Summary: Electrically conducting polypyrrole‐poly(ethylene oxide) (PPy‐PEO) composite nanofibers are fabricated via a two‐step process. First, FeCl3‐containing PEO nanofibers are produced by electrospinning. Second, the PEO‐FeCl3 electrospun fibers are exposed to pyrrole vapor for the synthesis of polypyrrole. The vapor phase polymerization occurs through the diffusion of pyrrole monomer into the nanofibers. The collected non‐woven fiber mat is composed of 96 ± 30 nm diameter PPy‐PEO nanofibers. FT‐IR, XPS, and conductivity measurements confirm polypyrrole synthesis in the nanofiber.An SEM image of the PPy‐PEO composite nanofibers. The scale bar in the image is 500 nm.imageAn SEM image of the PPy‐PEO composite nanofibers. The scale bar in the image is 500 nm.

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Maskless fabrication of periodic patterns of a conjugated polymer is achieved by regioselective condensation of 2,5-diiodothiophene on chemically patterned substrate surfaces followed by in situ photochemical conversion of the condensed molecules into oligothiophenes and polythiophenes. This approach utilizes preferential aggregation of monomer molecules on the substrate that is periodically patterned with wetting regions surrounded by nonwetting regions. Since the monomer molecules are confined in the specific regions on the substrate, the polymer patterns can be produced at those locations by blanket irradiation of UV light without mask. The effects of wettability contrast and the dimension of periodicity are important factors for good pattern recognition during the monomer deposition.

We describe the use of hard etching methods to create nanodimensional channels and their use as templates for the formation of polymer filament arrays with precise dimensional and orientational control in a single integrated step. The procedure is general as illustrated by the radical, coordination, and photochemical polymerizations that were performed in these nanochannels. The nanochannel templates (20 nm high, 20-200 nm wide, and 100 mum long) were fabricated by the combined use of electron-beam lithography and a sacrificial metal line etching technique. Radical polymerization of acrylates, metal-catalyzed polymerization of norbornene, and photochemical polymerization of 1,4-diiodothiophene were carried out in these nanochannels. The polymers grown follow the dimensions and orientation of the channels, and the polymer filaments can be released without breaking. The approach opens up the possibility of just-in-place manufacturing and processing of patterns and devices from nanostructured polymers using well-established polymer chemistry.

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In contrast to the traditional thermally-activated Ullmann coupling, a photo-activated Ullmann coupling for facile synthesis of oligothiophene and polythiophene films and micropatterns is reported.

Monte Carlo simulations of polymer chains on a discretized lattice, where each atom occupies multiple lattice sites, have been shown to provide accuracies comparable with off-lattice simulations in one-tenth the computation time. For polyatomic molecules, the main requirement for the level of discretization required is set by the intramolecular geometry of the molecule. The current work provides a method to determine this level of discretization without running full off lattice simulations for comparison of results. Chains are generated off-lattice, placed on lattices of various discretizations, and the resulting errors are analyzed. We apply the method to three cases, united atom polyethylene, united atom polypropylene, and atomistic polyethylene. The atomic diameter to lattice size ratios required are 12 for the united atom cases, and 17 for atomistic polyethylene.

Back Cover: PPy-PEO composite nanofibers with an average size 96 AE 30 nm are synthesized by vapor phase polymerization of pyrrole over electrospun PEO-FeCl 3 fibers. The pyrrole monomer vapor diffuses into the nanofibers and is oxidatively polymerized by FeCl 3 into polypyrrole. Further details can be found in the Communication by S. Nair, S. Natarajan, and S. H. Kim* on page 1599.