Sparklers have captivated and amazed both children and adults for centuries, but the chemistry behind them is even more alluring. Though some people are content with how a sparkler works being chalked up to “magic,” there is a lot of real science that makes them possible. Also, there are chemical differences between smokeless wedding sparklers and the blue and red sparklers that you see at 4th of July parties, and understanding the differences can be quite fascinating. If you are curious like I am, take a journey with me to better understand the chemistry behind sparklers.
There are 4 key components to a sparkler that makes them work, and they are as follows:
- An oxidizer
- A fuel
- Iron, steel, aluminum, or other metal powder
- A combustible binder
Though there are other compounds added to certain types of sparklers to add vibrant colors or crackling effects, these are the basics of your typical sparkler. To fully understand how a sparkler works, we will need to take a closer look at each part.
Oxidizers have only one job, and that’s to produce oxygen for the rest of the mixture to use as it burns. There are three common types of oxidizers; nitrates, chlorates, and perchlorates. Chlorates and perchlorates contain the most amount of oxygen and thus create larger and brighter effects, but nitrates are much safer and are used in most sparklers sold today. Nitrates contain about 1/3 the amount of oxygen as its counterparts.
Fuel is what actually burns as the sparkler creates its sparks, and usually, the fuel is either charcoal or sulfur. Sulfur produces an unwanted smell when it burns, but it produces less smoke than charcoal. Charcoal has fewer odors, but it can make a lot of smoke as it burns. Manufacturers of sparklers determine which fuel will work best based on the purpose of their sparklers.
The metal powder is where all of the magic lies in sparklers because this is what creates their hallmark sparks. As the fuel burns, it literally creates hot specks of metal that eject from the sparkler as sparks. The color of the sparkler is determined by the type of metal powder used in the chemical slurry. If you buy sparklers for weddings, for instance, they will burn gold which means they are made from aluminum and magnesium powder. If you want your sparklers to burn white, you will use titanium powered. Iron burns red, and there are all sorts of other metal powders used to create other colors. In some cases, color pigments are added to enhance or chance the color of the metal powder as the sparkler burns.
The last component is a binder which holds everything together. Think of it as glue for all of the other chemicals and compounds except that it must also be combustible. Sugars and starches are prime candidates to be used as a combustible binder, and most sparkler manufacturers use dextrin since its readily available and are very cost efficient.
Though sparklers may seem like magic at first, once you dissect them you can see that it’s just basic science that makes them work. All you need is a fuel, oxygen to make it burn, metal powder to eject as sparks, and a binding agent to hold the entire mixture together to make one of the world’s favorite fireworks possible.