|Pyrotechnics is the manufacture of fireworks. Pyrotechnics also deals with modern aviation and spaceflight. Making fireworks requires chemicals with very specific properties and characteristics in specific proportions to create the perfect effect.
Sparklers are made with a paper tube. It uses charcoal and sulfur as fuel, also gunpowder. There’s also a binder that is sugar or starch. When mixed with water, these chemicals form slurry that can be coated on wire or poured into a tube. Once it dries it is now a sparkler. The sparkler burns from one end to the other and because the fuel and oxidizer, and some other chemicals are proportioned, the sparkler burns slowly instead of exploding like a firecracker. There are metal filings that fly off as bright sparks while burning.
There are two main groups of light emitters: solid state emitters and gas phase emitters. Fireworks usually have aluminum, iron, steel, zinc, or magnesium dust, which create bright sparks. There are many different chemicals that can be added to make different colors shines. The different colors created in fireworks result from different compounds with different wavelengths. Some examples are: red from strontium salts, lithium salts lithium carbonate, Li2CO3 = deep red strontium carbonate, SrCO3 = bright red, with wavelength:650 nm; orange from calcium salts calcium chloride, with wavelength:670; yellow from sodium salts sodium chloride, NaCl, with wavelength:610-620; green from barium compounds + chlorine producer barium chloride, BaCl2 , with wavelength: 590 ; blue from copper compounds + chlorine producer copper(I) chloride, CuCl, with wavelength: 500-535; purple from mixture of strontium (red) and copper (blue) compounds, with wavelength: 420-460; silver from burning aluminum, titanium, or magnesium.
Some common oxidizers and fuels are potassium perchlorate, potassium nitrate, sodium nitrate, strontium nitrate, aluminum and some other metal powders. Some other commonly used oxidizers are nitrates, which are composed of nitrate ions with metals. The most common oxidizer is potassium nitrate. The decomposition reaction of potassium nitrate turns to potassium oxide, nitrogen gas, and oxygen gas.
Decomposition reactions have a compound as a reactant and a smaller compound or element as the product. Decomposition is also the opposite of chemical synthesis.
Fireworks provide thrust to power the package into the sky and to ignite each bundle of stars. Some chemicals used in specific types of fireworks aren’t always used in all types of fireworks like nitrates, which aren’t used in star explosions because their reactions don’t produce high enough temperature to energize the colorful metal salts. High temperatures of 1700 to 2000°C create more intense colors. Oxidizers are the chlorates which give up all their oxygen during the reaction.
This is another decomposition reaction.
Chlorstes are less stable than nitrates and they can sometimes be detonated by throwing them on the ground. This is because chlorine normally bonds with 4 oxygen atoms, but it only bonds with 3 so it leaves the chlorine atom unsaturated and reactive. Oxidation by chlorates have much faster detonations than compounds containing nitrate. Now most manufacturers use perchlorate because its more stable and has more oxygen release. Perchlorates contain the perchlorate ion (ClO4). Perchlorates are able to release all four of its oxygen atoms. Perchlorates aren’t really more stable, but they have more oxygen and have more vigorous reactions then nitrates.
The oxygen released by nitrates, chlorates, and perchlorates in the star compartments combines with the reducing agents to produce hot gasses. The most common reducing agents are sulfur and carbon (charcoal), which react with oxygen to produce sulfur dioxide and carbon dioxide.
These are combination reactions. Combination reactions have two elements or two compounds as reactants and a single compound as a product. Similar to chemical synthesis.
These compositions must be safe and stable in storage. They must also have the perfect proportions to operate creating the desired effect. An example is that too much fuel is bad because the carbon particles would take over the red color making it too light.