Migration of low-molecular-weight(LMW)siloxanes from bulk to surface plays a key role in the hydrophobicity recovery mechanism for the polydimethylsiloxane(PDMS)coated insulators.Molecular dynamics simulations were carried out systematically to reveal the microscopic structures and the diffusion behavior of the LMW siloxanes.Chain length and weight dependence have been examined extensively.Mean-square displacement(MSD)analysis shows that the shorter chains prefer to be accumulated into the interfacial region where the LMW siloxanes exhibit much higher diffusion velocities.Orientations of the methyl groups near the PDMS interface were characterized using the order parameter(S).It was concluded that the interfacial width is around 1nm.