Programming nanostructures of polymer brushes by dip-pen nanodisplacement lithography (DNL)

We report a facile and versatile scanning probe based approach-dip-pen nanodisplacement lithography (DNL)--for manipulating nanostructures of polymer brushes. Nanostructured polymer brushes with sizes as small as 25 nm are made by DNL patterning of the initiator molecules and subsequent surface-initiated polymerization. Nanoconfinement effects including chain collapsing and spreading are observed in the nanopatterned polymer brushes. In addition to chemical structure, size, topography and shape, our approach can also readily program the grafting density, chain configuration, hierarchical structure and multiplexing of the polymer brushes, which allows for the realization of complex chemical surfaces.