Final Report Summary - NON-EQ-SA (NON-EQuilibrium Self-Assembly) The long-term goal of the applicant of this Marie Curie Career Integration Grant entitled “NON-EQ-SA” is to obtain adaptive, self-healing, self-replicating and ultimately “living” synthetic systems using molecular self-assembly under far-from-equilibrium conditions. In this NON-EQ-SA grant two projects have been proposed: 1) using biological building blocks to achieve dissipative self-assembly to mimic a biological function in vitro, and 2) using artificial building blocks to achieve dissipative self-assembly with molecules that have been synthesized in our laboratory. Both systems are in fact so-called supramolecular polymers, that is, long chains consisting of smaller building blocks that stick together using weak and reversible interactions. Such supramolecular polymers have been studied widely, but mostly at (or close to) the thermodynamic equilibrium (note: a living system at thermodynamic equilibrium is dead). Instead, nature uses an input of energy (for example food or air) to keep its supramolecular polymer systems away from the thermodynamic equilibrium. Developing non-equilibrium artificial systems will led to a completely new class of life-like materials that can perform complex (biological or biomimetic) functions.In the first project, we developed a new method to keep systems out of the thermodynamic equilibrium for extended periods of times in so-called non-equilibrium steady states. Specifically, a chemically fueled supramolecular polymer was kept in various non-equilibrium steady states using a 3D printed membrane reactor developed over the course of this NON-EQ-SA project. The fuel and waste molecules can cross the membrane barrier, whereas the supramolecular polymers (and the enzymes catalyzing the overall system) stay confined. It is comparable to the cell membranes in living systems, where high energy fuel molecules and waste can be transported across. This work has been published in Nature Communications in 2017 and is available via this link: https://www.nature.com/articles/ncomms15899In the second project, we used a different method to push a supramolecular polymerization process out of equilibrium, namely using magnetic fields. We synthesized a three-armed flat molecule based on the benzene-1,3,5-carboxamide motif, containing chelating end-groups that can hold (para)magnetic ions. In this way, the molecules become small magnets themselves. In the absence of a magnetic field, the molecules form supramolecular polymers. Surprisingly, we found that upon exposure to weak magnetic fields (0.5–1.9 Tesla), the number of molecules that are self-assembled (into supramolecular polymers) changes significantly. This is in contrast with theoretical predications that weak fields cannot exert significant forces on single magnetic ions. Parts of this work have led to the development of new magnetic oils that have been recently patented (EP18305042.6).Overall, this project has given new insights in how to push artificial systems out of equilibrium, and how to make long-lived non-equilibrium states. This has increased our understanding of how living being control their supramolecular structures such as actin fibers and microtubules, and how the next generation of artificial materials can be made with similarly complex properties.For more information contact Dr. Thomas Hermans (hermans@unistra.fr) or go to http://www.hermanslab.com.
