FRIDAY, DECEMBER 23, 2022
A newly developed conductive coating from the University of Sussex reportedly mimics the network spread of a virus through a process called “explosive percolation.” This method is a mathematical process that can also be applied to population growth, financial systems and computer networks, but according to researchers, has not been used before in materials systems.
The finding, which was recently published in the journal Nature Communications, was reportedly a “serendipitous” development and a scientific first for the researchers.
About the Research
For the experiment, scientists took polymer latex spheres and added graphene oxide, then dried the solution. The grapheme oxide thus became trapped between the spheres and, as more graphene was added, the sheets eventually formed a “percolating” network within the latex film.
They then reportedly heated the graphene oxide to 150 degrees Celsius (302 degrees Fahrenheit) to eliminate chemical defects and make it electrically conductive, kickstarting the process for the conductive system to grow exponentially. As a result, the new material created consumed the network, similar to the way a new strain of a virus can become dominant.
“The most exciting aspect of these nanocomposites is that we are using a very simple process, similar to applying emulsion paint and drying with a heat gun, which then kickstarts a process creating chemical bridges between the graphene sheets, producing electrical paths which are more conductive than if they were made entirely from graphene,” said Dr. Sean Ogilvie, a research fellow in Professor Dalton’s Materials Physics Group who worked on the development.
A lucky find! Our physicists from @materialssussex demonstrate how a highly conductive paint coating they developed mimics the network spread of a virus through a process called 'explosive percolation' ???? https://t.co/27P6DfxVBq
— Physics at Sussex (@PhysicsAtSussex) December 21, 2022
“The growth of this network is analogous to the emergence of high-transmission viral variants and could allow us to use epidemic modelling to develop exciting new materials or even materials to understand epidemic transmission.”
The researchers report that the reason they are so conductive is due to the sheets being trapped together between the latex spheres, rather than randomly arranged. The mild heating then spurs chemical modification of the graphene, which in turn chemically modifies the polymer to produce small molecules which crosslink, or form chemical bridges between, the sheets which dramatically increases their conductivity.
The phenomenon of percolation that causes the materials to go through a “phase transition” to form a completely different network than if they weren’t connected is known as explosive percolation. It can reportedly be thought of reaching a critical level of connectivity where the new material grows explosively through the network.
According to the university, because graphene oxide is a cheap and easy to mass produce nanomaterial, the new highly-conductive paint solution is one of the most affordable and most conductive low-loading composites reported. Prior to the study, researchers report that it was accepted that such paints or coatings were necessarily one or the other.
Electrically conductive paints and inks could be used in a variety of applications, imparting coatings with properties such as anti-static or block electromagnetic interference. They could be applied to materials such as batteries, electric vehicle materials or health monitors, among others.
“My research team and I have been working on developing conductive paints and inks for the last ten years and it was to both my surprise and delight that we have discovered the key to revolutionizing this work is a mathematical process that we normally associate with population growth and virus transmission,” explained Alan Dalton, professor of experimental physics, who heads up the Materials Physics Group at the University of Sussex.
“By enabling us to create highly-conductive polymer composites that are also affordable, thanks to the cheap and scalable nature of graphene oxide, this development opens up the doors to a range of applications that we’ve not even been able to fully consider yet, but which could greatly enhance the sustainability of Electric Vehicle materials – including batteries – as well as having the potential to add conductive coatings to materials, such as ceramics, that aren’t inherently so. We can’t wait to get going on exploring the possibilities.”
Tagged categories: Coating chemistry; Coating Materials; Coatings; Coatings technology; Coatings Technology; Colleges and Universities; Graphene; Latex; Paint; Polymers; Program/Project Management; Research and development
