An integrated AFM and SANS approach toward understanding void formation inconductive composite materials

The morphology of voids within carbon black-filled polyethylene conductive composites has been studied by both atomic force microscopy and small-angle neutron scattering. Both void size and polyethylene crystalline lamellae t hickness were measured with both techniques, and the results were compared. Atomic force micrographs indicate that voids form at the carbon black-poly ethylene interface as previously hypothesized from the interpretation of ne utron scattering experiments alone. This result supports the conclusion tha t voids provide a stress release mechanism during polyethylene crystallizat ion and that variables such as filler morphology, volume fraction, and poly mer crystallinity may he used to quantitatively predict the extent of void incorporation as composite composition is varied.