STEM Topic 17: VOCABULARY
Alkaline: Having a pH greater than 7; it refers to substances that are basic ( in chemistry, a substance that can accept hydrogen ions in water and can neutralize an acid. An example of a base is sodium hydroxide (NaOH).
Ammonium thioglycolate: A chemical compound used in hair products for perming or straightening.
Bi-products: Secondary or unintended products resulting from a process.
Cardinal: Basic or fundamental.
Cortex: The inner layer of something, in this case, the inner layer of hair.
Deactivating: Making something inactive or stopping its action.
Degradation: The process of breaking down or deteriorating.
Descent: The origin or background of a person.
Disassociate: To separate or break apart into smaller parts.
Exothermic: A chemical reaction or process that releases heat.
Filaments: Thin threads or strands.
Genetics: The study of genes and heredity, how traits are passed down from parents to offspring.
Hydrogen bonds: Weak bonds between hydrogen atoms and other atoms in a molecule.
Perception: The way someone thinks about or understands something.
Triglycerides: A type of fat found in the body and in certain foods.
According to [ comedian Chris] Rock, he was inspired to make the movie after his three-year-old daughter Lola asked him, "Daddy, how come I don't have good hair?" She has curly, wiry hair typical of many people of African descent. He realized she had already absorbed the perception among some blacks that curly hair was not "good". - https://en.wikipedia.org/wiki/Good_Hair
Hair, nails and skin are comprised primarily of the protein keratin. Keratin forms long chains like a very thin strand of rope. Groups of these thin strands form filaments. Groups of filaments, in turn, form the bulk of the hair’s inner layer, called the cortex. Hair straighteners change how strands of keratin stick together.
Different hair-straightening methods target various chemical connections that hold keratin strands together.
The Last Tangle in Paris
Marcel Grateau revolutionized hair styling in 1872 when, while styling the hair of prostitutes in the slums
of Paris, he invented the Marcel Wave.
Most women wore their hair long at the time, and Marcel used heated irons to produce a stylish wave as an alternative to the curls which were in trend at the time.
The tongs he invented were heated over gas burners, and so could only be used by trained operators. The resulting look remained in vogue for the next 50 years, earning Marcel a fortune and many high-profile clients.
It also marked the beginning of hairdressing taking on its contemporary shape, with women flocking to salons in unparalleled numbers and creating a huge new source of revenue.
Meanwhile, at Indian-no-place
The first patent for a straightening iron was filed on November 3rd, 1893. “Be it known,” the patent application begins, “that I, ADA HARRIS, of Indianapolis, county of Marion, and State of Indiana, have invented a certain new and useful Hair- Straightener.” A device “heated like a curling iron” with two flat faces held together by a hinge that “when they press the hair will make it straight.”
Running a flat iron through blown-dry hair breaks the hair’s hydrogen bonds. It flattens hair until water or water vapor (from humidity, drizzle or the shower) penetrates the hair fiber and allows the hydrogen bonds to revert to their natural positions. The flat-iron process is chemical free. The biggest danger is the hot iron.
“My invention relates to a hair straightener whose purpose is to straighten curly hair,” Ada Harris wrote in her patent filing for the hair straightener, “and is especially of service to; colored people in straightening their hair.” But Ada Harris never built an empire of hair products. Her place in history is almost completely forgotten.
Madam C. J. Walker whose name is most associated with African-American hair care in the early 20th century was successful as a business woman but did not have a role as an inventor.
From the High Heat to the Chemical Head
Alkaline (salt forming) relaxers were informally discovered in the United States during the 1905 by Garrett A. Morgan, an African-American. A clothing manufacturer, Morgan experimented with a liquid that gave sewing machine needles a high polish and prevented the needle from scorching fabric as it sewed. The story goes that after a long day of work, Mr. Morgan wiped his hands off on a wool cloth, returning the next day to find that the rough hairs of the cloth were laying straight and flat. He went from wool to canines, trying out his new formula on an Airedale dog.
He was impressed to find that the formulas worked there also. Morgan then decided try the fluid on himself, to small portions of his hair at first, and then to his entire head. He was successful and had invented the first human-hair straightener. He marketed the product under the name the G. A. Morgan Hair Refining Cream, along with a hot comb to be sold by his G. A. Morgan Refining Company.
Though the advertisement doesn’t state directly, Morgan’s product was most likely an alkaline (salt forming) based product. The clue is that he originally used the substance to make a needle run more smoothly through fabric. One of the bi-products of at exposure of an alkaline to human skin is a greasy residue that would help ease a needle through cloth.
Alkaline straighteners are said to smell better, work more quickly and last longer than perm treatments using other chemicals. The commonly used alkaline in hair straighteners is sodium hydroxide more generally known as lye. Lye’s chemical name is sodium hydroxide (NaOH) and it’s the standard human tissue-dissolving chemical. In water (H2O), sodium hydroxide will disassociate into the sodium and hydroxide ions. This reaction releases a LOT of heat (exothermic), enough to boil water in some circumstances. Great care is needed.
It works because the negatively charged hydroxide ion (OH) is a strong attractor of hydrogen. That means that it strips hydrogen atoms off from organic molecules like triglycerides (a major component of human flesh) to form water (H2O). Triglycerides, composed of carbon, oxygen and hydrogen are the main constituents of body fat in humans and other animals, as well as vegetable fat. They are also a major component of human skin oils.
Sodium Hydroxide Molecule
Sodium Atom and Hydroxide Ion
Triglycerides are carbon based and as such they are complex molecules of substantial size. When the sodium hydroxide breaks some of the bonds of the triglycerides into simpler chemicals, heat is released and this causes the burning sensation when skin is exposed to this chemical process.
Morgan’s “war on bad hair” led to attempts to defeat “bad hair” through cost-cutting, do-it-yourself methods. A man named Malcolm Little relates his own experience:
“my hair was finally long enough to be conked. He had promised to school me in how to beat the barbershops' three- and four-dollar price by making up Congolene [commercial name for a lye based hair straightener], and then conking ourselves.
…went to a grocery store, where I got a can of Red Devil lye, two eggs, and two medium-sized white potatoes. Then at the drugstore near the poolroom, I asked for a large jar of Vaseline, a large bar of soap, a large-toothed comb and a fine-toothed comb, one of those rubber hoses with a metal sprayhead, a rubber apron and a pair of gloves.
"Going to lay on that first conk?" the drugstore man asked me. I proudly told him, grinning, "Right!"
Shorty…peeled the potatoes and thin-sliced them into a quart-sized Mason fruit jar, then started stirring them with a wooden spoon as he gradually poured in a little over half the can of lye. "Never use a metal spoon; the lye will turn it black," he told me.
A jelly-like, starchy-looking glop resulted from the lye and potatoes, and Shorty broke in the two eggs, stirring real fast--his own conk and dark face bent down close…."Feel the jar," Shorty said. I cupped my hands against the outside, and snatched it away. "Damn right, it's hot, that's the lye," he said. "So now you know it's going to burn when I comb it in--it burns bad. But the longer you can stand it, the straighter the hair."
.. from the big Vaseline jar, he took a handful and massaged it hard all through my hair and into the scalp. He also thickly vaselined my neck, ears and forehead…."You always got to remember that any Congolene left in burns a sore into your head."
Shorty starting combing it in. But then my head caught fire…I gritted my teeth and tried to pull the sides of the kitchen table together. The comb felt as if it was raking my skin off.
My eyes watered, my nose was running. I couldn't stand it any longer; I bolted to the washbasin. I was cursing Shorty with every name I could think of when he got the spray going and started soap-lathering my head.
He lathered and spray-rinsed, lathered and spray-rinsed, maybe ten or twelve times, each time gradually closing the hot-water faucet, until the rinse was cold, and that helped some.
"You feel any stinging spots?"
"No," I managed to say. My knees were trembling.
"Sit down, then. I think we got it all out okay."…"The first time's always worst. You get used to it better before long. You took it real good, homeboy. You got a good conk."
When Shorty let me stand up and see in the mirror, my hair hung down in limp, damp strings. My scalp still flamed, but not as badly; I could bear it. He draped the towel around my shoulders, over my rubber apron, and again began vaselining my hair.
I could feel him combing, straight back, first the big comb, then the fine-tooth one.
My first view in the mirror blotted out the hurting. I'd seen some pretty conks, but when it's the first time, on your own head, the transformation, after a lifetime of kinks, is staggering.
The mirror reflected Shorty behind me. We both were grinning and sweating. And on top of my head was this thick, smooth sheen of shining red hair--real red--as straight as any white man's.
Malcom Little became…
The process still has, however, some adherents.
Prince Nelson (8th grader)
Prince Nelson (Superstar)
It Don’t Hardly Stand to Reason
If the best chemical to dissolve a human body is used to straighten hair then you might think that the best chemical to preserve a human body would have the opposite effect.
You’d be wrong.
“Brazilian Blowout” a contemporarily popular chemical hair straightener relies on a combination of formaldehyde and keratin. Formaldehyde (CH2O) is the major component of embalming fluid, and is used for the preservation of tissue samples. Keratin is the fibrous structural protein that forms hair and nails in humans, and horns, hoofs, wool, and feathers in animals.
A stylist coats hair with a keratin/formaldehyde solution. Formaldehyde molecules diffuse into the hair and cross-link strands of new keratin with the keratin in the customer’s hair. By blowing saturated hair dry and compressing it with a flat iron, the stylist accelerates the cross-linking reaction, transforming curly hair to flat.
Formaldehyde poses a significant danger to human health. In 2011, the US National Toxicology Program described formaldehyde as "known to be a human carcinogen".
Brazilian Blowout without formaldehyde uses glycolic acid (C2H4O3) with a flat iron to smooth hair.
The Cosmetic Ingredient Review has determined that glycolic acid is safe at concentrations of less than 10 percent in home use products and less than 30 percent in salon products.
Permanent solutions can curl or straighten hair, depending on the hair is styled when they are applied. The first solution breaks the hair’s disulfide bond. Then a fixative remakes the chemical bond in the new position. Water can serve as a fixative, but most brands rely on faster-reacting compounds like hydrogen peroxide (H2O2). Stylists flat iron hair to speed the chemical reactions.
Perm solutions are much less aggressive than lye-type relaxers. Drawbacks are unpleasant odors and degradation of the hair fibers. the character Elle Wood in the film Legally Blond said “…isn’t it the first cardinal rule of perm maintenance that you’re forbidden to wet your hair for at least 24 hours after getting a perm at the risk of deactivating the ammonium thioglycolate [HSCH₂CO₂NH₄]?” In other words, the chemical reaction continues long after the client leaves the salon.
People with curls have elliptical, not circular hair follicles. The elongated opening waves the hair like curling ribbon. No matter what is done to the hair above the skin line, the person’s hair will continue to grow in the pattern initially decided by genetics.
STEM Topic 17: Problem Set - 1
A hair product costs $15. If the sales tax rate is 8%, what is the total cost of the product?
A hair salon charges $75 for a haircut and $150 for a coloring service. If a customer gets both services, what is the total cost?
A bottle of shampoo contains 16 ounces of product. If a person uses 1/4 of an ounce of shampoo per wash, how many washes can they get from one bottle?
A hair dryer uses 1800 watts of power. If the cost of electricity is $0.15 per kilowatt-hour, how much does it cost to use the hair dryer for one hour?
A hair stylist wants to make a hair dye mixture that is 25% red and 75% brown. If the stylist has 16 ounces of brown dye, how many ounces of red dye should be added?
A hair salon has a total of 12 stylists, and each stylist can serve 6 clients per day. How many clients can the salon serve in a week?
A hair treatment requires 2 tablespoons of oil for every 1/4 cup of conditioner. If a person has 1 cup of conditioner, how much oil should they add?
A hair extension is 18 inches long. If a person wants to cut the extension into thirds, how long will each piece be?
A hair styling tool is on sale for 20% off its original price of $80. What is the sale price?
A hairbrush has 50 bristles. If 2 bristles fall out every week, how many weeks will it take for the hairbrush to have 30 bristles left?
STEM Topic 17: Problem Set - 2
If a bottle of hair straightening chemical contains 500 milliliters of a solution of Sodium Hydroxide (NaOH) and each treatment requires 50 milliliters, how many treatments can you perform with one bottle?
The concentration of a Guanidine Hydroxide (CH5N3O) is 2.5%. If a salon needs to prepare 1 liter of solution, how many milliliters of CH5N3O should they use?
A hairstylist mixes two hair straightening chemicals in a ratio of 3:1. If they need 60 milliliters of the mixture, how much of each chemical should they use?
The recommended exposure time for a hair straightening chemical is 30 minutes. If a stylist accidentally leaves it on for 45 minutes, what percentage of the recommended time was exceeded?
A salon applies hair straightening formaldehyde (CH2O) to an average of 15 clients per day. If each treatment takes 1 hour, how many hours do they spend on treatments in a week (assuming 7 days)?
NOTE: The flash point of a substance is the lowest temperature at which it can vaporize to form an ignitable mixture in the air near its surface. In simpler terms, it is the temperature at which a substance can ignite or catch fire when exposed to an open flame, spark, or heat source.
The safety data sheet of a hair straightening chemical indicates that it has a flash point of 40 degrees Celsius (C= 5/9(F-32). If the salon's storage room temperature is kept at 86 degrees Fahrenheit, is it safe to store the chemical there?
Answer: Yes, it is safe to store the chemical as the temperature is below the flash point.
A hair salon wants to design a new logo in the shape of a rectangle. The length of the logo should be twice its width, and the area of the logo should be 72 square centimeters. What are the dimensions of the logo?
A hairdresser is planning to create a hairstyle using a curling iron that has a circular barrel with a diameter of 2 inches. What is the circumference of the curling iron's barrel?
A hairstylist is creating a complex braided hairstyle for a client. The stylist uses three strands of hair and wants to make sure the braid is perfectly balanced. How many degrees should each strand turn to complete one full rotation of the braid?
A salon using Ammonium Thioglycolate: NH4C2H3O2S to straighten hair salon charges a fixed fee plus an additional $10 for each hour of hair straightening service. If a customer paid a total of $70 for 4 hours of hair straightening, what is the fixed fee charged by the salon?
A bottle of hair straightening serum contains 200 milliliters (ml) of Cysteine: C3H7NO2S. Each time Sarah uses the serum, she applies 10 ml to her hair. How many times can she use the bottle?
A hair salon charges a flat rate of $50 for a hair straightening treatment. If a customer wants to leave a 20% tip based on the treatment cost, how much will they pay in total, including the tip?