Surface Modification of Microchannels with Fluorinated Polymer Langmuir-Blodgett Films

Abstract

The Langmuir-Blodgett (LB) technique was utilized to control surface properties of narrow microchannel walls at the molecular scale. Fluorinated amphiphilic polymer (pC7F15MAA) was synthesized and its ultrathin films were prepared by the LB technique. Microchannel was fabricated with glass substrates. A laminar flow of water in hydrophilic and hydrophobic microchannels was monitored in situ using an optical microscope equipped with a digital CCD camera. Shape of meniscus was clearly monitored with 250 ms time-resolution. The fluorinated polymer LB film can be a good candidate to control water motion in the microchannel.

Surface tension driven flow for open microchannels with different turning angles

“…According to these studies, the curved meniscus shape and the radius of the curvature were changed when the pumping force was changed both in a close microchannel (Takei et al 2007) and open microchannel (Kim et al 2006). However, the change in the meniscus shape is minor for a constant pumping force (Mitsuishi et al 2004). …”

Fabrication of fluorinated polymer nanosheets using the Langmuir–Blodgett technique: characterization of their surface properties and applications

“…This section describes some possible applications of fluorinated polymer nanosheets as in ultra‐thin lubricants for hard disks in magnetic recording technology104 and surface modification of microchannels in microfluidic devices 105…”

“… Time course of water meniscus profile in microchannels modified with six‐layer pC7F15MMA nanosheets. (Reprinted with permission from Fan and Mitsuishi et al 105 Copyright 2004, Taylor & Francis, London). …”