Examples of hydrophobic substances include fats, oils, waxes, alkanes and other greasy substances. The term hydrophobic comes from the Greek and is translated as “having a horror of water” or “water fearing.”
In other words, hydrophobicity is a property of a substance that repels water. This means lacking affinity for water, tending not to combine with water or incapable of dissolving in water.
Hydrophobic materials are used to manage oil spills, remove oil from water and decrease corrosion rates. This is because they are waterproof, corrosion resistant and stable against inorganic and organic pollutants.
Hydrophobic substances cannot dissolve in water as their molecules tend to be nonpolar. These molecules are known as hydrophobes or water-insoluble molecules, and they tend to attract nonpolar solvents and neutral molecules.
Unlike water, hydrophobes cannot form hydrogen bonds; therefore, water tends to repel hydrophobes; instead, preferring to bond with itself. This is referred to as the hydrophobic effect or hydrophobic interaction. When a nonpolar substance like oil is added to water, its molecules tend to cluster together, instead of spreading. When this happens, the hyrophobes have less contact with water.
The hydrophobic effect is important for biological structures and is responsible for protein folding, protein-to-protein interactions and the formation of nucleic acid structures and lipid-bilayer membranes.