Assessing durability of superhydrophobic surfaces

Abstract

Superhydrophobic surfaces (SHS) show remarkable water repellency properties, and their use may have a tremendousimpact for a plethora of applications, where liquid water accumulation needs to be controlled or minimised. However, the durability of SHS in operational conditions is a severe issue that currently represents a bottleneck for the technology transfer from laboratory to industrial applications. In the present work, we try to fill in the gap caused by the absence of a standard for evaluation for SHS durability, by developing a protocol for testing surface durability.The proposed protocol includes nine tests as follows: water immersion, acidic environment, alkaline environment, ionic solution, mechanical erosion, ultraviolet exposure, resistance to heating, alcohol immersion and hydrocarbon immersion. The protocol can serve to give an indication of surface robustness in a variety of potentially harmful environments, by providing a global figure of merit and ranking for different SHS and thereby allowing for identifying those surfaces fulfilling requirements for a specific application. To illustrate the protocol, we tested a SHS developed in-house by grafting of lauric acid molecules on an aluminum substrate. This article contains supporting information that is available online.

Fast and Simple Fabrication of Superhydrophobic Coating by Polymer Induced Phase Separation

“…In contrast, a gradual decrease of WCAs is found for the coatings irradiated by UV with the final WCAs of 124° and 117° but still remain hydrophobic. From the results of chemical and mechanical properties, the ruggedness for both optimal polymers on the glass slides are better or close to some previous reports [24,25,26,27].…”

A Novel Simple Anti-Ice Aluminum Coating: Synthesis and In-Lab Comparison with a Superhydrophobic Hierarchical Surface

“…The durability study on the samples followed a protocol consisting of four tests (three in wet chemicals and one for ice shedding) and, for each test, different conditions were implemented according to [12,24,29] Hydrophobic and/or ice-phobic properties of the samples were measured after each test phase and compared to the pristine sample. The test frequencies and applied procedure allow distinguishing the different aging behaviors of the samples.…”

Editorial

“…The proposed protocols include tests on immersion in water, acidic solutions, basic solutions, ionic solutions, alcohol and hydrocarbons, along with tests on mechanical erosion and ultraviolet exposure. 16 I hope that this paper will stimulate further discussion on development of measurement methods and tests that could lead to quantification of durability of engineered surfaces and coatings, and I welcome any comments and new papers on this topic.…”