Hydrofilitet

Hydrofilitet, commonly translated as hydrophilicity, is the property of a substance, surface, or molecule to interact favorably with water. It describes the tendency to attract water and to form hydrogen bonds with water molecules, promoting wetting and hydration. Hydrophilic materials typically contain polar or charged groups, such as hydroxyl, carbonyl, carboxyl, amino, or sulfonate functionalities, which enable strong interactions with water. By contrast, hydrophobic substances are dominated by nonpolar character and poor water interaction.

Measurement and indicators: Wetting behavior is often quantified by the contact angle formed between a water droplet and the surface. Low contact angles indicate higher hydrophilicity, while high angles indicate hydrophobicity. Surface energy and roughness also influence wetting; micro- and nanoscale structuring can enhance or suppress hydrophilicity, sometimes creating superhydrophilic surfaces with very low contact angles.

Relevance and applications: Hydrophilicity influences processes such as lubrication, corrosion resistance, and adhesion. In biology, hydrophilic surfaces support hydration layers, protein adsorption patterns, and cell attachment, which can affect biocompatibility and device integration. In industry, hydrophilicity can be engineered by oxidation, plasma treatment, or grafting of hydrophilic polymers such as polyethylene glycol, to improve wettability and interaction with aqueous environments.

Examples and contrasts: Glass and cellulose are naturally hydrophilic, as are many oxidized polymers and sugars. In contrast, hydrocarbons and fluorinated polymers are typically hydrophobic. Apparent hydrophilicity can change over time due to aging, fouling, or environmental conditions.