Theoretical Study On Interface-dependent Mass Transfer And Microphase Behaviors

The mass transfer is of significantly importance in a wide range of industrial processes.However,in current the mass transfer theory,empirical correlations are still required because of the lake of detailed model of the interfaces.For the same reason,fundamental understanding of the states and phases for gas in nanobubbles is still unclear.In this paper,through theoretical analysis and combined with classical thermodynamical and kinetic theories,we study on interface-dependent mass transfer and microphase behaviors.The main research contents are as follows:1)Through theoretical analysis,the liquid-liquid mass transfer process across the film has been theoretically improved.An interface phase is added between the extracted film and extraction phase.When the substance flows through the extracted film to the interface phase,it will be enriched in the interface phase.When it is enriched to a certain concentration,it will flow from the interface phase to extraction phase.After considering the effect of interface enrichment,we derived relationships between the concentration of the extraction phase and that for the extracted film,as a function of time and position,from which we discussed the effects of diffusion coefficient,bulk phase concentration,constant factor and interface phase thickness in this mass process.(2)Through the analysis of van der Waals molecules encapsulated in nanobubbles,the corresponding states for supercritical gas(nitrogen)as well as their stability were discussed.The stability of nanobubbles as a function of the environmental pressure and number of gas molecules is discussed separately by the dynamic equation(RP equation)and by free energy analysis.(3)The microphase behaviors for subcritical gas(C3F8)in nanobubbles are theoretical analysis by using van der Waals equation,and richer phase behaviors are found compared to the bulk gas.To consider the effects of contaminant adsorbed on nanobubble surfaces,a mathematical models based on varied-surface tension has been developed and the corresponding changes of microphase behaviors are discussed.Finally,we also compared the phase transformations from the adiabatic model with those from the isothermal model.