1.1 Introduction
When you are young “bath time” is another word torture and a harmless block of soap can seem like an offensive weapon. Fortunately, most of us soon grow out of that little problem and learn to recognizes soap and water for what they are. We use soap and detergent in our daily life to wash our hands body and to clean our clothes without knowing how it works.
Soap and detergent are substances used to enhance the cleaning action of water. They cleans by acting as an emulsifier which penetrates and breaks up the only file that bind direct particles, and wetting agent which help them to float off. They are similar in their chemical properties. However, there is a significant difference between them, which soaps are produced from natural products and detergent are synthetic, or man — made.
Soaps and detergents are used for cleaning because pure water only can't remove oily, organic soiling. Basically, soap allows oil and water to mix so that oily grime can be removed during rinsing. Detergents were developed in response to the shortage of the animal and vegetable fats used to make soap during World War 1 and world war 11. Detergents are primarily surfactants, which could be produced easily from petrochemicals. Surfactants lower the surface tension of water, essentially making it “wetter” so that is less likely to stick to itself and more likely to interact with oil and grease.
For most practical purposes, the term soap (soap detergent) refers to any water soluble salt of a fatly acid. When this salt of fatly acid solution is applied to grease coated piece of fabric the soap molecule first approach the grease spot, at the interphase of grease and water, the hydrophobic tail of the soap particles dissolved in grease while the hydrophilic end dissolve in water the water molecular attract the polar ionic heads of the soap molecules, this action helps to lift the grease spots upward, enabling more is emulsified and on rinsing the fabric, the grease is removed.
In washing woven cotton fabric contains fibers surface, the detergent solution must come into content with all these fibers for this cleansing action to take place, the lowered interfacial tension assisted this soaking also promote cleaning by penetration of the internal channels of many kinds of fiber by water. This displaces the air through the capillaries radiating to the surfaces of the fabric. Air so displaced has been observed to form bubbles inside oil globules formed, helping to detach them from the fabric. If the bath had sufficient wetting power to displace air, detergency is achieved. Here, the term “ wetting” however mean the displacement of one liquid by another. For instance the oil being displaced by water from the surface of a solid in cleaning of fabric is a significant example of displacement.
1.2 A Brief History of Cleansing Soap and Detergent
The earliest recorded evidence of the production of soap like materials dates back to around 2008 Bc in Ancient Babylon. in the reign of Nabonidus (556 — 539 BCE) a recipe for soap consisted of uhulu (ashes) cypress (oil) and sesame (seed oil) “ for washing the stones for the servant girls”. A formula for soap consisting of water, alkali and cassia oil was written on a Babylonian day tablet around 2200 Bc.
The Ebers papyrus (Egypt, 1550 Bc) indicates that ancient Egyptians bathed regularly and combined animal and vegetable oils with alkaline satts to create a soap- like substance. Egyptain documents mention that a soap- like substance was used in the preparation of wool for weaving.
In roman history, the word soap, latin for Soap, First a appear in Pliny the Elders of Historian Naturalis which discusses the manufacture of soap from fellow and ashes, but the only use he mentions rather disapproving that the men of the Gauls and Germans were more likely to use it then their females center parts.
1.3 The Aim / Objective of the Study
The aim / objective of the study ( the effects of action of detergent and soap on soil/ dirty substances during washing) apply to chemical engineering is to know the working principle of soap and detergent (how soap and detergent works) on soil / dirty substance during washing.
