| Author(s): |
Chang Xu; Susan E. Barnes; Tao Wu; Daniel A. Fischer; Dean M. DeLongchamp; J Batteas; Kathryn L. Beers; |
| Title: |
Solution and Surface Composition Gradients via Microfluidic Confinement: Fabrication of a Statistical-Copolymer-Brush Composition Gradient |
| Published: |
June 06, 2006 |
| 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 |
| Pages: |
pp. 1427 - 1430 |
| Keywords: |
ATRP;copolymer brushes;gradient thin films;microfluid |
| Research Areas: |
Microfluidics, Polymers |
| PDF version: |
 Click here to retrieve PDF version of paper (201KB) |
