Definition - What does Solvent mean?
A solvent is a substance that can dissolve or extract other substances, usually without causing chemical changes to itself or the other substances. Solvents are valuable for processing materials, cleaning surfaces, diluting solutions, separating materials and a wide range of other applications.
Although most solvents are in the liquid state, some are solids or gases. In terms of composition, solvents can be inorganic (substances without carbon) or organic (substances with carbon). Water, the most common and widely used solvent, is inorganic.
Organic solvents are more widely used in the coating industry than inorganic solvents.
Some solvents can be recycled and reused. While very useful, many solvents are also considered health, safety and environmental hazards.
Corrosionpedia explains Solvent
Solvents are essential in the coating industry as ingredients for many coatings, cleaning agents, thinners and for other functions that improve the performance of coating and cleaning products.
Water is the dominant solvent for residential purposes. However, that is not the case for industrial solvent applications where the majority of the solvents are organic.
Water is cheap, easily available and environmentally friendly, but it does not dissolve many of the substances used in various industries, which require organic solvents.
Choosing the appropriate solvent or solvent blend for a given application is dependent on how similar the chemical characteristics of the solvent are to the substance that it is trying to dissolve. Experts call it the principle of "like dissolves like."
The polarity of a solvent determines the types of substances it can dissolve as well as the liquid substances it can be miscible with. In terms of polarity, solvents and solutes are classified as polar (hydrophilic) and nonpolar (lipophilic). Hydrophilic or polar compounds completely dissolve in water while lipophilic or nonpolar substances more easily dissolve in lipids or fats than in water.
In addition to the solvent's dissolving capability, other important factors to consider in choosing an appropriate solvent are viscosity, evaporation rate, odor, toxicity, flammability and environmental impact (volatile organic compounds emitted).
Legislation and technological advances aim to reduce the negative effects of organic solvents to health and the environment.