Antonio Checco
Brookhaven National Lab
Monday, April 6, 2009
4:00 p.m.
Cardwell 102
Wetting on the Nanoscale: How That Works?
Wetting phenomena are commonly observed in everyday life: rain drops rolling down a glass window and oil drops spreading on a frying pan are notable examples. Although the basic laws describing these macroscopic phenomena are relatively well understood, the picture changes significantly at the nanometer scale. At this small scale, microscopic effects – such as long range van der Waals interaction, thermal fluctuations of the liquid free surface, structural forces– become important leading to significant changes of the wetting and spreading behavior.
Research in this field is fostered by advancements in nano-patterning techniques which allow surfaces with well-defined chemical and or geometrical nanostructures to be routinely fabricated. These nanostructured surfaces can be used to confine liquids within extremely small volumes thereby performing complex biological or chemical analysis in a single miniature device (the “lab on a chip” concept).
In this talk, I will describe
experimental studies of the wetting and spreading of liquids on nanostructured
surfaces performed with atomic force microscopy and X-rays scattering
techniques. The results of this research provide valuable insight into the
wetting behavior at the nanoscale and a stringent test for available theories.