Nanostructure evolution during thermal treatment of polyimide-fullerene composites as revealed by WAXS and SAXS

The nanostructure formation in polyimide-fullerene composites during thermal treatment was investigated in situ, by means of wide-angle (WAXS) and small-angle X-ray scattering techniques. The WAXS patterns of the PI composites do not reveal the presence of C-60 reflections. However, the Pl/C-60 Composite, obtained by adding the C60 solution to the diamines-solution during the first step of the reaction (preparation of the polyamic acid, PAA), shows a maximum at small X-ray scattering angles. Results show that this intensity maximum is markedly affected by thermal treatment of the Pl/C60 composite, disappearing at high temperature. From in situ X-ray scattering experiments, the manner in which the C-60 nanoparticles are added to the other reactants and influences the properties of the final polymer is discussed. (c) 2005 Elsevier Ltd. All rights reserved.