A kinetic Monte Carlo analysis for the production of singularly tethered carbon nanotubes

Nanoparticles that possess a single covalent tether to either another particle or a surface play an increasingly important role in nanotechnology, serving as a foundation for aggregation-based plasmonic sensors, chemically assembled framework structures, and scanning probe tips. Using a theoretical approach, we explore the reaction conditions necessary to maximize singular tethering for several cases of homogeneously dispersed nanoparticles, with a particular focus on single-walled carbon nanotubes. In the limit of particles of monodisperse size and equal site reactivity, the number of tethers versus the reaction conversion is statistically described by the well-known binomial distribution, with a variance that is minimal for the single tether case. However, solutions of nanoparticles often deviate from this ideal, and reaction events can introduce steric hindrance to neighboring sites or alter particle electronic properties, both of which can influence local reactivity. In order to study these cases we use the electron transfer reactions of single-walled carbon nanotubes. We find that the distribution in the number of monofunctional tubes, as a function of conversion, is largely dependent on the distribution of nanotube rate constants, and therefore tube chiralities, in the initial solution. As a contemporary example, we examine the implications of this result on the metallic-semiconductor separation of carbon nanotubes using electron transfer chemistry.