1. Crystal Whisker Growth on Porous Coatings
Lorraine F. Francis, Department of Chemical Engineering and Materials Science, University of Minnesota
The goals of this research are to elucidate the mechanism of crystal growth for needle-like KCl whiskers on the surfaces of solution saturated porous coatings, to control the whisker dimensions, and to explore the applications of the whiskers.
Year 3 Results:
A systematic study of whisker growth on porous coatings under controlled experimental conditions was conducted, and results interpreted with transport models.
(2) Visualization results show that salt solution rises to much higher levels in porous coatings than water
(3) Whiskers form on bare substrate when nanoparticles are included in salt solution. This process is faster and requires lower relative humidity than whisker formation on porous coatings.
Porous Coating
Whisker Growth Zone
Glass Substrate
Initial liquid level
Final liquid level
Initial liquid level
Salt Solution Reservoir
Final liquid level
Humidity Control Chamber
Experiment set-up for whisker growth on porous coating.
Digital images of whiskers grown on porous coating from solution of varying KCl concentration.
Digital image of whiskers grown on bare substrate with nanoparticles in solution