Small Angle X-Ray Scattering studies in colloidal silica/PMMA nanocomposites

PERUZZO, P.J.; ANBINDER, P.S.; PLIVELIC, T.S.; AMALVY, J.I.

Campinas

Congreso; 20ª Reunión Anual de Usuarios LNLS - RAU 2010; 2010

LNLS

In a previous work (1) we have studied the morphology of silica/polymethylmethacrylate nanocomposites in solid form. SAXS results indicated the existence of different morphology according to silica particles characteristics. However agglomeration of particles in the solid state could modify the scattering pattern. To avoid solid state e®ects we have performed new SAXS determinations using the colloidal form of particles. SAXS measurements on samples were performed at the SAXS2 beam line at the LNLS (Campinas, Brazil) using a monochromatic beam of wavelength 1.608 ºA and exposure time of 300 sec, and a sample detector distance of 1805.6 mm. As expected the curves obtained in the dispersion state exhibit more signals allowing a more detailed analysis of the morphology which include information about the particle size and their PSD. Porod`s plots have an asymptotic linear regime for all the samples indicating the presence of abrupt and well deffined interfaces. The modeling of the latex particles is performed assuming that the particles are randomly oriented in the sample using the morphology suggested by transmission electron microscopy.