Oil, by nature, does not conduct electricity. This is because it combines long hydrocarbon chains that readily resist ionization. Lack of ionization means the absence of ions; when ions are absent, there will be no conductivity.
However, oil conducts electricity slightly when it contains impurities like salt. Although this conductivity directly depends on the concentration of the impurities, it works for both edible and industrial oils.
In this guide, you will learn about oils’ general properties and structure, their various classifications, why they are natural insulators in their pure form, and how they can be made to conduct electricity.
You will also learn about their approximate electrical conductivity, how they fare in heat, and their various uses.
General Structure and Properties of Oil
- Oils are triglycerides composed of three fatty acids connected to glycerol.
- The melting point of these esters is inversely proportional to the amount of unsaturated or shorter-chain fatty acids. In other words, when the percentage of unsaturated fatty acids increases, the melting point reduces.
- Oils naturally have an internal resistance to flow or exhibit viscosity. The higher the viscosity, the heavier the oil.
- Oil float on water and are not soluble in water
- They are greasy and can serve as a lubricant.
- Oils are not very volatile. They can burn without leaving any remnants
Classes of Oils
1. Edible and medicinal oils
These are nutritional oils that you use for cooking and other medicinal purposes. They include vegetable oil, peanut oil, coconut oil, cannabis oil, groundnut oil, soybean oil, and palm oil.
These oils do not conduct electricity in the absence of impurities. When they do, their conductivity is very minimal.
2. Industrial oils
Industrial oils range from raw esters to lubricating oils. This type of oil has 5 major groups:
Group I oils
These oils have been slightly refined and exhibit very low electrical conductivity. Examples include phosphate ester and bio lubes.
Group II oils
Oils in this group have been treated with hydrogen and possess low conductivity. Examples include turbine oils and other lubricating oils.
Group III and IV oils
These oils are more refined than the previous two groups and are mostly used as lubricants. They also have low conductivity.
Examples of group III and IV oils are car engine oils.
This is the only class of crude oil or its derivatives with high electrical conductivity. They do not feature as base oils or electrical components, as they can damage electrical discharges. Examples include esters and polyglycols.
Does Oil Conduct Electricity?
Oils naturally do not conduct electricity because their atoms contain only closely packed and immobile electrons. Hence, these electrons will not vibrate under an electric field or conduct electricity.
Any oil that conducts electricity must contain impurities like ionic salts or polar compounds. In impurities, oils will dissociate into positive and negative electrolytes.
This results in conduction and the movement of electric current in one direction in edible and non-edible oils. For context, oil has an approximate electrical conductivity of about 2.5 ×10−8υm−1 (it may be more or less).
Does oil conduct electricity when dissolved in water?
When you dissolve oil in distilled water, it will not conduct electricity. This is because both oil and pure water are natural insulators. However, conduction will occur when this mixture is exposed to salts or any polar impurity.
Please note that the oil is responsible for conduction here, not the water. Factors that affect this conductivity include temperature and viscosity.
Is oil a conductor of heat?
Surprisingly, oil is a good conductor of heat. This conductivity is usually high in crude oil and engine oil. For context, the thermal conductivity of various oils ranges from 0.12 to 0.18 W/mK.
Factors That Affect the Electrical Conductivity of Oil
The presence of polar purity in oil induces conductivity. This is because positive and negative ions move towards the positive and negative poles of the external electrostatic field respectively.
When you increase the temperature of an impure oil, its electrical conductivity increases, and vice versa. This is because the movement of the positive and negative ions accelerates toward the external electrostatic field.
3. External electromagnetic interference
External or environmental electromagnetic interference such as air compressors, motors, and high voltage alternating current will reduce the electrical conductivity of oil products.
Allowing these oils to escape into the atmosphere in their raw form can be poisonous upon inhalation especially if the temperature is high.
Uses of Oil
- Edible oils are ideal for preparing various delicacies.
- Medicinal oils feature in skin care and treatment of gastrointestinal upset.
- Crude oil derivatives include gasoline, diesel, and aviation fuel. This form of oil help in transportation and cooking.
- Petroleum-based fibers such as acrylic, vegan leather, nylon, and polyester are lightweight and durable. Hence, they help produce clothing, shoes, and purses.
- Oil produces construction materials such as roofing, linoleum flooring, furniture, and interiors like rugs, curtains, and paints.
- Kitchen items such as non-stick pans, dishes, dish detergents, and cups have oil properties.
Does oil affect electrical connections?
Oil can damage the polymer used for cable insulation or jacket.
This may result in severe consequences such as cable failure, downtime, and a high replacement cost.
Why is mineral oil not conductive?
Mineral oil looks like water and does not conduct electricity because it does not have free electrons that can conduct electricity.
Can electronics work in oil?
Electronics will be fine temporarily if they come in contact with a water-free oil.
However, if allowed to stay long, oil (especially mineral oil) may cause the seal on electrolytic capacitors to swell and become useless.
One thing is clear – oils (edible or industrial) will naturally not conduct electricity because they lack freely moving ions. However, conduction occurs slightly when they come in contact with additives or impurities like salt.
This is because impurities contain charged particles and will induce dissociation in oils under an electric field. As a result, the flow of electricity will occur in one direction.
Oil, however, does not need impurities to conduct heat. They are natural conductors of heat, although their conductivity is nowhere near that of metals.
I hope you found this article helpful. Ethanol plays a major role in refining crude oil into gasoline. To know how this affects the conductivity of gasoline, please see is ethanol conductive.
Thanks for reading.