The Contact Angle Calculator helps determine the angle formed between a liquid droplet and a solid surface, which is a key factor in understanding surface wettability and adhesion properties. This angle is crucial in materials science, coating technology, and surface chemistry.
Formula
The contact angle (θ) is calculated using the Young's equation:
cos(theta) = (surface tension of solid-gas minus surface tension of solid-liquid) divided by surface tension of liquid-gas
How to use
- Enter the surface tension between solid and gas (γSG).
- Enter the surface tension between solid and liquid (γSL).
- Enter the surface tension between liquid and gas (γLG).
- Click the "Calculate" button.
- The contact angle in degrees will appear in the result field.
Example
Suppose γSG = 100 mN/m, γSL = 40 mN/m, and γLG = 60 mN/m:
cos(θ) = (100 - 40) / 60 = 1
θ = arccos(1) = 0 degrees (perfect wetting)
FAQs
Q1: What is a contact angle?
A1: It's the angle at which a liquid interface meets a solid surface, indicating how well a liquid wets the surface.
Q2: What does a low contact angle mean?
A2: A low angle (close to 0°) indicates high wettability and strong adhesion between the liquid and solid.
Q3: What does a high contact angle mean?
A3: A high angle (above 90°) suggests poor wetting and weak adhesion.
Q4: What is perfect wetting?
A4: When the contact angle is 0°, meaning the liquid completely spreads over the solid surface.
Q5: Can the contact angle be more than 180°?
A5: No, the angle is always between 0° and 180°.
Q6: What does it mean if cos(θ) is outside the range of -1 to 1?
A6: It indicates unrealistic or incorrect input values.
Q7: Why is surface tension important in this calculation?
A7: Surface tensions define how the liquid interacts with the solid and air, which determines the contact angle.
Q8: What are typical units for surface tension?
A8: Common units are mN/m (millinewtons per meter) or dyn/cm.
Q9: Can I use this calculator for any liquid-solid combination?
A9: Yes, as long as the surface tension values are accurate and consistent.
Q10: What materials have high contact angles?
A10: Hydrophobic surfaces like Teflon or wax tend to have high contact angles.
Q11: What materials have low contact angles?
A11: Hydrophilic materials like glass and clean metals often show low contact angles.
Q12: Does temperature affect contact angle?
A12: Yes, temperature can alter surface tension values, which in turn affect the angle.
Q13: How is contact angle used in coating industries?
A13: It helps determine how well a coating will spread and adhere to a surface.
Q14: Is contact angle measurement used in biology?
A14: Yes, it’s used in studying cell adhesion, biomaterials, and surface interactions.
Q15: What if the result says "cos(θ) out of range"?
A15: Your inputs may be incorrect; verify that γSG ≥ γSL and that all values are reasonable.
Q16: Can this calculator be used for both hydrophobic and hydrophilic surfaces?
A16: Yes, it works for both by showing how the liquid behaves with different surfaces.
Q17: Is this calculator useful in 3D printing?
A17: Absolutely, for understanding how resin or liquid adheres to surfaces during printing.
Q18: How accurate is this calculator?
A18: It is accurate based on the precision of your input values.
Q19: Can I use values with decimals?
A19: Yes, the calculator accepts and properly computes decimal inputs.
Q20: Is this suitable for academic or research purposes?
A20: Yes, it's a practical tool for educational, experimental, or industrial analysis.
Conclusion
The Contact Angle Calculator provides a straightforward method to evaluate wettability through surface tension values. Whether for scientific study, material design, or industrial applications, this tool delivers quick and accurate insights into liquid-solid interactions.