Metals have a variety of behaviors when deposited onto diblock copolymer films, in particular, poly(styrene-b-methylmethacrylate). Silver is known to form nanowires, whereas gold forms ellipsoidal nanoparticles of different sizes on each of the blocks, and chromium creates a uniform film on PS-b-PMMA. We show that with UV light we can alter the separation between silver nanowires, by making each wire narrower. We also demonstrate the effects of UV light on ...
Nanoscale diblock copolymer domains are aligned via top-down/bottom-up hierarchical assembly. Grating substrates template cylinder alignment with demonstrated 5000:1 aspect ratio for 100 micrometers domains extendable to arbitrary length scales. Depending on trough depth and amount of deposited polymer, aligned domains are (1) confined to the channels or (2) expanded across the grating frequently with (3) a complete absence of defects. This methodology can be exploited in hybrid hard/soft matter systems ...
We report a combined top-down/bottom-up hierarchical approach to fabricate massively parallel arrays of aligned nanoscale domains by means of the self-assembly of asymmetric polystyrene-block-poly(ethylene-alt-propylene) diblock copolymers. Silicon nitride grating substrates of various depths and periodicities are used to template the alignment of the high-aspect-ratio cylindrical polymer domains. Alignment is nucleated by polystyrene preferentially wetting the trough sidewalls and is thermally extended throughout the polymer film by defect annihilation. Topics discussed ...
Ultrathin diblock copolymer films have been offered as promising candidates for bottom-up templates in nanotechnological applications. Their natural tendency to self-organize into laterally alternating domains with a length scale tunable in the range of 10-100 nm is fundamental to their potential in this arena. However, having arbitrary control over the orientation of these domains is equally crucial and, until now, largely unrealized. We will present a novel lithographically assisted self-assembly ...
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