No abstract

Model growth of fullerene C 60 clusters in the solution in Nmethyl-2-pyrrolidone (NMP) is considered in the frame of nucleation theory. In addition to the previous models, the reason for the supersaturation caused the cluster formation is related to the appearance of new C 60 -NMP complexes with NMP. The dissolution process is taken into account. Different regimes of the proposed models depending on the kinetic parameters are distinguished and analyzed.1 Introduction The solubility of fullerenes in various solvents is of current interest especially regarding biomedical applications. However, in many cases fullerene solutions are not stable from the structural viewpoint and show a tendency towards the cluster formation [1][2][3]. The reasons and mechanisms of this effect are not fully understood. It is mostly pronounced in polar solutions [3]. Particularly, the active study of C 60 in N-methyl-2-pyrrolidone (NMP) [4][5][6][7][8][9] revealed a number of specific phenomena related to the cluster development in the neat solvent and its mixtures with other liquids of various polarity. In fact, the system C 60 /NMP shows somewhat a transition from the molecular solution (formed after dissolution) into the colloidal solution with time, which is followed by the cluster stabilization; again, the reason for the last fact is unclear.Recently, it was shown [3,9,10] that the principle kinetic features of the cluster growth observed experimentally in solutions of C 60 can be well characterized in terms of the nucleation theory [11]. After the corresponding equations of the limited growth model were proposed for low-polarity solutions of C 60 [3,10], the next step was their application to the solutions of higher polarity (such as C 60 /

No abstract