Surfactants

About Surfactants

Surfactants are chemical compounds, usually referred to as surface active agents, that decrease the surface tension between two liquids, a liquid and a gas, or a liquid and a solid. The term surface active means that the surfactant reduces the free energy of surfaces and interfaces.

Surfactants are amphiphilic or amphipathic molecules consisting of a non-polar hydrophobic portion, a straight or branched hydrocarbon or fluorocarbon chain containing 8–18 carbon atoms attached to a polar or ionic part (hydrophilic). The hydrocarbon chain interacts weakly with the water molecules in an aqueous environment, whereas the polar or ionic head group interacts strongly with water molecules via dipole or ion-dipole interactions. This strong interaction with the water molecules renders the surfactant soluble in water. All surfactant molecules consist of at least two parts, one soluble in a specific fluid, like water (the hydrophilic part), and one insoluble in water (the hydrophobic part).

The significant properties of Surfactants are solids wetting, solubilization, emulsification, solid dispersion in solution, micellization, and detergency. Surfactants can also be classified based on the nature of the hydrophilic segment of the surfactant molecules or head group; this approach creates four large groups of chemicals: amphoteric, anionics, cationics, and nonionics.

Amphoteric: These are very mild, making them particularly suited for use in personal care preparations over sensitive skin. These Surfactants have excellent dermatological properties and are frequently used in shampoos and other cosmetic products, also, in hand dishwashing liquids, because of their high foaming properties.

Anionic Surfactants: These are the most widely used class of Surfactants in industrial applications. This is due to their relatively low cost of manufacture, and they are practically used in every type of detergent. These Surfactants are very common for preparing shampoos because of their excellent cleaning properties and high hair-conditioning effects. Anionic surfactants are particularly effective at oil cleaning and oil/clay suspension.

Cationic Surfactants: These Surfactants are quaternary ammonium compounds and are primarily used for their disinfectant and preservative properties as they have good bactericidal properties. 'They are also used on the skin for cleansing wounds or burns.

Non-ionic Surfactants: Have no electrical charge, making them resistant to water hardness deactivation; they are less irritant than other anionic or cationic Surfactants. Non-Ionic Surfactants are excellent grease/oil removers and emulsifiers and are widely used in technical applications such as detergency, emulsification, cosmetics, and pharmaceuticals.

Surfactants find application in almost every chemical industry related to detergents, paints, dyestuffs, cosmetics, pharmaceuticals, agrochemicals, fibers, and plastics. Moreover, they play a major role in the oil industry in enhanced and tertiary oil recovery. Surfactants are also used for environmental protection in slick oil dispersants as well.

Surfactants are involved in the chemical industry in the preparation of emulsions and suspensions and their subsequent stabilization in nano emulsions, microemulsions, wetting spreading, and adhesion.

In the Cosmetic Industry, surfactants can be classified as agents in different functional categories: Cleansing, Emulsifying, Foam Booster, Hydrotropes, solubilizing, and suspending agents.

In the Pharmaceutical Industry, surface-active agents have been widely shown to enhance drug dissolution rates; this may be due to wetting effects, resulting in increased surface area, effects on solubility and effective diffusion coefficient, or a combination of effects. Consequently, surfactants have been included in tablet and capsule formulations to improve the wetting and disaggregation of drug particles and thus increase the surface area of particles available for dissolution. Therefore, their primary use in the Pharmaceutical Industry is the manufacture of hard gelatin capsules and tablets and suppositories. Additionally, Surfactants are also utilized in the formulation of solution as a solubilizing agent, which increases drug solubility.

Common Uses and Applications

• Shampoos
• Body Wash
• Liquid hands soap
• Bath products
• Facial cleansers
• Syndet bars
• Detergent
• Toothpaste
• Paints
• Dyestuffs
• Cosmetics
• Pharmaceuticals
• Oil recovery
• Textile
• Paper de-inking
• Metal
• Petroleum additives
• Leather processing
• Lubricants
• Fabric softener

Industries

• Food Manufacturing
• Oil
• Petroleum
• Cleaning
• Agrochemical
  
• Pulp And Paper
• Textile
• Metal Working