近年來環保意識的抬頭，針對廢棄潤滑油所造成的汙染逐漸受到重視，其中一個解決辦法是尋求機油的潔淨替代品，其中若能以水溶液作為媒介流體來代替機油，則可以大幅降低對環境的污染。
水溶液本身的黏度表現不佳，但水溶液的離子特性有助於形成電雙層，而電雙層的存在則會為水流體提供電黏度的特性。傳統的電雙層現象模型解是在半無限幾何條件下推導而來，但在兩物體接觸的過程中，其間距逐漸縮小，也逐漸無法滿足推導過程中對半無限幾何的假設。因此，本篇研究致力於建立不受限於邊界電位與半無限幾何條件之電雙層模型，並將電黏度的效應與邊界滑移條件考慮其中，對傳統雷諾方程式執行進一步的修正，推導出適合用於接觸學上之修正型雷諾方程式。
研究結果發現電雙層效應越強，其引發的電黏度也隨之增強。邊界滑移條件的存在雖然會降低該方向的壓力黏度項，但對於該方向之電黏度卻有提升的效果。而在接觸區域內，水溶液流體視黏度由電黏度項主導，因此水流體的黏度表現有大幅提升的現象。但由於水流體本身黏度低落，即使考慮到電黏度的貢獻後，液膜厚度之尺度仍舊被壓在奈米級，接觸體之間具有更高的機會發生干涉，造成破壞。水流體仍不適合作為工業用油的替代品。但電雙層之電黏度效果顯著，未來可搜尋本身流體黏度較高且具有電雙層現象之對象再進行更進一步的研究。

The classical solution for electric double layer known as Debye-Hückel solution and nonlinear Poisson-Boltzmann solution is derived with the assumption of semi-infinite space. When it comes to contacting mechanics, two objects is getting close to each other. In this process, the assumption of semi-infinite space is gradually invalid. The classical solution of EDL is malfunctioned. In this research, we developed a numerical solution for EDL with ion conservation rule instead of semi-infinite space assumption. On the other hand, we modified the Reynolds equation with consideration of electro-viscosity induced by EDL and anisotropic boundary slip condition. In the end, the property of water solution as lubricant is analyzed in elastohydrodynamic lubrication theory by using finite element method to solve modified Reynolds equation.
As a result, it surprisingly shows that the electro-viscosity in water solution is quite effective and occurrence of slip condition is help to improve the electro-viscosity. One more issue needed to understand is that we assumed electrical conductivity is constant in this study. The electrical conductivity increases with the decrease of the film thickness. The increased conductivity weakens the electro-viscosity. The apparent viscosity of water solution is overestimated without consideration of variation of conductivity.

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