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Morphological Changes from Silica Tubules to Hollow Spheres Controlled by the Intermolecular Interactions within Block Copolymer Micelle Templates

Cited 20 time in Web of Science Cited 22 time in Scopus
Authors
Lee, Hyemin; Char, Kookheon
Issue Date
2009-04-09
Publisher
American Chemical Society
Citation
ACS Appl. Mater. Interfaces, 2009, 1, 913-920
Keywords
hollow silicablock copolymer micelle(s)quaternizationdielectric constantintermolecular interaction(s)
Abstract
The morphological changes from tubules to large hollow spheres to (micelle-sized) small hollow-spherical silica were realized by polystyrene-block-poly(vinylpyridine) (PS-b-PVP) block copolymer micelle templates by controlling the intermolecular interactions with the corona chains. PS-b-PVP with weak intermolecular interactions among PVP corona chains yields the coexistence of tubules, large hollow spheres, and small hollow spheres. The coexistence of the three phases arises from the direct aggregation of block copolymer micelles during hydrolytic condensation of a silica precursor (tetraethylorthosilicate), as evidenced by transmission electron microscopy. When the degree of intermolecular interactions within the PVP corona blocks is increased by a change in either the degree of quaternization of the PVP blocks or the dielectric constant of the medium, small hollow spherical silica, with size equivalent to the block copolymer micelles, were solely obtained. We believe that this morphological change is due to the fact that the dipole-dipole interactions among quaternized PVP blocks physically cross-link the PVP coronas in micelles resisting the curvature change during the silica condensation.
ISSN
1944-8244
Language
English
URI
http://hdl.handle.net/10371/5657
DOI
https://doi.org/10.1021/am900026s

https://doi.org/10.1021/am900026s
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College of Engineering/Engineering Practice School (공과대학/대학원)Dept. of Chemical and Biological Engineering (화학생물공학부)Journal Papers (저널논문_화학생물공학부)
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