A density functional study onthe inter-molecular interaction of isooctane and short ether chain

Inter-molecular interaction between isooctane and short ether chain of polyurethane molecule is studied using density functional theory based on first-principles.The results show that physical adsorption can be formed on the top of every O atom.Onto the O atom labeled 3,adsorption heat is-1.6 KJ/mol,with a 0.2637 nm adsorption distance.While onto the O atom labeled 6,adsorption heat is-1.5 KJ/mol,with a 0.2710 nm adsorption distance.Inter-molecular interaction is van der Waals force.The electric dipole-dipole interaction is zero,the induction force is relatively weak,and the dispersion force is relatively strong.After adsorption,absorption peak of isooctane at 3044.39 cm-1 disappears.Adsorption plays a strong inhibitory effect on asymmetric stretching vibration of H-C-H at the site of the C atom labeled 5.