Posts

Showing posts from 2021

Green Solvents: Definition, Examples and Types of Green Solvents

Image
What are Green Solvents? Green solvents, also known as environmentally friendly bio solvents which are derived from the processing of crops. There are many types of green solvents like ionic liquids, supercritical fluids, water, and supercritical water. These green solvents are way much eco-friendly, less toxic, less hazardous than traditional volatile organic compounds (VOCs). For example, Ethyl lactate Ethyl lactate is a green solvent derived from processing corn. Ethyl lactate is the ester of lactic acid which is used as solvents in the paints and coating industry. Types of Green Solvents 1. Supercritical Fluids A compound that exists above its critical pressure (Pc) and above its critical temperature (Tc) is known as supercritical fluid or SCF. Their chemical and physical properties are between those of a gas and a liquid. Phase diagram showing the supercritical fluid region Supercritical liquids are the perfect replacement for organic solvents for industrial and lab processes d

Microwave Assisted Reactions in Green Chemistry

Image
Definition of microwave A microwave (MW) is a form of electromagnetic energy. It is defined as a measurement of the frequency of 300 to 3000000 MHz which comes from the lower end of the electromagnetic spectrum, corresponding to wavelengths of 1 cm to 1 m.  The main difference between microwave energy and other forms of radiation such as X-rays and Y-rays is that microwave energy is non-ionizing and thus does not change the molecular structure of the compounds, it only provides thermal activation. Mechanism of microwave heating Microwave heating works upon the interaction of molecules in a reaction mixture with electromagnetic waves generated by a "microwave dielectric effect" . The heating effect of microwaves can be understood by two different mechanisms: 1. Dielectric polarization (Dipole interaction) The heating effect generated in microwave-assisted organic transformations is mainly due to dielectric polarization . This mechanism states that when a molecule is irrad