Dynamic surface tension of surfactant TA: experiments and theory.
Dynamic surface tension of surfactant TA: experiments and theory.
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DOI：
10.1152/jappl.1994.77.6.2681
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发表时间：
1994-12
影响因子：
3.3
通讯作者：
D. Otis;E. Ingenito;R. Kamm;Mark P. Johnson
中科院分区：
文献类型：
--
作者：
D. Otis;E. Ingenito;R. Kamm;Mark P. Johnson
使用气泡表面活性计来测量表面活性剂TA的水性悬浮液的表面张力，其作为循环速率和表面活性剂本体浓度范围内的气泡面积的函数。表面张力-界面面积环的结果表现出丰富多样的现象，其特征随频率和体积浓度而系统地变化。开发了一个模型来解释和解释这些数据，并用于描述更一般情况下的表层动态。表面活性剂被建模为单一组分，表面张力仅取决于界面表面活性剂浓度。两种不同的机制被认为是体相和界面之间的表面活性剂的交换。第一个是由一个简单的吸附和解吸的动力学关系，仅涉及当界面浓度低于其最大平衡值。第二种机制是“挤出”，通过该机制，表面活性剂分子从被压缩超过最大堆积状态的界面排出。该模型提供了良好的协议与实验测量的循环速率从1到100个周期/分钟和散装浓度之间的0.0073和7.3毫克/毫升。
A bubble surfactometer was used to measure the surface tension of an aqueous suspension of surfactant TA as a function of bubble area over a range of cycling rates and surfactant bulk concentrations. Results of the surface tension-interfacial area loops exhibited a rich variety of phenomena, the character of which varied systematically with frequency and bulk concentration. A model was developed to interpret and explain these data and for use in describing the dynamics of surface layers under more general circumstances. Surfactant was modeled as a single component with surface tension taken to depend on only the interfacial surfactant concentration. Two distinct mechanisms were considered for the exchange of surfactant between the bulk phase and interface. The first is described by a simple kinetic relationship for adsorption and desorption that pertains only when the interfacial concentration is below its maximum equilibrium value. The second mechanism is "squeeze-out" by which surfactant molecules are expelled from an interface compressed past a maximum packing state. The model provided good agreement with experimental measurements for cycling rates from 1 to 100 cycles/min and for bulk concentrations between 0.0073 and 7.3 mg/ml.