Soaps and Detergents
Soaps and Detergents
The goal of this project was to make, and test four soaps, and two detergents. The purpose of making four different soaps and two detergents was needed in order to decide which one would be best for the environmental group to use in the future that would allow for the safest cleanup of an oil spill while not harming the animals or the environment in the process. It was necessary to test the impact of the four soaps and two detergents by analyzing their different properties based off of their specific characteristics and the wastewater left over from the vacuum filtration procedure. This procedure had to be undertaken in order to confirm which of the soaps and detergents synthesized is most environmentally suitable, and which one would result in the most minimal environmental damage as possible after clean up. Other test that were essential in determining the characteristic and properties of each individual soap and detergent included testing for lather ability, cleaning ability, and solubility.
Each soap and detergent was tested for lather ability, solubility and clean- ability, by cleaning dirty lab glass wear by means of mixing a small amount of each soap and detergent in a beaker with water, and creating a lather by the use of a scrub brush. The individual results can be seen in Table 4. The greater the lather, more cleaning ability the soap or detergent was capable of. The test of lather ability was done first by using tap water. The soap will make more bubbles with the soft water than with the hard water, because it reacts with the calcium and magnesium salts to form ‘scum’, which is insoluble in water when mixed with hard water. This means there is less soap for making bubbles, or for cleaning.
The tap water used to test the properties of the soap would most likely be considered hard water more than it would be considered soft which is why the conclusion of the least lather ability meant more cleaning ability. After the clean ability, lather ability, and solubility test were completed, it was important to test each soap and detergent by us of the titration procedure. The titration phase of procedure is to be performed on the wastewater to determine which would take the least time to neutralize pH levels. Amongst completion of the steps mentioned to determine the properties of each specimen, and their characteristics based off of basic testing can help in concluding the best candidate to be used for the environmental group cleanup.
Soap and detergent have similar properties even though they are synthesized by use of different technique. Soaps and detergents are made up of micelles, which are clusters of molecules made from long hydrocarbon chains. The hydrocarbon chains are attracted to the other, and held together by Van der Waal forces. Van der Waals forces include attractions between atoms, molecules, and surfaces, as well as other intermolecular forces. They differ from covalent and ionic bonding in that they are caused by correlations in the fluctuating polarizations of nearby particles. These molecules have two parts, a hydrophobic hydrocarbon tail attached to a hydrophilic head. The hydrophobic part surrounds the dirt particles, and holds them, while the hydrophilic head attaches to the water molecules so the dirt and soap is rinsed away by the water.
Detergents can also act as surfactants. A surfactant is a substance that lowers the surface tension of water, which makes the water more effective at conjoining with and removing dirt. Soaps are water-soluble sodium or potassium salts of fatty acids. Soaps are made from fats and oils, or their fatty acids, by treating them chemically with a strong alkali. Hydrolysis, otherwise known as saponification, is the procedure that is used for producing soaps. Fats and oils are hydrolyzed (split) with a high-pressure steam to yield crude fatty acids and glycerin. This was accomplished by placing the soap and detergent in a beaker on a hot plate, until the solution of each individual soap and detergent began to boil. This was accomplished by constant vigorous stirring while the solutions were brought to a boil, being stirred until each soap and detergent turned pasty in consistency. The fatty acids are then purified by distillation and neutralized with an alkali to produce soap and water.
The fats and oils used in soap-making come from animal or plant sources. The four basic soaps used in this procedure were made using olive oil, vegetable oil, vegetable shortening, and lard. Each fat or oil is made up of a distinctive mixture of several different triglycerides. In a triglyceride molecule, three fatty acid molecules are attached to one molecule of glycerin. There are many types of triglycerides; each type consists of its own particular combination of fatty acids. They are weak acids composed of two parts: A carboxylic acid group consisting of one hydrogen (H) atom, two oxygen (O) atoms, and one carbon (C) atom, plus a hydrocarbon chain attached to the carboxylic acid group. Generally, it is made up of a long straight chain of carbon (C) atoms each carrying two hydrogen (H) atoms. The carboxylate end of the soap molecule is attracted to water. It is called the hydrophilic end; this end of the fatty acid chain prefers water.
The hydrocarbon chain is attracted to oil and grease and is the hydrophobic end. However, when soap is presented to hard water which is water containing minerals, such as calcium, magnesium, and seldom minerals like iron. Soap produces what is known as soap scum, or residue from the minerals that are found in hard water, because the salts create an insoluble participates when introduced to the fatty acid carbon chain. This can be absorbed by mixing for example, basic tap water with soap, and observing the color of the water becoming slightly cloudy and creation of less bubbles or foam. Hard water is often indicated by a lack of suds formation when soap is agitated in water.
Water’s hardness is determined by the concentration of multivalent cations in the water. Multivalent cations are cations (positively charged metal complexes) with a charge greater than 1+. Usually, the cations have the charge of 2+. Common cations found in hard water include Ca2+ and Mg2+. These ions enter a water supply by leaching from minerals within an aquifer. Common calcium-containing minerals are calcite and gypsum. A common magnesium mineral is dolomite (which also contains calcium). Rainwater and distilled water are soft, because they also contain few ions.The following equilibrium reaction describes the dissolving/formation of calcium carbonate scales:
CaCO3 + CO2 + H2O ⇋ Ca2+ + 2HCO3-
Temporary hardness is a type of water hardness caused by the presence of dissolved carbonate minerals (calcium carbonate and magnesium carbonate). When dissolved, these minerals yield calcium and magnesium cations (Ca2+, Mg2+) and carbonate and bicarbonate anions (CO32-, HCO3-). The presence of the metal cations makes the water hard. However, unlike the permanent hardness caused by sulfate and chloride compounds, this “temporary” hardness can be reduced either by boiling the water, or by the addition of lime (calcium hydroxide) through the process of lime softening. Boiling promotes the formation of carbonate from the bicarbonate and precipitates calcium carbonate out of solution, leaving water that is softer upon cooling. Soap scum or residue can be harmful to the environment due to the fact it can take long periods of time to remove an insoluble participate. The more soap scum produced, results in less soap available to essentially clean a designated area or surface.
It is essential after the mentioned pH titration procedure is completed, and that other test procedures are carried out to test the newly created soaps and detergents reactions to hard water. Each soap and detergent was tested using tap water, pound water, and even distilled water to test for soap scum or any other residue which will result in a unwanted by product. After performing the indicated procedures, by using calcium carbonate, otherwise known as lime softening, the relative pH’s of the new solutions can be tested with the initial pH’s of the previous titrated waste water, in order to accurately presume that the calcium or magnesium cations have been removed properly deeming the newly synthesized soap and detergent good enough for us. This can be seen in figure 1-6 of the test results. Adding a base to an acidic solution or addend an acid to a basic solution by titration is done in order to bring a desired solution to a neutralized state. This will result is what was once too acidic or too basic a soap or detergent, to becoming a more neutralized one suitable for cleaning up wild life affected by the oil spill.
Detergents are not much different than soaps. Detergents are derived from petroleum which performs similar to that of fats and oils that contain hydrocarbon chains as the water does, but tends to be attracted to oil and grease in soils similar to the properties discussed in the fatty acid chains found in soap. The detergents in this case were created from laurel alcohol and NaOH. These hydrocarbon chain sources are used to make the hydrophobic end of the surfactant molecule.
Detergents occasionally act differently when introduced to hard water by producing little to no soap scum or harsh residue that in turn can be harmful to the environment. Detergents tend to act more quickly to binding to the oil, dirt and grease resulting to faster cleaning time than that of soap. Soap scum is produced because of multivalent cations as mentioned. The production of soap scum arises because the 2+ ions destroy the surfactant properties of the soap by forming a solid precipitate. A major component of such scum is calcium stearate, which arises from sodium stearate, the main component of soap:
2 C17H35COO- + Ca2+ → (C17H35COO)2Ca
Surfactants molecules allow the properties of water to change by decreasing the surface tension, allowing the detergent to be able to wet a desired material more sufficiently like dishes, clothe or even an animal that has been submerged in crude oil. Detergents differ in the sense that most detergents are not true soaps, and can be synthesized to react in a specific way when introduced to hard water, and are soluble in acidic and alkali solutions resulting in little to no soap scum. This is why detergent for example is used for cleaning of ones clothes rather than basic soap being added to a washer machine.
Surfactants act as an emulsifier preventing oily soils from transferring back onto surface areas, allowing enough time to remove the released oil and dirt. Detergents and soaps are able to draw these oils and dirt off of surfaces because of their polar and nonpolar properties, as well as the hydrophobic and hydrophilic properties. This allows for the structure of the micelle that is a characteristic property that is fundamental in removing dirt, oil and grease found on surfaces. The hydrophilic and hydrophobic ends are the properties that produce the micelle, which is what creates a spherical structure. The hydrophilic end is what holds the sphere together by the strong hydrogen bonding that is holding tightly to the surrounding solvent. The hydrophobic ends are attracted to the grease, oil or dirt on surface areas of counters, dishes, or even animals. The hydrophobic ends are what allow the micelle to emulsify greasy surfaces allowing for the desired area to be better cleaned then using water alone.
After the pH, titration, and learning about the properties of soaps and detergent one could conclude that the vegetable oil or olive oil soap would make the best environmentally friendly cleaning agent, then the more acidic detergent that could be harmful to the animals, and less desirable to the animal friendly environmental group due to animal fats being the key ingredient used in the production of detergents, not to mention that detergents yield a greater risk of being more corrosive if the pH is not neutralized properly or in time. See table 2 for pH properties of both detergents tested.
Overall detergents are better at removing dirt and oil from surfaces and clean faster than soaps. Detergent synthesized using method one gave the best results compared to all the rest, see table 1; however, it is made with animal byproducts, deeming it an undesirable means to be used by the environmental group for cleaning. Vegetable shortening and lard being heavy animal fats are more saturated then vegetable oil or olive oil, deeming them less water soluble and not an effective soap or detergent, unlike the vegetable oil or olive oil based soap. See table 3.
Olive oil and vegetable oil based soap also had the lowest pH level, and produces the least lather making it the more effective soap for cleaning then the lard soap , however, the vegetable based soap seem to leave the glass wear after cleaning with a less slimy residue unlike the olive oil. See table 4. The reason why olive oil and vegetable oil was determined to be the best soap or detergent was because they both simply have higher quality. The fact that both of these soap produced little to no bubbles, indicated a higher quality of cleaning than the other soaps did. First, soap lathers better in soft water than in hard water, so it’s easy to use too much. The more dissolved soap there is, the more water you need to rinse it away. Second, the ions in softened water lessen its ability to ‘stick’ to the soap molecules, making it more difficult to rinse the cleanser off your body or that of an animal covered in crude oil.
The reaction between a triglyceride molecule (fat) and sodium hydroxide (lye) to make soap yields a molecule of glycerol with three ionically-bonded molecules of sodium stearate. This sodium salt will give up the sodium ion to water, while the stearate ion will precipitate out of solution if it comes into contact with an ion that binds it more strongly than sodium. This is why Vegetable oil and olive oil can be absorbed effortlessly by the pores of the skin, allowing for an all-around better clean by removing dirt and oil that is trapped in small crevasses. As mentioned, Animal oils tend to be more saturated than vegetable or olive oil and can be harder to remove due to their inability or desire to want to bond with the water molecules. This explains why the soaps made with olive oil or vegetable oil are more soluble than the soaps made with lard or vegetable shortening both consisting of saturated fatty chains.
The vegetable oil based soap would be ideal for the environmental group for cleaning up crude oil spills because it pH can be neutralized quickly, it is environmentally friendly compared to its more acidic revival detergent, and it has a higher quality cleaning ability then olive oil see table 4, and is not made with animal byproducts like the detergents are. Soap is a very simple, low impact cleaning agent that improves water’s ability to clean particulate and oily soils. It is made in a one-step process, with no waste products, and quickly and completely biodegrades. The synthetic manufacture of many surfactants used in detergents even though they are similar to the ones used in synthesis of soaps, especially those built from petroleum, generates undesirable waste. Surfactants also do not biodegrade as rapidly as the soap bases products would be capable of. However, within detergents, there is a wide range in both effectiveness and ecological impact.
Renewable resource plant-based detergents usually have less ecological impact than those that are petroleum-based, like the ones synthesized during this project.. After synthesizing of the four soaps and two detergents, it would be suited to test the best soap and detergent chosen, on the wild life affected by the oil spill, and further determine which soap and detergent would be best for the environmental group to use. It also important to properly dispose of each soap and detergent in proper waste containers due to their ability to be overly acidic or basic which can cause negative implication to the environment.
The procedures used in creating soap and detergents were not without fault, or enough fault to render the results inaccurate. The mistakes that could of occurred mainly by over boiling and human error. It would be best after all the above have been noted to test the corrosiveness and possible creation of soap scum, and if each soap and detergent had any negative impact on the environment before concluding the results to be accurate and deeming a soap/detergent suitable for use by the environmental group.
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