capillary attraction capillary attraction, attraction causing a liquid to rise, in capillary tubes or interstices, above its level outside, as in very small glass tubes, or a sponge, or any porous substance, when one end is inserted in the liquid. it is a special case of cohesive attraction. (4.).. see attraction
Capillary action (sometimes capillarity, capillary motion, or wicking) is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to lift the liquid.
The attraction of the surface of a liquid to the surface of a solid. Capillary attraction or capillarity adversely affects the recovery of crude oil from a porous formation because a portion of the oil clings to the surface of each pore in the rock. Flooding the formation with certain chemicals the capillary attraction, the surface tension, permitting the oil to drain out of the pores of the rock. See Tertiary Recovery.
The force that results from greater adhesion of a liquid to a solid surface than internal cohesion of the liquid itself and that causes the liquid to be raised against a vertical surface, as water is in a clean glass tube. It is the force that allows a porous material like soil to soak up water from lower levels.