超疏水表面利用壓板法量測接觸角的遲滯現象與超疏水表面因缺陷存在造成水珠停滯不前的現象

Contact Angle Hysteresis by Superhydrophobic Surface Compression and Defect Pinning on Superhydrophobic Surface

曾祥慶(Seong-heng Chan)

指導教授 ： 曹恒光

國立中央大學/工學院/化學工程與材料工程學系/碩士(2011年)

摘要

本實驗利用自行改質的二氧化矽奈米粒子塗佈在玻璃上所形成的超疏水表面來探討水滴接觸角的遲滯現象。
實驗分為兩部分，第一部分針對水滴接觸角的遲滯現象提出新的量測方法－壓板法，實驗利用超疏水表面擠壓在壓克力表面上的水珠，探討在固定的水珠體積之下，旋轉平台上升使水珠被超疏水表面擠壓以及旋轉平台下降水珠回復的過程當中，水珠高度、水珠於壓克力上的接觸面直徑與水珠在壓克力上的接觸角三者之間的相對關系是如何來呈現接觸角的遲滯現象。
第二部分實驗探討在沒有遲滯現象的超疏水表面上刻意製造出缺陷，觀察水珠在缺陷上方隨著傾斜角慢慢增加而開始出現滾動的行為，藉由探討缺陷大小、缺陷上方水珠的大小、水珠前端與後端的接觸角與水珠滾動時的傾斜角之間的相對關係來模擬遲滯現象的成因。

關鍵字

二氧化矽 ； 表面改質 ； 接觸角 ； 壓板法 ； 超疏水 ； 遲滯效應

並列摘要

Abstract
In this thesis, a homemade superhydrophobic surface,fabricated by spraying the coating of surface-modified nanosilica on glass slice, is employed as an experimental material to discuss the phenomenon of contact angle hysteresis.
The experiment is divided into two parts. In the first part, a new measurement of contact angle hysteresis, compression of plate, is presented. Through observation of the droplet compressed and stretched by downward and upward movement of superhydrophobic surface, the relation between the height, base diameter and contact angle of droplet can be recorded and hence the behavior of contact angle hysteresis can be verified.
In the second part, different sizes of defects are made on the superhydrophobic surface which is originally free of contact angle hysteresis. The cause of contact angle hysteresis can be simulated by observation of the relation between sizes of defects, sizes of droplets, the forward and backward contact angle of droplet and the sliding angle of droplet.

並列關鍵字

contact angle ； nanosilica ； pinning ； hysteresis ； superhydrophobic

參考文獻

5. Gennes,P.G.De,B.Wyart,Francoise,Quere and David "Capillarity and wetting Phenomena Drops, Bubbles,Pearls, Waves", Springer, (2004)

8. F.M.Chang,S.J.Hong,Y.J.Sheng and H.K.Tsao“High contact angle hysteresis of superhydrophobic surfaces: Hydrophobic defect” Appl.Phys.Lett.95,064102(2009)

9. R.E.Johson and R.H.Dettre, Contact Angle ,Wettability and Adhesion in Chemistry Series 43,112 and 136(1964)

11. S.J.Hong,F.M.Chang,T.H.Chou ,S.H.Chan,Y.J.Sheng , and H.K.Tsao“Anomalous Contact Angle Hysteresis of a Captive Bubble:Advancing Contact Line Pinning” Langmuir,(2011)

12. E. Ramé“The Interpretation of Dynamic Contact Angles Measured by the Wilhelmy Plate Method”Journal of Colloid and Interface Science .185,245-251(1997)