∞ generated and posted on 2016.08.22 ∞

Property of a substance indicating propensity to display relatively high affinity for water and other polar molecules.

Polar substances are hydrophilic, though only portions of molecules, rather than entire molecules, too can be hydrophilic (indeed, the latter is usually the case). An example of the substances which are hydrophilic over only a fraction of their surfaces are detergents, soaps, phospholipids, and cholesterol, all of which possess hydrophilic regions in combination with hydrophobic ones.

Hydrophilic substances tend to easily dissolve in water if they are small in size. Alternatively, they can form colloids if they are larger (semi-dissolved suspensions, here in water). Substances instead can be readily "wet" by water if they are larger still.