[P-man]

What regulates, or gives a substance the viscosity it has? Is it a particular molecular pattern with which you can determine the viscosity of a substance beforhand or is it something you just have to know?

[Donaldson Tan]

Viscosity only applies to fluids, ie. gas and liquid.

However, the nature of viscosity for gas and liquid are different.

In general, the liquid viscosity is dependent on the strength of intermolecular attraction. The stronger the intermolecular attraction, the more the viscous the liquid is. In fact, raising the temperature of the liquid decreases its viscosity. This reflects the viscosity of a liquid is indeed dependent on the intermolecular attraction.

In general, the viscosity of a gas is dependent on the frequency of molecular collision. The higher the frequency of molecular collision, the more unlikely each gas molecule were to gain in displacement as their movement is being impeded by the molecular collision. In fact, raising the temperature of the gas increases its viscosity.

[eugenedakin]

Hello P-man,

I have a few comments to further support the great comments that geodome has mentioned ...

One of my specialized area's is with viscosity control in liquids.  Viscosity in liquids are usually classified into two general categories, 1) Mechanical (inactive solids) and 2) chemical (molecular bonding).  Each area has its strengths and weaknesses. 

Mechanical viscosity is increased if small solids remain in the liquid phase.  The higher the concentration of solids, the more viscous the liquid. 

Chemical viscosity is due to molecular interactions, such as those caused by flocculation.  Usually, an increase in the number of charges (typically cationic) will increase a fluids viscosity.

Almost all solids (which give rise to mechanical induced viscosity) and charged particles (with give rise to chemically induced viscosity) vary in the type and amount of viscosity that a fluid has.  There are also approximately 4 different ways to measure viscosity, and each one has its own unique characteristics for varying uses.

I hope this helps.  If you have further questions, do not hesitate to ask.

Sincerely,

Eugene

[dashing]

I think eugenedakin  be a good drilling fluid engineer

[eugenedakin]

Hi dashing ...

I have been known to have an interest in drilling fluids ... 

Sincerely,

Eugene