Description of the thesis topic

Context
As part of the transition toward bio-based and renewable materials, and within the framework of the PEPR B-BEST program (Biomass, Biotechnology and Sustainable Technologies for Chemistry and Fuels), the WallMat project (link) brings together several research laboratories to valorize agri-food industry by-products that are rich in cellulose, hemicellulose, and pectin. The project aims to draw inspiration from the natural mechanisms at work in plant cells to design novel materials with unique properties.

The plant cell wall is a fascinating structure, composed of a pectin gel reinforced by a network of cellulose and hemicellulose, providing it with remarkable mechanical strength to withstand high osmotic pressures. Moreover, plant tissues can remodel themselves thanks to enzymatic reactions that temporarily weaken the cellulose network while modifying the reactivity of the pectin gel.

The objective of this PhD project is to exploit these biomimetic principles to develop micro-objects capable of combining mechanical strength with the ability to be remodeled in response to external stimuli.

PhD Objectives
The PhD candidate will develop an experimental approach to fabricate composite microcapsules made of biopolymers and cellulose, whose structure and physical properties (e.g., stiffness, permeability) can be remodeled in response to enzymatic stimuli.

The originality of the project lies in:

Miniaturization of capsules already developed in the lab, by exploring different shaping techniques such as piezoelectric injection or jet atomization of biopolymer suspensions.
Advanced characterization of the capsules using techniques such as microindentation to probe mechanical properties before and after enzymatic remodeling, and confocal microscopy to explore shell permeability.
Monitoring enzymatic action and its effects on mechanical and permeability properties.
The entire PhD project will be carried out in close collaboration between LRP and CERMAV, and in interaction with Jérôme Pelloux's team at the University of Picardie Jules Verne, specialists in plant cell wall remodeling enzymes and leaders of another work package within the WallMat project.

Activities and Methodology

Literature review and scientific monitoring.
Development of experimental approaches for fabrication, optimization, and characterization of microcapsules.
Data analysis (using Python or equivalent tools).
Documentation of protocols and results for communication and sharing within the project team.
Writing scientific papers and presenting work at international conferences.
Participation in interdisciplinary exchanges within the ANR WallMat project and the PEPR B-BEST program.
Writing and defense of a PhD thesis to obtain the title of Doctor from Université Grenoble Alpes.
This PhD will contribute to shaping the materials of tomorrow, inspired by living systems!

Candidate Profile
We are looking for a curious and motivated candidate with a strong interest in research, eager to get involved in an ambitious scientific project at the crossroads of bio-based material physico-chemistry, soft matter rheophysics, and processing technologies.

Education: Master's degree or engineering diploma in chemical engineering, soft matter physics, fluid mechanics, or materials science.
Strong interest in experimentation and in developing experimental setups.
Solid skills in data analysis and result interpretation.
Proficiency in scientific English (written and spoken).
Throughout the PhD, the candidate will benefit from scientific training and dedicated support for post-PhD career development. They will also be trained in advanced techniques in soft matter physics and chemistry, as well as in cross-disciplinary skills in project management and scientific communication.

Work Context

The selected candidate will be recruited by the CNRS, a public multidisciplinary research organization under the supervision of the French Ministry of Higher Education, Research and Innovation.

The PhD student will join a dynamic collaboration between the Laboratory of Rheology and Processes (LRP) and the Center for Research on Plant Macromolecules (CERMAV), both located on the university campus in Grenoble. These two neighboring and complementary laboratories provide an ideal environment to carry out this interdisciplinary project.

LRP, a joint research unit of CNRS and Université Grenoble Alpes, specializes in rheology, processing, and soft matter, with applications ranging from biomaterials to advanced industrial processes.
CERMAV, a center of excellence in glycoscience, conducts cutting-edge research on polysaccharide materials and biopolymers.

This PhD project is part of the PEPR B-BEST program, which aims to foster innovation in the field of biomaterials and sustainable biotechnologies.

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.

Constraints and risks

The position falls within a sector subject to the protection of scientific and technical potential (PPST). In accordance with regulations, your appointment will therefore require authorization from the competent authority of the Ministry of Higher Education and Research (MESR).