Abstract
摘要：本研究計畫探討具有表面調節現象的微小高分子液滴於電解質溶液中之電泳以及沉降行為。
乳液系統是工業界中經常運用的一種膠體分散系統。特別是當分散相是具有非牛頓流體流變特性的高分子液滴時，整個乳液系統更是難以捉摸，電泳及沉降現象的預測與觀察結果將會與牛頓流體假設下得結果相去甚遠，再加上高分子微液滴具有極為重要之學術與應用價值，所以吾人對如此的系統進行深入的探討。因此我們在這裡提出高分子液滴之電泳與沉降等電動力學現象的研究。
對於生物膠體粒子(生物細胞或為組織)，或是表面具有人造薄膜或表面具有可解離官能基的膠體粒子，其表面電位為了反應所處環境的情形(pH值以及離子強度)而進行表面帶電量的調節，而改變其粒子表面的帶電情形，導致表面的帶電特性介於表面電位固定與表面電荷固定之間。
吾人分別引用Kuwabara 所提出的單一晶格模型以及Zydney來描述此微乳液系統，並以卡羅流體模型描述高分子液滴的流變行為，修正了傳統上為了簡化計算的困難而使用牛頓流體模型所產生的偏差，另一方面可完整並真實描述非牛頓流體的高分子液滴之流動情形；此外，吾人考量表面調節的情形，修正了傳統上使用表面電位固定以及表面電量固定等兩簡化的模型，可進一步得到接近真實情況之結果。
吾人預計於本計畫中的第一年探討表面調節的密集高分子微液滴在電解質溶液中之電泳運動，使用能描述高分子流變行為的卡羅流體模型，可比較其與以牛頓流體模型描述的液滴電泳運動之差異。計畫的第二年，吾人模擬表面調節的密集高分子液滴在電解質溶液之沉降電位，可與電泳比較定性上的差異及了解電泳與沉降間的關係。計畫的第三年，吾人考慮邊界效應對電泳以及沉降等電動力學現象造成的影響。
Abstract: In this project, we propose to investigate electrophoresis and sedimentation of concentrated polymeric liquid drops with charge-regulated surface dispersed in aqueous electrolyte solution.
The emulsion of liquid drops is frequently encountered in the industrial applications. The polymeric liquid drops are even more complicated to reckon with because of the non-Newtonian rheological behaviors of a polymeric liquid. The prediction and observation of electrophoresis and sedimentation will be dramatically altered, and which makes it necessary to conduct the proposed study.
For bio-colloids (cells or tissue), or colloids with artificial membrane or functional groups which may undergo dissociation, it will adjust its surface potential to reflect the ambient condition, for example, pH value or ionic strength, to make its surface property maintain between constant potential and constant charge.
We adopt Kuwabara’s unit cell model and the cavity model proposed by Zydney to describe the emulsion system, respectively. Carreau model fluid is adopted to describe the rheology of polymeric liquid drops, and consider the case of surface with charge regulation.
We plan to study the electrophoresis of concentrated polymeric liquid drops with charge-regulated surface in the first year, sedimentation in the second one, and boundary effect on the electrokinetic phenomena concerning with electrophoresis and sedimentation in the final year. Through the proposed investigation, we expect to learn the fundamental electrokinetic phenomena of polymeric liquid drops suspended in aqueous electrolyte solution, both qualitatively and quantitatively. The observations should serve as the basis for future applications in associated industrial fields.
Keyword(s)
高分子液滴
電泳
沉降
表面調節現象
非牛頓流體模型
孔洞模型
Polymeric Liquid Drop
Electrophoresis
Sedimentation
Charge-regulated Surface
Carreau Model Fluid
Cavity Model
