Doctorant.e M/F en physique des matériaux

Job Description

Thesis Subject

Preparation and numerical modeling of the organization of antimicrobial heterostructures based on graphene oxides


Graphene oxide (GO) is a low-dimensional colloidal material that has attracted considerable attention from both the scientific and industrial communities owing to its unique mechanical, chemical, and electrical properties. The introduction of oxygen-containing functional groups into the graphitic framework through the oxidation of graphite precursors enables the tuning of GO electrical properties while simultaneously imparting excellent dispersibility in aqueous media. Depending on the lateral dimensions of the nanosheets and their volume fraction, GO dispersions can spontaneously self-assemble into lyotropic liquid-crystalline (LC) phases. The formation of these lyotropic LC phases, including nematic and lamellar mesophases, is primarily driven by entropic excluded-volume interactions. Although these effects are relatively well understood for mono-colloidal systems, they remain far more challenging to describe in multicomponent colloidal assemblies, where competing and antagonistic interactions may arise. Beyond the fundamental questions they raise in soft-matter physics, particularly regarding their influence on the organization of other organic and inorganic colloidal systems, GO-based self-assembled structures offer promising opportunities in materials science. In particular, GO nanosheets can serve as versatile templating platforms for the spatial organization of functional nanoparticles with diverse morphologies. To this end, graphene oxide has been successfully employed as a support for the incorporation of various colloidal species, including Mo₆-based metal clusters, leading to the development of antimicrobial nanocomposite materials.


The objective of this PhD is to exploit the unique self-assembly behavior of low-dimensional inorganic colloids such as graphene oxide and the associated excluded-volume effects to investigate their influence on the organization of other organic and inorganic colloidal species, particularly photosensitizing compounds. The ultimate goal is the design and fabrication of heterostructured hybrid materials exhibiting antimicrobial activity.
This interdisciplinary Ph.D. project, situated at the interface between physics and chemistry, is based on a close and complementary collaboration between ICMN (UMR 7374), researchers from NIMS (Renzhi Ma, group leader of the group functional nanomaterials), and the LINK (IRL 3629, Fabien Grasset, director of this international research unit), an international research unit located at Tsukuba (Japan). This collaboration was initiated through an international research project (Projet EIG CONCERT Japan, PHOTOMOS-H2O) and builds upon the complementary expertise of the participating teams. Leveraging the established know-how of ICMN in the synthesis of GO nanosheets with controlled lateral dimensions (200 nm, 1 um & 10 um), as well as its expertise in the experimental and numerical investigation of their structural organization, a range of hierarchical composite architectures will be developed and studied. These systems will combine GO nanosheets with photosensitizing nanostructures, such as Mo₆ clusters and other organic chromophores, as well as functional inorganic colloids including zinc oxide nanoparticles, for which LINK lab also possesses recognized expertise. The structural organization of these multicomponent systems will be investigated experimentally using small-angle X-ray scattering (SAXS) and modeled numerically to predict and rationalize their self-assembly behavior and resulting properties. Complementary characterization will be performed using high-resolution transmission electron microscopy (HRTEM) and X-ray focused ion beam scanning electron microscopy (X-ray FIB–SEM). By combining advanced experimental characterization with numerical modeling, this research will provide fundamental insights into the design principles governing heterostructured hybrid materials and their antimicrobial performance. The proposed research is fully aligned with the scientific strategy and research priorities of ICMN, as well as those of LINK and selected researchers at ICMN, whose expertise encompasses the synthesis, characterization, and application of antimicrobial materials.

We are seeking a highly motivated candidate for a PhD position in Materials Physics. Applicants should have a strong background in physics, preferably with knowledge of condensed matter physics, materials science, or related fields. Experience in numerical modeling and scientific computing is highly desirable. Knowledge of materials science and/or materials chemistry would be considered a valuable asset for the project. The successful candidate should demonstrate strong analytical skills, scientific curiosity, and the ability to work both independently and collaboratively in an interdisciplinary research environment. The project will involve the study of materials through a combination of theoretical, computational, and/or experimental approaches, depending on the candidate's profile and the specific research objectives. Furthermore, the candidate would be required to travel within France or abroad, including the NIMS (LINK lab) in Japan.

Your Work Environment

The ICMN is a joint research unit of the CNRS and the University of Orléans. Its activities focus on the design and development of new materials with diverse potential and functionalities that can be applied in numerous fields such as nanotechnology, health, the environment, and cosmetics. Its expertise in the development and structural and chemical characterization of materials and fluids confined within materials relies on a very extensive range of instruments, as well as strong digital skills and numerous instrumental developments.

Keywords: Divided matter, Physical chemistry, Cosmetics, Health, Confined fluids, Instrumental developments

Permanent staff: 37: 4 CNRS researchers (2 Senior Researchers, 2 Research Fellows); 21 faculty members (4 Professors, 17 Associate Professors); 12 engineers and technicians (8 CNRS and 4 University of Orléans)
Number of Habilitations to Supervise Research: 14
Contractual staff: 18 (7 fixed-term researchers, 11 doctoral students)
Number of doctoral students: 11
Number of publications in peer-reviewed journals since 2018: 160
Building area: 1983 m²

Constraints and risks

X-ray diffraction experiments, or synchrotron radiation experiments, may be planned. (Radiation protection)

Experiments with organic solvants (DMSO, EtOH)

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

The research professions