Cooee bitumen. II. Stability of linear asphaltene nanoaggregates.

نویسندگان

  • Claire A Lemarchand
  • Thomas B Schrøder
  • Jeppe C Dyre
  • Jesper S Hansen
چکیده

Asphaltene and smaller aromatic molecules tend to form linear nanoaggregates in bitumen. Over the years bitumen undergoes chemical aging and during this process, the size of the nanoaggregate increases. This increase is associated with an increase in viscosity and brittleness of the bitumen, eventually leading to road deterioration. This paper focuses on understanding the mechanisms behind nanoaggregate size and stability. We used molecular dynamics simulations to quantify the probability of having a nanoaggregate of a given size in the stationary regime. To model this complicated behavior, we chose first to consider the simple case where only asphaltene molecules are counted in a nanoaggregate. We used a master equation approach and a related statistical mechanics model. The linear asphaltene nanoaggregates behave as a rigid linear chain. The most complicated case where all aromatic molecules are counted in a nanoaggregate is then discussed. The linear aggregates where all aromatic molecules are counted seem to behave as a flexible linear chain.

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عنوان ژورنال:
  • The Journal of chemical physics

دوره 141 14  شماره 

صفحات  -

تاریخ انتشار 2014