聚氧乙烯醚类表面活性剂表面扩张粘弹性质研究

研究了非离子表面活性剂壬基苯酚聚氧乙烯醚NP-8, NP-10和NP-12水溶液的表面扩张粘弹性质, 考察了氧乙烯数的变化对表面吸附膜特性的影响. 研究结果表明, 三种表面活性剂的扩张弹性随着工作频率的增大而增大, 扩张粘性则在0.1~0.01 Hz范围内通过不明显的极大值; 扩张弹性和粘性随着浓度的增加在同一浓度处通过一个极大值; 氧乙烯数从8增加到12, 表面扩张弹性、粘性和相角的变化不大. 从发生在表面上和表面附近的微观弛豫过程的角度对实验结果进行了讨论.

Study of Surface Dilational Elasticity and Viscosity of Nonylphenol Polyoxyethylene Ethers

The surface dilational viscoelasticity properties of nonylphenol polyoxyethylene ethers solutions, NP-8, NP-10 and NP-12, were investigated by Langmuir trough method. The influences of concentration and the number of polyoxyethylene groups on the surface dilational properties were expounded. It is shown that the surface dilational elasticity increased with the increase of frequency, while dilational viscosity passed through an indistinctive maximum. Surface dilational elasticity and viscosity passed through the distinctive maximum with the increase of bulk concentration and changed little with the increase of the number of polyoxyethylene groups from 8 to 12. The mechanisms responsible for the experimental results were discussed based on the relaxation processes existed in or near the surface. It showed that the arrangement of polyoxyethylene chain at the surface played an important role in film properties.