Facile non‐lithographic route to highly aligned silica nanopatterns using unidirectionally aligned polystyrene‐block‐polydimethylsiloxane films

Abstract

Thin films (monolayer and bilayer) of cylinder forming polystyrene-block-polydimethylsiloxane (PS-b-PDMS) were shear aligned by the swelling and deswelling of a crosslinked PDMS pad that was physically adhered to the film during solvent vapor annealing. The nanostructures formed by selfassembly were exposed to ultraviolet-ozone to partially oxidize the PDMS, followed by calcination in air at 500 8C. In this process, the PS segments were fully decomposed, while the PDMS yielded silica nanostructures. The highly aligned PDMS cylinders were thus deposited as silica nanolines on the silicon substrate. Using a bilayer film, the center-to-center distance of these features were effectively halved from 38 to 19 nm. Similarly, by sequential shear-alignment of two distinct layers, a rhombic array of silica nanolines was fabricated. This methodology provides a facile route to fabricating complex topographically patterned nanostructures.

Developing Anisotropy in Self‐Assembled Block Copolymers: Methods, Properties, and Applications

“…Similarly, Vogt et al fabricated a 3D silica nanomesh by stacking two different layers of unidirectionally aligned cylinder forming PS-b-PDMS nanotemplates and followed by ultraviolet-zone exposure and calcination in air at high temperature to remove organic components. [475] Very recently, Deng et al developed a general strategy to construct 3D multilayer-crossed metal oxide nanowire arrays, such as Si-doped metastable -phase WO 3 , through co-assembly of PEO-b-PS and polyoxometallates followed by the calcination induced structure transformation. The 3D multilayer-structured metal oxide semiconducting material exhibits not only ultrahigh sensitivity and fast response-recovery dynamics, but also excellent selectivity, rendering it to be an excellent candidate as acetone sensors.…”

Optical Alignment of Si-Containing Nanodomains Formed by Photoresponsive Amorphous Block Copolymer Thin Films

“…Such surfaces having highly-ordered silica precursor domainforming line and space patterns can be used as guides for the long range order nanofabrication of features (e.g., dots, holes and pillars) derived from the BCP self-assembly processes. 36,38,[52][53][54]…”

Bio‐Inspired Silica Films Combining Block Copolymers Self‐Assembly and Soft Chemistry: Paving the Way toward Artificial Exosqueleton of Seawater Diatoms

“…Qiang et al. [ 58 ] used a copolymer composed of PS and polydimethylsiloxane (PDMS) as silica precursor to create silica nanopattern. The nanopattern is induced by the self‐assembly into nano‐lines with tunable center‐to‐center distances.…”