★★☆ Moderate

🧲 Molecular Self-Assembly — Micelles & Bilayers

Watch amphiphilic molecules spontaneously organise into micelles and bilayers. Control concentration to cross the critical micelle concentration (CMC) and see vesicle formation driven by the hydrophobic effect.

Concentration (×CMC) 0.50×

Packing parameter p p = 0.25

Temperature (kT) kT = 1.0

Monomers: 0 Aggregates: 0 Avg N_agg: — Phase: — ΔG: — kT

Monomers — below CMC

At low concentration molecules remain as individual amphiphiles. The hydrophobic tails are exposed to water, raising free energy. No stable aggregates form.

The Physics

Self-assembly is driven by minimising free energy: ΔG_transfer ≈ −kT·ln(CMC⁻¹). Below CMC, monomers dominate. Above CMC, aggregation number N_agg determines shape via packing parameter p = v/(a₀·l_c): p < 1/3 → spherical micelle; 1/3 < p < 1/2 → cylindrical; p ≈ 1 → bilayer/vesicle.