Molecular weight dependence of mean square displacement in ultrathin polymer films as studied by inelastic neutron scattering.
In previous papers, we found that the mean square displacement [u(2)] in polystyrene thin films decreased with film thickness and discussed two possible causes for the decrease. One is the hard interface layer between the polymer thin film and the substrate, and the other is the spatial confinement effect of polymer chains. In order to disclose the cause of the decrease of [u(2)] with film thickness, we studied the molecular weight M(w) dependence of [u(2)] in polystyrene thin films. We found that [u(2)] was independent of M(w) within experimental error, concluding that the interface effect is a main reason for the decrease of [u(2)] with film thickness.
Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611-0011, Japan.
Rintaro
R
Inoue
Toshiji
T
Kanaya
Koji
K
Nishida
Itaru
I
Tsukushi
Kaoru
K
Shibata
D001703:Biophysics / Q000379:methods*; D008567:Membranes, Artificial; D015233:Models, Statistical; D008970:Molecular Weight; D009502:Neutrons; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D012542:Scattering, Radiation; D013499:Surface Properties; D013696:Temperature
D008567:Membranes, Artificial; D011108:Polymers; D011137:Polystyrenes