|
Authors
|
Tokarev, I. ; Kreneke, R. ; Burkov, Y. ; Schmeisser, D. ; Sidorenko, A. ; Minko, S. ; Stamm, M.
|
|
Title
|
Microphase Separation in Thin Films of Poly(styrene-block-4-vinylpyridine) Copolymer - 2-(4'-Hydroxybenzeneazo)benzoic Acid Assembly
|
|
Date
|
22.09.2005
|
|
Number
|
12394
|
|
Abstract
|
The fine structure of thin films of poly(styrene-<I>block</I>-4-vinylpyridine) copolymer-2-(4'-hydroxybenzeneazo)benzoic acid (PS-PVP+HABA) assembly has been studied using the combination ofatomic force microscopy, ellipsometry, X-ray reflectivity, GISAXS, XPS, and XPEEM. The films consistof cylindrical nanodomains formed by PVP+HABA associates surrounded by PS matrix. Alignment ofthe domains can be switched upon exposure to vapors of different solvents from the parallel toperpendicular orientation and vice versa with respect to the surface plane. Swelling in 1,4-dioxane leadsthe system from the cylindrical to the spherical morphology. Solvent evaporation results in a shrinkageof the matrix in the vertical direction and subsequent merging of the spheres into the perpendicularlyaligned cylinders. The cylinders form a regular hexagonal lattice with a spatial period of 25.5 nm. Onthe other hand, vapors of chloroform induce in-plane alignment. The films consist of parallel layers ofthe cylinders separated by PS matrix and demonstrate the fingerprint-like structure. The nanocylindersof PVP+HABA are packed into a distorted hexagonal lattice exhibiting 31 nm in plane and 17 nm verticalperiodicity. In both cases a thin wetting layer<br /> is found at the polymer-substrate interface. The free surfaceis enriched with PS.
|
|
Publisher
|
Macromolecules
|
|
Wikidata
|
|
|
Citation
|
Macromolecules 38 (2005) 507-516
|
|
DOI
|
https://doi.org/10.1021/ma048864i
|
|
Tags
|
block-copolymer microstructure asymmetric diblock copolymers surface-induced orientation ion mass-spectrometry electric-fields phase-behavior domain alignment length scales morphology brushes
|
