Enrichment of (8,4) Single-Walled Carbon Nanotubes Through Coextraction with Heparin

Abstract

Heparin sodium salt is investigated as a dispersant for dispersing singlewalled carbon nanotubes (SWNTs). Photoluminescence excitation (PLE) spectroscopy is used for identification and abundance estimation of the chiral species. It is found that heparin sodium salt preferentially disperses larger-diameter Hipeo SWNTs. When used to disperse CoMoCAT nanotube samples, heparin has a strong preference for (8,4) tubes, which have larger diameter than the predominant (6,5) in pristine CoMoCA T samples. PLE intensity due to (8,4) tubes increases from 7% to 60% of the total after threefold extractions. Computer modeling verifies that the complex of (8,4) SWNTs and heparin has the lowest binding energy amongst the four semiconducting species present in CoMoCA T. Network field-effect transistors are successfully made with CoMoCAT/heparin and CoMoCAT/sodium dodecylbenzene sulfonate (SDBS)-heparin (x3), confirming the easy removability of heparin.