1. What is Van der Waals Interaction Energy?

Definition: Van der Waals Interaction Energy includes attraction and repulsions between atoms, molecules, and surfaces, as well as other intermolecular forces.

Purpose: This calculator helps quantify the weak electromagnetic forces that influence molecular interactions at nanoscale distances.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( E \) — Van der Waals Interaction Energy (Joules)
• \( A \) — Hamaker Coefficient (Joules)
• \( h \) — Surface Separation (meters)
• \( \pi \) — Archimedes' constant (~3.1416)

Explanation: The energy decreases with the square of the separation distance and is proportional to the Hamaker coefficient.

3. Importance of Van der Waals Calculations

Details: These calculations are crucial in nanotechnology, surface science, colloidal chemistry, and biological systems where weak interactions dominate.

4. Using the Calculator

Tips: Enter the Hamaker coefficient (typically 10^-21 to 10^-19 J) and surface separation in nanometers (1-100 nm range). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical Hamaker coefficient value?
A: For most materials, A ranges from 0.4-4 × 10^-19 J. The default 3.2 × 10^-21 J is typical for hydrocarbon interactions.

Q2: Why is the energy negative?
A: The negative sign indicates an attractive interaction between the surfaces.

Q3: How does distance affect the interaction?
A: The energy falls off rapidly (as 1/distance²), becoming negligible beyond ~100 nm.

Q4: What are limitations of this formula?
A: It assumes ideal, smooth surfaces and doesn't account for relativistic effects at very small separations (<10 nm).

Q5: Where can I find Hamaker coefficients?
A: Published tables in surface science literature or through specialized measurement techniques.