Electrokinetic Flow between two Planar Surfaces Covered by Ion-Penetrable Membrane in an Asymmetric Electrolyte Solution

• Main Authors: KAO, CHEN-YUAN, 高承遠
• Other Authors: JYH-PING HSU
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/66229046706302306823

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.