Scalable manufacturing and durability characterization of functional surfaces for condensation and anti-frosting purposes

Qiu, Haoyun

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https://hdl.handle.net/2142/127157 Copy

Description

Title

Scalable manufacturing and durability characterization of functional surfaces for condensation and anti-frosting purposes

Author(s)

Qiu, Haoyun

Issue Date

2024-10-09

Director of Research (if dissertation) or Advisor (if thesis)

Miljkovic, Nenad

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• surfaces
• coating
• frosting
• defrosting
• superhydrophobic
• durability
• biphilic
• hybrid
• condensation
• patterns
• structures

Abstract

The rapid implementation of renewable energy technologies has exacerbated potential for economic loss and safety concerns caused by ice and frost accretion. The past decade has seen advances in surface chemistry and micro and nanostructures which can promote passive anti-frosting and enhanced defrosting. However, durability of these surfaces remains the major obstacle preventing real-life application. To address this need, we conducted durability tests on assorted anti-frosting surfaces. and slippery liquid infused surfaces. For superhydrophobic surfaces, we demonstrate durability with progressive degradation for up to 1000 cycles of atmospheric frost-defrost and month-long outdoor exposure tests. We show that progressive degradation results from the molecular-level degradation of the low-surface-energy self-assembled monolayer (SAM), which leads to local high-surface-energy defects that promote accumulation of atmosphere particulate matter during cyclic frosting and defrosting. One of the functional surfaces that can benefit condensation and anti-frosting is the bioinspired hybrid surfaces, which juxtapose hydrophilicity and hydrophobicity. However, controlling hydrophilicity on hybrid surfaces in a scalable fashion is a challenge, limiting their application. Here, by using widely available metal meshes, we can scalably fabricate hybrid surfaces with controlled pattern density. Condensate-frosting experiments reveal that on grid patterned hybrid surfaces, frost propagates at ~160% higher velocity and provides ~20% less frost coverage when compared to homogeneous superhydrophobic surfaces. We adapt our fabrication technique to roll-to-roll patterning, demonstrating wettability contrast on round metallic tubes via atmospheric water vapor condensation. This work provides guidelines for the rapid, substrate independent, and scalable fabrication of hybrid wettability surfaces for a wide variety of applications.

Graduation Semester

2024-12

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/127157

Copyright and License Information

Copyright 2024 Haoyun Qiu

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