Filamentous viruses as chiral building blocks for hierarchical helical self-assembly

Envoyé par Eric Grelet 
Filamentous viruses as chiral building blocks for hierarchical helical self-assembly
vendredi 12 mai 2023 17:17:01
Open PhD position at Paul Pascal Research Center (http://www.crpp.cnrs.fr), a multidisciplinary research laboratory belonging to French National Center for Scientific Research (CNRS) and to the University of Bordeaux (UB).

Research Project: Filamentous viruses as chiral building blocks for hierarchical helical self-assembly

The phase behavior of rod-shaped colloidal particles is much richer than that of their spherical counterparts because the additional orientational degrees of freedom allow for the formation of liquid crystal phases. The physics becomes even more complex when additional non-adsorbing polymers are present imparting so-called depletion interactions between the rods. In this PhD project, we will perform experiments to study and understand the chirality transfer from the particle scale to the mesoscale through self-assembly of virus rods into a variety of chiral supramolecular morphologies (1D twisted ribbons, 2D hexagonal membranes, hexatic and bulk cholesteric phases,…). While chirality is ubiquitous in Nature from DNA to living organisms, the understanding of chirality amplification from chiral building blocks to ordered helical superstructures remains a challenge. For this project, we will use a model system of chiral rod-like particles, the filamentous fd viruses, which have unique physical properties, that are not found in other model systems of rod-like colloidal particles, such as uniform particle lengths, rod helicity that can be tuned from left to right handed through the use of viral mutants. Rod-like viruses can also be used as aqueous non-toxic, cheap building blocks to create functional materials and biosensors. As colloids, they can be visualized and tracked at the single particle scale with optical microscopy. This enables a detailed and quantitative comparison with theoretical predictions and numerical simulations which has significantly advanced our understanding of soft matter physics in general and self-organization into liquid crystals.
In this PhD Project, we will study the formation of helical superstructures formed by attractive fd viruses, with a specific focus devoted to the role of topological defects in the mechanisms of chirality transfer at the mesoscopic scale, as well as to the influence of the geometric confinement in the resulting helical superstructures.

Your Profile: This PhD project is mainly experimental with international for physics modelling. It is fundamentally interdisciplinary, combining soft matter physics, physico-chemistry, as well as the production and manipulation of biological objects. The candidates should be in possession of, or expect to attain, a Master’s in a relevant discipline (Physical Chemistry, Materials science, Physics, Nanoscience, etc). Good skills in written and oral communication in English are important.

Applications should include a CV, contacts of two referees and a brief statement of interests for this specific PhD research project. Please send your application or any inquiry, to eric.grelet@crpp.cnrs.fr.
More information: Prof. Eric Grelet
CRPP, CNRS & University of Bordeaux, 115 av Schweitzer, 33600 Pessac, France
Phone: +33 5 56 84 56 13 Fax: +33 5 56 84 56 00 [www.crpp.cnrs.fr]