Automated aqueous two-phase separation of single walled carbon nanotube species for enrichment process optimization and scale up

Single-walled carbon nanotubes (SWCNT) are known to have a variety of unique functional properties with utility in applications including optical sensing, electronics, pharmaceuticals, and water filtration. However, when manufactured, SWCNT occur as a heterogenous, polydisperse material that exhibits a range of properties that diminish performance. Purification of SWCNT by aqueous two-phase (ATP) separation is a process developed at NIST that is efficient and effective. Yet, until recently, its use has been limited to manual, bench-scale deployment. To greatly expand potential SWCNT use and practicality, Zymosense—as part of a successful Phase I SBIR proof-of-concept NIST project—has demonstrated a high-throughput, semi-automated method to screen/optimize ATP separations. It is the intent of the follow-on Phase II project proposed here to achieve the following: 1) screen and optimize this process to maximize separation quality and efficiency; 2) improve process yield by developing/validating methods to mitigate losses due to material aggregation; and 3) prototype purified SWCNT for use and evaluation by beta-testers. Phase II success will allow optimized protocols to then be licensed to SWCNT manufacturers for distribution to end-users. Purified SWCNT will also be used at Zymosense to manufacture enzyme-activity probes with improved stability (>3x) and signal-to-noise ratios (>50x).