Verma S, Kumar VV
Gas Equipment Engineering Corporation, 1240 Oronoque Road, Milford, Connecticut, 06460
J Colloid Interface Sci. 1998 Nov 1;207(1):1-10. doi: 10.1006/jcis.1998.5750.
Detergency of oily soil is a complex kinetic process that includes contributions from the wash system physical properties, time and temperature of wash, and the hydrodynamic forces exerted during the wash process. Generally, surfactant mixtures that exhibit a low oil-water interfacial tension are considered to provide superior oily soil detergency. In our investigations, we measured the oil-water interfacial tension for C12EO3/NaLAS and C12EO7/NaLAS blends as a function of temperature (18-80 degreesC) and time (0-60 min). The oil-water interfacial tension was found to decrease as a function of time for all blends containing nonionic surfactants, and this decline was most rapid for blends containing a higher fraction of ethoxylated alcohol with less than 3 mol of ethylene oxide. It is proposed that the diffusion of this hydrophobic fraction into the oil phase leads to the measured decline in the oil-water interfacial tension. Also, due to this limitation, no general correlation of oil-water interfacial tension with oily soil removal was observed. In view of these observations, it appears that the measurement of the oil-water interfacial tension (using a spinning drop tensiometer) for solutions containing hydrophobic surfactants may give misleading results. Copyright 1998 Academic Press.
去除油性污垢是一个复杂的动力学过程，它受到洗涤系统物理性质、洗涤时间和温度以及洗涤过程中施加的流体动力的影响。通常，具有低油水界面张力的表面活性剂混合物被认为具有更好的去除油性污垢的能力。在我们的研究中，我们测量了C12EO3/NaLAS和C12EO7/NaLAS混合物的油水界面张力随温度（18 - 80摄氏度）和时间（0 - 60分钟）的变化。对于所有含有非离子表面活性剂的混合物，发现油水界面张力随时间降低，并且对于含有较高比例的环氧乙烷摩尔数小于3的乙氧基化醇的混合物，这种下降最为迅速。有人提出，这种疏水部分向油相的扩散导致了所测量的油水界面张力的下降。此外，由于这个限制，未观察到油水界面张力与去除油性污垢之间的普遍相关性。鉴于这些观察结果，对于含有疏水表面活性剂的溶液，使用旋转滴张力计测量油水界面张力可能会给出误导性的结果。版权所有1998年学术出版社。
