Nano- and Microtechnology from A - Z: From Nanosystems to Colloids and Interfaces

V

Vacuole

Membrane-bound sacs (essentially large vesicles) that are contained in cells. Vacuoles are involved in intracellular nutrient storage and digestion, and in the release of cellular waste products. They exist in both plants and animals. See also Vesicle.

Vacuum Aerodynamic Diameter

See Aerodynamic Diameter; Table 7.

van der Waals Adsorption

An older term now replaced by “physical adsorption” or “physisorption”. See also Chemisorption.

van der Waals Bearing

A mechanical component in nanotechnology comprising a cylinder-and-sleeve bearing in which the mating surfaces are covered with close-packed atoms selected to provide repulsive van der Waals forces and therefore provide frictionless rotation. Example: a drive-shaft, in which the axle is less than 2 nm in diameter, made from diamond and where the mating cylinder and sleeve surfaces are both covered with fluorine atoms. Reference [319].

van der Waals Forces

The attractive interaction forces between any two bodies of finite mass. van der Waals forces include the Keesom orientation forces between permanent dipoles, Debye induction forces between dipoles and induced dipoles, and London (dispersion) forces between two induced dipoles. Also referred to as Lifshitz–van der Waals forces. See also Dispersion Forces.

van der Waals–Hamaker Constant

See Hamaker Constant.

van der Waals, Johannes Diderik (1837–1923)

A physicist who worked on molecular physics and thermodynamics. He is known for the van der Waals equation ...