Substrate patterning using regular macroporous block copolymer monoliths as sacrificial templates and as capillary microstamps

TL;DR

This paper introduces novel substrate patterning techniques using macroporous block copolymer monoliths as sacrificial templates and capillary microstamps, enabling precise nanostructure fabrication and reusable stamping under ambient conditions.

Contribution

It presents new methods for substrate patterning with macroporous block copolymer monoliths as templates and stamps, expanding capabilities beyond classical elastomer stamps.

Findings

Ordered arrays of NaCl nanocrystals and iridium films were fabricated using the templates.

Capillary microstamping with these monoliths is repeatable and maintains pattern quality.

The methods enable versatile nanostructure patterning and are compatible with advanced microscopy.

Abstract

Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) monoliths containing regular arrays of macropores (diameter ~1.1 microns, depth ~700 nm) at their surfaces are used to pattern substrates by patterning modes going beyond the functionality of classical solid elastomer stamps. In a first exemplary application, the macroporous PS-b-P2VP monoliths are employed as sacrificial templates for the deposition NaCl nanocrystals and topographically patterned iridium films. One NaCl nanocrystal per macropore is formed by evaporation of NaCl solutions filling the macropores followed by iridium coating. Thermal PS-b-P2VP decomposition yields topographically patterned iridium films consisting of ordered arrays of hexagonal cells, each of which contains one NaCl nanocrystal. For the second exemplary application, spongy-continuous mesopore systems are generated in the macroporous PS-b-P2VP monoliths by selective-swelling induced pore generation. Infiltrating the spongy-continuous mesopore systems with ink allows capillary microstamping of continuous ink films with holes at the positions of the macropores onto glass slides compatible with advanced light microscopy. Capillary microstamping can be performed multiple times under ambient conditions without re-inking and without quality deterioration of the stamped patterns. The macroporous PS-b-P2VP monoliths are prepared by double replication of primary macroporous silicon molds via secondary polydimethylsiloxane molds.