Ionic materials are substances composed of ions held together by strong electrostatic forces, known as ionic bonds. These materials typically consist of a lattice structure formed by positively charged cations and negatively charged anions. They are commonly associated with salts like sodium chloride (NaCl), but ionic materials encompass a wide range of compounds, including ceramics, electrolytes, and ionic liquids.
These materials are characterized by (1) high melting and boiling points which are the result of strong ionic bonds (for instance, NaCl melts at 801 °C), (2) electrical conductivity (ionic materials conduct electricity when melted or dissolved in water as their ions become mobile), (3) solubility (many ionic compounds dissolve in polar solvents like water, (4) mechanical strength (ionic ceramics are often hard and brittle) and (5) thermal stability (many ionic compounds are stable at temperatures above 1,000 °C).
Because of their unique properties, ionic materials have a wide range of uses ranging from (1) energy applications including batteries (ionic electrolytes are essential in lithium-ion and solid-state batteries, powering everything from smartphones to electric vehicles), fuel cells (ionic materials enable efficient energy conversion in hydrogen fuel cells) and solar cells where perovskite materials, often ionic in nature, are revolutionizing solar energy efficiency.
Ionic materials can also have a major impact on the environment where (1) green solvents (specifically room temperature ionic liquids) are environmentally friendly alternatives to volatile organic solvents and (2) CO₂ capture, where ionic materials can trap this greenhouse gas, aiding in climate change mitigation.
Healthcare and medicine are other areas in which ionic material can have a major impact. These include (1) drug delivery, where ionic compounds are used in creating biocompatible materials for targeted drug delivery and (2) antibacterial coatings in which, for instance, ionic silver compounds are used for their antimicrobial properties and (3) production of medically pure oxygen for patients with COPD and other breathing disorders.
Smart materials based on ionic materials are used in sensors, actuators, and devices that respond to environmental changes and include conductive ceramics which are crucial for electronics and telecommunication.
In agriculture, many fertilizers are ionic compounds (e.g., potassium nitrate), which dissolve easily in water supplying essential nutrients to plants; and ion-exchange materials are used in water purification to remove contaminants like heavy metals and soften hard water.
