Soap and Detergents

Fat or Oil

Fatty acids

Fat or Oil

Fat or oil Example of an unsaturated fat triglyceride. Left part: glycerol, right part from top to bottom: palmitic acid, oleic acid, alpha-linolenic acid. Chemical formula: C55H98O6

Soap Soap is a salt of a fatty acid

Soaps are less effective in hard water, which is water that contains a significant concentration of Mg2+ and Ca2+ ions. These ions form precipitates with soap molecules, and this precipitate is often seen as a gray line on a bathtub or sink and is often called “soap scum”.

Surfactant (Detergents): Surface Active Agent Surfactants have amphiphilic structure: Hydrophilic Hydrophobic

Classification of surfactant According to charges of head group: 1- Ionic Anionic Cationic Amphoteric 2- Nonionic

Classification of surfactant According to charges of head group: 1- Ionic 􀀹 anionic

Alkyl ether carboxylate: Alkyl ether sulfate:

Classification of surfactant According to charges of head group: 1- Ionic 􀀹 Cationic

Classification of surfactant According to charges of head group: 1- Ionic 􀀹 Amphoteric

Classification of surfactant According to charges of head group: 2- Nonionic

Behavior of surfactants: When a molecule with amphiphilic structure is dissolved in aqueous medium, the hydrophobic group distorts the structure of the water. As a result of this distortion, some of the surfactant molecules are expelled to the surfaces of the system with their hydrophobic groups oriented to minimize contact with the water molecules. Nonpolar tail Polar head

Properties of Surfactants

Surface Tension lecb.physics.lsa.umich.edu

Interfacial Tension

Krafft Point Cloud Point Wetting time The temperature at which 0.1 % surfactants solution becomes clear by heating is gauge the aqueous solubility. (IONIC) Cloud Point The temperature at which 0.1 % surfactants solution becomes clear by cooling is gauge the aqueous solubility. (NONIONIC) Wetting time Wetting power of the tested surfactants were determined by immersing a sample of cotton fabric in 1.0 wt% aqueous solution of the surfactants and measuring the sinking time in second.

Emulsification power Examples of Emulsions uses lecb.physics.lsa.umich.edu Examples of Emulsions uses

Foaming Foam consists of gas covered with thin liquid film. Surfactants molecule absorbed to interface between gas and liquid. Foaming agent is a surfactant, which when present in small amounts facilitates the formation of a foam. Food industry Detergent

Critical micelle concentration (CMC)

Critical micelle concentration (CMC) The Critical micelle concentration was determined from the plot of the surface tension versus the logarithmic molar surfactant concentration.

Vesicle

Characterization of drug loaded With or without Or

Hydrophilic-lipophilic balance: The hydrophilic-lipophilic balance of a surfactant is a measure of the degree to which it is hydrophilic or lipophilic, determined by calculating values for the different regions of the molecule.

Kent, J., Riegel's Handbook of Industrial Chemistry, Van Notrand Reinhold, New York, N.Y., 1992. Austin, G., Shreve's Chemical Process Industries, 5th ed., McGraw-Hill Book Company, New York, N.Y., 1985. Davidsohn, A. S. and B. Milwidsky, Synthetic Detergents, Longman Scientific and Technical, Burnt Mill, Harlow-England, 1987. K. Tsujii, “Surface Activity: Principles, Phenomena And Applications”, Academic Press, 1998. D. J. McClements, “Food Emulsions: Principles, Practices, and Techniques”, CRC Press, 2nd ed., 2005. K. Robert Lange, “Surfactants: A Practical Handbook”, Hanser, 1999. J. Goodwin, “Colloids and interfaces with surfactants and polymers”, Wiley 2nd ed., 2009. B. P. Binks,” Particles as surfactants – similarities and differences”, Current Opinion Colloid Interface Sci. 7 (2002) 21 (review). N. D. Denkov et al., “Role of surfactant type and bubble surface mobility in foam rheology”, Soft Matter 5 (2009) 3389 (review).

http://www.bu.edu.eg/staff/mohamedaborya7 http://www.bu.edu.eg/staff/mohamedaborya7-courses/12004/files