结合图像数字化技术用悬滴法测动态界面张力——动态界面张力与表面活性剂浓度的关系  

DETERMINATION OF DYNAMIC INTERFACIAL TENSION BY COMPUTER-AIDED PENDANT DROP DIGITIZATION ——EFFECT OF SURFACTANT CONCENTRATION ON DIT

作　　者：李啸风[1] 陈志荣[2] 潘海华[1] 刘迪霞[1] 李浩然[1] 韩世钧[1] 

机构地区：[1]浙江大学化学系,浙江杭州310027 [2]浙江大学化学工程系,浙江杭州310027

出　　处：《化工学报》2001年第6期545-548,共4页CIESC Journal

基　　金：国家自然科学基金重点资助项目!(No.2 973 6170 )

摘　　要：A pendant drop tensiometry apparatus aided by video-image digitization technology was established, by which static interface or surface tension of some liquids was measured with satisfactory results.In order to study the effect of emulsifier concentration on emulsion stability, dynamic interfacial tension was measured between toluene and water against concentration of Tween 60(Polyoxyethylene(20) stearyl-sorbitanate). As expected, higher concentration is the Tween 60 solution in toluene injected into the toluene phase, faster falls the interface tension between toluene and water.Furthermore, it reveals interestingly that two steps of diffusion occur in the system, i.e ., at low and high concentration, after the surfactant solution is injected.The characteristic process of dynamic interface tension can be ascribed to diffusion control because of linearity between interface tension and the minus second root of aging time.The discovery is correlated to the fact that much higher concentration of surfactant above its critical micelle concentration is often required when a stable emulsion is planned to prepare.A pendant drop tensiometry apparatus aided by video-image digitization technology was established, by which static interface or surface tension of some liquids was measured with satisfactory results.In order to study the effect of emulsifier concentration on emulsion stability, dynamic interfacial tension was measured between toluene and water against concentration of Tween 60(Polyoxyethylene(20) stearyl-sorbitanate). As expected, higher concentration is the Tween 60 solution in toluene injected into the toluene phase, faster falls the interface tension between toluene and water.Furthermore, it reveals interestingly that two steps of diffusion occur in the system, i.e ., at low and high concentration, after the surfactant solution is injected.The characteristic process of dynamic interface tension can be ascribed to diffusion control because of linearity between interface tension and the minus second root of aging time.The discovery is correlated to the fact that much higher concentration of surfactant above its critical micelle concentration is often required when a stable emulsion is planned to prepare.

关 键 词：图像数字化 动态界面张力 扩散控制 悬滴法 表面活性剂 浓度 乳状液 稳定机理 

分 类 号：O657.91[理学—分析化学] O647.1[理学—化学]