形狀及邊界效應對聚電解質電泳行為的影響

Abstract

本論文對聚電解質的電泳行為做了理論分析。聚電解質，如DNA，蛋白質，和微生物都被廣泛應用於現代技術。在電泳動時，由於電力與流力間的交互作用，聚電解質形狀的改變將會變得很重要。為了使模擬更貼近真實的情況，此聚電解質的電泳模型同時考慮了聚電解質的形狀效應、電雙層極化效應以及反離子凝聚效應。我們發現聚電解質的形狀顯著地影響了電雙層極化及反離子凝聚，進而造成其與圓球狀聚電解質在定性與定量上的不同。而這結果並不曾在以前的理論研究中被描述過。此外，邊界效應以及由帶電荷的奈米管道所產生的電滲透流效應，其對聚電解質電泳行為的影響也都進行了討論。我們也期望這些結果能為電泳實驗的數據提供了有價值的資訊。

Electrophoretic bahavior of a polyelectrolyte is investigated theoretically. Polyelectrolyte such as proteins, DNA, and microorganisms are applied widely in modern technology. Due to the interaction between the electric force and hydrodynamic force, the deformation of the polyelectrolyte during its electrophoresis can be significant. To simulate a case to a more realistic condition in practice, the electrophoresis of a polyelectrolyte is modeled taking account of its shape, the effect of double-layer polarization, and the effect of counterion condensation simultaneously. We show that both the double-layer polarization and the counterion condensation can be influenced significantly by the shape of a polyelectrolyte, making its behaviors different both quantitatively and qualitatively with those of a spherical polyelectrolyte, which has not been reported in previous theoretical studies. In addition, boundary effect and the effect of electroosmosis arising from a charged nanochannel on the electrophoretic behavior of the polyelectrolyte are also discussed. We expect that the results provide valuable information for the experimental data of electrophoresis.