Werner Kuhn
Encyclopedia
Werner Kuhn is a Swiss physical chemist who developed the first model of the viscosity
of polymer solutions using statistical mechanics
. He is known for being the first to apply Boltzmann's entropy formula
:
to the modeling of rubber
molecules, i.e. the "rubber band entropy
model", molecule
s which he imagined as chains of N independently oriented links of length b with an end-to-end distance of r. This model, which resulted in the derivation of the thermal equation of state
of rubber, has since been extrapolated to the entropic modeling of proteins and other conformational polymer chained molecules attached to a surface.
Kuhn received a degree in chemical engineering
at the Eidgenössische Technische Hochschule (ETH, Federal Institute of Technology), in Zürich, and later a doctorate (1923) in physical chemistry
.
In a 1951 lecture along with his student V.B. Hargitay, he was the first to hypothesize the countercurrent multiplier mechanism in the mammalian kidney, later to be discovered in many other similar biological systems.
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
of polymer solutions using statistical mechanics
Statistical mechanics
Statistical mechanics or statistical thermodynamicsThe terms statistical mechanics and statistical thermodynamics are used interchangeably...
. He is known for being the first to apply Boltzmann's entropy formula
Boltzmann's entropy formula
In statistical thermodynamics, Boltzmann's equation is a probability equation relating the entropy S of an ideal gas to the quantity W, which is the number of microstates corresponding to a given macrostate:...
:
to the modeling of rubber
Rubber
Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...
molecules, i.e. the "rubber band entropy
Entropy
Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...
model", molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s which he imagined as chains of N independently oriented links of length b with an end-to-end distance of r. This model, which resulted in the derivation of the thermal equation of state
Equation of state
In physics and thermodynamics, an equation of state is a relation between state variables. More specifically, an equation of state is a thermodynamic equation describing the state of matter under a given set of physical conditions...
of rubber, has since been extrapolated to the entropic modeling of proteins and other conformational polymer chained molecules attached to a surface.
Kuhn received a degree in chemical engineering
Chemical engineering
Chemical engineering is the branch of engineering that deals with physical science , and life sciences with mathematics and economics, to the process of converting raw materials or chemicals into more useful or valuable forms...
at the Eidgenössische Technische Hochschule (ETH, Federal Institute of Technology), in Zürich, and later a doctorate (1923) in physical chemistry
Physical chemistry
Physical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts...
.
In a 1951 lecture along with his student V.B. Hargitay, he was the first to hypothesize the countercurrent multiplier mechanism in the mammalian kidney, later to be discovered in many other similar biological systems.
External links
- Hirsch, Warren (2003). "Disorder in un-stretched rubberbands", JCE, Feb. Vol. 80, No. 2, p. 145