Tomorrow's seminar

[Cond.Matt. & Stat.Mech.Section]

Joint ICTP/Democritos    INFORMAL SEMINAR on Chemical Physics



Thursday, 25 February   -    4:30 p.m.





Oppenheimer Meeting Room -   ICTP Main Building  (second floor)



  Yunfeng LIANG    ( Kyoto University )



"Self-accumulation of aromatics at oil-water interface - A molecular  
dynamics study"



Abstract



The interface between two immiscible liquids is a noncentrosymmetric  
environment about which we know very little in comparison with other  
condensed-matter materials and their surfaces. Experimental probes of  
liquid-liquid interfaces are limited because of the relatively small  
size---typically only a few molecular diameters wide and the buried  
nature of the interface. Here we have investigated the water and a  
light-oil model interface. It was found that aromatics concentrate on  
the interfacial regions, whereas the other hydrocarbons of oil are  
uniformly distributed along the oil slab. We attributed the self- 
accumulation of the aromatics to the favorable Gibbs free energy due  
to the lower interfacial tension between the aromatics-water  
interfaces. Further, we suggest that the “weak hydrogen bonding”  
between the aromatic rings and the proton of the water are the cause  
of the lower interfacial tension among others.

*In collaboration with Makoto Kunieda, Kennichi Nakaoka, Caetano R.  
Miranda,Akira Ueda and Toshifumi Matsuoka.