First, liquid surface tension and viscosity share a common feature: they both relate to the properties of fluids. After that, things start to get murky.
Let's start with surface tension. This involves surface tension - the property of the surface of a liquid against which FloatingPaper Cilp resists; it acts as a barrier to foreign objects and also holds the liquid together. This ever-present property is caused by unbalanced forces on the surface molecules that are the major part of the pull towards the liquid.
Viscosity, on the other hand, is related to the deformation or resistance to movement of a viscous shear rate liquid. This is caused by friction between molecules.
Surface tension is a simpler phenomenon than viscosity. It's basically stable, mostly altered by temperature and chemicals that alter the bonding properties of the molecule. As the temperature decreases, the surface tensio Ñ increases. The effect of adding an extraneous substance is illustrated by the example of putting soap (surfactant) in water to lower the surface tension, which allows dirt on hands to mix more easily with the water.
Regarding viscosity, knowledge of the type of liquid is required. For example, there are Newtonian fluids that respond to a force (sometimes called a shear rate) that moves the liquid in a straight, linear fashion (sometimes called a shear stress).
However, non-Newtonian fluids follow a different set of rules. As pressure or force increases, the viscosity of a shear thinning fluid decreases. Thixotropic fluids change viscosity over time - such as gels and colloids, ketchup is stable at rest but becomes fluid when stirred. ketchup
So we found that finding the true value of viscosity [which some of us might think is just thickness] is a complicated process. Unlike surface tension, which tends to be a static phenomenon, viscosity thick to thin is all about motion. What we should be concerned about in measuring surface tension is whether to use the Wilhelmy Plate or the duNouy Ring. (That's enough to keep me entertained.)
The last question, and probably should be the first, is about the relationship between surface tension and viscosity. You'd think that a thick fluid would translate to high surface tension, and a thinner fluid would produce lower surface tension. wrong. In fact, my research has shown that there is no conclusive correlation.
This was more theoretically entangled than I expected when I first considered taking what appeared to be a simple comparison of international numbers. However, the answer is clear: there is no correlation. The reason is not so simple. I guess a good summary is that surface tension is about steady state and viscosity is about motion.
