This work proposes a new approach to controlled generation of nanoparticles with tunable sizes via a top-down approach. Block copolymers containing immiscible blocks can self-assemble to generate ordered nanostructures. Our approach is based on sectioning thin slices of a block copolymer that adopts a cylindrical morphology using a microtome (nanoskiving). Tens of nanometers-thick sections can be achieved using this technique. Dispersing these sections in a good solvent for the matrix block results in nanoparticles (nanocylinders). In one example, we utilize a poly(styrene)-block-poly(lactide) block copolymer (PS-PLA), with 26 volume percent of PLA that self-assembles into cylinders of PLA in a matrix of PS. Following a previously-described procedure, the morphology was aligned using a channel die. The highly ordered samples subsequently were sectioned using a diamond knife and dispersed in cyclohexane, a selective solvent for the PS matrix. With these preliminary experiments we demonstrated some level of control on the size of the resulting nanocylinders by varying the thickness of the sections.  Figure 1.1. Schematic representation of nanoparticle generation combining block copolymers self-assembly and nanoskiving. The work in progress consists of developing a new cylinder-forming system, poly(N,N- dimethylacrylamide)-block- poly(styrene) (PDMA-PS) copolymer, with a matrix of the water-soluble PDMA. By incorporating PDMA, we were able to prepare aqueous dispersions of nanoparticles that hold promise as delivery vehicles for various cargos.

Polymeric nanocylinders by combining block copolymer self-assembly and nanoskiving

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.