Constructing the Phase Diagram of an Aqueous Solution of Poly(N-isopropyl acrylamide) by Controlled Microevaporation in a Nanoliter Microchamber
✍ Scribed by Xuechang Zhou; Junfang Li; Chi Wu; Bo Zheng
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 247 KB
- Volume
- 29
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
Abstract
This paper describes a poly(dimethylsiloxane) (PDMS)‐based microfluidic platform for constructing the phase diagram of poly(N‐isopropyl acrylamide) (PNIPAM) in aqueous solution. The PNIPAM solution was delivered into a nanoliter chamber through the main microchannel. An osmotic pressure difference was established between the chamber and the control microchannel by flowing a high‐concentration salt solution in the control microchannel. Controlled evaporation of water resulted in increasing concentration of PNIPAM. A phase diagram of PNIPAM was built by measuring the cloud points at different concentrations, with a minimum point at ≈40 wt.‐%. The microfluidic platform has the advantages of low sample consumption and rapid heat exchange rates, and allows studying viscous polymer solution.
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