mz9b00036_si_001.pdf (641.37 kB)
Irreversible Physisorption of PS‑b‑PMMA Copolymers on Substrates for Balanced Interfacial Interactions as a Versatile Surface Modification
journal contribution
posted on 2019-04-18, 12:11 authored by Wooseop Lee, Yeongsik Kim, Seungyun Jo, Seongjin Park, Hyungju Ahn, Du Yeol RyuWe
present a direct approach to fabricating the perfect neutral
layer for block copolymer (BCP) self-assembled thin films. An irreversible
physisorption of polystyrene-b-poly(methyl methacrylate)
(PS-b-PMMA) itself onto the bottom substrates, though
extremely thin, offers such a compositional randomness for the substrates,
directing the balanced interfacial interactions toward both blocks
of the top-layer PS-b-PMMA. Owing to the neutral
property from the skin layers, the chemically identical BCP self-assembles
into perpendicular microdomains on the adsorbed layer composed of
itself, as identified in symmetric PS-b-PMMA films.
Intriguingly, the compositional randomness turns out to be valid when
the correlation length (ξ) of the BCP layer adsorbed on the
substrates is shorter than equilibrium lamellar spacing (L0) of the BCP. Our strategy provides its versatility applicable
to various substrates without any necessity of specific random copolymer
brushes or mats, enabling the design of a neutral platform for PS-b-PMMA films.