Development and Stabilization of Hybrid Structure of Asphaltene and Graphene
Doctoral thesis, 2023
Petroleum and its derivatives, such as bitumen, are complex colloidal system. Their chemical behavior is influenced by various internal and external factors. Adding graphene derivatives to this system will only increase its complexity, thus it must be carefully considered to ensure successful integration. In this thesis, we examine the challenges of introducing graphene derivatives into bitumen and focus on three key questions: a) phase stability of graphene derivatives in bitumen, b) interaction between graphene and asphaltene aggregates, and c) an environmentally friendly and optimal method to modify graphene derivatives for improved bitumen properties. We use various characterization techniques to answer these questions and find that the best strategy for introducing graphene derivatives into bitumen is non-covalently functionalized graphene using the Molecular Wedging method (MW-graphene). The MW-graphene is compatible with asphaltene aggregates and stabilizes in bitumen through mutual interaction. The use of MW-graphene improves the mechanical stability of asphaltene aggregates in bitumen.
Non-covalent functionalization, functionalized graphene, asphaltene aggregates,
Author
Govin Induchoodan
Chalmers, Architecture and Civil Engineering, Building Technology
Bitumen has been used for thousands of years, with the earliest recorded use dating back to 4000 BC in Babylon, where it was used as mortar for building walls and towers. Today, bitumen plays a crucial role in our society as it is used to construct roads that allow us to travel worldwide. However, maintaining these roads poses significant environmental and economic challenges. In this thesis, we explore the potential of graphene, a wonder material, to enhance the properties and durability of bitumen. However, although its great potential, our studies on how graphene interacts with bitumen show some challenges of incorporating graphene into bitumen. By numerous experimental studies, we find that the surface properties of graphene have to be chemically modified for graphene to disperse and form a stable structure, i.e. to make graphene compatible with bitumen constituents and to avoid phase separation. We discuss how the surface of graphene should be modified and show that the stability of graphene in bitumen can be improved by such a method. We believe our proposed method can be used to enhance the mechanical properties of bitumen, and thereby also making roads more sustainable.
Subject Categories
Physical Chemistry
Other Engineering and Technologies not elsewhere specified
Other Chemistry Topics
Publisher
Chalmers
PJ Lecture room, Physics, Origo building
Opponent: Prof. Johan Sjøblom, Department of Chemistry, NTNU, Trodheim, Norway