Researchers film energy material formation
Shooting a movie in the lab necessitates specialized equipment. Especially when the actors are molecules — invisible to the naked eye—interacting with one another. ” Imagine attempting to record small lava flows during a volcanic eruption. Your smartphone’s camera would be inadequate. Prof. Emiliano Cortés, Professor of Experimental Physics and Energy Conversion at LMU, explains that first, a particular approach must be developed to make the movement you wish to capture visible.
But the effort is worthwhile, especially since the reaction produces a promising energy material known as covalent organic frameworks (COFs). This material class, which is still in its early stages, offers enormous promise for use in battery technology and hydrogen production. Despite 20 years of continuous research, scientists have been unable to fully understand what happens during the synthesis of COFs. Materials are frequently generated by trial and error. This has also been true for COFs, where numerous molecular components must find their proper location during synthesis. Only then does the necessary porous framework emerge across wide areas.
“I’ve been curious about why synthesis works under certain conditions but not others since I was in graduate school. Our approach to this project was to employ physics techniques to help chemists do their work. We wanted to throw more light on the intricate synthesis processes and so optimize them,” says Christoph Gruber, who is exploring this topic as part of his PhD dissertation with Cortés’ team. To that purpose, the two scientists formed a relationship with LMU chemist Prof. Dana Medina’s research group, which specializes in COF synthesis.
Gruber used a special microscope to film the molecular stars. With this technology, the team was able to track the formation mechanism of COFs at the nano level. The LMU researchers recently published their remarkable findings in the journal Nature, along with a video demonstrating the processes that occur during synthesis in real time. The e-conversion Cluster of Excellence (DFG), the Center for Nanoscience (CeNS), the Bavarian solar technology initiative SolTech, and the European Commission (EC) all provided money for their research.
The synthesis of molecular frameworks requires precise control of the reaction and self-assembly of molecular building blocks. However, our knowledge of the early stages of nucleation and growth is limited. Researchers have used iSCAT microscopy to visualize the reaction as it unfolds, focusing on the earliest stages when mixed molecular components are starting to react. This method captures dynamic processes and real-time measurements, allowing researchers to watch the synthesis live, as it were, revealing nano-scale COF particles.
Researchers at LMU discovered tiny droplets in the reaction medium, controlling the entire kinetics at the beginning of the reaction. These droplets are crucial for the formation of COFs, as they prevent the reaction from happening too quickly and losing the desired order. The iSCAT method allowed the team to record a film showing the molecular frameworks’ formation from the beginning, closing a gap in knowledge.
Researchers at LMU have developed an energy-efficient synthesis concept using a film clip and analyzed reactions. They found that adding normal table salt reduced temperature, allowing molecular frameworks to form at room temperature. The findings could revolutionize COF synthesis and drive industrial production advances, potentially impacting other materials and real-time chemical reactions.
Reference – Researchers film energy materials as they form