New insight into the melting behavior of nanoconfined semicrystalline polymers -The effect of an immobile interfacial layer at the substrate-

It is known that when semicrystalline polymer chains are confined on a nanometer length scale, the crystalline structures and dynamics differ from bulks, the so-called ``nanoconfinement effects.'' In this talk, we will report the anomalous melting behavior of nano-confined polyethylene spin cast films prepared on Si substrates by integrating various in-situ grazing incidence scattering techniques. We found that a very thin adsorbed layer at the weakly interactive substrate interface plays a crucial role in the melting behavior.