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PROJECT ON FOAMING CAPACITY OF SOAPS – XII CLASS - CBSE
I'd like to express my greatest gratitude to the people who have helped & supported me throughout my project. I' m grateful to Sir Francis Xavier for his continuous support for the project, from initial advice & encouragement to this day.
Special thanks of mine goes to my colleague who helped me in completing the project by giving interesting ideas, thoughts & made this project easy and accurate.
I wish to thanks my parents for their undivided support & interest who inspired me & encouraged me to go my own way, without which I would be unable to complete my project. At last but not the least I want to thanks my friends who appreciated me for my work & motivated me and finally to God who made all the things possible…
S. no.
Contents
Page No.
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INTRODUCTION
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2
EXPERIMENT 1
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3
EXPERIMENT 2
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BIBLIOGRAPHY
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Soaps are sodium or potassium salts of higher fatty acids like stearic, palmitic and oleic acids can be either saturated or unsaturated. They contain a long hydrocarbon chain of about 10-20 carbon with one carboxylic acid group as the functional group.
A soap molecule a tadpole shaped structure, whose ends have different polarities. At one end is the long hydrocarbon chain that is non-polar and hydrophobic, i.e., insoluble in water but oil soluble. At the other end is the short polar carboxylate ion which is hydrophilic i.e., water soluble but insoluble in oil and grease.
Long Hydrocarbon Chain Hydrophobic end Hydrophilic end
When soap is shaken with water it becomes a soap solution that is colloidal in nature. Agitating it tends to concentrate the solution on the surface and causes foaming. This helps the soap molecules make a unimolecular film on the surface of water and to penetrate the fabric. The long non-polar end of a soap molecule that are hydrophobic, gravitate towards and surround the dirt (fat or oil with dust absorbed in it). The short polar end containing the carboxylate ion, face the water away from the dirt. A number of soap molecules surround or encircle dirt and grease in a clustered structure called 'micelles', which encircles such particles and emulsify them.
Cleansing action of soaps decreases in hard water. Hard water contains Calcium and magnesium ions which react with sodium carbonate to produce insoluble carbonates of higher fatty acids.
2C17H35COONa +Ca2+ (C17H35COO) 2 Ca +2Na+
(Water soluble) (ppt.)
2C17H35COONa + Mg2+ (C17H35COO) 2 Mg +2Na+
This hardness can be removed by addition of Sodium Carbonate.
Ca2++ Na2CO3 CaCO3 + 2Na+
Mg2++ Na2CO3 MgCO3 + 2Na+
Aim:
To compare the foaming capacities of five different commercial soaps.
Apparatus:
5 test tubes, 5 conical flasks (100 ml), test tube stand, Bunsen burner and stop watch.
Materials Required:
5 different samples of soap and distilled water
Theory:
The foaming capacity of a soap sample depends upon the nature of soap and its concentration. This can be compared for various samples of soaps by taking the same concentration of solution and shaking them.
The foam is formed and the time taken for disappearances of foam in all cases is compared. The lesser the time taken by a solution for the disappearance of foam, the lower is its foaming capacity.
Procedure:
Five conical flasks (100 ml each) are taken and numbered 1 to 5.
In each of these flasks equal amounts (say 5 gm) of the given samples of soap shavings or granules are taken and 50 ml of distilled water is added.
Each conical flask is heated few minutes to dissolve all the soap completely.
In a test-tube stand, five big clean and dry test tubes are taken and numbered 1 to 5
One ml of the five soap solution is then poured in the test tubes of corresponding number.
10 ml. of distilled water is then added to each test tube.
Test tube no 1 is then shaken vigorously 5 times.
The foam would be formed in the empty space above the container. Stop watch is started immediately and the time taken for the disappearance of foam is noted.
Similarly the other test tubes are shaken vigorously for equal number of times (i.e., 5 times) with approximately with the same force and the time taken for the disappearance of foam in each case is recorded.
The lesser the time taken for the disappearance of foam, the lower is the foaming capacity.
Observation:
Amount of each soap sample taken
Amount of distilled water taken
Volume of each soap solution taken
Volume of distilled water added
= 5 gm.
= 50 ml.
= 1 ml.
= 10 ml.
S. No.
Soap Sample
Time taken (seconds)
1.
2.
3.
4.
5.
Conclusions:
The soap for which the time taken for the disappearance of foam is highest has maximum foaming capacity and is the best quality soap among the soaps tested.
Aim:
Study the effect of the addition of Sodium Carbonate (Washing Soda) on the foaming capacity of different soap solutions.
Apparatus:
3 test tubes, test tube stand, Bunsen burner and stop watch.
Materials Required:
0.5 g sample of soap, water (distilled & tap both) and M/10 Na2CO3 solution.
Theory:
When sodium or potassium soaps are put into water containing calcium and magnesium ions (Hard water), results in formation of scum which applies grey appearance on the cloth. To achieve the same washing or cleaning action, more soap must be added.
2C17H35COONa +Ca2+ (C17H35COO) 2 Ca +2Na+
(Water soluble) (scum)
Hard water is water that has high mineral content (mainly calcium and magnesium ions) (in contrast with soft water). Hard water minerals primarily consist of calcium (Ca2+), and magnesium (Mg2+) metal cations, and sometimes other dissolved compounds such as bicarbonates and sulphates. Calcium usually enters the water as either calcium carbonate (CaCO3), in the form of limestone and chalk, or calcium sulphate (CaSO4), in the form of other mineral deposits.
When Na2CO3 is added to tap water the calcium (Ca2+), and magnesium (Mg2+) ions precipitate as their carbonates .i.e. foaming capacity of soap increases.
Ca2++ Na2CO3 CaCO3 + 2Na+
Mg2++ Na2CO3 MgCO3 + 2Na+
Procedure:
Dissolve 0.5g of soap and dissolve it in 50 ml of distilled water.
Take three test tubes and add distilled water in first, tap water in second and third test tube.
Add 5 ml of M/10 sodium carbonate to third test tube.
To above test tubes add soap solutions separately.
Now shake first test tubes for formation of foam.
Now start the stop watch to calculate time taken for disappearance of foam.
Similarly, perform the experiment with other soap solutions. Record the observations in a tabular form.
Observation:
Amount of each soap sample taken
Amount of distilled water taken
Volume of each soap solution taken
Volume of distilled water added
= 0. 5 gm.
= 50 ml.
= 1 ml.
= 10 ml.
S. No.
Water used
Time taken (seconds)
1.
2.
3.
Conclusions:
Foaming capacity of soap in maximum in distilled water. The foaming capacity of soap increases on the addition of Sodium Carbonate.
Soap and cleanliness are inseparable, and cleansing, be it personal hygiene or laundering, is part of human history. Stringent guidelines with regard to the cleanliness of holy sites are a part of all the major religions, and the sanctification of the state of cleanliness as well as its signification of purity of body and soul are recurrent themes in their liturgies.
The origins of the word "soap" and of the first use of soap are obscure. According to one Roman legend, soap was discovered serendipitously near Mount Sapo, an ancient location for animal sacrifice not far from Rome. Animal fat mixed with wood ashes (the ancient source of alkali) and rain-water created an excellent soap mixture. Roman housewives noticed that the strange yellow substance in the water of the Tiber River (flowing near Mount Sapo) made their clothes cleaner and brighter than ordinary water.
Soapmaking became an art among the Phoenicians (fl. ca. 600 B.C.E. ) and underwent significant advances in Mediterranean countries in which local olive oil was boiled with alkali ashes (as part of soapmaking) at around the same time.
Ascribing value to cleanliness seems to have been a part of the civilizing of humankind. After the fall of Rome (in 467 C.E. ), a decline in attention paid to personal cleanliness and the maintenance of sanitation contributed to the great plague of the Middle Ages, and made especially grim contributions to the Black Death plague epidemic of the fourteenth century. Cleanliness and regular bathing became unremarkable in much of Europe not until 300 years later.
For several centuries in Europe, soapmaking was limited to small-scale production that often used plant ashes containing carbonate ( esters of carbonic acid) dispersed in water, which were then mixed with animal fat and boiled until the water evaporated. The reaction of fatty acid with the alkali carbonate of the plant ashes formed a soap and glycerol.
The real breakthrough in soap production was made in 1780 by a French chemist and physician, Nicolas Leblanc, who invented the process of obtaining soda (sodium carbonate, Na 2 CO 3 ) from common salt (the Leblanc process), and increased the availability of this alkali at a reasonable cost. With the development of power to operate factories, soapmaking grew from a "cottage industry" into a commercial venture and became one of the fastest-growing industries of the modern era. Body soap, which had been a luxury item affordable by royalty and the very rich, became a household item of ordinary folks as well.
Throughout the nineteenth century, physicians were realizing the value of soap as a medicinal agent. A well-known protagonist of soap was scientist and educator Ignaz Phillipp Semmelweis, who in 1847 discovered the infectious etiology of puerperal fever and therefore required medical students to wash their hands before they examined patients. Semmelweis encouraged
Table 1. Ingredients of soaps and detergents.
INGREDIENTS OF SOAP, SHAMPOO, AND DETERGENT
Ingredients
Percent of Total by Weight
Surfactants
30–70
Plasticizers and binders
20–50
Lather enhancers
0–5
Fillers and binders
5–30
Water
5–12
Fragrance
0–3.0
Opacifying agents
0–0.3
Dyes and pigments
<1
his colleagues to adopt his antiseptic methods, telling them, "while we talk, talk, talk, gentlemen, women are dying. I am not asking anything world-shaking. I am asking you only to wash.… For God's sake, wash your hands." In a circular handed out in Budapest during the summer of 1865, he implored new mothers: "Unless everything that touches you is washed with soap and water and then chlorine solution, you will die and your child with you!"
The chemistry of soap manufacturing stayed essentially unchanged until World War II, at which time synthetic detergents (syndets) became available. There had been a search for cleansing agents that would foam and clean when added to seawater in response to the need of sailors who spent months at sea under severe freshwater restrictions.
The Chemistry of Soaps, Shampoos, and Laundry Detergents
Soaps, shampoos, and laundry detergents are mixtures of ingredients (see Table 1). The surfactants are the essential cleaning substances and they determine the cleansing and lathering characteristics of the soap, as well as its texture, plasticity, abrasiveness, and other features. Surfactants are compounds that have a dual affinity: They are both lipophilic and hydrophilic . A surfactant molecule consists of a lipophilic tail group, which links to greasy soil, and a hydrophilic and polar head group, which renders the molecule water-soluble; this arrangement helps to disperse and rinse away greasy soil. Variations in the balance betweenhydrophobic and hydrophilic features determine the use of the surfactant as a detergent, wetting agent , or emulsifier .
Surfactants are classified according to the nature of the hydrophilic head. There are four main classes: anionic, cationic, amphoteric, and nonionic. The first three refer to charged surfactant molecules. An anionic surfactant possesses a negative charge and needs to be neutralized with an alkaline or basic material in order for its full detergent capacity to be realized, whereas a cationic surfactant is positively charged and needs to be neutralized by an acid. Amphoterics include both acidic (negative) and basic (positive) groups, and nonionics contain no ionic constituents. "Natural" soap contains an anionic surfactant. The majority of surfactants that are used in personal cleansing bars and shampoos have anionic head groups.
It is noteworthy that almost all anionic surfactants are sodium or potassium salts of the negatively charged head groups; thus the advertising slogans "alkali free" and "soapless soap" are incorrect. Most soaps and shampoos contain a mixture of two to four surfactants (out of the thousands of synthetic surfactants that are currently available). In addition, there are innumerable plasticizers, binders, moisturizers, and fillers that are also used to formulate these soaps and shampoos. Creation of the formula of a soap is a complicated enterprise and it requires, in addition to a knowledge of chemistry and even engineering, both imagination and inspiration. The contemporary formulation of soaps is the result of research and development, as well as trial and error, carried out over a course of many years by research teams. It is as much art as it is science, and it requires a long learning experience.
The Process of Washing
The most obvious target of cleansing is the outermost layer of the skin, the keratinizing epithelium. It is a cornified (hardened) cell envelope and it has an extremely tough protein/ lipid polymer structure. This hard and lipophilic layer of the epidermis and the surface hairs would not easily retain dirt if it were not for a hydrolipid film that covers the outermost layer of skin and that picks up particles of soil. This natural outer film of lipid entraps and glues environmental dust, pollutants, smoke, keratinous debris, organic and inorganic compounds in sweat, cosmetics, and other substances that come in contact with it. The hair of the scalp (corresponding to a surface area of about 8 square meters, or 86 square feet, for an average female head) is cleansed regularly. The scalp gets coated with sebum, the product of the sebaceous appendages that flows into hair follicles and a natural lubricating oil that contributes luster to the hair, on the one hand, but entraps dirt, on the other.
Washing the skin consists of the removal of the outer layer of grease (lipid) in which the soil (no matter what kind) is embedded. It is a complex physicochemical process that includes the following:
A weakening of the binding forces between the keratinized epithelium and the layer of grease via the reduction of the surface tension between the water and the water-resistant oil/grease. Because of this reduced surface tension, water (and surfactant molecules) can penetrate into the finest wrinkles of the skin. In this way, more and more interface is occupied by surfactant, and the adhesiveness of the soil-containing layer is further weakened, a process facilitated by mechanical rubbing.
Transfer of portions of the layer of oil to the aqueous vehicle. It is facilitated by the action of the micelles created when the soil was emulsified. The micelles have negatively charged surfaces and are repulsed by the overall negative charge of the keratin of the skin epithelium.
Dispersion/suspension of the oil and dirt particles in the soap foam, preventing these particles from being redeposited on the surface.
The Interaction of Soaps with the Skin
Surgeons need to scrub. Health-care providers and employees of food services must take a range of precautions against the dissemination of microorganisms. Very often, the simple act of washing one's hands is not fateful but nevertheless wise. Most experts in infection control and epidemiology maintain that hand washing remains the most powerful defense against infections. Germs are all around us, and can linger anywhere: the office phone, door handles, shopping baskets, money, even the button you push when you call for an elevator. You can unknowingly come into contact with germs. One simple rub of the eye or bite of a sandwich using unwashed hands can introduce any number of illnesses into your body. Hand washing reduces the risk. At the same time, most contemporary dermatologists agree that the comfortable classes have become preoccupied with cleanliness. Less, not more, washing is better for the skin. However, the irritant, toxic, and harmful effects of soaps have been exaggerated by some advertisers. (After all, what better way to promote their "mild," "nonallergenic," and "soapless" products?)
Washing with soap makes no discretely identifiable contribution to health. Its value lies more in the feeling it engenders in the user. People derive great enjoyment from washing: It gives them a tremendous sense of well-being.
