The 9th International Conference on Multiscale Materials Modeling

講演情報

Symposium

H. Multiscale Mechanics of Polymers, Soft Matter and Network Materials

[SY-H8] Symposium H-8

2018年11月1日(木) 11:15 〜 12:30 Room9

Chair: Patrick R. Onck(Univ. of Groningen, Netherlands)

[SY-H8] DNA-particle vitrimer systems

francesco sciortino (Sapienza Universita' di Roma, Italy)

Vitrimers are a new class of polymeric materials in which the network nodes, despite the covalent bonding, can change their bonded partners via reversible exchange reactions with unreacted sites. The ability to dynamically rearrange the network structure and the external control (for example, via temperature) of the rate of exchange opens up the possibility to spontaneously heal internal fractures, recycle the material shape, and release applied stresses.

Along the lines of using DNA as a material, we have proposed an innovative design of a vitrimer system entirely made of DNA sequences [1]. In this DNA gel, bonds can switch without breaking, providing a mechanism for changing the network structure under an external driving force, retaining at all times the same number of bonds. To implement the bond switching mechanism, we use toehold-mediated displacement, one of the basic processes underlying dynamic DNA nanotechnology.

Beside discussing how a DNA vitrimer can be designed in silico and in the lab, I will discuss some other examples of particle vitrimer systems[2] in which the bond-swithching dynamics is modeled numerically with a three-body potential[3]. Preliminay application of this method show how the self and collective dynamics of these particles sensitively depend on microscopic swaps. Finally, I will discuss the origin of the observed non-dispersive (in wavevector) collective relaxation mode[4].

[1]Flavio Romano and Francesco Sciortino
Switching Bonds in a DNA Gel: An All-DNA Vitrimer
Phys. Rev. Letts. 114, 078104 (2015)

[2] Lorenzo Rovigatti, Giovanni Nava, Tommaso Bellini and Francesco Sciortino
Self-Dynamics and Collective Swap-Driven Dynamics in a Particle Model for Vitrimers
Macromolecules, 51 ,1232-1241 (2018).

[3] Francesco Sciortino, Three-body potential for simulating bond swaps in molecular dynamics
Eur. Phys. J. E (2017) 40: 3 DOI 10.1140/epje/i2017-11496-5

[4] Giovanni Nava, Marina Rossi, Silvia Biffi, Francesco Sciortino, and Tommaso Bellini
Fluctuating Elasticity Mode in Transient Molecular Networks
Phys. Rev. Lett. 119, 078002 (2017).