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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 Farming & Agriscience Industry.
In this all-new guide you’ll learn all about:
Let’s dive right in.
Understanding the physical and chemical properties of surfaces is crucial in agriculture. For instance, knowing how water droplets behave on plant leaves, how pesticides adhere to crops, and how efficiently irrigation systems operate can significantly impact agricultural outcomes, sustainability, and productivity.
We use the important surface properties below to understand the behavior of Farming & Agriscience 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 Farming & Agriscience industry, several case studies exemplify the advantages of conducting surface property measurements.
Challenge: Uneven pesticide distribution can lead to pest infestations and diseases in agriculture.
Importance of Contact Angle: Proper contact angles in pesticide formulations ensure balanced coverage on plant surfaces.
Solution: A farm tested various pesticide formulations with different contact angles. They found that formulations with a contact angle close to zero adhered better to plant leaves, reducing pesticide runoff and enhancing pest control, which led to healthier crops.
Challenge: Pesticide droplets need to spread evenly on plant surfaces to maximize effectiveness.
Importance of Surface Tension: Optimized surface tension in pesticide formulations ensures uniform coverage.
Solution: Researchers developed a new pesticide formulation with low surface tension. This formulation produced finer droplets that spread more uniformly on plant leaves, improving pest control and reducing pesticide usage.
Challenge: Maintaining soil moisture is critical for crop health.
Importance of Surface Energy: Modifying soil with the right surface energy can improve moisture retention.
Solution: Researchers created a soil amendment to optimize surface energy. This improved the soil’s water-holding capacity, reduced the need for frequent irrigation, and enhanced crop resilience during droughts.
Challenge: Inefficient seed germination can reduce crop yields.
Importance of Contact Angle: Seed coatings with specific contact angles can enhance germination by controlling water absorption and retention.
Solution: Researchers analyzed the contact angles of different seed coatings and found that hydrophilic coatings (contact angles <90°) promoted better germination by accelerating imbibition and active metabolism phases. This improved water and air availability in drought-prone regions, boosting crop yields.
Challenge: Uneven water distribution in drip irrigation systems can cause water wastage and inconsistent crop growth.
Importance of Surface Tension: Controlling the surface tension of irrigation water droplets is crucial for uniform delivery.
Solution: A research team found that surfactants adsorbed onto hydrophobic soil particles, reducing water surface tension and improving infiltration. A farm added surfactants to their irrigation water, which led to more consistent droplet sizes and better water distribution, enhancing crop yields and conserving water.
If you are interested in implementing these or any other applications, please contact us.
In an industry where precision reigns supreme, where do Farming & Agriscience 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 standard provides a method of the measurement of the static angle of repose of solid fertilizers. This method is applicable to free-flowing fertilizers and is suitable for measuring static angles of repose greater than 20°. The method is not suitable for materials in which a large proportion of particle size is greater than 5 mm in diameter.
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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