Soap stain removal principle and laundry concentration
Our country is a large country with a population of 1.3 billion people, thrift and simplicity is the fine tradition of our Chinese nation, saving energy for us, has an extraordinary significance. In daily life everyone has to wear clothes, washing clothes, soap, laundry detergent use is a huge number, that how to better use of laundry detergent and soap, so that it reaches a better concentration of laundry, trying to achieve savings? So, I first go online to find out the principle of stain removal of soap and laundry detergent.
Soap is a fatty acid and alkali (caustic soda) at a certain temperature, by boiling and refining (neutralization) and de-glycerol and become, the main component is the sodium salt of hard fatty acids, also known as sodium soap. Its PH value is generally around 9, weakly alkaline.
Soap decontamination principle – soap molecules have a characteristic, one end of the molecule has a hydrophilic, the other end has a lipophilic, called hydrophobic base. If the clothes are stained with oil, wet it, wipe the soap, gently rub, soap break-up in the hands of the oleophilic part of the oil will be with the oil “hold together”, fused together with each other to form the appearance of hydrophilic tiny “glue group”. In this way, the oil is surrounded by soap and water, gradually dissolved from the clothes into the water, and then rinsed with water, oil and soap molecules together with the water to wash away.
Laundry detergent is composed of a variety of chemical components, playing a major role is the surfactant, the main ingredient is sodium p-dodecylbenzene sulfonate. All of them have a pH value above 11, which is highly alkaline. In the laundry detergent, there are also added bio-enzymes, surfactants, detergents, stabilizers, dispersants, whitening agents, flavors and so on. In this way, various chemicals promote and make up for each other, so that the washing and decontamination effect is more ideal.
The detergent principle of washing powder – washing powder in water can be hydrolyzed into hydrophilic sodium ions, and lipophilic alkylbenzene sulfonic acid ions can be very good fusion, which is due to the molecular structure of the same substances similar to the reason for compatibility. The molecule of laundry detergent is a macromolecule of organic matter at one end, with a structure similar to that of an oil molecule, and a small molecule of ions at the other end, with a structure similar to that of a water molecule. The lipophilic end fuses with the oil, and the hydrophilic end, which is affinity with water, separates the oil from the clothes. Laundry detergent also has the function of emulsification, it can make the oil dirt dispersed into countless tiny droplets.
It can be seen that the basic decontamination principle of soap and laundry detergent is the same, are the use of surfactant components, which is a kind of hydrophilic performance at one end, the other end of the oleophilic performance of the matchstick structure, according to the similarity theory of solubility, the oleophilic end of the oleophilic molecules can be inserted into grease, hydrophilic end of the molecules can be formed with a large number of water molecules in micellar clusters. In this way, the oil molecules “pull” into the water, and then through mechanical friction, the dirt with oil washed away. Figure out the soap box detergent staining principle, I did a small experiment. Experiment specific operation:
Test supplies:
Concentration of 20% 40% 60% 80% of the soap and water 500ml stained with oil four cotton cloths
Four small pots
A bucket of water
Experiment:
(1) Put the oily cloths into 500 ml of soapy water of 20%, 40%, 60% and 80% concentration.
(2) Soak for 10 minutes.
(3) Scrub repeatedly
(4) Place the cloths in four small basins and rinse with water.
(5) Record the results of the experiment.
Observation of the experimental phenomenon: the higher the concentration of soapy water to clean the cotton cloth.
Analysis of experimental phenomena: soap molecular structure can be divided into two parts. One end is charged with polar COO- (hydrophilic parts), the other end of the non-polar carbon chain (lipophilic parts). Soap can destroy the surface tension of water, when the soap molecules into the water, with the polarity of the hydrophilic part, will destroy the attraction between the water molecules and make the surface tension of the water to reduce the water molecules to be cleaned in the average distribution of clothing or skin surface. Soap oleophilic parts, in-depth oil, and hydrophilic parts dissolved in water, the combination of this mixture after stirring to form smaller oil droplets, the surface of which is covered with hydrophilic parts of the soap, and will not be regathered into a large oil. This process (also known as emulsification) repeated many times, then all the oil will become very small oil droplets dissolved in water, can be easily rinsed clean.
Conclusion: The higher the concentration of soapy water, the better the ability to remove dirt.
