What is meant by surface active agent?

A surface active agent, or surfactant, is a substance which lowers the surface tension of the medium in which it is dissolved, the interfacial tension with other phases, and is positively adsorbed at the liquid-vapour interface and other interfaces.

What are surface active agents give example?

Alkyl sulfates include ammonium lauryl sulfate, sodium lauryl and the related alkyl-ether sulfates sodium laureth sulfate, also known as sodium lauryl ether sulfate (SLES), and sodium myreth sulfate. These are the most common surfactants and comprise the alkyl carboxylates (soaps), such as sodium stearate.

What are surface active agents in physical chemistry?

1 INTRODUCTION. Surface active agents (surfactants) are amphiphilic compounds with two opposing portions, one part is hydrophilic and the other is hydrophobic [1]. They reduce the free energy of the system by replacing the bulk molecules of higher energy at an interface.

What are the properties of surfactant?

Surfactants, or surface-active agents, are amphiphilic molecules. Their heads are polar, or hydrophilic, and their tails hydrophobic. They are soluble in both organic solvent and water. The surfactant reduces the surface tension of water by adsorbing at the liquid–gas interface.

Which is the best definition of a surface active agent?

Surface-active agent definition, any substance that when dissolved in water or an aqueous solution reduces its surface tension or the interfacial tension between it and another liquid. See more.

What is the medical definition of surface active?

Medical Definition of surface-active. : altering the properties and especially lowering the tension at the surface of contact between phases soaps and wetting agents are typical surface-active substances. More from Merriam-Webster on surface-active.

When does a thin film of a surface-active agent?

When a thin film of a solution of a surface-active agent is stretched or deformed, surface elasticity forces arise because of variations in surface tension. “It’s also a component in household detergents and soaps.”

How are surface active agents used in dyeing?

In the dyeing of textiles, surface-active agents help the dye penetrate the fabric evenly. Surface-active agents are widely used to impart special characteristics to surface coating formulations.