CIFRE PhD candidate (M/F) – Microfluidic rheology of natural latex"

Job Description

Thesis Subject

Natural latex from *Hevea brasiliensis* is a complex colloidal suspension whose rheological behaviour directly governs both plantation productivity and the efficiency of industrial rubber processing. Despite its major economic importance, the fundamental understanding of latex rheology and interfacial properties remains incomplete. The colloidal stability of this suspension evolves over time and is strongly dependent on pH, ionic strength, and the presence of stabilizing agents such as ammonia.

This PhD project aims to quantitatively characterize the viscoelastic and interfacial properties of natural latex using microfluidic approaches, from laboratory-scale investigations through to on-site deployment. The work is organized along three axes: (i) laboratory characterization of the dynamic properties of ammonia-stabilized latex, including dynamic interfacial tension and viscoelastic moduli, as well as the evolution of these properties upon destabilization by pH reduction; (ii) development of tailored microfluidic methodologies — sinusoidal channel geometries for oscillatory deformation, droplet relaxation experiments for interfacial tension measurements — with clogging controlled by dispersing latex into oil phases of tunable viscosity; (iii) design and validation of a portable microfluidic device based on glass chips fabricated by femtosecond laser-assisted wet etching (FLAE/FemtoPrint), enabling real-time analysis at tapping sites in collaboration with SAPH (Société Africaine de Plantation d'Hévéas, Toupah, Côte d'Ivoire).

This project is funded through a CIFRE industrial agreement with Michelin, whose strategic interest in controlling the quality and variability of natural latex is direct. It is conducted jointly by the CPCV laboratory (UMR 8228, ENS Paris / Sorbonne Université / CNRS, Institut Pierre-Gilles de Gennes) and the C3M laboratory (ESPCI Paris).

Your Work Environment

The PhD will be carried out under a joint supervision arrangement between two complementary Paris-based laboratories. The primary host unit is CPCV (UMR 8228, ENS Paris – Sorbonne Université – CNRS). The group of J. Fattaccioli develops interdisciplinary approaches at the interface between micro/nanotechnologies, physics, chemistry and biology, with a strong focus on materials science and biophysics. The second laboratory is C3M (ESPCI Paris, 10 rue Vauquelin, 75005 Paris), where the group of S. Aimé specializes in physicochemical and rheological measurements of complex fluids and interfacial characterization methods. Both supervising teams are members of the Institut Pierre-Gilles de Gennes (6 rue Jean Calvin, 75005 Paris), a leading centre in microfluidics and its applications. The geographical proximity of the two units will facilitate regular exchanges and effective day-to-day co-supervision throughout the doctoral program. Supervision is distributed as follows: 40% J. Fattaccioli (ENS Paris / IPGG), 40% S. Aimé (ESPCI / C3M), and 20% Michelin, within the framework of a CIFRE industrial agreement.

Constraints and risks

Stays at the Michelin site in Clermont-Ferrand are expected for characterization experiments. Field visits to the SAPH plantation in Côte d'Ivoire may also be required during the sensor deployment phase.

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

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