Design and Fabrication of Bio-Inspired Multi-Functional Slippery Surface Coatings with Novel Functionalities

Restricted (Penn State Only)
Author:
Wang, Jing
Graduate Program:
Mechanical Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
May 30, 2018
Committee Members:
  • Tak Sing Wong, Dissertation Advisor
  • Tak Sing Wong, Committee Chair
  • Pak Kin Wong, Committee Member
  • Donghai Wang, Committee Member
  • Seong Han Kim, Outside Member
Keywords:
  • Bio-inspired Engineering
  • Surface Science
  • Robustness
  • Viscoelastic Solid Repellency
Abstract:
Bio-inspired multi-functional liquid-repellent surfaces have been intensively studied for the past decades because of their significant potentials for many industrial and biomedical applications. To this end, state-of-the-art surfaces including superhydrophobic surfaces, superoleophobic surfaces, and slippery liquid-infused porous surfaces (SLIPS) have been developed, where these surfaces display a number of remarkable functions such as self-cleaning, anti-biofouling, anti-icing, drag reduction, enhanced heat transfer and water harvesting. Despite recent advances, surfaces that possess self-cleaning and anti-fouling properties while at the same time are capable of repelling both liquids and viscoelastic solids or with enhanced mechanical robustness are rare. A central feature of this dissertation is to develop design principles to create such a multi-functional repellent coating, and develop a facile and scalable fabrication method to apply the coating onto common materials such as glass, ceramics, metals, and plastics. Here, I have developed a new form of cross-species bio-inspired slippery liquid-infused porous surfaces (X-SLIPS) that can self-repair under thermal stimulation even under large area of physical and chemical damages. These thermally self-healing omniphobic coatings can be applied onto a broad range of metals, plastics, glass, and ceramics of various shapes, and show excellent repellency towards aqueous and organic liquids. In addition, I have designed and fabricated liquid-entrenched smooth surfaces (LESS) – a sprayable, anti-biofouling surface coating that is capable of repelling both aqueous liquids and viscoelastic solids with dynamic viscosities spanning over 9 orders of magnitude, i.e., three orders of magnitude higher than previously reported. LESS can significantly reduce adhesion from different viscoelastic solids up to ~90% compared to state-of-the-art liquid-repellent materials. The amount of water required to clean LESS is only ~10% of that required for untreated surfaces. The results have implications for significant reduction of wastewater generation and biofouling in industrial and household settings, which may mitigate global water scarcity and transmission of the infectious diseases, associated with poor sanitation facilities.