Polymeric nanocylinders by combining block copolymer self-assembly and nanoskiving

A new facile fabrication approach to generate polymeric nanostructures is described. Block copolymers containing immiscible segments can self-assemble to generate ordered nanostructures, such as cylinders of one block in a matrix of the other in the bulk, which can then be sectioned on the nanoscale using a microtome (nanoskiving). Dispersing these sections in a selective solvent for the matrix block results in nanocylinders. In one example, we utilized a poly(N,N-dimethylacrylamide)-block-poly(styrene) (PDMA-PS) copolymer containing 36% by volume of PS. This composition was selected as it self-assembles into cylinders of PS in a matrix of PDMA. Following a previously described procedure, the cylinders were aligned using a channel die. The aligned samples were subsequently sectioned using a microtome containing a diamond knife and dispersed in water, a selective solvent for the PDMA matrix, affording PS nanocylinders with a PDMA corona. This technique allows tuning of nanocylinders without the requirement of specialty fabrication equipment.