| Summary: | 碩士 === 國立臺灣大學 === 化學工程學系研究所 === 86 === The electrokinetic flow of an arbitrary a : b electrolyte solution between two
identical, planar, parallel surfaces covered by an ion-penetrable membrane iss
tudied theoretically for the case the distribution of fixed charge in the memb
rane phase is uniform. In particular, the effects of the ratio of the valenc
es of ions, the viscosity, permittivity, fixed char ge concentration, and drag
coefficient ofthemembrane phase, and ionic strength, on the electrokinetic pr
operties of the system under consideration, including the electroosmotic veloc
ity, the volumetric flow rate,and total electric current are investigated.If t
he electrical potential is low,the Poisson-Boltzmann equation governing it ssp
atial variation can be solved directly by adopting the Debye-Huckel approximat
ion. On the other hand, if it is not low, then solving it analytically becomes
almost impossible. Here, an approximate method is proposed which leads to an
analytical expression for the electrical potential distribution. The performa
nce of the method proposed is found tobe satisfactory for the case where the D
onnan potential in the membrane phaseis higher than about 12.5 mV.
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