Characteristics of solubilization and encapsulation of fullerene C60 in non-ionic Triton X-100 micelles

The solubilization and encapsulation of monomeric C60 in Triton X-100 micelles were investigated. Characteristic hydrophobic interactions of the type pi-pi and CH-pi between the Triton X-100 micelle and C60 resulted in stable aqueous dispersions of C60 in the micellar medium, as evidenced from UV-vis, fluorescence emission and micro-Raman spectroscopy. Cyclic voltammetry of C60 encapsulated Triton X-100 in aqueous 5mM LiClO4 solution revealed a quasi-reversible one-electron reduction peak with E1/2=-0.61V and a reversible reduction peak at E1/2=-1.11V vs. Ag/AgCl reference electrode at a scan rate of 10mVs-1, a redox behaviour drifting substantially from that of pure C60. An onset concentration of 0.025mM for C60 aggregation in the micellar core was substantiated from the characteristic absorption spectral broadening and quenching of pyrene fluorescence. The molar solubilization capacity of C60 in aqueous Triton X-100 micellar solution was estimated spectrophotometrically to be 0.22.