Preparation and characteristics of alpha-Fe2O3 nanocrystalline/block copolymer heterostructure composite

alpha-Fe2O3 nanocrystalline was encapsulated by block copolymer, hydroxylat ed poly(styrene-b-butadiene-b-styrene) (HO-SBS), and formed alpha-Fe2O3/HO- SBS heterostructure composite consisting of nanocrystalline core and copoly mer shell. Transmission electron microscopy (TEM) and atomic force microsco py (AFM) are used to investigate the structure of the composite. And the re sults show that alpha-Fe2O3 core is 45nm in diameter and copolymer shell is 10nm. Cyclic voltammetry demonstrated copolymer shells can act as potentia l barriers, while electric field introduced surface photovoltage spectrosco py (EFISPS) testifies that charges can be introduced to penetrate through t he shell under external electronic field.