Mechanochemistry might be an entirely new topic for many of you. But don’t worry, we’ve got you covered! To help you navigate this fascinating branch of chemistry, we’ve prepared a handy mechanochemical glossary featuring some of the most used terms and concepts.
Today’s article marks the first in a series of four blogposts. We’ll be launching our personal dictionary with terms arranged in alphabetical order, of course. This current edition covers terms from A to D. The next instalment will feature entries from E to L, then M to R, and the final one will conclude our glossary with terms starting from S. Let’s dive in!
12 principles of green chemistry
Mechanochemistry mashes molecules together towards greener chemistry by avoiding solvents, which ensures energy efficiency and reduces environmental impact. But how do we know our chemistry is truly green? We have some rules to follow: the 12 principles of green chemistry. Originally proposed by chemists Paul Anastas and John Warner in 1998, these principles provide guidance for making chemical processes more sustainable. Some of them include waste prevention, designing for energy efficiency or minimising auxiliary substances, like solvents. Hooray for us! You can read more about them here.
Active Pharmaceutical Ingredient (API)
Of all the ingredients that make up a pill or a tablet, credit goes to a very specific part of the medicine: the Active Pharmaceutical Ingredient, or API. An API is, therefore, the component that produces the therapeutic effects within the pills and tablets we take—in other words, the functional compound. For example, in the famous antidepressant medicine Prozac, the API is fluoxetine, a molecule that inhibits the uptake of serotonin. Some medicines may even include more than one API. This is the case with Nurofen Plus, which includes both ibuprofen and codeine, a mild opioid analgesic.
Ball mill
A type of grinder consisting of a large jar that contains balls inside. Once the materials are inside, the jar is spun, and the collisions and clashes between the balls and the reactants trigger the chemical reactions. Depending on the process, we use ball mills with different geometries, as well as balls of different materials and sizes.
Batch or discontinuous process
Chemistry can work in batches, much like cooking pots of pasta. In this process, a set amount of reactants is loaded into a reactor or vessel, where the reaction is then initiated, allowed to proceed, and completed before the mixture is removed. This is also known as discontinuous processing, in contrast to continuous processing, where the mixture flows in and out of the vessel without interruption.
Bead mill
This is a type of grinder similar to a ball mill, but instead of using balls, it employs fixed pieces (beads) to mill and grind chemicals. The beads within the grinding chamber are rotated, where their collisions and shear forces cause the particles to be ground and dispersed. The outlet of the grinding chamber is equipped with a filter that separates the beads from the ground particles, keeping the beads inside the chamber and enabling the continuous production of fine particles.
Chemical reaction
A chemical reaction is a process in which one or more substances, known as reactants, are transformed into one or more different substances, called products. These substances can be either chemical elements or compounds. During a chemical reaction, the constituent atoms of the reactants are rearranged to form new substances, resulting in products that are chemically distinct from the original reactants.
Cocrystal
A cocrystal is a type of multi-component molecular crystal, defined as a solid crystalline material consisting of two or more different molecules within the same crystal lattice. These molecules are typically held together by non-covalent interactions, such as hydrogen bonds or van der Waals forces, resulting in a stable, single-phase structure with unique physical and chemical properties that differ from those of the individual components.
Continuous process
Chemistry can be carried out through discontinuous or continuous processes. The latter involves a setup where chemical reactions take place in a continuously flowing stream, much like flowing water. This approach offers several advantages: it enables faster and safer reactions, increases efficiency, provides better control over reaction conditions, and reduces the environmental impact. Flow chemistry also ensures more consistent product quality and, critically, allows chemists to perform reactions that would be challenging or even impossible to achieve in traditional batch mode.
Deracemisation
Some chemical compounds are like the hands of our body: they have the same form and structure, but you can’t superimpose them. In chemistry, we refer to this property as chirality. Obtaining only one of these “chemical hands”, known as enantiomers, through synthesis is achieved through a chemical process known as deracemisation.
Drug or medicine
A drug or medicine is a substance or combination of substances used to treat, prevent, or alleviate the symptoms of illness. It works by interacting with the body and/or targeting specific conditions, including pathogens such as bacteria or viruses. Medicines are typically chemical substances, but they can also include other elements, such as proteins or hormones, like insulin used in the treatment of diabetes.
