College of Engineering and Polymer Science

Date of Last Revision

2021-09-14 17:36:28


Chemical Engineering

Honors Course

3470 498

Number of Credits


Degree Name

Bachelor of Science

Date of Expected Graduation

Spring 2021


The primary objective of this research project was to gain a better understanding of surface characteristics to produce a long-lasting superhydrophobic or superhydrophilic surface. In other words, when will a droplet of water remain on top of a featured surface and when does the transition occur to water filling the grooves of the surface? This research focused on how to best fabricate porous structures that would stay completely dry at all times by preventing the liquid from penetrating. In particular, we followed the behaviors of water droplets placed on top of 3-D printed featured surfaces with various geometries and surface treatments. Cylindrical pillars in a hexagonal array were 3-D printed with varying pillar diameter (D) and height (H) as well as the spacing ratio (S/D). The as printed models, models oxidized using air plasma, and models treated with hydrophobic octadecyl trichlorosilane (OTS) were tested. Both the as printed and plasma treated models didn’t retain water on top of the features due to their surfaces being hydrophilic, while the hydrophobic OTS treated models were able to prevent water droplets from penetrating down to the surface. The inversed features molded from the 3-D printed models using hydrophobic silicone elastomer also showed complete prevention of water drops from penetrating the features. Varying the geometry of the pillars had a significant effect in a majority of the cases across the various surface treatments on the transition. Meanwhile, the contact angle was affected by varying the pillar height but rarely by a change in diameter.

Research Sponsor

Bi-min Zhang Newby

First Reader

Roya Gitiafroz

Second Reader

Kevin Cavicchi

Honors Faculty Advisor

Bi-min Zhang Newby



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