polymer chain near an impenetrable, non-interacting flat surface showed that the chain at first contracted and orientated itself to slightly parallel when it pulled close to the surface and at last elongated and reoriented itself to slightly perpendicular to the surface at very small distance from the surface. Simulation showed that most of the disappeared configurations were of large size at moderate distance from the surface while they were of small size at very small distance from the surface; and that the mean-square end-to-end distance was much more prone to be influenced by the surface than the mean-square radius of gyration . The orientational correlation between the direction of the longest principal axis of the moment of inertia and end-to-end vector was also discussed.