Credit: Tew Research Group, UMass Amherst
Figure shows the block copolymer (left) and homopolymer (right) samples. The background of both figures is a transmission electron microscopy image showing that the block copolymer is made of nanoscopic domains visualized as a honeycomb pattern of cobalt-rich cylinders while the homopolymer is unstructured but contains small cobalt particles shown in black. Similar small cobalt particles are present in the block copolymer but they are not easily observed due to the nanoscopic block copolymer super-structure. The chemical structure of both polymers is also shown along with powder samples of the two materials. The block copolymer is attracted to the white magnet bar shown in the photograph while the non-magnetic homopolymer sample has no such attraction.