• 作者： Horng, Jun-Shiung; Maa, Jer-Ru
• 中文摘要： 本文是在一個合併小室中測定液滴與水平界面下的流體的合併速率。下層為水相; 上層為有機相; 使相同成份的水相小滴由有機相中落下而與界面下方之水相合併。合併過程所需之時間,t/sub c/,之實驗值大致成常態分佈。加入少量之表面活性劑使t/sub c/值大幅度增加。液滴直徑,d,和表面活性劑濃度,C,對平均合併時間的影響可分別用簡單的方程式tbar/sub c/=K/sub 2/d/sup n1/和tbar/sub c/=K/sub 3/C/sup n2/來表示,式中K/sub 2/、K/sub 3/、n /sub 1/及n/sub 2/是在不同系統中有不同的值的實驗常數。當液滴與平的界面下的液體合併時會產生較小的「子滴」。與母滴相較,子滴的t/sub c/值較大,其分佈範圍較狹窄。當表面活性劑的濃度在CMC之下時,其對合併時間的影響可以用液膜伸張的模式來解釋。利用「部分不動模式」,由實驗所得的tbar/sub c/數據得知滴與下層液體間的液膜在破裂時的厚度,h/sub r/約為10/sup -4/cm。C值很低時h/sub r/值並不會大幅度增加。當C=0時,有機相與水相間界面的「不動性」,並不等於零。
• 英文摘要： The coalescence times of the organic-aqueous interface with drops of the same aqueous sample falling through the upper organic layer by gravity were determined in a coalescence cell. The resulting data of coalescence time ,t/ sub c/, distribute approximately normally and a small amount of surface active additive makes the tbar/sub c/ value considerably larger. Simple equations, tbar/sub c/=K/ sub 2/d/sup n1/ and tbar/sub c/=K/sub 3/C/sup n2/, express the effects of drop diameter, d, and surfactant concentration, C, on the average coalescence time, tbar/sub c/, satisfactorily, where K/sub 2 /, K/sub 3/, n/sub 1/ and n/sub 2/ are empirical constants having different values for different systems. Smaller secondary drops were generated as a drop coalesces with a planary interface. The tbar/ sub c/ values of the secondary drops are larger and distribute over a narrower range as compared with the primary drops. The effect of surfactant on the coalescence time can be explained by the film stretching model if its concentration is below the CMC. A comparison of the tbar/sub c/ data with the partial-immobility model shows that the rupture thickness of the intervening film between the drop and lower liquid, h/sub r/, is in the order of 10/sup -4/cm. The h/ sub r/ value is not considerably larger when C is very low and the "immobility" of the organic-aqueous interface is not zero when C=0.
• 中文關鍵字： 合併; 液滴; 表面活化劑; 合併時間; 部分不動模型; 液膜伸張模型
• 英文關鍵字： Coalescence; Liquid Drops; Surfactants; Coalescence Time; Partial Immobility Model; Film Streching Model