氣液二相流體於突縮T型微流道使用不同界面活性劑增進傳輸之研究

Effects of various surfactants on bubble/liquid transport in a T-junction microchannel with sudden contraction

陳淮駐(Huai-Jhu Chen)

指導教授 ： 潘國隆

國立臺灣大學/工學院/機械工程學研究所/碩士(2012年)

https://doi.org/10.6342/NTU.2012.01792

摘要

本研究主要探討氣液兩相流之氣泡在方型微流道中的傳輸現象。採用T-junction微流道，流道寬度200μm，深度100μm。並於流道中間添加突縮口，利用變換連續相不同性質的流體，觀察各氣泡通過流道突縮口的速度變化。本研究方向為(1)藉由Fluent模擬降低水表面張力，固定其他物理性質，來探討表面張力的效應(2)藉由改變乙醇水溶液濃度，表面張力與黏度會改變的特性，來討論表面張力與黏度帶來的效應(3)藉由添加S111n與S131兩種不同界面活性劑，比較不同界面活性劑所產生的影響。我們發現於水中添加S111n和S131兩種界面活性劑在超過CMC(critical micelle concentration)，且在同樣的表面張力時，氣泡會有不同的樣式，氣泡與壁面的濕潤程度會不同，其中S131所帶來的濕潤程度會較高，氣泡於流道中傳輸速度也會比較快。

關鍵字

界面活性劑 ； 兩相流 ； 突縮流道 ； 氣泡

並列摘要

The present study focused on the transport phenomena of gas-liquid two-phase flow of bubbles in microchannels. The T-junction microfluidic device with a sudden contraction section was used in the experiment, and the channel dimensions were 200 μm × 100 μm. Variations in the transport velocities of different bubbles were observed when they passed through the sudden contraction section. In addition, different liquids were adopted as the continuous phase in the study. There are three major aspects of this study: First of all, the commercial software, Fluent, was used to analyze the surface tension effect on transportation phenomena in the microchannel. Second, effects of surface tension and viscosity effect were investigated by changing the concentration of ethanol solution. Third, the effects of surfactant type were observed by adding S111n and S131 respectively into the water.
Experimental results showed that when the concentration of surfactants S111n and S131 exceeded the CMC limit at the identical surface tension, the bubbles would exhibit different patterns. The wetting behaviors of bubbles were different between two different types of surfactant solutions. Transport velocities of bubbles in S131 solution were faster than bubbles in S111n solution, and the wettability of S131 was also higher than that of S111n.

並列關鍵字

surfactant ； two-phase flow ； sudden contraction microchannel ； bubble

參考文獻

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