Smart Materials Built With The Power Of Sound

Researchers have used sound waves to precisely manipulate atoms and molecules, accelerating the sustainable production of breakthrough smart materials.  Metal Organic Frameworks, or MOFs, are incredibly versatile and super porous nanomaterials that can be used to store, separate, release or protect almost anythingPredicted to be the defining material of the 21st century, MOFs are ideal for sensing and trapping substances at minute concentrations, to purify water or air, and can also hold large amounts of energy, for making better batteries and energy storage devices. Scientists have designed more than 88,000 precisely-customised MOFs – with applications ranging from agriculture to pharmaceuticals – but the traditional process for creating them is environmentally unsustainable and can take several hours or even days

Now researchers from RMIT in Australia have demonstrated a clean, green technique that can produce a customised MOF in minutes. Dr Heba Ahmed, lead author of the study published in Nature Communications, said the efficient and scaleable method harnessed the precision power of high-frequency sound waves.

Dr Heba Ahmed holding a MOF created with high-frequency sound waves

MOFs have boundless potential, but we need cleaner and faster synthesis techniques to take full advantage of all their possible benefits,” Ahmed, a postdoctoral researcher in RMIT’s Micro/Nanophysics Research Laboratory, said. “Our acoustically-driven approach avoids the environmental harms of traditional methods and produces ready-to-use MOFs quickly and sustainably. “The technique not only eliminates one of the most time-consuming steps in making MOFs, it leaves no trace and can be easily scaled up for efficient mass production.

Metal-organic frameworks are crystalline powders full of tiny, molecular-sized holes. They have a unique structuremetals joined to each other by organic linkers – and are so porous that if you took a gram of a MOF and spread out its internal surface area, you would cover an area larger than a football pitch. Some have predicted MOFs could be as important to the 21st  century as plastics were to the 20th.

During the standard production process, solvents and other contaminants become trapped in the MOF’s holes. To flush them out, scientists use a combination of vacuum and high temperatures or harmful chemical solvents in a process called “activation”. In their novel technique, RMIT researchers used a microchip to produce high-frequency sound waves. Co-author and acoustic expert Dr Amgad Rezk said these sound waves, which are not audible to humans, can be used for precision micro- and nano-manufacturing.

At the nano-scale, sound waves are powerful tools for the meticulous ordering and manoeuvring of atoms and molecules,” Rezk said.

Source: https://www.rmit.edu.au/

Leave a Reply

Your email address will not be published. Required fields are marked *