Missions

The research project concerns an innovative process, electrospinning, which enables the manufacture of nanofibrous materials with applications in various fields such as mechanical reinforcements, filters, sensors and biomedicine. The principle of the process is based on propelling a jet of viscous polymer solution using an intense electric field. Industrial-scale manufacturing is now possible thanks to the design of electrodes that ensure the simultaneous emission of a very large number of jets. However, many polymers require the use of toxic organic solvents. The postdoctoral project aims to develop a process for producing biodegradable elastomer nanofibrous mats by electrospinning and in-situ photopolymerisation. These prepolymers will be cross-linked photochemically during the electrospinning process (during the flight phase of the electrospinning jet or when the fibre is deposited on the collector) or post-electrospinning. To achieve the main objective, several intermediate steps will be carried out. i) Formulations for electrospinning will be studied, with and without carrier polymer, in different solvents (alcohols or green solvents), with the aim of achieving rapid photoreticulation. ii) Irradiation conditions will be studied during the electrospinning process: in the jet or in-line, post-process. iii) The membranes obtained will be characterized, and their mechanical and physicochemical properties (hydrophilicity) will be optimized through chemical modifications of the prepolymers used.

Activities

• To select and to study different formulations from photopolymerizable oligomers.
• To study the influence of formulation parameters on the kinetics of the photopolymerisation reaction by casting and characterize the materials obtained.
• To adapt an existing electrospinning set-up combining UV-visible illumination to allow photocrosslinking of nanofibers.
• To study the electrospinning of optimized prepolymer formulations by varying the process parameters and the illumination conditions of the jet and/or the deposit.
• To characterize the fibre structure (IR, SEM, DSC) and mechanical properties of the materials produced. and to optimize the mechanical and physico-chemical properties of the obtained elastomeric mats.
• To write publications and patents.

Skills

• The candidate must have an experimental PhD in polymer chemistry, or physical-chemistry and characterization of polymers. Additional knowledge of photochemistry would be an advantage.
• English level: mnimum C1 (indicate TOEIC level or equivalent)
• Very good communication skills required.
• Rigorous experimental work.
• Autonomy and ability to take initiative.
• Ability to work in a team and communicate results.

Work Context

The ICPEES is a joint research unit between the CNRS and the University of Strasbourg, with 150 people working in the fields of chemistry, materials and processes for applications related to energy, environment and health. The ICPEES research team involved in the project has been developing expertise in the synthesis and characterization of nanofibrous materials via the electrospinning process for over 10 years. The research aims at i) controlling the structuring of fibrous membranes, ii) developing eco-friendly strategies using only water as solvent and finally iii) functionalizing nanofibers for various applications such as biomedical, filtration or energy. The team has access to all the ICPEES resources (SEM, XPS, rheology, mechanical tests, electrical characterizations, surface property measurements, BET, etc…) to characterize the materials.
MICHELIN places innovation at the heart of its strategy, with a 2020 R&D budget of nearly €646 million, 10700 active patents, and 6000 people working in the field, including 3400 at the Ladoux site in France. The MICHELIN Group is undergoing a major transformation to contribute to innovation in the field of low environmental footprint materials and high-tech materials. The objectives are to make offerings and mobility more efficient and sustainable with new technologies, bio-based and recycled materials, zero-emission solutions as well as to position itself on new high-potential profitable growth markets such as flexible composites, medical applications, 3D metal printing and hydrogen mobility.
The work will be done within the framework of a project with the company MICHELIN in which chemists, physical-chemists, physicists and polymer processing specialists work in close collaboration. The candidate will interact with other people involved in the project and may be required to carry out experiments on the MICHELIN site.

Working conditions:
- Easy access to the Cronenbourg campus by public transportation
- Possibility of partial reimbursement of transportation costs by the CNRS
- Possibility of dining in a university restaurant on the Cronenbourg campus with meal subsidies from the CNRS

The position is located in a sector under the protection of scientific and technical potential (PPST), and therefore requires, in accordance with the regulations, that your arrival is authorized by the competent authority of the MESR.