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Solution and Surface Composition Gradients via Microfluidic Confinement: Fabrication of a Statistical-Copolymer-Brush Composition Gradient

Published

Author(s)

Chang Xu, Susan E. Barnes, Tao Wu, Daniel A. Fischer, Dean M. DeLongchamp, J Batteas, Kathryn L. Beers

Abstract

A simple method to generate solution gradients through microfluidic confinement is described. The solution gradient inside a microchannel was formed by varying the relative infusion rates of two solutions that differed in compositions. The establishment and maintenance of a stable solution gradient in a microchannel was confirmed using the Raman spectroscopy. The stable solution gradient was explored to synthesize a surface-grafted statistical copolymer brush gradient of n-butyl methacrylate (BMA) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) via surface-initiated atom transfer radical polymerization (ATRP). The resulting gradient exhibits a surface energy change from the homopolymer brush of BMA to that of DMAEMA, as indicated by water contact angle measurement. Further evidence from near-edge absorption fine structure (NEXAFS) spectroscopy confirmed the gradual transition of surface composition from one end of the substrate to the other.
Citation
Advanced Materials
Volume
18

Keywords

ATRP, copolymer brushes, gradient thin films, microfluid

Citation

Xu, C. , Barnes, S. , Wu, T. , Fischer, D. , DeLongchamp, D. , Batteas, J. and Beers, K. (2006), Solution and Surface Composition Gradients via Microfluidic Confinement: Fabrication of a Statistical-Copolymer-Brush Composition Gradient, Advanced Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852560 (Accessed June 15, 2024)

Issues

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Created June 6, 2006, Updated February 19, 2017