Liquid-liquid two-phase microflow patterns and mass transfer of radionuclides

Abstract

Two phases (liquid-liquid extraction) stratified flows in a rectangular geometry are analyzed in a double-Y shape glass chip. The influence of physical properties, in particular the viscosity of the two liquids affects the microflow. The extraction conditions (acid concentrations, contact times) in batch and in the microfluidic device were considered for a liquid anion exchanger and a neutral extractant for the extraction of U(VI) and Eu(III), respectively. From the relationship between the outlet analyte concentrations and the contact times, the initial rate constants are determined for U(VI) and Eu(III).

Analysis of radionuclides in microsystem: application to the selective recovery of 55Fe by solvent extraction

“…Moreover, recent technological breakthroughs allow to work with automated microsystems which can be used in parallel processing to increase the throughput or in multiplexed processing of separation/purification steps coupled to a detection system [13,14]. There are few examples of microchemical systems that utilize two or more liquid streams with parallel laminar flow in a microchannel for radiochemical applications [15][16][17][18]. Examples include the extraction of uranium (VI) in nitric acid media by tributylphosphate in dodecane or in ionic liquids [19,20].…”

Flow patterns and mass transfer performance of miscible liquid-liquid flows in various microchannels: Numerical and experimental studies

“…However, no studies have been carried out to determine the conditions that achieve the separation of co-flow phases in asymmetric devices where different volumetric ratios between the fluids are employed, although these devices are useful for different processes [24]. Furthermore, it has been also demonstrated that fluids with different properties (especially, different viscosities), at the same volumetric flow rate are not completely separated at the outlets of symmetric channels because the interface between the two streams is not located at the channel midline [25][26][27], and as a result, different approaches have been used 4 to achieve phase separation [7], some of them based on trial-and-error experimental procedures [28,29].…”

A novel method for the online measurement of impurities in uranium by coupling microfluidics with ICP-MS

“…16,17 Theoretically, the micro-extraction via PTL is more efficient than conventional bulk liquid-liquid extraction due to the larger surface-to-volume ratio and shorter diffusion distance. 18 Indeed, PTL has been utilized for the extraction of minor amounts of the radionuclides [19][20][21] such as uranium, 22 americium 23 and plutonium, 24 and the advantages of the reduced waste and sample consumption were highlighted. For online detectors, although a thermal lens microscope (TML) has been utilized successfully for the online detection of various metals extracted by PTL, 25,26 this technique suffers from the lack of selectivity of metal species.…”