Cleansing Agents

Cleansing agents are substances we use to put off stains, dust, foul smells, dirt, and many others from surfaces. These are the chemicals we use to decrease the surface tension on planes so that water can be properly used to clean. Cleaning with only water does not work effectively, as the surface tension is too high for coherent forces to work.

Purposes of cleaning agents encompass health, beauty, removing offensive odor, and avoiding the spread of dirt and contaminants to oneself and others.

Cleansing agents in chemistry:

Soaps and detergents are used as cleansing agents. Soap is the sodium or potassium salt of higher fatty acids chemically. Detergents are sodium salt of alkyl hydrogen sulfates or alkyl benzene sulphonic acids.

C17H35COONa or sodium stearate is the chemical formulation for soap, while the chemical formulation for detergent is C18H29NaO3S.

Cleansing agents soaps and detergents:

Soaps :

Soaps are a common detergent. They are the most known of cleansing agents. Soaps are typically made by reacting an alkali (similar to sodium hydroxide) in liquid form with naturally occurring fats or fatty acids, produced from animals and plants. The process is known as saponification.

The molecular structure of soaps is formed up of long chains of molecules. At one end we have the hydrophobic end (the tail), made from the hydrocarbon chain. These molecules repel water and stick themselves to the oils and the grease. Then at the head of the chain, we have the hydrophilic chain made up of anionic molecules.

Soaps have surface-active agents that are known as surfactants. They lower the surface tension of the water. The surfactants attach on one end to the water molecules, which allows the water to better wet the surface. At the other end, surfactants get stuck to oils and the dirt. Overall they allow water to clean the surface in a better way.

Chemical equation:

Ester + Base → Alcohol + Soap

C17H35COO-Na+, C15H31COO-Na+

Types of Soaps:

By using various types of raw materials different kinds of soaps are prepared :

• Toilet Soaps: They are formed by using better grades of fats and oils and care is taken to lower excess alkali.

Color and perfumes are added to make these more attractive.

• Floating Soaps: Soaps that float in water are formed by beating tiny air bubbles before their hardening.
• Transparent Soaps: They are formed by dissolving the soap in ethanol and then evaporating the excess solvent.
• Medicated Soaps: In this type of soap, substances that have medicinal value are added.
• Shaving Soaps: Shaving soaps contain glycerol to prevent drying rapidly. A gum called rosin is added while making them. It forms sodium rosinate which lathers well.
• Soap Chips: Soap chips are made by running a thin sheet of melted soap onto a cool cylinder and scraping off the soaps in smaller pieces.

Detergents :

The other type of cleansing agent is synthetic detergents. These are just like soaps. They have all the properties of soap. But they do not contain any soap at all, their chemical structure is different from soaps.

Detergent is derived from the Latin word “detergent” which means “to wipe off”.

One of the greatest advantages of detergents over soaps is that detergents can work in any condition, unlike soaps. They can work in normal water as well as hard water. They do not form scum in hard water. Some detergents can even work in ice-cold water.

The concentration at which micelle formation starts is known as critical micelle concentration (CMC).

Detergents are long chains of molecules just like soaps. One of the types of molecules is hydrocarbons made of carbon and hydrogen atoms. These hydrocarbons are derived from fats, oils, fatty acids, and many more. The other things will depend on the type of detergent.

Types of Detergents:

• Anionic Detergents:- Are anion active synthetic detergents. There are sulfate salts which are long chains of hydrocarbons. The anion active part is the cleansing agent. A common example is sodium alkyl sulfates. The formation involves treating long-chain alcohol with concentrated sulphuric acid. Then it is neutralized by Sodium hydroxide.

Anion detergents are the most common type of detergents. They are used in household work mostly in washing clothes, mopping floors, etc. Anionic detergents are even used in toothpaste.

• Cationic Detergents:- Cationic detergents are ammonia salts, usually of chlorides or acetates. They have a long-chained molecular structure of hydrocarbons. And the active part of the molecule is a positive ion that is a cation. This explains the name cation detergents. A popular example is cetyltrimethylammonium bromide.

Cationic detergents also have bactericidal properties. One common use for them is in hair conditioners. Cationic detergents tend to be expensive so they do not have many industrial uses.

• Non-ionic Detergents:- As the name suggests they do not have any ions in their molecules, so they are uncharged. To produce nonionic detergents we react polyethene glycol with stearic acid. There are two main types of nonionic detergent polyoxyethylene and glycosidic.

Natural Cleansing Agents:

Natural cleansing agents consist of a chemical called saponin. Soap nuts and soap pods are naturally obtained cleansing agents. A chemical substance named saponin is present in these cleansing agents which produce lather with a soap solution.

Various Natural Cleansing Agents are:

Borax: Also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. Powdered borax is white, consisting of soft colorless crystals that dissolve in water. Some closely related minerals or chemical compounds that differ in their crystal water content are referred to as borax, and the word is usually used to refer to the octahydrate.

Sodium bicarbonate: Commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3.

Vinegar: The term “vinegar” is sometimes reserved for the stronger variety (5 to 24%[33] acetic acid) made from sugar cane or chemically produced acetic acid.[34] To be called “spirit vinegar”, the product must come from an agricultural source and must be made by “double fermentation”. The first fermentation is sugar to alcohol and the second is alcohol to acetic acid.

Essential Oil: An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the oil of the plant from which they were extracted, such as oil of clove. Essential oil is “essential” in the sense that it contains the “essence of” the plant’s fragrance.

Other Natural Cleansing agents could be:

• Chickpea Powder And Turmeric
• Milk
• Cucumber And Curd
• Honey
• Coconut Oil
• Yogurt
• Lemon

Conclusion

Cleaning and sanitizing contact surfaces is to remove food (nutrients) that bacteria need to grow and to kill those bacteria that are present. The clean, sanitized equipment and surfaces must drain dry and are stored dry to prevent bacteria growth.

The most common cleansing agents include alkalies, acids, detergents, abrasives, sanitizers, and spirit solvents.