Fabrication and characterization of smooth omniphobic surfaces
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Khatir, Behrooz
issued: 2020-08-14T22:47:55Z
issued: 2020
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: Liquid fouling can reduce the functionality of critical engineering surfaces. Recent studies have shown that minimizing contact angle hysteresis is a promising strategy for achieving omniphobic (all-liquid repellent) properties, thereby inhibiting fouling. Prior omniphobic films can repel a broad range of liquids, but the applicability of these coatings has always been limited to silicon wafers or smooth glass. Here we develop a facile procedure to generate an omniphobic coating on any surface, including metals, paper, ceramics, etc. The coating involves depositing an ultra-smooth, silicon wafer-like silica layer and then treating this layer with a highly reactive chlorosilane, which grafts polydimethylsiloxane chains onto the surface. Negligible contact angle hysteresis (≤ 1°) for various liquids, including ultra-low surface tension oils, alcohols, and fluoro-solvents, was achieved on many different substrates regardless of their initial roughness or chemistry. In fact, the contact angle hysteresis was so low we were forced to propose an alternate measurement technique, using tilt angles, that reduced the inherent errors associated with traditional contact angle goniometry. The coating’s durability was characterized and, when it was damaged, could be repeatedly repaired, fully restoring the omniphobic properties to their initial state. Moreover, we introduced another potential application of these surfaces. Viscosity measurement using a small amount of fluids is crucial since it is one of the most important parameters of a liquid. Recent studies have shown that there is a relation between viscosity and dynamic behavior of droplets on a surface. Our coating showed a promising performance confirming these relationships due to it ultra-low contact angle hysteresis. Hence, we used them to create a surface viscometer which can measure the viscosity of a wide range of liquids using only one droplet.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/75557
note: FABRICATION AND CHARACTERIZATION OF SMOOTH OMNIPHOBIC SURFACES by Behrooz Khatir B.Sc., Islamic Azad University Central Tehran Branch, 2017 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE COLLEGE OF GRADUATE STUDIES (Mechanical Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) August 2020 © Behrooz Khatir, 2020 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, a thesis/dissertation entitled: Fabrication and Characterization of Smooth Omniphobic Surfaces submitted by Behrooz Khatir in partial fulfillment of the requirements for the degree of Master of Applied Science in Mechanical Engineering Examining Committee: Dr. Kevin Golovin, School of Engineering, Faculty of Applied Sciences Supervisor Dr. Mina Hoorfar, School of Engineering, Faculty of Applied Sciences Supervisory Committee Member Dr. Mohammad Hossein Zarifi, School of Engineering, Faculty of Applied Sciences Supervisory Committee Member Dr. Ian Foulds, School of Engineering, Faculty of Applied Sciences University Examiner iii Abstract Liquid fouling can reduce the functionality of critical engineering surfaces. Recent studies have shown that minimizing contact angle hysteresis is a promising strategy for achieving omniphobic (all-liquid repellent) properties, thereby inhibiting fouling. Prior omniphobic films can repel a broad range of liquids, but the applicability of these coatings has always been limited to silicon wafers or smooth glass. Here we develop a facile procedure to generate an omniphobic coating on any surface, including metals, paper, ceramics, etc. The coating involves depositing an ultra-smooth, silicon wafer-like silica layer and then treating this layer with a highly reactive chlorosilane, which grafts polydimethylsiloxane chains onto the surface. Negligible contact angle hysteresis (≤ 1°) for various liquids, including ultra-lo…
has type: Thesis/Dissertation
date issued: 2020-09
is shown at: 10.14288/1.0392806
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/75557