Nonlinear Spontaneous Oscillations at the Liquid/Liquid Interface Produced by Surfactant Dissolution in the Bulk Phase

Abstract

The results of theoretical and experimental studies of spontaneous nonlinear oscillations produced at the liquid/liquid interface by surfactant transfer from a point source situated in one of the bulk phases are presented. The theoretical analysis is based on the direct numerical simulation of the system evolution. The experiments are performed for the heptane/water interface using middle-chain aliphatic alcohols as surfactants. The results for the oil/water interface are compared with the corresponding data obtained for the air/water interface. The presented results allow the conclusion that auto-oscillations at the air/liquid and liquid/liquid interfaces are governed by very similar mechanisms but their characteristics are strongly dependent on the properties of the two contacting media, in particular, on the surfactant partition coefficient.

Second harmonic generation response by gold nanoparticles at the polarized water/2-octanone interface: from dispersed to aggregated particles

“…It is difficult at present to perform a statistical analysis of these fluctuations, but work along the lines reported by Zhao et al could well be envisaged [22]. Such an analysis would be desirable for disentangling any other possible effects such as instabilities [23]. It is interesting to note here that the timescale of the loss of the correlation for these fluctuations, as deduced from the decay of the correlation function g (2) (τ ) = I (t + τ )I (t) / I (t) 2 , is rather long (approximately 300 s).…”

Auto-Oscillation of Surface Tension: Effect of pH on Fatty Acid Systems

“…The oscillation mechanism generated in liquid membrane systems either at the donor/membrane or at the acceptor/membrane interface is shown to be similar to the mechanism underlying spontaneous oscillations at a liquid interface due to surfactant transfer from a point source, for example, a surfactant droplet situated in the bulk phase. , The measuring cell for experiments with droplet dissolution under a liquid interface is presented in Figure . The comparison with Figure makes it clear that the conditions for surfactant transfer and adsorption at the acceptor/membrane interface in liquid membrane systems are very similar to the conditions in the system with a droplet.…”

Propagation and Synchronization of Potential Oscillations in Multiple Liquid Membrane Systems

“…Following the pioneer work on the electrical instability at an oil/water interface by Dupeyrat and Nakache, 3,4 the oscillations of the interfacial potential difference or the interfacial tension in two-phase systems have been investigated. [5][6][7][8][9][10][11][12] Further, the oscillations of the membrane potential or the current in three-phase liquid membrane systems have been investigated extensively. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] One of the typical liquid membrane systems is composed of an aqueous solution containing cetyltrimethylammonium chloride (CTACl) and alcohol, W1, a nitrobenzene solution containing picric acid (HPic), O, and a pure water phase, W2, 13,[15][16][17][18][19][20][23][24][25] where such a potential oscillation appeared with an amplitude of 0.3 to 0.4 V and a period of 1 min.…”