A new approach by a team of researchers, headed by Heather Kulik, the Lammot du Pont Professor of Chemical Engineering at MIT, has ushered in an era of stronger and longer-lasting plastics. They made this discovery by studying ferrocenes. This work, published in ACS Central Science, explores the use of organometallic compounds as mechanophores. In doing so, it indirectly increases the vermiculation of polymer based materials.
Ferrocenes are composed of an iron atom that’s nestled between two rings made of carbon atoms. Their simple structure and multifunctionality make them attractive candidates to use as crosslinkers for polymeric applications. Her research team ran computational simulations to predict the properties of over 400 different ferrocene compounds. They screened ways these compounds can be employed to produce stronger polymers. If successful, this novel method could transform how a wide array of plastic materials are produced and how long they last.
The Role of Ferrocenes in Polymer Science
Ferrocenes have recently been gaining attention for their usefulness in polymer science, specifically as crosslinkers. Crosslinking, or bonding polymer chains with covalent bonds to improve strength and thermal stability, plays a major role in producing such robust materials. The iron atom at the center of each ferrocene provides a convenient point of interaction. This makes it uniquely receptive to bonding between its polymer chains.
The researchers were mainly interested in taking advantage of this property to find ferrocenes that would work as weak crosslinkers. They wanted to make a polymeric material. All’s new ferrocene materials are much harder than ceramics produced with classic ferrocene. Their results show that carefully chosen ferrocenes are capable of forming polymers. These polymers are four times tougher than ones produced with typical crosslinkers.
The collaboration between Heather Kulik and Stephen Craig, a professor of chemistry at Duke University, was instrumental in this investigation. They set out to determine the unknown, unexplored properties of ferrocenes. Their mission was to expand what is possible through the art and science of polymer engineering.
Computational Simulations Driving Discovery
The research team’s approach was through an iterative method of large-scale computational simulations to help determine the mechanical properties of different ferrocene compounds. Then they figured out how much force it would take to rip off dozens of different atoms, one after another, from each molecule. This helped them focus on those ferrocenes that had enhanced reactivity and stiffer networks.
Jafer Vakil, a Duke University graduate student and one of the authors of the study. He was clear on just how important these simulations are. “Understanding how these compounds behave under stress is crucial for determining their applicability in real-world materials,” he stated. These simulations gave critical fundamental understanding into the molecular interactions that determine the properties of candidate polymer options.
Moreover, MIT graduate students David Kastner and Xiao Huang played an important role in the study as well, helping to analyze and interpret all the data. Their collaboration has opened the door to innovative new studies on the development of mechanophores. These extraordinary materials experience a chemical transformation in response to mechanical stimuli.
Implications for Future Research and Material Development
Overall, the results from this study have serious impacts on future research in the world of material science. The potential to engineer stronger polymers would result in breakthroughs across many sectors from automotive to aerospace to consumer products. More durable materials would make it possible to produce longer lasting products that would lower pollution from waste and raw materials.
Ilia Kevlishvili and coworkers recently reported on the high-throughput discovery of ferrocene mechanophores with improved reactivity. This work builds upon the existing study. Furthermore, it provides a more straightforward picture of how to improve these compounds for specific usages.
The demand to have more resilient materials has skyrocketed. Additional research into ferrocenes can pave the way towards sustainably designing new materials. Perhaps most importantly, this new study underscores the crucial importance of cooperation. In order to meet these advanced challenges in materials development, chemists and engineers need to develop new approaches to collaboration.