What You Need to Know
Lecithin, a phospholipid, adsorbs at the air‑water interface, aligning its hydrophilic head groups with water and hydrophobic tails with air, thereby lowering surface tension from ~72 mN/m to 30‑40 mN/m. This interfacial film stabilizes bubbles against coalescence, while the amphiphilic balance is maintained within a pH range of 3‑9. Optimal concentration (0.5‑2 % w/w) and temperature (20‑80 °C) ensure sufficient solubility and film integrity without hydrolyzing phosphatidic bonds.
The Science
Primary Reaction
Adsorption of lecithin at the air‑water interface forming a stabilizing film