Unlike battery or electricity powered lighting fixtures, glow sticks do not use any external sources of energy to glow. This feature of glow sticks has played a major role in making the glow sticks, easy to carry and ideal lighting aids during emergencies.
Though unaware of the actual working principle of glow sticks, we tend to use them as accessories or as handouts or as lighting sources during outdoor games and emergencies. Therefore, read on to know the exciting reason behind using glow sticks. But before that let’s have a short glance on the history of glow sticks.
Glow sticks – brief history
Though glow sticks had originated 40 years ago, they became popular only twenty years back. In 1960s, Edwin Chandross invented a glow technology that uses chemical energy for light emission. This has given rise to the invention of glow sticks. However, the light sticks were earlier used prominently to handle military operations. Later on, they turned to be effective illuminating sources in recreational and emergency happenings.
Don’t require any outside sources of energy
Generally, the traditional lighting equipments require an outside energy to produce light. But in case of glow sticks, they do not require any external energy inputs to emit light, that is the significant reason in making the use of glow sticks popular in varied fields.
Electricity, heat or radiation are the common input energy sources for various lighting appliances. Glow sticks, however, emit light using chemical energy which is produced by the reaction of chemicals present inside them. They don’t require outside energy sources and continue to glow with the chemical energy for a long time.
Emit light through chemiluminescence
Glow sticks work on a basic principle called chemiluminescence, which is the emission of light through a chemical reaction. The result of a chemiluminescent reaction is that the electrons in the chemicals are excited to the higher levels on reacting with each other and when they fall back to the ground level, they release energy in the form of electromagnetic radiations of specific wavelength. If the wavelength of the emitted radiation is in the range of visible light spectrum, then the light is emitted by the chemical reaction. It is this energy from a chemical reaction that a glow stick uses and emits light.
Chemical reaction involved in glow sticks
As you know, a glow stick contains two chemicals separated by a glass vial. It contains diphenyl oxalate ester, a dye in the plastic tube and hydrogen peroxide in the glass vial. When the glass vial is broken by bending the plastic tube, the two chemicals combine.
Hydrogen peroxide oxidizes the ester compound forming phenol and peroxyacid ester. The peroxyacid ester then decomposes into carbon dioxide releasing energy which excites the dye. The electrons in the dye atoms jump to a higher level and then fall down releasing energy in the form of light. The color of the emitted light is based on the molecular structure of the dye.
The chemicals used in glow sticks are non-toxic and non-flammable. Moreover, no emission of heat is evident with chemiluminescent reactions and you don’t experience any heat even when you hold them in your hand for a long time. As these chemicals are inside a translucent tube. They are also unaffected by the environment and are non radio active.
No requirement of outside energy sources like electric power or heat makes glow sticks cost-effective. Even though these are single use lighting aids, the inexpensive nature of these sticks makes even the repeated purchasing affordable. Even the constant repairing and maintenance costs associated with reusable lighting fixtures can be evaded by using glow sticks. These glow sticks when purchased in bulk come in wholesale prices, which makes them still more cost effective.
The concentration of chemicals in the glow sticks determine the life span of its cool glow. However, no outer sources of energy are required to activate them and hence, they are flexible to use anywhere.