(Co-)solvent selection for single-wall carbon nanotubes: best solvents, acids, superacids and guest–host inclusion complexes

Abstract

Analysis of 1-octanol-water, cyclohexane-water and chloroform (CHCl(3))-water partition coefficients P(o-ch-cf) allows calculation of molecular lipophilicity patterns, which show that for a given atom log P(o-ch-cf) is sensitive to the presence of functional groups. Program CDHI does not properly differentiate between non-equivalent atoms. The most abundant single-wall carbon nanotube (SWNT), (10,10), presents a relatively small aqueous solubility and large elementary polarizability, P(o-ch-cf) and kinetic stability. The SWNT solubility is studied in various solvents, finding a class of non-hydrogen-bonding Lewis bases with good solubility. Solvents group into three classes. The SWNTs in some organic solvents are cationic while in water/Triton X mixture are anionic. Categorized solubility is semiquantitatively correlated with solvent parameters. The coefficient of term β is positive while the ones of ε and V negative. The electron affinity of d-glucopyranoses (d-Glcp(n)) suggests the formation of colloids of anionic SWNTs in water. Dipole moment for d-Glcp(n)-linear increases with n until four in agreement with 18-fold helix. The I(n)(z-) and SWNT(-) are proposed to form inclusion complexes with cyclodextrin (CD) and amylose (Amy). Starch, d-Glcp, CD and Amy are proposed as SWNT co-solvents. Guests-hosts are unperturbed. A central channel expansion is suggested.