Spectroscopic Analysis of Liquid/Liquid Interfaces in Multiphase Microflows

Abstract

Microscopic quasi-elastic laser scattering (muQELS) spectroscopy has been developed for analysis of interfacial phenomena at laminar multiphase microflow in a microchannel. Transport phenomena of a metal chelate through a water/toluene interface were measured, and transient adsorption of the chelate in the initial step of the transport was measured. A water/methanol miscible interface was also measured, and the interfacial free energy of a miscible interface was determined for the first time. The muQELS is expected to be very effective not only for physicochemical investigations of transport and mixing, but also for elemental process analysis of heterogeneous reactions.

Microflow Systems for Chemical Synthesis and Analysis: Approaches to Full Integration of Chemical Process

“…Therefore, novel MUOs taking these issues into account are needed. Kitamori et al have developed MUOs for various purposes, such as mixing and reaction [4,5], phase confluence and separation [6][7][8][9][10][11][12][13][14][15][16][17], solvent extraction [18], gas/liquid extraction [19][20][21][22], solid-phase extraction and reaction on surfaces [23][24][25][26][27][28][29][30][31][32][33][34], heating [35][36][37][38][39], cell culture [40][41][42][43][44], and ultrasensitive detection [45][46][47][48][49][50][51][52]…”

“…Integration of chemical processes utilizing solvent extraction has been demonstrated for various applications [8][9][10][11][12][13][15][16][17]. Here, we focus on two such examples.…”

“…Some groups have proposed selective chemical surface modification to change surface-free energy for stabilization of the multiphase microflows [7,11,14,15,[66][67][68][69][70]. Figure 6b illustrates the shape of the liquid-liquid interface in a microchannel with chemically patterned surfaces.…”

Interfacial Phenomena and Fluid Control in Micro/Nanofluidics

“…The in situ interfacial tension measurement remains a significant challenge, although some attractive image-based methods, [132][133][134] a light scattering method, 135,136 and an electrochemical method 137 have been reported. These new challenges are expected to advance the science and technology in this field in the next years.…”

Effects of Surfactants and Electrolytes on Chemical Oscillation at a Water/Nitrobenzene Interface Investigated by Quasi-elastic Laser Scattering Method

“…Kovalchuk et al [21][22][23][24][25][26][27][28][29][30][31][32] showed that the dynamics at an air/water or a water/ organic interface affect the heterogeneity of the interfacial tension caused by the addition of an alcoholic surfactant through a capillary. Using time-resolved quasi-elastic laser scattering (QELS) measurements, [33][34][35][36][37][38][39][40][41][42][43] Ikezoe et al [33][34][35] found that surfactant molecules are rapidly adsorbed and gradually desorbed when an aqueous surfactant solution is introduced to the interface between aqueous and organic phases with a capillary.…”