amphiphil

Amphiphil is a term used in chemistry to describe a molecule that contains both hydrophilic (water-loving) and hydrophobic (water-repelling) regions. It is commonly treated as an alternative spelling of amphiphile. The dual affinity typically arises from a polar headgroup attached to a nonpolar tail.

In aqueous environments, amphiphiles self-assemble into organized structures to minimize unfavorable interactions, forming micelles, bilayers, or vesicles. The specific structure depends on geometry and concentration; a packing parameter p = v/(a0 l) helps predict whether spherical micelles, cylindrical aggregates, or planar bilayers will form. Amphiphiles are classified by headgroup charge as ionic (anionic or cationic), zwitterionic, or nonionic.

Biology relies on amphiphiles such as phospholipids to build cell membranes. Industrially they serve as detergents, emulsifiers, and surfactants; in pharmaceuticals and cosmetics they enable drug delivery and formulation. Some microorganisms produce biosurfactants, biodegradable amphiphiles with diverse applications. Etymology: from Greek amphí 'both' and philos 'loving'.