Liquids - Dielectric Constants
Dielectric constants or permittivities of some fluids or liquids.
The Dielectric Constant, or permittivity - ε - is a dimensionless constant that indicates how easy a material can be polarized by imposition of an electric field on an insulating material. The constant is
- the ratio between the actual material ability to carry an alternating current to the ability of vacuum to carry the current
The dielectric constant can be expressed as
ε = εs / ε0 (1)
where
ε = the dielectric constant
εs = the static permittivity of the material
ε0 = vacuum permittivity
The Dielectric Constant of common fluids are indicated in the table below. The Dielectric Constant is in general influenced by
- temperature
- moisture levels
- electrical frequency
- part thickness
| Liquid | Temperature (oC) | Dielectric Constant - ε - |
|---|---|---|
| Acetal | 25 | 3.8 |
| Acetaldehyde | 18 | 21.8 |
| Acetamide | 91 | 67.6 |
| Acetic acid | 20 | 6.2 |
| Acetone | 25 | 20.7 |
| Acetonitrile | 20 | 36.6 |
| Acetophenone | 18 | |
| Acetyl bromid | 16.2 | |
| Acetyl chloride | 22 | 15.8 |
| Acetylacetone | 23 | |
| Acetylene | -78 | 2.48 |
| Acetylene dibromide | 7.2 | |
| Acetylene tetrabromide | 5.6 | |
| Acrylonitrile | 20 | 33 |
| Aconite acid ester | 6.3 | |
| Adipic Acid | 1.8 | |
| Aerosile | 1.0 | |
| Air (at STP, for 0.9 MHz)) | 1.00058986 ± 0.00000050 | |
| Alcohol, allyl | 20 | 19.7 |
| Alcohol, benzyl | 30 | 11.9 |
| Alcohol, cetyl | 60 | 3.6 |
| Alcohol, diacetone | 18.2 | |
| Alcohol, ethyl (ethanol) | 20 | 25.3 |
| Alcohol, methyl (methanol) | 20 | 33.0 |
| Alcohol, propyl | 20 | 21.8 |
| Allene | -4 | 2.03 |
| Allylbenzene | 20 | 2.63 |
| Allyl chloride | 8.2 | |
| Allyl iodide | 6.1 | |
| Allyll isocyanate | 15 | 15.2 |
| Aluminum bromide | 100 | 3.38 |
| Ammonia | 20 | 16.61 |
| Ammonia solution 25% | 31.6 | |
| Amyl amine | 4.5 | |
| Aniline | 20 | 7.06 |
| Anisole | 21 | 4.3 |
| Antimony hydride | 1.8 | |
| Anthracene | 229 | 2.65 |
| Argon | -133 | 1.32 |
| Arsine | 2.1 | |
| Arsole | 2.3 | |
| Azoxybenzene | 36 | 5.2 |
| Benzaldehyde | 20 | 17.9 |
| Benzene | 20 | 2.28 |
| Benzil | 95 | 13.04 |
| Benzonitrile | 20 | 25.9 |
| Benzyl acetat | 30 | 5.34 |
| Benzyl formate | 30 | 6.34 |
| Benylamine | 20 | 5.18 |
| Biphenyl | 75 | 2.35 |
| Bromine | 25 | 3.15 |
| Bromine trifluoride | 25 | 107 |
| Bromoethane | 25 | 9.01 |
| Butane | 22 | 1.77 |
| Butanoic acid | 3.0 | |
| 1-Butanol | 20 | 17.8 |
| Butyl acetate | 20 | 5.07 |
| Butyl acrylate | 28 | 5.25 |
| Butylamine | 20 | 4.71 |
| Butylbenzene | 20 | 2.36 |
| Butyl nitrate | 20 | 13.1 |
| Caproic acid | 71 | 2.6 |
| Caprylic acid | 2.5 | |
| Carbon dioxide | 22 | 1.45 |
| Carbon disulfide | 20 | 2.63 |
| Carbon tetrachloride | 20 | 2.23 |
| Castor Oil | 15 | 4.7 |
| Chlorine, chlor fluid | -65 | 2.15 |
| Chlorine pentafluoride | -80 | 4.28 |
| Chlorine trifluoride | 20 | 4.39 |
| Chlor benzene | 5.7 | |
| Chloroacetic acid | 65 | 12.4 |
| Chlorocyclohexane | 30 | 7.95 |
| Chloroethane | 20 | 9.45 |
| Chloroform | 20 | 4.8 |
| Chlorodifluoromethane refrigerant R-22 | 25 | 2.0 |
| Coconut oil, refined | 2.9 | |
| Cotton seed oil | 3.1 | |
| Cresol | 17 | 10.6 |
| Cumene | 20 | 2.4 |
| Cyanoacetic acid | 4 | 33.4 |
| Cyanoacetylene | 19 | 72.3 |
| Cycloheptane | 20 | 2.08 |
| Cycloheptene | 22 | 2.27 |
| Cyclohexane | 20 | 2.02 |
| Cyclohexene | 20 | 2.22 |
| Decane | 20 | 2.0 |
| Diacetone alcohol | 25 | 18.2 |
| Dichlorodifluoromethane refrigerant R-12 | 25 | 2.0 |
| Diesel oil, fuel | 2.1 | |
| Diethyl ether | 20 | 4.27 |
| Diethyl sulfide | 25 | 5.7 |
| Difluoromethane | -121 | 53.7 |
| Dimethyl ether | -15 | 6.18 |
| Docosane | 20 | 2.08 |
| Dodecane | 20 | 2.01 |
| Ethane | -178 | 1.94 |
| Ether | 20 | 4.3 |
| Ethylamine | 21 | 6.3 |
| Ethylene glycol | 20 | 37.0 |
| Ethoxybenzene | 20 | 4.22 |
| Ethylamine | 0 | 8.7 |
| Ethyl acrylate | 30 | 6.05 |
| Ethylbenzene | 20 | 2.44 |
| Ethylene | -3 | 1.48 |
| Ethyl isocyanate | 20 | 19.7 |
| Ethyl lactate | 30 | 15.4 |
| Ethyl salicylate | 35 | 8.48 |
| Ethyl silicate | 20 | 2.5 |
| Eucalyptol | 25 | 4.57 |
| Fish oil | 2.6 | |
| Fluorbenzene | 20 | 6.4 |
| Fluorine | -220 | 1.49 |
| Fluoromethane | -142 | 51.0 |
| Formamide | 20 | 111 |
| Formic acid | 25 | 51.1 |
| Furan | 25 | 2.94 |
| Furfural | 20 | 42.1 |
| Furfuryl alcohol | 25 | 16.9 |
| Gasoline, gas | 21 | 2.0 |
| Glycerine | 47-68 | |
| Glycerol | 20 | 46.5 |
| Glycerol water | 37 | |
| Glycol | 37 | |
| Helium | -271 | 1.056 |
| Heptadecane | 20 | 2.06 |
| Heptanal | 22 | 9.07 |
| Heptane | 20 | 1.92 |
| Heptanoic acid | 15 | 3.04 |
| 1-Heptanol | 20 | 11.75 |
| Heptyl acetat | 20 | 4.2 |
| Heptylamine | 20 | 3.81 |
| Heptylbenzene | 20 | 2.26 |
| Hexadecane | 20 | 2.05 |
| Hexane | 20 | 1.89 |
| Hexanoic acid | 25 | 2.6 |
| 1-Hexanol | 20 | 13.03 |
| 1-Hexene | 21 | 2.1 |
| Hexyl acetate | 20 | 4.42 |
| Hexylamine | 20 | 4.1 |
| Hexylbenzene | 20 | 2.3 |
| Hydrazine | 25 | 51.7 |
| Hydrogen | -260 | 1.279 |
| Hydrogen bromide | -86 | 8.23 |
| Hydrogen chloride | -114 | 14.3 |
| Hydrogen cyanide | 20 | 114.9 |
| Hydrogen fluoride | 0 | 83.6 |
| Hydrogen peroxide | 17 | 74.6 |
| Hydrogen sulfide | 10 | 5.93 |
| Iodine | 118 | 11.08 |
| Iodine heptafluoride | 25 | 1.75 |
| Isobutane | 22 | 1.75 |
| Isobutyl acetat | 20 | 5.1 |
| Isobutylbenzene | 20 | 2.3 |
| Isopentane | 20 | 1.85 |
| Isopentyl acetat | 20 | 4.72 |
| Isopentyl lactate | 0 | 11.2 |
| Isopentyl salicylate | 20 | 7.26 |
| Isopropanol (2-Propanol, Isopropyl alcohol, propan-2-ol, (CH3)2CHOH) | 18.2 | |
| Isopropylamine | 20 | 5.6 |
| Isopropylbenzene | 20 | 2.38 |
| Jet fuel | 21 | 1.7 |
| Kerosene | 21 | 1.8 |
| Krypton | -153 | 1.66 |
| Lead chloride | 20 | 2.78 |
| Linoleic Acid | 0 | 2.6-2.9 |
| Linseed Oil | 3.2-3.5 | |
| Menthol | 36 | 3.9 |
| Mercury (vapor) | 148 | 1.00074 |
| Methane | -182 | 1.68 |
| Methyl acetate | 15 | 7.07 |
| Methyl acrylate | 30 | 7.03 |
| Methylamine | -58 | 16.7 |
| Methyl benzoate | 30 | 6.64 |
| Methylcyclohexane | 20 | 2.02 |
| Methyl nitrate | 20 | 23.9 |
| Methyl nitrite | 27 | 27.8 |
| Napthalene | 20 | 2.5 |
| Neon | -247 | 1.19 |
| Neopentane | 23 | 1.77 |
| L-Nicotine | 20 | 8.9 |
| Nitric oxide | -149 | 2.0 |
| Nitrobenzene | 20 | 35.6 |
| Nitroethane | 15 | 29.1 |
| Nitrogen | -210 | 1.47 |
| Nitrogen tetroxide | 20 | 2.44 |
| Nitromethane | 20 | 37.3 |
| Nonane | 20 | 1.97 |
| Nonanoic acid | 22 | 2.48 |
| 1-Nonanol | 20 | 8.83 |
| Nonyl acetat | 20 | 3.87 |
| Octane | 20 | 1.95 |
| Octanoic acid | 15 | 2.85 |
| Octyl acetat | 15 | 4.18 |
| Oil | 2 | |
| Olive Oil | 20 | 3.1 |
| Oxygen | -219 | 1.57 |
| Ozone | -183 | 4.75 |
| Palmitic Acid | 71 | 2.3 |
| Palm seed oil | 1.8 | |
| Paraffin | 1.6 | |
| Pentaborane | 25 | 21.1 |
| Pentadecane | 20 | 2.04 |
| Pentanal | 20 | 10 |
| Pentane | 20 | 1.84 |
| Pentanoic acid | 21 | 2.66 |
| Pentamethylbenzene | 61 | 2.36 |
| 1-Pentanol | 25 | 15.3 |
| Pentyl acetat | 20 | 4.79 |
| Pentylamine | 20 | 4.27 |
| Pentyl nitrite | 25 | 7.21 |
| Pentyl salicylate | 28 | 6.25 |
| Phenol | 30 | 12.4 |
| Phenyl acetat | 25 | 5.40 |
| Phenylacetylene | 25 | 2.98 |
| Phosgene | 0 | 4.7 |
| Phosphorus liquid | 3.9 | |
| Pinane | 25 | 2.15 |
| Pinene | 20 | 2.7 |
| Propane | 20 | 1.67 |
| Propanenitrile | 20 | 29.7 |
| Propanol (propyl alcohol, 1-Propanol, n-propanol, or propan-1-ol, CH3CH2CH2OH) | 20.1 | |
| Propene | -53 | 2.14 |
| Propyl acetate | 20 | 5.62 |
| Propylamine | 23 | 5.08 |
| Propylbenzene | 20 | 2.37 |
| Propylene | 11.9 | |
| Propylether | 3.3 | |
| Pyrazine | 50 | 2.80 |
| Pyridine | 20 | 1.12 |
| Resorcinol | 3.2 | |
| Stearic Acid | 71 | 2.3 |
| Styrene | 20 | 2.47 |
| Sulfur | 134 | 3.5 |
| Sulfur dioxide | 20 | 14.3 |
| Terpinene | 17 | 2.7 |
| Thymol | 60 | 4.3 |
| Toluene | 23 | 2.38 |
| Transformer oil | 2.1 | |
| Trichlorofluoromethane refrigerant R-11 | 20 | 2.0 |
| Turpentine (wood), white spirit | 20 | 2.2 |
| Vacuum (by definition) | 1 | |
| Vinegar | 24 | |
| Water | 20 | 80.1 |
| Water | 360 | 10 |
| Water, demineralised | 29.3 | |
| Water, heavy | 78.3 | |
| Water - oil emulsion | 24 | |
| Wine | 25 | |
| Xenon | -112 | 1.88 |
| o-Xylene | 20 | 2.56 |
| m-Xylene | 20 | 2.36 |
| p-Xylene | 20 | 2.27 |
| Xylitol | 20 | 40.0 |
Typical dielectric values for some common plastic materials are indicated below:
| Plastic Material | Dielectric Constant - ε - |
|---|---|
| Acetal | 3.7 - 3.9 |
| Acrylic | 2.1 - 3.9 |
| ABS | 2.9 - 3.4 |
| Nylon 6/6 | 3.1 - 8.3 |
| Polycarbonate | 2.9 - 3.8 |
| Polyester, TP | 3.0 - 4.5 |
| Polypropylene | 2.3 - 2.9 |
| Polysulfone | 2.7 - 3.8 |
| PPO, Modified | 2.4 - 3.1 |
| Polyphenylene sulfide | 2.9 - 4.5 |
| Polyacrylate | 2.6 - 3.1 |
| Liquid Crystal | 3.7 - 10 |
