gibbs-thomson effects - uliege · gibbs, thomson and thomson josiah willard gibbs 1839-1903...

Gibbs-Thomson effects

November 2014

Gibbs-Thomson effects

Small crystals melt at a lower temperature, which is the reason why ice cream gets crunchier with time.

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Melting of metal nanoparticles

Thermochimica Acta 463 (2007) 32–40 Phys. Rev. A 13, 2287–2298 (1976)

Au Al

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A related but simpler problem

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Gibbs-Thomson

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Gibbs, Thomson and Thomson

Josiah Willard Gibbs 1839-1903

Chemical potential

(1st PhD in Eng. in the US)

Joseph John « J.J. » Thomson 1856-1940

One of the fathers of

atomic physics (discoverer of the electron)

William Thomson (1st baron Kelvin) 1824-1907

The Joules-Thomson effect

etc. etc. etc. 6

Lamellar crystals in polymers

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Gibbs-Thomson for lamellar crystals

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Melting in nanopores

J. Chem. Phys. 93, 9002 (1990); The melting behavior of organic materials confined in

porous solids 9

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As an exercise…

11 Appl. Phys. Lett. 85, 5337 (2004)

Derive the Gibbs-Thomson relation in the case of a cylindrical nanowire

Liquid-vapor equilibria

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William Thomson (1st baron Kelvin) 1824-1907

What if there is no wetting layer?

A small and a large droplets lie on a fiber.

How does the system evolve?

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Ostwald ripening of metal nanoparticles: case of Ni in presence of CO

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16 Supported catalysts with monodispersed particles are more stable in time

Effect of size on solubility

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Stress generationby salt crystallization

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Laplace pressure 2γ/R

Laplace pressure γ/R + compressive stress σr

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Wheathering by salt crystallization

Honeycomb weathering (tafoni)

20 http://en.wikipedia.org/wiki/Weathering#Salt-crystal_growth

The mechanism is still unclear…

Capillary condensation in nanopores: Kelvin’s equation with a negative curvature

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Surface phenomena

Pore-filling phenomena

Chemical potential

Adsorption and desorption

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Adsorption

Desorption

Richard Adolf Zsigmondy 1865-1929

Nobel Prize in Chemistry 1925