16-11-2021 | | By Robin Mitchell
Recently, researchers from the University of Cambridge have developed a new nano camera technology that allows for chemical reactions to be viewed using spectroscopy as they occur. What challenges can chemical reactions present, what did the researchers develop, and could it revolutionise future chemical processes?
Chemistry is a vast and complex field of science that is responsible for modern life to the same degree as engineering, physics, and mathematics are. Chemistry is the reason why oil can be distilled into various fuel types, why plastics have ideal properties, and why food looks and tastes great. Unless a product is sourced 100% naturally from trees and leaves, chemistry will have been involved in the production step at some point.
However, studying chemical reactions is not always trivial, and many chemical reactions can appear to be entirely benign. For example, sodium metal reacting with water creates a violent reaction where hydrogen is released and often ignited while the reacted sodium becomes sodium hydroxide creating a strong alkali solution. But, many other reactions show absolutely no change in appearance, and it can be challenging to determine if the reaction has been completed.
To determine the state of a reaction, chemists have come up with incredibly ingenious methods such as spectroscopy which shines light at a solution and reads the resulting spectra (this identifies what compounds are in the solution). Other methods may include direct sampling using litmus paper that can detect the presence of acids and alkalis, and titrations can be used to determine the exact concentration of free protons in a solution.
However, directly observing chemical reactions as they occur without interacting with the solution is extremely difficult and arguably near impossible, if not impractical. Such testing methods usually require a small sample to be removed and tested to confirm that a reaction has occurred.
Researchers from the University of Cambridge have recently developed a new technology that allows chemical reactions to be monitored in real-time to confirm that a reaction has taken place. It can be used to distinguish between different molecules with similar energies (such molecules would typically look the same under traditional testing methods). Furthermore, the technology allows for the specific identification of chemical species directly.
However, it should be noted that the media is referring to the development as “nano cameras”. In contrast, the truth is that the molecules are more like detectors that interact with chemicals and light to produce specific spectra lines.
The technology involves taking semiconductor nanocrystals that are combined with gold nanoparticles and a molecular glue called cucurbituril. When in solution, the combination self-assembles into nano cameras that interact with light and target molecules. To demonstrate the effectiveness of their technology, the researchers used their nano camera technology to observe the formation of radicals and a reversible carbon-carbon bond, which was thought to be only theoretical.
The use of nano cameras to monitor chemical reactions could prove to be advantageous for chemical processes in the future, especially those reactions that are expensive and have small yields. For example, large scale production of commonly used chemicals such as ammonia and nitrates will not benefit from such technology as yields for these reactions are already very high. However, industries (pharmaceuticals) could massively benefit where access to reagents is limited either by cost or legislation.
Such technology would also give researchers better insight into what products are being formed explicitly in real-time. Reactions that are not well understood could be improved upon, and chemical previously thought theoretical compounds could be proven to exist.