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Updated: May 14, 2026
Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications
Published on: August 15, 2018
Novel method to characterize superhydrophobic coatings.
Mohamed A Samaha1, Hooman Vahedi Tafreshi, Mohamed Gad-el-Hak
1Department of Mechanical & Nuclear Engineering, Virginia Commonwealth University, Richmond, VA 23284-3015, USA.
This study introduces a new way to measure how much air is trapped in superhydrophobic coatings, which are materials that strongly repel water. These coatings are used in applications where reducing water drag is important. The method uses a sensitive scale and height gauge to measure buoyancy force on a coated object when it's submerged in water. From this, the volume of trapped air and the coating's thickness can be calculated. The technique works for both ordered and disordered microstructures and is more precise than traditional methods. It can detect thicknesses as small as 3 micrometers and could be improved with even more sensitive equipment.
Area of Science:
- Surface chemistry and materials science
- Fluid dynamics in biomedical and industrial contexts
- Coating technology in applied physics
Background:
Superhydrophobic surfaces are known to repel water efficiently, which can reduce drag in fluid systems. However, measuring the air trapped within these surfaces remains a challenge, especially in disordered microstructures. Prior research has shown that air entrapment is essential for maintaining superhydrophobicity. Yet, no prior work had resolved how to quantify this air volume with high precision. This gap motivated the development of new measurement techniques. Existing tools lack the sensitivity required for thin or disordered coatings. The need for accurate methods is clear in both academic and industrial applications. This paper introduces a novel approach to address these limitations. The study focuses on improving the measurement of air volume and coating thickness in superhydrophobic systems.
Purpose Of The Study:
The study aims to develop a precise method for measuring air volume and coating thickness in superhydrophobic surfaces. Superhydrophobic coatings rely on trapped air to function, but quantifying this remains difficult. The researchers propose a new technique using buoyancy force measurements. This method is designed to work with both ordered and disordered microstructures. The goal is to improve accuracy for thin or complex coatings. The approach is intended to complement or replace conventional tools. The method is tested on aerogel and electrospun fibrous coatings. The results aim to provide a reliable alternative to existing measurement techniques.
Main Methods:
The technique involves measuring buoyancy force on a submerged coated substrate. A sensitive weighing scale detects small mass changes. A height gauge measures the substrate's position with high precision. The buoyancy force is calculated from the measured mass and height. This force is used to determine the volume of trapped air. The coating’s effective thickness is also derived from these calculations. The method is applied to both aerogel and fibrous coatings. The setup allows for measurements down to 3 μm in thickness.
Main Results:
The method successfully measures air volume and coating thickness in superhydrophobic systems. The technique works for both ordered and disordered microstructures. The weighing scale detects changes as small as 10(-4) grams. The height gauge provides measurements down to 10 μm. Calculations from buoyancy force yield the volume fraction of trapped air. The method achieves a sensitivity of 3 μm for thickness measurements. Conventional tools cannot reach this level of precision. The results suggest the method is suitable for a wide range of coating types.
Conclusions:
The novel method provides accurate measurements of air volume and coating thickness. The technique is effective for both ordered and disordered microstructures. The use of buoyancy force allows for high precision in volume calculations. The method outperforms conventional tools in sensitivity. The approach is applicable to aerogel and electrospun fibrous coatings. The sensitivity of the scale enables measurements down to 3 μm. Smaller thicknesses could be measured with more advanced equipment. The results support the use of this method in superhydrophobic surface analysis.
Frequently Asked Questions
The new method uses buoyancy force to measure air volume and coating thickness with high precision, even for disordered microstructures.
The volume of trapped air is calculated from the buoyancy force measured on a submerged coated substrate using a sensitive weighing scale.
Trapped air is essential for maintaining superhydrophobicity, so measuring it helps assess coating performance and durability.
The method was applied to both aerogel and electrospun fibrous coatings, showing broad applicability.
The method can measure thicknesses down to 3 μm, which is not possible with conventional thickness gauges.
The researchers suggest that smaller thicknesses could be measured using even more sensitive weighing scales.
