Explaining Fullerene Dispersion by using Micellar Solutions

Abstract

An effective computational strategy to describe the dispersion of C60 by surfactants is presented. The influence of parameters such as surfactant concentration and molecular length on the final morphology of the system is explored to explain the experimental results and to understand the incorporation of C60 inside micelles. Both neutral and charged amphiphilic molecules are simulated. The long-discussed problem of the location of fullerenes in micelles is addressed and C60 is found in the hydrocarbon-chain region of the micelles. If the available hydrophobic space increases, C60 is localized in the inner part of the micellar core. Short, charged amphiphilic stabilizers are more efficient at dispersing fullerenes monomolecularly. Two different phases of C60 are observed as the C60/surfactant ratio varies. In the first, aggregates of C60 are entrapped inside the micelles, whereas, in the second, colloidal nanoC60 is formed with surfactants adsorbed on the surface.

Proteins as supramolecular hosts for C60: a true solution of C60 in water

“…iii) Use of dispersants such as surfactants, block copolymers, amphiphilic polymers, micelles and liposomes. 28,29 The use of dispersants is effective and a large quantity of C 60 can be dispersed also in water. The resulting solutions are characterized by polydispersion of fullerene aggregates of different sizes, because the fullerenes may exist in the form of both small aggregates solubilized within the hydrophobic core of the nanostructures formed by the dispersants and large aggregates stabilized by surface adsorption of the dispersants.…”

“…The resulting solutions are characterized by polydispersion of fullerene aggregates of different sizes, because the fullerenes may exist in the form of both small aggregates solubilized within the hydrophobic core of the nanostructures formed by the dispersants and large aggregates stabilized by surface adsorption of the dispersants. 28,29 iv) Dispersion of C 60 by suitable carriers endowed with hydrophobic cores, such as cyclodextrins, calixarenes, and other macrocyclic receptors or molecular tweezers. [30][31][32] The supramolecular approach is the most effective way to obtain monodispersed pristine fullerenes.…”

Determination of the equilibrium constant of C60 fullerene binding with drug molecules

“…where A' is given as the second virial coefficient characterizing the cluster-cluster long-range interaction [26], which may depend on the charge of the ligand. (10) where η is the solvent viscosity; k is the Boltzmann constant; T is the absolute temperature; d0 is the diameter of the solution component used to acquire NMR magnetization decay, which in case of DOSY is the characteristic ligand dimension; A' is the second virial coefficient [26];…”

“…This arises as a consequence of strong πstacking interactions with other small molecules in aqueous solution [5]. The effect of complexation had mainly been investigated in terms of the formation of supramolecular C60 fullerene-ligand ordered structures [6,7], host-guest phenomena [8,9] or C60 fullerene binding with micelles [10,11]. However, during the past five years the complexation of pristine C60 fullerene with small drug molecules in aqueous solution has become a major focus of scientific investigation.…”

C60-dyad aggregates: Self-organized structures in aqueous solutions

“…(1) the solubilisation of fullerenes using different solubility enhancers -surfactant micelles, 17 liposomes, 18 and lipid membranes, 19,20 which are of biopharmaceutical interest for covering biocompatible surfaces or for the controlled release of drugs;…”