EmulsifiersEmulsifiers are used to maintain a uniform dispersion of one liquid in another, such as oil in water(O/W) or water in oil (W/O) systems. The basic structure of an emulsifying agent includes a hydrophobic portion, usually a long-chain fatty acid, and a hydrophilic portion that may be either charged or uncharged. The hydrophobic portion of the emulsifier dissolves in the oil phase, and the hydrophilic portion dissolves in the aqueous phase. This hydrophilic and hydrophilic portions could vary in different compositions, named as HLB (Hydrophilic Lipophilic Balance). A high value of HLB states more hydrophilic content in an emulsifier. Emulsifiers referred to as surfactants because of reducing surface tension. Thus, surfactants are used in many areas as wetting agents, oil and soil removers, retarders or leveling agents. Surfactants are classified as:
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