the preference of a solid to be in contact with one fluid over another in a system of two or more immiscible fluids

water wet

oil-wet

tend to have a preference to be in contact with either oil or water

Knowing the wettability is very important in understanding the flow behavior when ___________________________

happens between water and gas or between solid and a fluid (liquid or gas)

happens between two liquids, and the lower the IFT is the closer the fluids are to become miscible

the ability of two fluids to mix

energy per unit area or the force per unit length in [N/m] or [dynes/cm]

IFT is a function of

• fluid pairs

• temperature

• pressure