Recent developments and future opportunities for mechanochemistry

In 2019, IUPAC named mechanochemistry as one of the ten emerging technologies in chemistry. To mark the five-year anniversary of this announcement, we hear from RSC Mechanochemistry Editorial Board members as they reflect on recent developments and future opportunities for mechanochemistry.

Kerstin Blank, Johannes Kepler University Linz, Austria

In my field of soft matter mechanochemistry, we have seen some pretty exciting progress thanks to the development of increasing numbers of synthetic molecules that respond to mechanical force in specific ways. Some key examples are mechanochromic, mechanofluorescent and mechanoluminescent reporters, as well as force-triggered release mechanisms through mechanochemical linkers, reactions kick-started by radicals or mechanocatalysts, mechanochemical switches, and, more recently, artificial catch bonds. What is really exciting is that more and more of these mechanoresponsive systems are working in water, which opens up a lot of possibilities for integrating them with biological systems.

Looking forward, I believe these advances have huge potential in material science. They are paving the way for creating dynamic and tunable soft materials with self-healing, self-reporting, and eventually, even self-reinforcing properties. Such materials provide new opportunities for soft robotics and wearable devices, where being able to adapt to mechanical forces is super important. Biocompatible mechanoresponsive polymers could completely change the game of tissue engineering, offering new materials that mimic and direct how natural tissues respond to mechanical cues. And in the area of drug delivery, force-triggered release systems could make therapies much more precise, targeting specific tissues or disease sites based on mechanical properties.

Franziska Emmerling, Federal Institute of Materials Testing and Research, Germany

There is considerable evidence that mechanochemistry is often better than other synthetic methods, especially solution-based ones. Mechanochemistry uses mechanical force to drive chemical reactions, and it can be more efficient, resource-saving and environmentally friendly than traditional solutions.

Although the benefits of mechanochemistry are well known, researchers around the world continue to make exciting and unexpected discoveries in this field. New materials, reaction pathways and efficient ways of transforming difficult substances are constantly being found.

Over the next 5 years, advances in computer modelling and theory will help us to better understand the molecular details of mechanochemical reactions. This, combined with the scaling up of industrially relevant mechanochemical processes, will allow mechanochemistry to contribute to solving major societal problems and achieving the UN Sustainable Development Goals.

James Mack, University of Cincinnati, USA

Mechanochemistry has always been a paradigm-shifting method for conducting chemical reactions. While we often celebrate groundbreaking ideas in hindsight, they are not always embraced immediately. Consider Galileo Galilei, who faced life imprisonment for endorsing Copernicus’ theory that the Earth orbits the sun. Similarly, Alfred Wegener encountered not just skepticism, but outright hostility for proposing the concept of continental drift, suggesting that continents were once connected and moved across the Earth. One of Wegener’s detractors stated “It is certain the Wegener’s theory was established with a superficial use of scientific methods, ignoring the various fields of geology.” He continued to state “We can only try to keep our distance and beg him not to deal with geology any longer…” Even Einstein’s view of quantum physics was not all that favorable, famously stating “God does not play dice with the Universe” and describing what we now call quantum entanglement as “spooky action at a distance”. These examples highlight not just a mere clash of ideas, but also the hostility directed towards the individuals advocating them.

Similarly, mechanochemistry was also seen in that light. I remember many of my people expressing to me that this is ruining “real chemistry”. It is funny to think about it this way now but similar to any “new” methodology it is threatening to the current paradigm. However, over the years the field has grown tremendously, and more people are entering the field. When I entered the field twenty years ago I could not have envisioned the vast amount of activity in the field. You have scientists and engineers now all working together to better understand chemistry using mechanical force. To continue to foster the growth of mechanochemistry, it’s essential to alleviate the apprehension linked with embracing change.

In the next decade, it is imperative to deepen our fundamental understanding of mechanochemical reactions and discern when mechanochemical conditions are preferable over established methods.  The prediction of chemical reactivity under mechanochemical conditions is growing, with many governing principles yet to be discovered. If this methodology is to reach its full potential, predictability across the field must increase substantially. Moreover, mechanochemistry will require assistance from fields beyond chemistry, particularly material science and mechanical engineering.

Another critical aspect for the progression of mechanochemistry is the creation of standardized milling equipment. Mechanochemists currently rely on market-available tools, but there’s a scarcity of companies dedicated to designing and manufacturing equipment specifically for mechanochemical applications. Presently, mechanochemists must modify commercial equipment, which results in inconsistent practices. Standardization or normalization of these essential tools is a critical step forward, necessitating innovation and uniformity in the field. Similar to how glass blowing transformed solution-based chemistry, collaboration with mechanical engineering is crucial for the progress of mechanochemistry.

Maria Elena Rivas, Johnson Matthey Technology Centre, UK

Mechanochemistry has the potential to revolutionise many industrial applications, such as energy, nanomaterials, and environmental remediation. By using mechanochemistry, our industry can potentially reduce their costs, waste, and environmental impact, while increasing their efficiency, quality, and innovation. Mechanochemistry can also enable the discovery of new compounds and mechanisms that are inaccessible by conventional methods.

Some of the examples of how mechanochemistry has evolved in the last 5 years:

– Energy: Mechanochemistry have been used to create new materials for energy storage and conversion, such as batteries, fuel cells, solar cells, and thermoelectric. Mechanochemistry also helped improving the performance and durability of existing materials, such as electrodes, electrolytes, and catalysts.

– Nanomaterials: Mechanochemistry has been used to fabricate nanostructures with novel properties and functions, such as nanocrystals, nanowires, nanotubes, and nanocomposites. Providing benefits in terms of size, shape, composition, and morphology of nanostructures, as well as their assembly and integration. For instance, mechanochemistry has been used to produce carbon nanotubes, and graphene.

In summary, mechanochemistry has demonstrated to be a game-changer for industrial applications in the next 10 years, as it offers a simple, efficient, and versatile way to manipulate matter at the molecular level. Mechanochemistry can open new avenues for innovation and discovery, as well as provide solutions for current and future challenges. Mechanochemistry is not only a branch of chemistry, but also an interdisciplinary field that connects chemistry with physics, engineering, biology, and materials science. Mechanochemistry is poised to become a key driver of scientific and technological progress in the near future.

 

RSC Mechanochemistry offers you an inclusive and dedicated home for the ideas, scientific language and approaches that cut across the many disciplines mechanochemistry touches. Here we are seeking to build knowledge, as well as foster innovation and discovery at this forefront of chemistry. Whether you are seeking to understand the fundamentals of mechanochemistry, or you are excited by its applications and potential, this journal is for you.