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Read a brief summary of this topicsoap and detergent, substances that, when dissolved in water, possess the ability to remove dirt from surfaces such as the human skin, textiles, and other solids. The seemingly simple process of cleaning a soiled surface is, in fact, complex and consists of the following physical-chemical steps:
If detached oil droplets and dirt particles did not become suspended in the detergent solution in a stable and highly dispersed condition, they would be inclined to flocculate, or coalesce into aggregates large enough to be redeposited on the cleansed surface. In the washing of fabrics and similar materials, small oil droplets or fine, deflocculated dirt particles are more easily carried through interstices in the material than are relatively large ones. The action of the detergent in maintaining the dirt in a highly dispersed condition is therefore important in preventing retention of detached dirt by the fabric. In order to perform as detergents (surface-active agents), soaps and detergents must have certain chemical structures: their molecules must contain a hydrophobic (water-insoluble) part, such as a fatty acid or a rather long chain carbon group, such as fatty alcohols or alkylbenzene. The molecule must also contain a hydrophilic (water-soluble) group, such as ―COONa, or a sulfo group, such as ―OSO3Na or ―SO3Na (such as in fatty alcohol sulfate or alkylbenzene sulfonate), or a long ethylene oxide chain in nonionic synthetic detergents. This hydrophilic part makes the molecule soluble in water. In general, the hydrophobic part of the molecule attaches itself to the solid or fibre and onto the soil, and the hydrophilic part attaches itself to the water. Four groups of surface-active agents are distinguished:
The first detergent (or surface-active agent) was soap. In a strictly chemical sense, any compound formed by the reaction of a water-insoluble fatty acid with an organic base or an alkali metal may be called a soap. Practically, however, the soap industry is concerned mainly with those water-soluble soaps that result from the interaction between fatty acids and alkali metals. In certain cases, however, the salts of fatty acids with ammonia or with triethanolamine are also used, as in shaving preparations. HistoryUseSoap has been known for at least 2,300 years. According to Pliny the Elder, the Phoenicians prepared it from goat’s tallow and wood ashes in 600 bce and sometimes used it as an article of barter with the Gauls. Soap was widely known in the Roman Empire; whether the Romans learned its use and manufacture from ancient Mediterranean peoples or from the Celts, inhabitants of Britannia, is not known. The Celts, who produced their soap from animal fats and plant ashes, named the product saipo, from which the word soap is derived. The importance of soap for washing and cleaning was apparently not recognized until the 2nd century ce; the Greek physician Galen mentions it as a medicament and as a means of cleansing the body. Previously soap had been used as medicine. The writings attributed to the 8th-century Arab savant Jābir ibn Hayyān (Geber) repeatedly mention soap as a cleansing agent. Get a Britannica Premium subscription and gain access to exclusive content. Subscribe Now In Europe, soap production in the Middle Ages centred first at Marseille, later at Genoa, and then at Venice. Although some soap manufacture developed in Germany, the substance was so little used in central Europe that a box of soap presented to the Duchess of Juelich in 1549 caused a sensation. As late as 1672, when a German, A. Leo, sent Lady von Schleinitz a parcel containing soap from Italy, he accompanied it with a detailed description of how to use the mysterious product. The first English soapmakers appeared at the end of the 12th century in Bristol. In the 13th and 14th centuries, a small community of them grew up in the neighbourhood of Cheapside in London. In those days soapmakers had to pay a duty on all the soap they produced. After the Napoleonic Wars this tax rose as high as three pence per pound; soap-boiling pans were fitted with lids that could be locked every night by the tax collector in order to prevent production under cover of darkness. Not until 1853 was this high tax finally abolished, at a sacrifice to the state of over £1,000,000. Soap came into such common use in the 19th century that Justus von Liebig, a German chemist, declared that the quantity of soap consumed by a nation was an accurate measure of its wealth and civilization. Early soap productionEarly soapmakers probably used ashes and animal fats. Simple wood or plant ashes containing potassium carbonate were dispersed in water, and fat was added to the solution. This mixture was then boiled; ashes were added again and again as the water evaporated. During this process a slow chemical splitting of the neutral fat took place; the fatty acids could then react with the alkali carbonates of the plant ash to form soap (this reaction is called saponification). Animal fats containing a percentage of free fatty acids were used by the Celts. The presence of free fatty acids certainly helped to get the process started. This method probably prevailed until the end of the Middle Ages, when slaked lime came to be used to causticize the alkali carbonate. Through this process, chemically neutral fats could be saponified easily with the caustic lye. The production of soap from a handicraft to an industry was helped by the introduction of the Leblanc process for the production of soda ash from brine (about 1790) and by the work of a French chemist, Michel Eugène Chevreul, who in 1823 showed that the process of saponification is the chemical process of splitting fat into the alkali salt of fatty acids (that is, soap) and glycerin. The method of producing soap by boiling with open steam, introduced at the end of the 19th century, was another step toward industrialization. What is the mechanical process of using soap and water or detergent water?Cleaning Mechanical process (i.e., scrubbing) using soap or detergent and water to physically remove dirt, debris, and many germs. It also removes invisible debris that interferes with disinfection. Sanitizing Chemical process of reducing the number of disease-causing germs on cleaned surfaces to a safe level.
Is a mechanical process using soap or water or detergent and water to remove dirt debris and many diseaseCleaning is a mechanical process using soap and water or detergent and water to remove all visible dirt, debris, and many disease-causing germs from tools, implements, and equipment. Disinfecting involves the use of a chemical to destroy most, but not necessarily all, harmful organisms on environmental surfaces.
Is cleaning a mechanical process?Cleaning is a mechanical process enhanced by germicidal detergents to remove dirt, debris, biofilm, and microbes, • Cleaning prepares a surface to be disinfected. Cleaning agents have a surfactant that removes dirt. Bleach is NOT a cleaning agent.
Which is a mechanical process Milady?Mechanical process ; using soap/water or detergent/water to remove all visible dirt, debris and many disease-causing germs from tools, implements, and equipment. A Chemical process; for reducing the number of disease-causing germs on clean surfaces to a safe level .
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