Syndiotactic polystyrene (sPS) nanorods of 200 and 80 nm diameters were prepared by infiltrating porous anodic alumina oxide templates with polymer melt, and the crystallinity and orientation of various forms of sPS crystals in the nanorods were studied by FTIR spectroscopy and electron diffraction. For sPS crystallized from amorphous state at lower temperatures, R-form crystals were found in the nanorods with random orientation and the same degree of crystallinity as that in the bulk. However, for sPS crystallized from molten state at 260 °C, while no preferred orientation was found for the chains in the melt, the β-crystals formed in the nanorods oriented preferentially with the c-axis aligning perpendicular to the axial direction of the nanorod, and the degree of crystallinity was significantly lower than that in the bulk. The crystallinity decrease was more profound for nanorods of smaller diameter. These results were also supported by electron diffraction data and can be attributed to competition between nucleation and crystal growth in the nanotemplates.

Au-Ag bimetallic core-shell nanoparticles are synthesized in situ in polyelectrolyte multilayers via a sequential ion-exchange/reduction process. The Au-Ag bimetallic nanoparticles show a higher catalytic activity than Au and Ag monometallic ones for the reduction of 4-nitrophenol by NaBH(4) .

A simple method for the fabrication of tunable surfaces with wettability that can be manipulated rapidly and reversibly from superhydrophilicity to superhydrophobicity is reported. A polyelectrolyte multilayer (PEM) was deposited on a rough substrate, and via ion exchange of the counterion in the PEM, the water contact angle of the surface was switched between <5 degrees and 164 degrees. By controlling the ion-exchange kinetics, on the same surface, completely erasable, rewritable gradient wettability from superhydrophilicity to superhydrophobicity was conveniently achieved.

In this paper, compositions of nanodomains in a commercial high-impact polypropylene (HIPP) were investigated by an atomic force microscopy-infrared (AFM-IR) technique. An AFM-IR quantitative analysis method was established for the first time, which was then employed to analyze the polyethylene content in the nanoscopic domains of the rubber particles dispersed in the polypropylene matrix. It was found that the polyethylene content in the matrix was close to zero and was high in the rubbery intermediate layers, both as expected. However, the major component of the rigid cores of the rubber particles was found to be polypropylene rather than polyethylene, contrary to what was previously believed. The finding provides new insight into the complicated structure of HIPPs, and the AFM-IR quantitative method reported here offers a useful tool for assessing compositions of nanoscopic domains in complex polymeric systems.

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Syndiotactic polystyrene (sPS) nanorods with different diameters have been prepared by using anodic aluminum oxide templates, and the orientation of the sPS crystals in the nanorods has been investigated by FT-IR spectroscopy. It is found that the c axis of the β' crystals preferentially oriented perpendicular to the axis of the nanorod, and the degree of orientation is lower as the diameter of the nanorod decreases. This unexpected result is attributed to nuclei formed at the surface of the nanopores and their subsequent growth, in addition to the preferential growth compatible with the pore direction by the nuclei formed in the bulk film and in the nanorods.

Isotropic Raman spectra of poly(ethylene oxide) in aqueous solution and in the melt show differences in the skeletal stretching vibration bands near 800 cm-1 and in the disordered longitudinal acoustic mode feature in the 200−400 cm-1 region. These spectra may be simulated by superposing calculated spectra resulting from a series of normal coordinate calculations performed for an ensemble of conformers. The conformational distribution for poly(ethylene oxide) in the molten state appears to favor the tgg‘ conformer, which dominates the spectrum calculated to match closely the observed isotropic Raman spectrum. It appears that the experimental data suggest that the tgg‘ conformation is present by a greater amount than is predicted by previous simulation methods. On the same basis, it appears that the aqueous solution of poly(ethylene oxide) contains mostly tgt conformers. The results for poly(ethylene oxide) were supported by measurements and computations made using 1,2-dimethoxyethane as a model.

A novel method to tune surface wettability rapidly and reversibly has been developed by ion exchange of the counterions at the surface of a multilayer film assembled via electrostatic interaction.