The inherent dynamic viscosity property of fluids quantifies how they resist internal flow when subjected to external force. Dynamic viscosity serves as an essential measurement standard across multiple industrial and scientific disciplines, especially in chemical processing, pharmaceuticals, and materials science sectors. Alfa Chemistry provides viscosity measurements for numerous liquids to help researchers and engineers make better product development and quality control decisions.
Here is a detailed table of the dynamic (absolute) viscosities of common liquids at room temperature (~25°C), expressed in millipascal-seconds (mPa·s) or centipoise (cP), where 1 mPa·s = 1 cP.
| Liquid | Viscosity (mPa·s or cP) | Notes |
| Water (Fresh) | 0.89 | Standard reference for viscosity measurements |
| Acetic Acid | 1.155 | Organic acid used in solvents and food applications |
| Acetone | 0.316 | Low-viscosity polar solvent |
| Ethanol (Ethyl Alcohol) | 1.095 | Slightly more viscous than water |
| Methanol (Methyl Alcohol) | 0.56 | Lower viscosity than ethanol |
| Propyl Alcohol | 1.92 | Higher viscosity compared to ethanol and methanol |
| Benzene | 0.601 | Aromatic hydrocarbon solvent |
| Blood | 3-4 | Varies with temperature and shear rate |
| Bromine | 0.95 | One of the only liquid elements at room temperature |
| Carbon Disulfide | 0.36 | Low-viscosity solvent |
| Carbon Tetrachloride (CCl₄) | 0.91 | High-density liquid with viscosity similar to water |
| Castor Oil | 650 | Extremely high viscosity, used in pharmaceuticals and lubricants |
| Chloroform | 0.53 | Common organic solvent |
| Decane | 0.859 | Low-viscosity alkane |
| Dodecane | 1.374 | Higher viscosity than decane, used in lubricants |
| Ether (Diethyl Ether) | 0.223 | Highly volatile, low-viscosity solvent |
| Ethylene Glycol | 16.2 | Used as an antifreeze component |
| Trichlorofluoromethane (Refrigerant R-11) | 0.42 | Common refrigerant fluid |
| Glycerine (Glycerol) | 950 | Highly viscous, hygroscopic liquid |
| Heptane | 0.376 | Low-viscosity alkane |
| Hexane | 0.297 | Common nonpolar solvent |
| Kerosene | 1.64 | Viscosity varies with composition |
| Linseed Oil | 33.1 | Used primarily in coatings and paints |
| Mercury | 1.53 | The only liquid metal at room temperature |
| Milk | 3 | Dependent on fat content |
| Octane | 0.51 | Low-viscosity hydrocarbon |
| Phenol | 8 | Moderate viscosity, used as a chemical precursor |
| Propane | 0.11 | Low-viscosity liquefied gas |
| Propylene | 0.09 | Low-viscosity liquefied gas |
| Propylene Glycol | 42 | Used in food, pharmaceuticals, and antifreeze |
| Toluene | 0.55 | Low-viscosity aromatic hydrocarbon solvent |
| Turpentine | 1.375 | Natural solvent derived from pine trees |
What is Dynamic Viscosity?
Dynamic viscosity represents the internal friction within a fluid, which occurs when different fluid layers move relative to each other and is expressed in pascal seconds (Pa·s) or centipoise (cP). The measure of fluid viscosity indicates how easily it flows because higher viscosity shows increased resistance to flow. Liquid dynamic viscosity varies according to its temperature levels, pressure conditions, and molecular structure.
How is Dynamic Viscosity Measured?
Viscometers and rheometers are standard instruments used to determine dynamic viscosity. Viscosity measurement often utilizes capillary viscometers, rotational viscometers, and falling ball viscometers as common methods. The appropriate method selection relies on both the fluid type and the required measurement accuracy as well as operational conditions. Accurate temperature regulation during viscosity measurement is necessary because viscosity changes significantly with temperature fluctuations.
How Does Temperature Affect Dynamic Viscosity?
Temperature significantly impacts the dynamic viscosity of liquids. As temperature increases, the kinetic energy of molecules rises, weakening intermolecular forces and reducing viscosity. For example, the viscosity of water decreases from 1.79 mPa·s at 0°C to 0.28 mPa·s at 100°C. Temperature-viscosity relationships are often modeled using the Arrhenius-type equation:
Where:
- μ(T) is the viscosity at temperature
- μ0 is a pre-exponential factor
- Ea is the activation energy
- R is the gas constant
- T is the absolute temperature
Applications of Dynamic Viscosity in Industry
Dynamic viscosity plays a critical role in various industries, including:
- Pharmaceuticals: Formulation of syrups, gels, and injectable solutions
- Petrochemicals: Crude oil transport, lubricant design
- Food Processing: Quality control of sauces, beverages, and oils
- Paints and Coatings: Rheological properties for optimal application
- Polymers: Extrusion and molding processes
