Study of the colloidal system of bitumens and its influence on the physico-chemistry of bitumen emulsions

Bitumen emulsion techniques represent a major solution for decarbonizing road construction and lead to a significant reduction in the carbon footprint of roadworks. Bitumen, a complex mixture of hydrocarbons obtained by distilling crude oil, is widely used as a binder in road construction due to its numerous qualities, including ease of use, viscoelastic and adhesive properties, recyclability, water impermeability, and chemical resistance. Bitumen is used in the formulation of various road products, such as hot mix asphalt and cold mix asphalt techniques, where it acts as the binder that ensures the cohesion of the entire material. However, the relationship between the composition of bitumens and the physicochemical properties of bitumen emulsions has been little investigated. From a physicochemical perspective, bitumen can be considered a colloidal system in which its two constituent families, asphaltenes (dispersed phase) and maltenes (continuous phase), play a determining role. Asphaltenes are high molecular weight polyaromatic molecular structures containing numerous heteroatoms. They constitute the heaviest and most polar compounds in bitumen. These characteristics make asphaltenes a key element for better understanding the behavior and variability of bitumens. This polarity plays an important role at the bitumen/water interfaces in bitumen emulsions for so-called "cold" technologies. The objective of this thesis, conducted jointly by Vinci Construction and IFPEN, is to improve the understanding of the link between the colloidal system of bitumen and the properties of emulsions in order to establish the structure-property relationship between bitumen composition and the properties of finished products, and to optimize emulsion formulations according to the origin of the bitumen.

Keywords: Emulsions, bitumen, interfaces, interfacial rheology

• Academic supervisor    Dr Christine DALMAZZONE, christine.dalmazzone@ifpen.fr, IFPEN, ORCID : 0000-0002-2567-9385
• Doctoral School    ED388, Sorbonne Université
• PhD location    Centre de Recherche Vinci Construction, Mérignac, France and IFPEN, Rueil-Malmaison, France
• Duration and start date    3 years, starting in the fourth quarter 2026 (Novembre 2)
• Employer    Vinci Construction (CIFRE contract)
• Academic requirements    University Master degree in Physical Sciences, Chemical Sciences, Materials Engineering   
• Language requirements    English level B2 (CEFR)    
• Other requirements    Physical Chemistry of Materials, Soft Matter

To apply, please send your cover letter and CV to the IFPEN supervisor indicated here below.