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Microtubules are an interesting type of microstructure that resemble miniature drinking straws. Such tubular microstructures are found in nature. In addition, we and others have been investigating strategies for making synthetic analogs. We are especially interested in the idea of making metal microtubules. Four procedures for preparing metal microtubules are described in this paper. The general approach, called template-synthesis, entails using the pores in a microporous membrane as templates for forming the tubules. Microporous anodic aluminum oxide membranes and nuclear track-etch membranes are used as the template membranes. Gold and silver microtubules are made with outer diameters as small as 200 nm. These microstructures are characterized by scanning electron microscopy.

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Sulfonated fluorochlorocarbon ionomer films were prepared by radio frequency plasma polymerization of trifluoroehloroethylene (TFCE) and trifluoromethane sulfonic acid (TFMSA). The TFMSA was introduced into the plasma chamber by bubbling a carrier gas through a vessel containing the neat acid. We show that the sulfonate content of the film prepared can be controlled by varying the temperature of the TFMSA-containing vessel. We also show that films with high sulfonate contents can be prepared by using TFCE as the carrier gas for the TFMSA and then allowing this gas mixture to sustain the plasma. This may be contrasted to previous experiments of this type, where Ar was used to sustain the plasma and as the carrier gas. To our knowledge, this approach (i.e., of using the reactant gases to support the plasma) has never been used in the synthesis of plasma-polymerized films. Finally, we have measured the ionic conduetivities of the plasmapolymerized films. The films prepared from the TFCE plasma are an order of magnitude more conductive than the films prepared from the Ar plasma.Perfluorosulfonate ionomers, such as Du Pont's Nation TM and the Dow Chemical ionomers, are important polymeric materials that have generated considerable scientific and technological interest. 1-17 These polymers contain a fluorocarbon main chain and side groups that are ionizable. Usually, the ionizable group is a su]fonic acid. The fluorocarbon main chain is thermally and chemically stable; the sulfonate sites render membranes of these polymers cationically conductive. Such membranes have been used in chloralkali cells, 14 water electrolyzers, 1~ batteries, 16 and as surface-derivatizing agents for chemically modified electrodes. I~2'~'17 Currently, only one of these polymers (Nation 117) .is commercially available. Further, this material is at present rather expensive. Hence, there are good reasons to explore alternative methods for preparing ionomers that may be chemically similar to the perfluorosulfonate ionomers.Ogumi and his co-workers have explored the possibility of using plasma polymerization to prepare ionomer films of this general type. 18' 19 They have shown that thin ionomer films can be plasma polymerized using TFCE and TFMSA as the monomers. 18' 19 However, the ionic conductivities of their plasma-polymerized films were substantially lower than that of Nation i 17.2~ Obviously, conductivity is an important issue since most applications of polymers of this type are in electrochemistry. We have been exploring alternative methods for plasma polymerization of ionomer films from these monomers. We have developed procedures that provide films with higher sulfonation levels, and higher conductivities, than the previously described 18' 19 plasmapolymerization methods. We describe these new polymerization methods, and the polymer films obtained, here. ExperimentalMaterials and reagents.--TFMSA (3M, FC-24), TFCE (Matheson, Halocarbon 1113), and benzene (Mallinkrodt * Electrochemical Society Student Member.

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