Surfactant

Surface Active agent

Surface Active agent

In aqueous solutions surfactant behave like organic compounds that are amphiphilic, meaning they contain both hydrophobic groups (their tails) and hydrophilic groups (their heads). The arrangement of the hydrophilic head is at the interface of water and the hydrophobic groups aligns toward oil. Therefore, a Surface Active agent contains both a water-insoluble (or oil-soluble) component and a water-soluble component. Surface Active agent will diffuse in water and adsorb at interfaces between air and water or at the interface between oil and water, in the case where water is blended with oil. This property allows surfactant to act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.

Many important surfactant include a polyether chain terminating in a polar anionic group. The polyether groups often comprise ethoxylated (polyethylene oxide-like) sequences inserted to increase the hydrophilic character of a surfactant. Polypropylene oxides conversely, may be inserted to increase the lipophilic character of a surfactant. Surface Active agent molecules have either one tail or two; those with two tails are said to be double-chained. Surface Active agent classification according to the composition of their head falls under nonionic Surface Active agent, anionic Surface Active agent, cationic Surface Active agent, and amphoteric Surface Active agent. A nonionic Surface Active agent has no charged groups in its head. The head of an ionic Surface Active agent carries a net positive, or negative charge. If the charge is negative, the Surface Active agent is more specifically called anionic; if the charge is positive, it is called cationic. If a Surface Active agent contains a head with two oppositely charged groups, it is termed zwitterionic. Zwitterionic or amphoteric Surface Active agent have both cationic Surface Active agent and anionic Surface Active agent centers attached to the same molecule.

Surface Active agent play an important role in personal care products such as cosmetics, shampoos, shower gel, hair conditioners, and toothpastes. The property of providing cleaning, wetting, and dispersing, emulsifying, foaming and anti-foaming effects are used in many practical applications and products. Surface Active agent with different HLB are used in detergents, fabric softeners, soaps, paints, adhesives, inks, emulsions, anti-fogs, ski waxes, snowboard wax, deinking of recycled papers, in flotation, washing and enzymatic processes. Agrochemical formulations such as some herbicides, insecticides, biocides (sanitizers), and spermicides also contain surfactant. surfactant find use in firefighting and pipelines as liquid drag reducing agents. Alkali Surfactant polymers are used to mobilize oil in oil wells for exploration.

Nonionic surfactant refers to the surfactant molecules, which do not undergo ionization when being dissolved in water. The Nonionic surfactant are not in the ionic state in the solution, thereby having high stability and being less susceptible to the effect of strong electrolyte inorganic salts as well as acid and alkalis. Nonionic surfactants have excellent compatibility with other types of surfactants and have excellent solubility (which vary depending on different structures, HLB etc) in both water and organic solvents.

Nonionic surfactants have covalently bonded oxygen-containing hydrophilic groups, which are bonded to hydrophobic parent structures. These Nonionic surfactants, are not ionized in water, and contain both hydrophilic groups (e.g. oxyethylene-CH2CH2O-, ether groups, hydroxyl group -OH or -CONH2 amide group, etc.) and lipophilic group (e.g., hydrocarbons which can be natural fatty alcohols or synthetic alcohols, acids or glyceryl esters/oils). The water-solubility of the oxygen groups is the result of hydrogen bonding. Hydrogen bonding decreases with increasing temperature, and the water solubility of Nonionic surfactant therefore decreases with increasing temperature. This result in formation of a milky/cloudy emulsion called the cloud point of surfactant. This property is very essential for determining the optimum use of Nonionic surfactant in formulations at elevated temperature especially in cleaning formulations like detergents, CIP etc.