Aligned coiled carbon nanotubes for capacitive deionization of potable water

Overview

This solution introduces a novel electrode design for capacitive deionization (CDI), a process that removes ions and contaminants from water using electrically charged electrodes. The approach uses vertically aligned helical carbon nanotubes grown directly on carbon-based current collectors, then coated with ion-selective membranes. This combination increases the surface area available for ion adsorption while reducing contact resistance between the membrane and the current collector, resulting in lower energy consumption and improved water treatment efficiency. The technology targets potable water applications, with a conservative cost estimate of under $7 per 1000 gallons of treated water, depending on influent concentration.

Technical specifications

• Vertically aligned helical carbon nanotubes grown via chemical vapor deposition (CVD) on carbon-based current collectors
• Ion-selective membrane coating applied through spin-coating over the nanotube structure
• Enhanced surface area for ion adsorption compared to conventional vertically aligned carbon nanotubes
• Reduced contact resistance at the current collector/active material interface, lowering in-house energy usage
• Scalable manufacturing process based on established CVD nanotube growth techniques
• Targeted contaminant removal aligned with EPA-set contaminant values for potable water
• Cost efficiency estimated at under $7 per 1000 gallons for typical influent concentrations

Technology readiness level

The technology builds on previously validated research, including demonstrated growth of vertically aligned helical carbon nanotubes for enhanced surface area in energy storage applications and a patented method for adsorbing redox polymers. The CVD nanotube growth process is commercially viable and developed by the principal investigator. Future validation will involve fabricating nanostructured electrodes using CVD-grown nanotubes, spin-coating ion-selective membranes, and testing the system for membrane-based capacitive deionization performance. The approach is positioned for further development and pilot-scale validation toward commercial deployment.