Photophoretic separation of single-walled carbon nanotubes: A novel approach to selective chiral sorting

For over two decades single-walled carbon nanotubes (SWCNTs) have been used in a broad range of electronic and optical applications, however the selective chiral sorting of SWCNTs with guaranteed optoelectronics characteristics is imperative to the industrial realization of such applications. In this paper we provide the results of modeling an optical sorting method that utilizes the inherent opto-electronic properties of the SWCNTs, thus guaranteeing the properties of the extracted populations. Utilizing the resonant transfer of photonic momentum, we simulate chiral sorting of two chiral populations in an aqueous environment based on the frequency dependent optical absorption properties of the nanotubes. We show that photonic sorting is not only feasible, but may be up to faster than density gradient centrifugation techniques. Our simulations investigate the effects of laser power, temperature and orientation. We find that 96% purity can be achieved in less than 12 minutes by operating at 9 × 10⁷ W m^-2 (20 mW in a 20 μm chamber) at elevated temperatures.