Numerical Simulation of Continuous Extraction of Li+ from High Mg2+/Li+ Ratio Brines Based on Free Flow Ion Concentration Polarization Microfluidic System

Abstract

Ion concentration polarization (ICP) is a promising mechanism for concentrating and/or separating charged molecules. This work simulates the extraction of Li+ ions in a diluted high Mg2+/Li+ ratio salt lake brines based on free flow ICP focusing (FF-ICPF). The model solution of diluted brine continuously flows through the system with Li+ slightly concentrated and Mg2+ significantly removed by ICP driven by external pressure and perpendicular electric field. In a typical case, our results showed that this system could focus Li+ concentration by ~1.28 times while decreasing the Mg2+/Li+ ratio by about 85% (from 40 to 5.85). Although Li+ and Mg2+ ions are not separated as an end product, which is preferably required by the lithium industry, this method is capable of decreasing the Mg2+/Li+ ratio significantly and has great potential as a preprocessing technology for lithium extraction from salt lake brines.

Rapid, Ultrasensitive, and Visual Detection of Pathogens Based on Cation Dye-Triggered Gold Nanoparticle Electrokinetic Agglutination Analysis

“…An ion-depletion zone was created near the Nafion membrane due to ICP when the electric field was applied across the microchannel with the Nafion membrane . Due to the strong cation permselectivity of the Nafion membrane, the negatively charged analytes would be trapped and concentrated in front of the Nafion membrane. – Here, the negatively charged product of hybridization (dsDNA–AuNPs), the free 16S rRNA, and cDNA-AuNPs were concentrated in the microchannel. The high local concentration led to further hybridization between the free 16S rRNA and cDNA-AuNPs.…”

High-performance cation electrokinetic concentrator based on a γ-CD/QCS/PVA composite and microchip for evaluating the activity of P-glycoprotein without any interference from serum albumin

“…ICP is a fundamental electrokinetic process that occurs near a nanojunction or an ion permselective membrane under a DC voltage, which enables efficient trapping and preconcentration of a charged molecule. [22][23][24][25][26] The current through a permselective membrane under DC voltage is characterized by the formation of an ion depletion zone (IDZ) and ion concentration regions at the opposite ends of the membrane. At the outer-boundary of the IDZ, ion preconcentration was achieved when the ions were simultaneously subjected to both an electrophoretic force and a force opposite to the electrophoretic forces.…”