The Daily Bulletin Archive

John-David Rocha, assistant professor of chemistry at the Rochester Institute of Technology, will present his research talk "Using Near-Infrared Spectrofluorimetric Analysis toward Production and Applications of High Purity Metallic and Semiconducting Single-Walled Carbon Nanotube Samples" at 12:30 p.m. Thursday, March 12, in Science Building 272. The Chemistry-Physics Seminar Series is supported by the Faculty-Student Association. An abstract of Rocha's talk appears below.

Abstract
Development of new instrumentation for near-infrared spectrofluorimetric analysis (NIR-SFA) of single-walled carbon nanotubes (SWCNTs) is useful in many applications relevant to SWCNT research and production level quality control. Synthesis methods such as CoMoCAT, HiPco, PLV, and CVD produce several different distributions of (n,m) structures. Post-synthesis processing such as functionalization and/or separations must therefore be employed to yield high-purity, electronically (metallic vs. semiconducting) separated SWCNTs or samples highly enriched in single (n,m) SWCNT species. Methods to rapidly detect and analyze these initially highly heterogeneous mixtures and the resulting enriched samples requires appropriate understanding of both spectrophotometric instrumental design techniques and fundamental photophysical data representing individual SWCNT species. Using multiple fixed wavelength lasers for excitation, appropriate near-infrared photodetection systems (Si or InGaAs), and in-house-developed "global" spectral analysis routines, one can obtain full (n,m) sample distributions in real time. This instrumentation further allows for concerted study of samples obtained following post-synthetic methods, for instance, individual (n,m) species are monitored in real time during a gel-based column separation process. System designs and optimization will be presented using initial datasets for SWCNT electronic and (n,m) separation, as well as the monitoring of (n,m) specific kinetics.