Micelles and critical micelle concentration (CMC)
Surface Chemistry and Colloids · Chemistry
Study notes
A detergent has CMC = 8 mM. You dissolve 2 mM in wash water. Will it clean well? What about 20 mM? Step 1: 2 mM < 8 mM CMC → no micelles form; molecules only sit at surfaces. Cleaning is poor. Step 2: 20 mM > 8 mM CMC → micelles form; greasy dirt gets trapped in micelle cores. Step 3: Extra soap beyond CMC (20 vs 10 mM) just adds more micelles, cleaning improves only slightly.