A key component of capacitors — devices that store electrical charges (like batteries) — is the dielectric material. These are a class of electrical insulators that can store electrical charges in the presence of an externally applied electric field. The charge stored is measured in terms of the ‘dielectric constant’ — the more the charge stored, the higher the constant.
In making the dielectric materials, scientists are up against a wall. Organic compounds (compounds with a carbon atom) are cheaper and flexible, but their dielectric constant is lower than that of inorganic compounds.
Researchers led by Deepak Chopra, associate professor, Department of Chemistry, Indian Institute of Science Education and Research (IISER), Bhopal, are developing a novel dielectric material from simple non-toxic organic compounds that have dielectric constants comparable to inorganic material and are probing the underlying molecular mechanisms that are responsible for the observed dielectric response. The researchers used the principles of ‘supramolecular chemistry’— the in-thing in scientific research that studies large molecules formed by weak and reversible (non-covalent) bonds.
“Using supramolecular chemistry and crystal engineering, we were able to design, synthesise and crystallise unique organic materials with high dielectric constants,” says Chopra. An analysis of the structures of these compounds provided insights into the observed phenomena.
The synthesis of these compounds uses raw materials that are easily available and inexpensive. ‘High dielectric constant organic materials’ can be a major breakthrough in capacitor manufacture.