Researchers at the National Graphene Institute (NGI) have developed a “smart” membrane (A smart membrane with memory makes the next generation smart filter) that can use “memory” to be used in areas such as fine separation technology, wound management, drug delivery, sensors and memory devices.
“The history of skin development is over 100 years old and has led to changes in the industry’s classification system,” says Professor Rahul Raveendran Nair, Carlsberg Research Chair/Royal Academy of Engineering and study team leader. “In recent years, efforts have been made to create skins that mimic biological processes, especially their “smart” qualities.
Now, in a study published today in Nature, scientists explain how they have created smart membranes that can change their properties depending on the environment and remember how permeable they were before. This means that membranes can adapt to different conditions in their environment and, more importantly, remember their position, something that can be used in many different applications.
What is known as hysteresis is a common term for memory or intelligence in materials. It refers to the situation where the current property of the system is dependent on its previous state. Hysteresis is often found in magnetic materials. For example, a magnet can have more than one magnetic moment per magnetic field depending on the region where the magnet was placed in the past. However, hysteresis is not observed in molecular transport across the membrane.
“Creating simple and effective solutions for clean water is one of our global challenges. This study shows that basic knowledge at the molecular level and materials at the nanoscale offer great potential for the development of ‘smart’ membranes for water purification and other applications,” said Professor Angelos Michaelides. Cambridge University said.
In this project, the Manchester team, in collaboration with scientists from the University of Cambridge, Xiamen University, Dalian University of Technology, York University and the National University of Singapore, have developed smart membranes based on MoS2 (a two-dimensional material called molybdenum disulfide) and can remember how permeable they were before. Researchers have shown that the passage of ions and water into membranes can be regulated by controlling the external pH.
The membrane mimics the function of living cell membranes and exhibits hysteretic ion and water transport behavior in response to pH, which means that they remember the pH to which they were previously exposed. “The memory effect we observed is unique to these membranes and has never been seen before in inorganic membranes,” said first author Dr Amritroop Achari from the University of Manchester.
The researchers showed that biomimetic effects can be used to improve the autonomic diagnosis of wound infections. To do this, they put membranes and artificial wound exudate, which makes the water produced by the wound, and put them in a pH change. The skin allows the elimination of wound exudate at a pH level corresponding to bacterial lesions, thus allowing their use as a sensor for disease diagnosis. The researchers said that the new membrane can also be used in many other applications based on pH, through nanofiltration that mimics neuronal cell activity.
Co-author Professor Kostya Novoselov, Distinguished Professor at the School of Physics and Astronomy at the University of Manchester and Professor at the Center for Advanced 2D Materials at the National University of Singapore, said: “The unique feature of this membrane is that its hysteretic response. to pH can be considered as a buffer function, which opens many interesting ways for creating smart membranes and other materials. Research in this direction can play an important role in creating the smart technology of tomorrow.
Source: University of Manchester.
