Poly(vinyl pyrrolidone)—C70 complexes in aqueous solutions

Aqueous solutions of poly(vinyl pyrrolidone)–fullerene complexes (PVP–C70) have been studied using static and dynamic light scattering methods. Two diffusive processes were detected. The slow diffusion was interpreted as dynamics of large intermolecular PVP–C70 complexes while the fast diffusion was associated with the presence of individual PVP molecules in solution. It was also shown that the molecular weights and dimensions of PVP–C70 complexes are smaller than for PVP–C60 by a factor of 2.5–3. In aqueous solutions of PVP–C70 complex the depolarization and dissymmetry of scattered light were observed in contrast to PVP–C60 solutions. It reveals the existence of anisotropic structures in PVP–C70 solutions. Intermolecular interactions within PVP–C70 complexes are weak and a hydrodynamic field can destroy complexes.