The crystallization of poly(ethylene-vinyl acetate) and linear low-density polyethylene (LLDPE) films spun-cast from the polymer/toluene solutions with as-cast thickness from 460 to 10 nm was studied. The lamellar thickness was measured using small-angle X-ray scattering (SAXS) and found to increase from 14 to 21 nm for films thinner than 100 nm. The morphology of LLDPE measured by scanning probe microscopy (SPM) showed an edge-on lamellae for the films thicker than 30 nm and flaton lamellae for the films thinner than 15 nm. A pseudo-"shish-kebab" tiny crystal structure was observed in between the larger lamellae. Crystallinity was confirmed using attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The shear modulation force microscopy technique (SMFM) was used to measure the melting point, T m, which was found to decrease for films thinner than 100 nm. The rate of decrease was a function of the annealing protocol, but in all cases for films approximately 20 nm thick Tm was depressed by 35-40 °C. This large value cannot be predicted from the classical Gibbs-Thomson relation, unless a change in the effective heat of fusion is assumed due to surface interactions.

The surface-induced ordering in thin films of asymmetric deuterated polystyrene (dPS)-poly(viny1pyridine) (PVP) diblock and triblock copolymers of comparable polymerization index and PVP volume fraction -0.25) was studied using transmission electron microscopy, atomic force microscopy, secondary ion massspectrometry, and neutron reflectivity. The morphology of both di-and triblock copolymer films was found to be cylindrical except for the layer adjacent to the silicon oxide surface, which due to the strong interaction of silica with PVP, was lamellar. The spacing between adjacent cylindrical layers was found to be consistent with mean field theory predictions. In the triblock copolymer films the cylindrical layers were oriented parallel to the silicon oxide surface, and no decay of the ordered structure was observed for at least 12 periods. If the total film thickness t' deviated from t = [ ( n + 0.711210 + 1821 A, where n is an integer, islands or holes formed at the vacuum interface. The height of the holes or islands reached its equilibrium value, 210 A, after annealing 24 hat 180 O C . In contrast, it was far more difficult to orient parallel to the silicon oxide surface the microphase-separated cylindrical domains in the diblock copolymer films. As a result no islands or holes were observed even after annealing for 5 days at 180 O C . We concluded that the difference in ordering behavior was due to the ability of the triblock copolymer to form an interconnected micelle network while the diblock copolymer formed domains that were free to move with respect to each other. This conclusion was further confirmed by diffusion measurements which showed that the PS homopolymer penetrated easily into the ordered diblock copolymer films and was excluded from the ordered triblock copolymer films.