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Written by Dr Amit Pratap Singh
Reviewed By Dr Alidad Amirfazli
Reviewed: 28
This is a practical guide to Surface Science for researchers working in the Shipbuilding Industry.
In this all-new guide you’ll learn all about:
Let’s dive right in.
The shipbuilding industry encompasses both the engineering behind ship development and the industrial sectors responsible for completing and repairing ships. This complex field involves various sectors, including the construction of vessels for commercial shipping, naval defense, and recreational boating. Surface properties such as contact angle, sliding angle, surface tension, and surface energy are crucial for ensuring ships’ integrity, performance, and longevity.
We use the important surface properties below to understand the behavior of Shipbuilding products and improve their quality.
Young – Laplace Method
Polynomial Method
Dynamic Contact Angle
Ideally, when we place a drop on a solid surface, a unique angle exists between the liquid and the solid surface. We can calculate the value of this ideal contact angle (the so-called Young’s contact angle) using Young’s equation. In practice, due to surface geometry, roughness, heterogeneity, contamination, and deformation, the contact angle value on a surface is not necessarily unique but falls within a range. We call this range’s upper and lower limits the advancing contact angle and the receding contact angle, respectively. The values of advancing and receding contact angles for a solid surface are also very sensitive. They can be affected by many parameters, such as temperature, humidity, homogeneity, and minute contamination of the surface and liquid. For example, the advancing and receding contact angles of a surface can differ at different locations.
Practical surfaces and coatings naturally show contact angle hysteresis, indicating a range of equilibrium values. When we measure static contact angles, we get a single value within this range. Solely relying on static measurements poses problems, like poor repeatability and incomplete surface assessment regarding adhesion, cleanliness, roughness, and homogeneity.
In practical applications, we need to understand a surface’s liquid spreading ease (advancing angle) and removal ease (receding angle), such as in painting and cleaning. Measuring advancing and receding angles offers a holistic view of liquid-solid interaction, unlike static measurements, which yield an arbitrary value within the range.
This insight is crucial for real-world surfaces with variations, roughness, and dynamics, aiding industries like cosmetics, materials science, and biotechnology in designing effective surfaces and optimizing processes.
Learn how Contact Angle measurement is done on our Tensiometer
For a more complete understanding of Contact Angle measurement, read our Contact Angle measurement: The Definitive Guide
This property measures the force that acts on the surface of a liquid, aiming to minimize its surface area.
Dynamic Surface Tension
Dynamic surface tension differs from static surface tension, which refers to the surface energy per unit area (or force acting per unit length along the edge of a liquid surface).
Static surface tension characterizes the equilibrium state of the liquid interface, while dynamic surface tension accounts for the kinetics of changes at the interface. These changes could involve the presence of surfactants, additives, or variations in temperature, pressure, and composition at the interface.
Dynamic surface tension is essential for processes that involve rapid changes at the liquid-gas or liquid-liquid interface, such as droplet and bubble formation or coalescence (change of surface area), behavior of foams, and drying of paints (change of composition, e.g., evaporation of solvent). We measure it by analyzing the shape of a hanging droplet over time.
Dynamic surface tension applies to various industries, including cosmetics, coatings, pharmaceuticals, paint, food and beverage, and industrial processes, where understanding and controlling the behavior of liquid interfaces is essential for product quality and process efficiency.
Learn how Surface Tension measurement is done on our Tensiometer
For a more complete understanding of Surface Energy measurement, read our Surface Tension measurement: The Definitive Guide
Learn how Surface Energy measurement is done on our Tensiometer
For a more complete understanding of Surface Energy measurement, read our Surface Energy measurement: The Definitive Guide
The sliding angle measures the angle at which a liquid film slides over a solid surface. It is commonly employed to assess the slip resistance of a surface.
Learn how Sliding Angle measurement is done on our Tensiometer
For a more complete understanding of Sliding Angle measurement, read our Sliding Angle Measurement: The Definitive Guide
Within the Shipbuilding industry, several case studies exemplify the advantages of conducting surface property measurements.
Challenge: A ship painting company faced uneven surface coatings due to the coating fluid’s viscosity, surface tension, and the substrate’s contact angle.
Solution: The company’s engineering team discovered that using a coating liquid with a contact angle less than 90° caused a pinning effect, reducing surface unevenness. By adjusting the contact angle to create this effect, they mitigated the impact of uneven coatings, leveraging the interplay between fluid viscosity and the substrate’s surface energy.
Challenge: The superhydrophobic coatings used in shipbuilding were expensive and complicated to fabricate.
Solution: Researchers developed cost-effective, mechanically stable micro/nano superhydrophobic coatings by combining laser processing with low-surface energy materials. These coatings, exhibiting excellent hydrophobicity through contact angle and sliding angle measurements, provided durable water repellency, simplifying the superhydrophobic coating process.
Challenge: Cargo shipping companies needed to reduce fuel consumption and emissions.
Solution: Companies adopted innovative hull coatings with low surface energy and sliding angles to minimize friction with seawater. By enhancing hydrodynamic efficiency, these coatings led to significant fuel savings, reduced operational costs, and a lower carbon footprint. Droplet Lab’s portable instrument can enable accurate measurement of surface energy and sliding angles, ensuring these coatings’ effectiveness in real maritime conditions.
Challenge: Aluminum 7075, despite its high strength, suffered from corrosion, limiting its use in subsea industries.
Solution: The research team experimented with bare aluminum and oil-impregnated anodic aluminum oxide (AAO) surfaces. Salt spray and pressure tests revealed that the oil-impregnated AAO maintained a high contact angle, significantly improving corrosion resistance. This modification made Aluminum 7075 viable for subsea applications.
Challenge: Slippery deck surfaces posed safety concerns.
Solution: To enhance deck surface hydrophobicity, engineers performed contact angle measurements on various surface treatments. Optimizing these treatments increased hydrophobicity, reducing slip risks in wet conditions and improving safety.
If you are interested in implementing these or any other applications, please contact us.
In an industry where precision reigns supreme, where do Shipbuilding manufacturers turn to ensure their products can survive scrutiny? The answer lies in standards and guidelines: the compass that guides cosmetics manufacturers through the complex maze of quality and performance.
This ASTM standard provides guidance on measuring advancing contact angles, which can be relevant to surface properties. According to this standard, a surface with high wetting capability is more likely to achieve strong adhesion and a desirable appearance when coated. Additionally, it is less prone to surface tension-related defects such as crawling, cratering, pinholing, and orange peel. Wetting can be defined by a low advancing contact angle value (<45°). Angles of 10 to 20° indicate excellent wetting.
This standard outlines a method for evaluating delamination and corrosion surrounding a scribe or other artificial defect on a coated panel or test specimen exposed to a corrosive environment. It pertains to the assessment of coating degradation, encompassing critical aspects such as delamination and corrosion, both of which are significant factors in the context of shipbuilding.
We hope this guide showed you how to apply surface science in cosmetics industry.
Now we’d like to turn it over to you:
Droplet Lab was founded in 2016 by Dr. Alidad Amirfazli, faculty member at York University, and two of his researchers, Dr. Huanchen Chen and Dr. Jesus L. Muros-Cobos.
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