Expo attendees could hardly be misled by the lengthy descriptor title “Influence of Inherently Super-Nonwetting Fiber and Fabric Designs Repellency and Resistance to Liquid Penetration.” So attendees at Dr. Quoc Troung’s presentation clearly held expertise and specific interest in the finer points of fabric structure.
The physical scientist at the U.S. Army Natick Solder Research, Development & Engineering Center discussed testing procedures for achieving superomniphobicity in fabrics: the ability of the surface to resist wetting by water, liquid chemicals, solvents and oils. Based on studies conducted with collaborative institutions, Truong offered these observations:
Reducing mesh size increases omniphobic robustness. Increasing fiber and fiber bundle size decreases robustness.
It is easier to resist liquids with higher surface tension than lower surface tension (water has a surface tension of 72.8 dynes/cm, compared to methanol’s 22.1), and the surface chemistry affects liquid repellency.
Surface texture design space can be manipulated (reduced) to achieve higher resistance to liquid penetration.
The key parameters are surface chemistry, fabric weave, and individual fiber and fiber bundle size.