What does hydrophilicity mean?
Hydrophilicity is the property of having a strong affinity for water. A hydrophilic substance or surface attracts water and allows it to spread across it rather than remain in isolated droplets. The property arises from features such as polar functional groups, ionic charges, or other molecular structures that interact favourably with water molecules. In materials science, high hydrophilicity can improve wetting, adhesion, and the performance of coatings, filters, sensors, and biomedical materials. In biology, it helps explain how substances such as cellulose and many proteins interact with water. The related term hydrophobicity describes the contrasting property of repelling water. Hydrophilicity is important because even small differences in this characteristic can alter how a material behaves when exposed to moisture. Although the word occurs across several scientific fields, its practical meaning remains consistent: the degree to which something is attracted to and wetted by water.
nounThe property of a substance or surface to have an affinity for water and to be readily wetted by it. The term is used especially in chemistry, materials science, biology, and surface engineering.
- The quality or property of being hydrophilic, especially the tendency of a material or molecular surface to attract water and permit it to spread or adhere.
"The coating's high hydrophilicity allows water to spread evenly across its surface."
"Increasing the surface's hydrophilicity helped the coating spread evenly in water."
"Researchers compared the hydrophilicity of cellulose fibres before and after chemical treatment."
Rare; hydrophilicity is normally treated as a mass noun.
"The researchers compared the hydrophilicity of several candidate materials."
Cellulose owes much of its usefulness to hydrophilicity: hydroxyl groups help plant fibres hold water.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does hydrophilicity come from?
Hydrophilicity is formed from the combining form hydro-, derived from Greek hydor, meaning “water,” and elements based on Greek philos, meaning “loving.” The closely related English adjective hydrophilic likewise combines these roots to mean “water-loving,” while the noun hydrophilicity expresses the quality or degree of that property through the suffix -ity. The terminology developed alongside modern scientific study of molecular interactions and the wetting of surfaces.
How hydrophilicity is actually used
This is a technical term used primarily in scientific and industrial contexts. It is normally treated as an uncountable noun, although plural forms occasionally occur when discussing different measured values.
Easily confused with hydrophilicity
Hydrophilicity is an affinity for water, whereas hydrophobia is an intense or persistent fear of water.