Water-Soluble Highly Charged Fullerene Derivatives as Spherical Electrolytes.
Electrostatic Contributions to Thermodynamic Functions of Systems Containing Mixtures of Counterions Differing in Charge and Size

Jože Škerjanc

Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5,
1000 Ljubljana, Slovenia

The Poisson-Boltzmann equation has been solved to obtain the electrostatic potential for the spherical cell model of a fullerene molecule at which charged functional groups are attached. The fullerene macroion is surrounded by mixtures of small counterions differing in size and charge. The electrostatic internal and free energies, degree of binding of counterions, osmotic coefficient, and distribution of counterions around the charged fullerene shell are calculated. These properties are presented as functions of radii, charges and mole fractions of counterions.

Key words: Poisson-Boltzmann equation, spherical cell model, thermodynamic functions, polyelectrolyte solutions, fullerene electrolytes, fullerenehexamalonic acid