NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

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
Pub Type
Journals

Download Paper

Local Download

Keywords

ATRP, copolymer brushes, gradient thin films, microfluid
Chemical engineering and processing and Polymers

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 October 27, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created June 6, 2006, Updated February 19, 2017
Was this page helpful?