Chemistry Hair Color

What is hair?

Hair is mainly keratin, the same protein found in skin and fingernails. The natural color of hair depends on the ratio and quantities of two other proteins, eumelanin and phaeomelanin. Eumelanin is responsible for brown to black hair shades while phaeomelanin is responsible for golden blond, ginger, and red colors. The absence of either type of melanin produces white/gray hair.

Black

Brown

White

Permeanent Hair Color

The outer layer of the hair shaft, its cuticle, must be opened before permanent color can be deposited into the hair. Once the cuticle is open, the dye reacts with the inner portion of the hair, the cortex, to deposit or remove the color. Most permanent hair colors use a two-step process (usually occurring simultaneously) which first removes the original color of the hair and then deposits a new color. It's essentially the same process as lightening, except a colorant is then bonded within the hair shaft. Ammonia is the alkaline chemical that opens the cuticle and allows the hair color to penetrate the cortex of the hair. It also acts as a catalyst when the permanent hair color comes together with the peroxide. Peroxide is used as the developer or oxidizing agent. The developer removes pre-existing color. Peroxide breaks chemical bonds in hair, releasing sulfur, which accounts for the characteristic odor of hair color. As the melanin is decolorized, a new permanent color is bonded to the hair cortex. Various types of alcohols and conditioners may also be present in hair color. The conditioners close the cuticle after coloring to seal in and protect the new color.

How Lightening Works

Bleach is used to lighten hair. The bleach reacts with the melanin in hair, removing the color in an irreversible chemical reaction. The bleach oxidizes the melanin molecule. The melanin is still present, but the oxidized molecule is colorless. However, bleached hair tends to have a pale yellow tint. The yellow color is the natural color of keratin, the structural protein in hair. Also, bleach reacts more readily with the dark eumelanin pigment than with the phaeomelanin, so some gold or red residual color may remain after lightening. Hydrogen peroxide is one of the most common lightening agents. The peroxide is used in an alkaline solution, which opens the hair shaft to allow the peroxide to react with the melanin.

Temporary Dyes

Most temporary dyes come in the form of rinses, gels, mousses, and sprays. Unlike permanent and semi-permanent dyes, these solutions do not penetrate the hair shaft, but simply “sit on top of” your hair. They bond to the surface and usually wash out the next time you shampoo. (There are some that can last up to five washings.) The main downside to using temporary dyes is that they will likely wash out the very next time your hair becomes wet. That means that if you go swimming or get caught in the rain, you will lose your new hair color (and potentially end up with it running onto your clothing and face). Since these dyes are easily removed, you must reapply temporary hair colors each time you wash your hair. The color vehicles in these dyes are mostly water, organic solvents, gums, surfactants and conditioning agents and therefore do less damage to your hair when used.

Rusting Iron Nails

BEFORE

Q. WHAT HAPPENS IN BETWEEN?

A. A CHEMICAL REACTION!

AFTER

A nail rusts because there is a chemical reaction !

When a nail, made of iron is left outside, the iron element of the nail reacts with oxygen in the air to form rust! The reactant is the iron and oxygen, and the product is rust! This rust is called iron oxide.

The reaction looks like this in an ionic iron oxide formation------ it follows the octet rule.

Rust ruins the nail and makes it look ugly. However, rust is not only a nuisance!

Iron oxides have been one of the most commonly used coloring agents for cosmetics and paintings for a long time. People have used iron oxides in natural minerals not only for cosmetics and paintings but also for religious ceremonies and skin protection. Manufacturing iron oxides as a coloring agent for cosmetics began around 1900, and manufacturing for paint, more than many centuries ago. Iron oxides have various colors which are classified into three major color groups: the yellow iron oxide (yellow), colcothar (red), black iron oxide (black). These iron oxides are fine powders with a slight unique odor.

However, many of the colors of iron oxide powder is a mixture of different compounds and elements. Reddish brown in the only color that forms in a pure iron oxide substance.

There are other ways you can make iron oxide, but the reaction introduced earlier is how iron oxide forms in a natural environment. You can further see how iron oxide can be made at home easily by going to the following URL: (However, keep in mind that it is very dangerous, and the people in these videos use some dirty language...!)

http://jp.youtube.com/watch?v=vazNo1Eq8pM&feature=related

http://jp.youtube.com/watch?v=2eiHNV4uvm8&feature=related

http://jp.youtube.com/watch?v=LEikDVfqkMo&NR=1

Next time you see rust, keep in mind that there is a chemical reaction that happened, and that rust (iron oxide) does not just make things look ugly, but mixtures of iron oxide makes people pretty too! :)

How fireworks work

FIREWORKS

In the science experiment in our class we dealt with different colors produced by salts with the bunsen burners. Similar to our experiment we did in class fire works use salts to produce different colors. Heres a chart that shows the different colors produced and the compounds salts that show the different colors of the fireworks during and explosion.

	Color	Compound
	red	strontium salts, lithium salts lithium carbonate, Li2CO3 = red strontium carbonate, SrCO3 = bright red
	orange	calcium salts calcium chloride, CaCl2
	yellow	sodium salts sodium chloride, NaCl
	green	barium compounds + chlorine producer barium chloride, BaCl2
	blue	copper compounds + chlorine producer copper(I) chloride, CuCl
	purple	mixture of strontium (red) and copper (blue) compounds
	silver	burning aluminum, titanium, or magnesium

What chemical reaction Occurs?

Chemical reaction occurs in the while seeing the fireworks and the sound of the explosion. The chemical reaction that occurs is oxidations and reductions, which take places when the fireworks explode. The Oxiders produce oxygen gas, which helps by helping to burn the mixtures, which have reducing agents, and by stimulating the atoms of the different lights releasing different types of compounds.

Heres url showing the different lights of fireworks.

http://jp.youtube.com/watch?v=1VySlPcbe24&feature=related

Do you know how fireworks are made?

While making fireworks the metal salts are taken and made in to shape of stars. These salts are put in to a type of dough about 3-4 diameters with the star shape. In these star shapes there it consists of oxidizing agent, reducing agent, and colors (metal salt). When the fireworks explode the starts that are in the fireworks are what produces the sound and the different lights. However fireworks can be dangerous in factories making fireworks sometime there can be explosions that destroys the whole factory. This url will show what it can do http://jp.youtube.com/watch?v=nb8sxJbRakU&feature=related.

We performed the Flame Test in Chemistry Class. We used the following materials: bunsen burner, 4 different salts (Potassium Nitrate, Sodium Nitrate, Barium Nitrate, Strontium Nitrate), magnesium ribbon, and hydrochloric acid. We would dip the magnesium ribbons in the hydrocholoric acid, and stick some salts to the magnesium, and hold it against the flame from the bunsen burner. The salts would react with the magnesium and produce different colored flames.




1.Barium Nitrate














The Barium Nitrate, when we performed the flame test, produced a yellowish green flame.

The picture on the right shows the flame color we get when the flame test is done under professional conditions.





2. Strontium Nitrate


















When we performed the flame test on the Strontium Nitrate, it produced a red flame. The camera was not so good, so it looks orange with the light, but you can see that the top part is red.
The picture on the right shows what the flame should look like if the experiment is done properly in the dark.





3.Potassium Nitrate


















When we performed the flame test on the Potassium Nitrate, it produced a pinkish purple flame. The camera again, was not able to clearly show the color of the flame. (we were also next to the window)


However, the picture on the right shows what the flame should look like if the experiment were to succeed and a good picture of it was captured.

4.Sodium Nitrate

When we performed the flame test on the Sodium Niterate, the flame turned orange.



The right picture is when the flame test on the Sodium Nitrate is done professionally under professional conditions.





The flame test can be applied in many ways. We can use the flame test to identify substances by their color.
Also, because the salts produce different colors, these salts are also used in fireworks.