SURFACTANTSINSOLUTION.pptVIP

SURFACTANTS IN SOLUTION Classification of Surfactants Anionic Cationic Zwitterionic Nonionic Surfactant Aggregates Solubilization Solubility Effects An example of an HLB value calculation BRIJ ? 98 INCI name : oleth-20 is a 20 mole ethoxylate of oleyl alcohol calculate the molecular weight of the 20 moles of ethylene oxide ( one mole ETO =44 ); 20 x 44 = 880 add this number to the molecular weight of the oleyl alcohol; 880+ 270 = 1150 ( the mol. wt of BRIJ 98 ) What percentage of 1150 is 880 ? 880/1150 = 76.5% 76.5% divided by 5 = 15.3 15.3 is the HLB value of BRIJ 98 Important to remember ! HLB and Use of Surfactants Required HLB HLB of Surfactant Blend Shampoo Ingredients Isobutane Cyclomethicone Aluminum Chlorohydrate Propylene Glycol Dicaprylate/Dicaprate Lichen extract Fragrance Quaternium-18 Silica Dimethiconol * * Sodium dodecylsulfate (SDS) Cetylpyridinium bromide Dipalmitoylphosphatidylcholine (lecithin) Polyoxyethylene(4) lauryl ether (Brij 30) 4 nm Unimers Normal micelles spherical cylindrical Bilayer lamella Reverse micelles Inverted hexagonal phase 0 2 4 6 8 10 12 14 0 1 Surfactant concentration CMC ? Critical Micelle Concentration CMC Below CMC only unimers are present Above CMC there are micelles in equilibrium with unimers Solution Properties 0 2 4 6 8 10 12 14 0 1 Surfactant concentration CMC Concentration unimers micelles 0 2 4 6 8 10 12 14 0 1 Surfactant concentration CMC Osmotic pressure ? 0 2 4 6 8 10 12 14 0 1 Surfactant concentration CMC Isc Light scattering Spontaneous transfer of a compound insoluble in the bulk solvent into solution due to incorporation into the surfactant micelles polar compound Reverse micelles non-polar compound Normal micelles amphiphilic compound Solubility of a poorly soluble compound increases as a result of solubilization in the micelles 0 2 4 6 8 10 12 14 0 1 Surfactant concentration CMC Solubility HLB ca. 1 to 3.5: Antifoams HLB ca. 3.5 to 8: Water-in-Oil Emulsifiers HLB ca. 7 to 9: Wetting and spreadi