ABSTRACT
Surfactants have long been known to us in the form of soaps, which are salts of naturally occurring fatty acids. Some of their properties have long been recognized, for example, the ability of alkali to convert fatty acids to soaps, the usefulness of sodium soaps for cleaning, and the precipitation of insoluble compounds in hard water (bathtub ring). The advent of petrochemicals has brought synthetic detergents, which are less readily precipitated. The most widely used of these today include (sodium) linear alkylbenzene sulfonates (LASs), alkyl sulfates, and ethoxylated long-chain alcohols. Such surfactants with straight hydrocarbon chains are preferred for common washing applications because they are more readily biodegradable than their branched-chain counterparts and hence are less likely to accumulate in rivers and lakes where they could cause undesirable foaming.
