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Reconfigurable Soft Acoustic Materials

Reconfigurable Soft Acoustic Materials figure

Category: Post docs

Duration: 18 months

Team: Biopolymers and bio-sourced polymers

Funding: GPR “Post Petroleum Materials”, IDEX Bordeaux

Laboratory: LCPO, CRPP, I2M

Contacts : Thomas Vidil

Applicant profile

PhD in macromolecular chemistry. The candidate should have a strong taste for multidisciplinary subjects.

Project summary

This project concerns the development of new reconfigurable, self-healing and/or recyclable materials for acoustics. The general idea is to give a material acoustic functions that can be modified through the application of an external stimulus and thus ensure its versatility.
In this context, porous polymer materials are used because their acoustic properties strongly depend on their mechanical properties. Thus, in a “soft” porous polymer matrix (i.e. a polymer having a glass transition temperature TG lower than room temperature RT), acoustic waves do propagate at a low speed (~100 m/s), which increases drastically [1] as the material toughness increases upon, for example, crosslinking of the matrix. This is a way to produce active acoustic tunable devices. To obtain versatile and reprogrammable devices, the objective of the project is to design a porous material in which the crosslinking density can be reversibly controlled upon the application of external physical stimuli. This is schematized below.

First attempts to make such a device were performed using UV stimuli to crosslink and un-crosslink an elastomeric matrix. However, UV light is not well adapted to thick film due to its low penetration depth. This is particularly the case for the short UV wavelenght (< 260 nm) used to un-crosslink the material. For this reason, we now want to explore another type of chemistry that allows the un-crosslinking step using a much simpler thermal stimulus.
The postdoc will be in charge of developing this chemistry and will work in a tight collaboration with a PhD student (Simon Colanges). The project involves two other labs (Centre de Recherche Paul Pascal for the formulation and shaping of the materials, and Instute of Mechanics & Engineering for acoustics) in which the postdoc will also be in strong interaction.
[1] Kovalenko, A., Fauquignon, M., Brunet, T. & Mondain-Monval, O. Soft Mat. 13, 4526–4532 (2017).