Size effect of nanomagnetite on magnetoresistance of core-shell structured polyaniline nanocomposites

In this work, magnetoresistive nanomagnetite@polyaniline (Fe3O4@PANI) composites with a core-shell structure were prepared by in situ polymerization method with KH-550 as coupling agent. All the samples demonstrated the positive MR, and compared with PANI composites reinforced with small (diameter 80 nm) size or large (diameter 450 nm) size of Fe3O4, the PANI composites reinforced with medium (diameter 220 nm) size of Fe3O4 exhibit the largest MR (8.41