hidrofilicity

Hydrophilicity refers to the tendency of a molecule or surface to be attracted to water. The word itself comes from Greek words, "hydro" meaning water and "philos" meaning loving. Substances that are hydrophilic readily interact with water molecules, often dissolving in them or forming strong bonds. This attraction is due to the presence of polar or charged groups within the molecule or on the surface. These polar groups, such as hydroxyl (-OH), carboxyl (-COOH), or amino (-NH2) groups, can form hydrogen bonds with water molecules, which are also polar.

Conversely, hydrophobic substances, meaning "water-fearing," lack these polar or charged groups and therefore do not readily interact with water. Instead, they tend to aggregate with other non-polar molecules.

Hydrophilicity plays a crucial role in many natural and industrial processes. In biology, cell membranes are composed of lipids, which have hydrophobic tails and hydrophilic heads. This amphipathic nature allows membranes to form a barrier that separates the aqueous interior of a cell from its aqueous exterior. Many drugs and food additives are designed to be hydrophilic to ensure they can be dissolved and transported within the body or incorporated into aqueous solutions. In materials science, hydrophilic surfaces can be useful for applications requiring good wettability, such as in textiles, coatings, and medical devices. The degree of hydrophilicity can be quantified using contact angle measurements, where a lower contact angle indicates a more hydrophilic surface.