Скачать или смотреть Critical Opalescence (Blue Interface)

The critical point of a fluid mixture is where the liquid and vapour phases become indistinguishable. At this condition a phenomenon known as critical opalescence can be observed. The interface between the colourless liquid and vapour phases disappears and the fluid takes on a cloudy appearance, often with a colour change. Critical opalescence is caused by the occurrence of density fluctuations in the fluid with a correlation length comparable to the wavelength of light.These cause certain wavelengths of light to scatter which gives rise to the coloured or cloudy appearance.

This critical point visualisation is for a methane and propane mixture at about T =286 K, and P = 95 bar. The mixture’s methane content at this critical point is 73% by mole. This work was conducted by the Fluid Science and Resources research group at The University of Western Australia

You can see another example where a cloudy band appears between the phases here:    • Critical Opalescence (Cloudy Interface)