Controlling dissipative molecular assemblies

• Applicant: Professor Dr. Job Boekhoven
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Organic Molecular Chemistry - Synthesis and Characterisation ; Polymer Materials
• Term: from 2018 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 411722921

Biological molecular assemblies, like the microtubules or the actin network, almost always exist far-from-equilibrium. In contrast, man-made molecular assemblies typically exist in equilibrium with their environment. Inspired by biological assemblies, researchers have started exploring artificial dissipative non-equilibrium materials. These dissipative assemblies have superior properties compared to their in-equilibrium counterparts, which include the ability to be controlled over space and time, the ability to rapidly switch morphology in response to a small change in their environment and the ability to self-heal. Exiting dissipative molecular assemblies driven by chemical fuels have been reported. But, there remains a fundamental lack of understanding of the governing principles of these assemblies. For instance, we do not understand how the fuel consumption rate affects morphology. Or how the size of the assemblies scales with the kinetics of building block activation. This fundamental knowledge hampers us from applying these materials with the versatilely as biology does.The main aim of this proposal is therefore to understand how the kinetics of building block activation and deactivation affect the morphology, size and stability of dissipative assemblies. We start by creating assemblies in which building block activation rate equals deactivation, a so-called steady state. We will develop new chemistry with which the average lifetime of a building block can be tuned. That means that we can tune for how long a building block on average resides in the reactor before being deactivated. We will use new kinetic models that allow to predict this residence time. With these tools, we will study how the morphology of an assembly is affected by its building block residence time. We will be able to tune the size of an assembly using this building block residence time. Finally, we will study if these dissipative assemblies can survive starvation periods, and how starvation is affected by residence times as well as feedback of assemblies on their own chemical reaction network.

• DFG Programme: Research Grants