Relationships between surface tension and bulk properties of liquids: Organic liquids near 298 K

The ratio of surface tension γ to shear viscosity η has units of speed. For many liquids at 298 K the value of γ/η is about 0.3 of the thermal average speed of the molecules in the liquid. However, for a selection of organic liquids the values of (γ/η)(M/kBT)1/2 range over a factor of 9, so it is not a useful general correlation. The product of γ with the isothermal compressibility κT for the same liquids at 298 K has an average value 27±3pm, independent of the ΔT from the triple point. The distance γκT is interpreted as the average elastic spacing between the stiff cores of the molecules, related to the multibody intermolecular potential function operating in 2π and 4π steradian space. © 1998 American Institute of Physics.