Study o f the Properties o f Pure Oil and Oil/Water I nterface by Molecular Dynamic Simulation

Most of the techn ological an d biological processes occur at an interface [۱]. Unlike the bulk materials, the interface system is a noncentrosymmetric environm ent. The surface compos itions of liquids are different from the bulk due to unb alanced forces exerted on the molecules at the interface. Surface tension, among other properties, is the most i mportant property that can be measur ed accurately, and represents the thermodyn amic of the liquid surface. Surface entropy and surface energy can be determined very accurately from the measurement of temperature dependent surface ten sion. Accordingly density profile, surface thickness, and m olecular ori entation c an be studied. Surface tension is the fundamental parameter of surface chemistry that characterizes the free energy per unit area requ ired for formation of an int erface betw een two ph ases at constant temp erature, pressure, and chemical compos ition [۲,۳]. Parallel to the experimental a dvances, theoretical methods based on molecular dynam ics (MD) computer simulation have contributed significantly to understanding the microscopic nature of liquid interfaces and molecular interaction s at the level of atom or molecule [۴]. In this work, using molecular dynamics s imulation, we study th e properties of pure oil, water, and oil/water system including material which their behavior is important as the properties of real system are co ncerned in p rocesses su ch enhance d recovery (EOR) of c rude oil.

کلیدواژه ها:

Oil/water interface ، Accum ulation ، ۴-E thylpyridin e ، Surface tension ، Molecular dynamics simulation