This Small Business Innovation Research (SBIR) Phase I project will develop high throughput metal ion-selective separation composites for the extraction and purification of critical metals in production, and water and metal recycling environments. The problem this research addresses is the high cost and inefficiency of existing metal separation resins. Ion exchange processes operate by passing the metal-containing solution through a bed of porous particles with functional chemistry inside the pores. Since the solution prefers to flow around the particle, the diffusion of metal ions into the pores is slow and rate limiting. This research literally turns the pore diffusion problem inside out by synthesizing composite column matrices composed of solid nonporous particles. The composite materials are assembled by formation of thinly crosslinked, functional polymers that are covalently tethered in the interstitial volumes between solid particles. The polymer networks can be visualized as an array of 'spider webs' suspended in the micron-scale interparticle volumes of the composite columns. The strands of the nano spider webs are functionalized with metal-selective chelating reagents. The research objectives are to synthesize and test transition metal-selective extraction composites. The project is expected to produce prototype high throughput columns that are manufacturable at an extremely low cost. The commercial applications of the research involve most fields of water and metal separations. The uses include extraction of toxic metals from water, water deionization and recycling, semiconductor wastewater recycling, and the mining of copper, gold, platinum, nickel, and cobalt.
