580 California St., Suite 400
San Francisco, CA, 94104
Key research themes
1. How does ion association, aggregation, and solvation influence the thermodynamic and transport properties of mixed electrolyte solutions?
This research area investigates the microscopic and thermodynamic mechanisms by which specific ions in mixed electrolyte solutions affect properties such as density, viscosity, conductivity, and phase behavior. Understanding ion pairing, aggregation beyond simple pairs, and ion solvation effects is critical for predicting electrolyte behavior in concentrated regimes relevant to industrial and biological systems.
Key finding: Developed a thermodynamic model extending beyond simple ion-pairing to describe distribution of ionic aggregates and the spontaneous formation of percolating ionic gels at a threshold ion association, applying polymer physics... Read more
Key finding: Using a coarse-grained explicit solvent-ion model parameterized by ion solvation energies, demonstrated that ion-specific effects on electrolyte solution thermodynamic properties (density, compressibility, surface tension)... Read more
Key finding: Applied ion-selective electrode measurements and Pitzer ion-interaction theory to model the thermodynamics of a ternary mixed 1:1 electrolyte system (NH4Cl + KCl + H2O). Identified how electrode selectivity coefficients limit... Read more
2. What are the effects and optimization strategies of electrodialysis and bipolar membrane technologies for processing mixed electrolyte or brine solutions?
This theme centers on the application of electrodialysis (ED) and electrodialysis with bipolar membranes (EDBM) to treat complex mixed electrolyte solutions such as brines from desalination, lithium mining, and industrial wastewaters. Research focuses on membrane selection, control of ion transport (including selective ions like Li+, Ca2+), mitigating fouling and scaling from multivalent ions, and valorizing resulting acid/base streams, enabling sustainability and improved resource recovery.
Key finding: Reviewed technical aspects of EDBM to convert concentrated NaCl brines primarily from reverse osmosis desalination and industrial processes into value-added acids (e.g., HCl) and bases (NaOH), demonstrating that EDBM enables... Read more
Key finding: Evaluated electrodialysis performance using cation- and anion-exchange membranes (PCSK, PCSA) for concentrating Li+ from complex brines with diverse ions (Na+, K+, Mg2+, Ca2+). Investigated impacts of varying brine... Read more
Key finding: Demonstrated that high calcium concentration (4000 mg/L) in brine causes fouling and efficiency decline in ED using standard CMX membranes due to calcium incursion into electrode rinse electrolyte. Implemented a cathode... Read more
Key finding: Investigated how varying sulfonated cation-exchanger resin content (45-65 wt%) in heterogeneous ion-exchange membranes affects current-voltage characteristics during ED of NaCl and NaCl + phenylalanine solutions. Found that... Read more
3. How do electrolyte composition and temperature empirically influence physical properties such as electrical conductivity, density, and viscosity in mixed electrolyte or solvent systems?
This research theme focuses on establishing empirical and semi-empirical relationships that describe how electrolyte concentration and temperature modulate physical properties critical to electrolyte performance, including electrical conductivity, density, and viscosity. Such relationships are essential for predicting behavior in mixed solvents and high concentration regimes relevant to industrial processes and energy storage.
Key finding: Proposed and validated a modified cubic empirical equation relating specific electrical conductivity to molar concentration and temperature for divalent metal sulfate aqueous solutions. Identified key parameters including... Read more
Key finding: Measured density and viscosity of ethanol-water mixtures with varying ethanol volume fractions and KCl electrolyte concentrations over 298-313 K. Demonstrated that increasing temperature decreases both density and viscosity,... Read more
Key finding: Synthesized solvent-free liquid alkali metal salts combining small alkali cations (Li+, Na+, K+) with asymmetric, structurally flexible organic anions, producing ambient temperature liquid salts with promising ionic... Read more