Lemarchand Claire A, Greenfield Michael L, Hansen Jesper S
DNRF Centre "Glass and Time", IMFUFA, Department of Sciences, Roskilde University , Universitetsvej 1, Postbox 260, DK-4000 Roskilde, Denmark.
Laboratoire de Chimie Physique, Université Paris Sud, CNRS , Bâtiment 349, 91405 Orsay, Cedex, France.
J Phys Chem B. 2016 Jun 23;120(24):5470-80. doi: 10.1021/acs.jpcb.6b01451. Epub 2016 Jun 9.
Systems of Cooee bitumen and water up to 4% mass are studied by molecular dynamics simulations. The cohesive energy density of the system is shown to decrease with an increasing water content. This decrease is due mainly to an increase in the interaction energy which is not high enough to counterbalance the increase in volume due to the addition of water. It is not due to a decrease of interaction energy between the slightly polar asphaltene molecules. The water molecules tend to form a droplet in bitumen. The size and the distribution of sizes of the droplets are quantified, with multiple droplets being more stable at the highest temperature simulated. The droplet is mainly located close to the saturates molecules in bitumen. Finally, it is shown that the water dynamics is much slower in bitumen than in pure water because it is governed by the diffusion of the droplet and not of the single molecules.
