Oily or greasy soil

Most of the LAB sulfonic acid that is produced is neutralized to the Na+ salt. However, sulfonic acid can be neutralized with other bases to make different salts such as NH4+, TEA+ (triethanolamine), Mg2+, among others. In the latter 1970s, a major U.S. laundry liquid contained about 20-25% Mg(LAS)2 as the major active ingredient, along with a smaller amount of TEA+ salt of LAS [17]. This product was reported to be a very effective detergent on oily or greasy soils. 

TLC is particularly useful for analysing cases of damage caused by soluble stains or oily or greasy soiling. The following examples serve to illustrate this. 

The observed structure of micelles permits the rationalization of the solubilization property of aqueous solutions of amphiphilic compounds. The interior of the micelles can be thought of as small pockets of essentially pure liquid hydrocarbon. The interiors of the micelles, the pockets of hydrocarbon, are then capable of dissolving other lipophilic or hydrophobic molecules added to the solution. The action of soap in cleansing materials of oily or greasy dirt or soil is precisely of this nature. 

Greasy and oily soils on polyester or polyester-containing fabrics are among the more difficult stains to displace. Removal of these soils from cotton fabrics, however, is far easier. This difference in cleaning can be attributed to the hydroxyl and carboxyl groups on the cellulosic fibers which give the surface of the cotton a hydrophilic nature and subsequently permit surfactants and water to more easily wash away adsorbed soils. The surface of polyester fabrics, in contrast, is hydrophobic since they are essentially composed of copolymers of terephthalic acid and ethylene glycol. This hydrophobicity not only creates an affinity towards oily soils, but makes them more difficult to remove. 

---