Despite the great advances in stereoselective synthesis and chromatographic separation methods during the last decades of the 20th century, chiral resolution is still a major challenge in pharmaceutical, food, pesticide and fragrance industries, and a very costly step in the production process. The possibility to achieve chiral separation through alternatives methods is therefore appealing and has found renewed interest in the past decade. One idea is that fluid flows could induce chiral migration, as initially proposed by Howard. Achieving separation of enantiomers without the use of a chiral stationary phase, but just by flow is not fully understood, but if successful would be of great benefit to the pharmaceutical industry. Over the past few years, we have studied increasingly smaller chiral structures. Your job is to shed light on the physical processes involved (you need a background in fluid dynamics, applied physics, or chemical engineering), and perform relevant experiments to push mechanical separation into the single-molecule domain. Knowledge on aggregation/crystallization behavior is beneficial.
The “Life-Cycle” ERC proposal aims to develop a new class of artificial supramolecular materials that are kept in sustained non-equilibrium states by continuous dissipation of chemical fuels. Supramolecular polymers in current artificial materials stick together through weak reversible bonds that can be exchanged by thermal energy. In contrast, natural supramolecular polymers such as those in the cytoskeletal network use chemical fuels such as adenosine triphosphate (ATP) to achieve an incredible adaptivity, motility, growth, and response to external inputs. Development of chemically fueled artificial supramolecular polymers should therefore lead to more life-like materials that could perform functions so far reserved only for living beings.
The proposed materials are based on supramolecular reaction cycles that have both positive and negative feedback in order to achieve emergent properties, such as oscillations and waves. Since the building blocks react, but also self-assemble they have built-in chemomechanical properties, much like in living materials such as the cytoskeleton.
https://rdcu.be/b3ZuFIt was a long process, but our work on wall-less liquid ‘antitubes’ is now online. Watch the short intro movie that explains the key concepts! Read for free here: https://rdcu.be/b3ZuF
The World Economic Forum recognizes 21 brilliant researchers under the age of 40 at the cutting edge of discovery with the announcement of its Class of 2019 Young Scientists. The Young Scientists play an important role at the Forum’s 13th Annual Meeting of the New Champions, Dalian, People’s Republic of China, 1-3 July 2019. They contribute ideas for solving complex challenges within and outside their core areas, together with leaders from government, business, civil society and other stakeholder groups during the sessions and workshops.
Chemically fuelled processes control size oscillations of natural fibres inside the body such as microtubules or actin filaments. Researchers from the University of Strasbourg have now discovered similar size oscillations in a completely artificial system. Brightly coloured molecules form extended supramolecular fibres that can be controlled by redox chemistry. In a continuous flow system, these fibres grow and shrink spontaneously. Self-oscillating artificial systems provide a stepping stone to life-like materials with applications in material science, medicine, and soft robotics. The results have been published in Nature Nanotechnology.
Living organisms use chemical fuels like guanosine triphosphate (GTP) to drive assembly and disassembly processes of fibres in the cytoskeleton. Microtubules for example are formed by tubulin bound to GTP, which self-assembles into long fibres. Once the fuel is consumed, which for microtubules is when GTP is hydrolysed to guanosine diphosphate GDP, the fibres disappear. Inside the cell such fibres can show spontaneous size oscillations, which serve to maintain the cytoskeleton and its functions.
Now researchers from the University of Strasbourg (France) and Aston University (UK) have developed a completely artificial system that works similarly to microtubules. They developed a molecule that can form fibres spontaneously through self-assembly, starting from small nuclei that rapidly grow. The molecule can be deactivated by reacting with a chemical reductant, which causes the fibres to disassemble. The molecules can be reactivated by oxygen (an oxidant), which makes the fibres grow again. In addition to spontaneous oscillations, the researchers have observed traveling waves of fibre formation, and intricate centimetre-scale patterns. They found that the interplay of self-assembly and fluid convection, leads to these mosaic-like structures. Overall, the work opens new pathways to obtain life-like artificial systems and materials, which can perform complex biological functions such as cell division in the future.