1. What is Volume of Hydrophobic Tail?

Definition: The volume of hydrophobic tail is defined as the amount of space the hydrophobic tail of a surfactant molecule occupies within a micelle core.

Purpose: This calculation helps in understanding micelle formation and surfactant behavior in solutions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( V_{hydrophobic} \) — Volume of hydrophobic tail (cubic meters)
• \( R_{mic} \) — Micelle core radius (angstroms)
• \( N_{mic} \) — Micellar aggregation number (dimensionless)
• \( \pi \) — Archimedes' constant (≈3.14159)

Explanation: The formula calculates the spherical volume of the micelle core and divides it by the number of surfactant molecules to get the volume per hydrophobic tail.

3. Importance of This Calculation

Details: Understanding hydrophobic tail volume is crucial for designing surfactants, predicting micelle behavior, and formulating detergents, emulsifiers, and other surfactant-based products.

4. Using the Calculator

Tips: Enter the micelle core radius in angstroms (Å) and the micellar aggregation number. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical micelle core radius?
A: For common surfactants, micelle core radius typically ranges from 10-30 Å, depending on the surfactant type and conditions.

Q2: What affects the micellar aggregation number?
A: The aggregation number depends on surfactant structure, temperature, concentration, and solution conditions.

Q3: Why is the volume calculated per hydrophobic tail?
A: This gives the average space occupied by each surfactant's tail in the micelle core, important for understanding packing efficiency.

Q4: How accurate is this calculation?
A: It assumes spherical micelles and uniform tail distribution, so actual values may vary for non-spherical micelles.

Q5: What units are used in this calculation?
A: Input radius is in angstroms (Å), but output volume is in cubic meters (m³) - conversion is handled automatically.