STTR Phase I:Nano Functionalized Capacitive Deionization For Water Purification

The broader impact of this Small Business Technology Transfer (STTR) Phase I project is to further develop a technology that will unlock large new supplies of water. The technology can potentially provide a much-needed alternative to reverse osmosis (RO) for water purification, currently the most widely used technology applicable to total dissolved solids.The proposed technology seeks to address unmet needs in water reuse, water recycling, water purification, brackish desalination, and salt-less water softening. The solution may be applicable to water quality, including water supplies impaired with total dissolved solids, nitrate, arsenic, fluoride, and other contaminants. The technology may have applications in electric grid, commercial, and industrial processes for the use of low-quality grey water, wastewater, re-used water, ground water, and residential water. Success of this project would help in mitigating environmental, social, and economic threats related to water.This STTR Phase I project seeks to enable optimization of third generation capacitive deionization electrodes for improved charge efficiency, energy usage, water recovery, lifetime and feed concentration.An initial target is to remove at least 2000 ppm from a mineral- or salt-contaminated feed and recover at least 70% at low cost. Higher concentrations of water impurities will be explored to determine the operational envelope. The planned experiments intend to help quantitate how surface functionalization with ionic groups increases charge efficiency and affects important electronic properties such as capacitance, resistance, and operating lifetime. These properties will be cross checked against different feed solution concentrations, the ability to purify a given concentration of feed solution, water recovery,and nanoscale electrode pore characteristics. Ionic molecules of different chain lengths will be tested for their ability to extend co-ion exclusion beyond mesopores into the macropore portion of capacitive electrodes. Adsorption studies will be performed to determine the number of ionic groups attached to the nanoscale electrode pore surfaces and to determine the robustness of their attachment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.