Monthly Archives: June 2024

Elucidating chirality transfer in liquid crystals of viruses

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2024-05-30
News:
How does the propagation of chirality across various length scales take place?

It unfolds within the intricate playground of virus self-assemblies – used as model system of chiral particles – to form helical liquid crystals. These chiral liquid crystals exhibit a fascinating duality: simple in structure yet complex in behavior. This work explores the physical mechanisms governing chirality transfer for two distinct virus mutants, M13 and Y21M. Despite their high structural similarity, these viruses exhibit cholesteric liquid crystalline phase phases with opposite handedness. This seemingly apparent paradox stems from the subtle interplay between steric repulsion, chiral supramolecular virus deformations, and electrostatic forces.

For the stiff Y21M virus strain, the local electrostatic interactions, which are highly sensitive to both ionic content and the detailed atomic symmetries of the capsid, play a crucial role. In this case, the molecular chirality originates primarily from the subtle helical distribution of surface charges around the symmetry axes of the capsid.

In contrast, the chirality of the M13 virus arises from weak, fluctuation-induced suprahelical deformations of its backbone. This chirality transfer and the resulting helical phase are chiefly driven by steric interactions occuring at the supramolecular length scale of the viruses themselves.

Overall, this study provides a quantitative description of chirality transfer across different length scales. It reveals the complex interplay of competing chiral interactions with opposite signs, governing the emergence of chiral structures and helical morphologies.

Laboratory : CRPP

seminar of Prof. Yoshihiko Togawa (Osaka Metropolitan Univeresity) : A role of chirality: Generation and transfer of spin and phonon angular momenta

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2024-07-05
News: We discuss a role of chirality in materials, being inspired by recent studies on chirality-induced selectivity of spin and phonon angular momenta with chiral materials. A comprehensive understanding of these nontrivial phenomena will clarify the interplay between structural and dynamical chirality.
when ? 05/07, 14h-15h
where ? IECB
Laboratory : CBMN