Surfactants are chemical compounds, which, at very low concentrations, modify the properties at liquid-gas, liquid-liquid, and liquid-solid interfaces by markedly reducing interfacial (surface) tension. Depending upon their behavior at such interfaces surfactants can exhibit, in varying degrees, properties which allow them to be used as wetting agents, detergents, emulsifiers, dispersants, foaming agents solublizers, etc. a surfactant is characterized by a molecular structure which can be more or less clearly divided into two distinct portions; one being hydrophilic or water loving and the other, hydrophobic (lipophilic) or water hating (oil loving). The hydrophobic portion of a surfactant usually consists of one or more, non-polar, aliphatic and/or aromatic, carbon chains, the hydrophilic portion usually consists of one or more charged functional groups and/or polar chains containing numerous hydratable groupings. The combination of these distinct hydrophilic and hydrophobic parts within a single molecule is responsible for the interfacial tension reduction and other unique properties peculiar to this class of chemical substances.

Based upon the hydrophile used, surface-active agents can be divided into four general classes.

ANIONIC SURFACTANTS carry a negative charge on the surfactants' hydrophilic portion, usually in the form of a carboxylate, phosphate, sulfate or sulphonate radical.

CATIONIC SURFACTANTS carry a positive charge on the surfactants' hydrophilic portion, usually on a nitrogen atom in the form of quaternary ammonium compound, an amine salt or an imidazoline salt.

NONIONIC SURFACTANTS carry no charge; the hydrophilic portion usually contains numerous polar ether linkages delivered from the polymerization of ethylene oxide and/or propylene oxide with the hydrophobe.

AMPHOTERIC SURFACTANTS contain both anionic and cationic radicals and depending upon the pH, may carry either a positive or negative charge or be electrically neutral.

All four surfactant classed are commonly used in industry. The class employed for a particular application is usually defined by the specific surfactant properties requeed and the chemical nature, e.g. charge, pH, stability, of the other substances involved in the process.

Surfactants have unlimited applications. They are most frequently employed as: detergents, wetting agents, emulsifiers, dispersants, foaming agents, foam stablizers, softeners, lubricants, solubilizers, corrosion inhibitors, antistatic agents and leveling agents. Their detergency, wetting and emulsification properties are of such prime importance, that they warrant further discussion.

DETERGENCY is basically the removal of soil from a substrate, immersed in a solvent and the subsequent suspension or emulsification of the soil in the solvent phase. A detergent must aid the solvent in wetting both the substrate and the soil, disperse in the solvent any solid soil present, emulsify any fats or soils present, and promote solubilization of the soluble soil. Alcohol Ethoxylates 7-9 and Nonylphenols 9-10 have proven to be excellent general detergents. By varying the surfactant properiest, detergents can also be formulated for special applications: for example, the 2:1 amides are excellent hard surface cleaners and Alchesurf HCS is an excellent detergent for dry cleaning purposes.

WETTING AGENTS basically reduce the surface tension of water or any other liquid, such that it can more easily come in contact with solid surface. They are used extensively in process where solid materials are treated with aqueous solutions. In such applications, the wetting agent ensures that the entire surface of the solid is in contact with the aqueous phase. In other applications, wetting agents are used to spread thin liquid films over solid surfaces. Sulfosucinates, LA7, NP6, 7 & 8 are a few of the most effective wetting agents.

EMULSIFICATION is, in general terms, the formation of a stable dispersion of one liquid phase within another. An emulsifier facilitates the breaking of the phase to be emulsified into microscopic droplets, disperses these droplets within the continuous phase and prevents the dispersed droplets from coalescing.

Surfactants, with regards to their emulsifying properties, can be divided into three groups: Those with low HLB values (2 to 8), those with moderate HLB values (8 to 14) and those with high HLB values (14 to 18). Emulsifiers are generally blends of two or more surfactants; for water in oil emulsifiers, blends of low and moderate HLB surfactants are generally used; for oil in water emulsifier's blends of moderate and high HLB surfactants are generally used. Many of our products, individually or in blends, can function as emulsifiers, those commonly used are:

LOW HLB NP-1, NP-4, LA-3 & 5

MODERATE HLB NP-6 to NP-11, IPA Sulphonate

HIGH HLB NP-15 to NP-40 AND LA-15

For the selection of the proper surfactant for your application, please send us your enquiry giving details of your application and if possible what you are presently using to sales@alchemychemicals.com.