Jared J. Victor

A low-cost method to produce superhydrophobic polymer surfaces

Here, we introduce a novel and inexpensive template-based structuring process to create superhydrophobic polymer surfaces adapted from the naturally occurring micro/nano structured surfaces found on the superhydrophobic leaves of the quaking aspen tree. Electroformed nanocrystalline nickel coupons were sandblasted and chemically etched to create a negative reproduction of the aspen leaf surface structure. These nanocrystalline nickel samples were then employed as re-useable templates and pressed against various polymers at elevated temperatures, transferring the desired superhydrophobic structure to their surfaces. This structuring process resulted in water contact angles above 150° and tilt angles below 5° for polyethylene, polypropylene and polytetrafluoroethylene samples. In addition, the effects of temperature, water drop size and surfactant concentration on these pressed polymer surfaces were investigated to assess potential application limitations for these surfaces.

Biology Inspired Superhydrophobic Surfaces

In this study, the surface structure of a self-cleaning, superhydrophobic leaf was examined using electron microscopy and optical methods, and its wetting properties were measured using a contact angle goniometer. Using the micro/nanostructural surface features of this leaf as a blueprint, an inexpensive surface structuring technique was developed by modifying the surface of nanocrystalline nickel to create a template. These templates were then pressed into softened polyethylene at elevated temperatures and pressures, thereby transferring the structured surface to the polymer samples. All templates and pressed polymers were characterized in the same manner as the leaves. This method increased the wetting angle for polyethylene from 96° to 151° and reduced the tilt angle from 38° to <5°.