Wetting in Polymer-Based Nanochannels

The development of lab-on-a-chip devices based, at least partially, on polymers has let to studying the wetting behavior of polymer-based nanochannels, as it can be used to control the flow of liquids in the chip. Additionally, polymer coatings have since long been used to alter the wettability of other materials, and this method is now applied to the nanoscale as well.  

Anodic aluminum oxide (AAO) membranes are a popular choice as templates for nanowires and nanotubes. As such they have been used to fabricate polymer nanochannels, mostly via melt inbltration, which has given the possibility of stud dng the wetting and flow of polymer melts in the alumina pores. In one such work an enhanced flow rate of poly-caprolactone was observed when mechanical vibration is applied to the AAO during the filling process. It 

MD and Monte Carlo simulations of the wetting of alumina nanochanneis by thermoplastic polymer melts have investigated the effect on wetting of surface functionalization and channel diameter. It was found that the flow rate of the pol5mier inside the nanochanneis was greatly increased when the pol5mier was 

Wetting experiments in polyurethane acrylate (PUA) rectangular nanochannels (with width ranging from 50 to 800 nm and a constant height of 200 nm) showed negative capillary pressure (as discussed earlier for silicon oxide nanochannels. Fig. lO.lS). Several surface chemistry treatments were performed to alter the wettability of the channels. In the case of complete wetting, the formation of a 

The Collected Works of ]. Willard Gibbs—Voiume I. Thermodynamics. New Haven, CT Yale University Press. 434 (1928). 

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