Ultrathin binary grafted polymer layers with switchable morphology

Authors
LeMieux, MCJulthongpiput, DBergman, KNCuong, PDAhn, HSLin, YHTsukruk, VV
Issue Date
2004-11-09
Publisher
AMER CHEMICAL SOC
Citation
LANGMUIR, v.20, no.23, pp.10046 - 10054
Abstract
Polymer surface layers comprised of mixed chains grafted to a functionalized silicon surface with a total layer thickness of only 1-3 nm are shown to exhibit reversible switching of their structure. Carboxylic acid-terminated polystyrene (PS) and poly (butyl acrylate) (PBA) were chemically attached to a silicon surface that was modified with an epoxysilane self-assembled monolayer by a "grafting to" routine. While one-step grafting resulted in large, submicron microstructures, a refined, two-step sequential grafting procedure allowed for extremely small spatial dimensions of PS and PBA domains. By adjusting the grafting parameters, such as concentration of each phase and molecular weight, very finely structured surfaces resulted with roughly 10-nm phase domains and less than 0.5-nm roughness. Combining the glassy PS and the rubbery PBA, we implemented a design approach to fabricate a mixed brush from two immiscible polymers so that switching of the surface nanomechanical properties is possible. Post-grafting hydrolysis converted PBA to poly(acrylic acid) to amplify this switching in surface wettability. Preliminary tribological studies showed a difference in wear behavior of glassy and rubbery surface layers. Such switchable coatings have practical applications as surface modifications of complex nanoscale electronic devices and sensors, which is why we restricted total thickness for potential nanoscale gaps.
Keywords
SELF-ASSEMBLED MONOLAYERS; POLY(METHYL METHACRYLATE)/POLYSTYRENE BRUSHES; TRANSFER RADICAL POLYMERIZATION; THIN-FILMS; NANOCOMPOSITE COATINGS; MODIFIED SILICON; WEAR STABILITY; SURFACE; ADSORPTION; LUBRICANTS; SELF-ASSEMBLED MONOLAYERS; POLY(METHYL METHACRYLATE)/POLYSTYRENE BRUSHES; TRANSFER RADICAL POLYMERIZATION; THIN-FILMS; NANOCOMPOSITE COATINGS; MODIFIED SILICON; WEAR STABILITY; SURFACE; ADSORPTION; LUBRICANTS
ISSN
0743-7463
URI
https://pubs.kist.re.kr/handle/201004/137062
DOI
10.1021/la048496b
Appears in Collections:
KIST Article > 2004
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML

qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE