New sulfonated pyrrole and pyrrole 3-carboxylic acid copolymers membranes via track-etched templates

New copolymers of polypyrrole and poly(3-carboxylic acid pyrrole) have been synthesized via diaphragmatic method using track-etched polycarbonate matrix. The carboxylic acid presence permits to introduce new functionalities such as sulfonate groups. The resulted copolymer membranes with tubules microstructure has been characterized by Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, Time-of-flight Secondary Ion mass Spectrometry and FTIR. By SEM it was observed that ion-track trajectories present characteristic of crossing. FTIR, XPS and ToF-SIMS proved the attachment of the Taurin molecule to the membrane. The thermal stability study shows that the polypyrrole copolymer membranes have an exceptional stability; decomposition was not observed up to 900°C

New sulfonated pyrrole and pyrrole 3-carboxylic acid copolymer membranes via track-etched templates

International audienceNew copolymers of polypyrrole and poly(3-carboxylic acid pyrrole) have been synthesized via a diaphragmatic method using a track-etched polycarbonate matrix. The presence of carboxylic acid substituents enables the introduction of new functionalities such as sulfonate groups. The resulting copolymer membranes with tubules microstructure have been characterized through scanning electron microscopy, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry and FT-IR. By SEM, it was observed that ion-track trajectories can cross. XPS, ToF-SIMS and FT-IR spec-troscopy showed that it was possible to attach other molecules to the membrane. The polypyrrole copolymer membranes have exceptional thermal stabilities, with decomposition observed at 900 °C

Chemical damage in poly(phenylene sulphide) from fast ions: Dependence on the primary-ion stopping power

Thin poly(phenylene sulphide) foils were bombarded with fast atomic ions (4He, 12C, 16O, 32S, 79Br, 127I) in the energy range between 2.5 to 78 MeV. In order to maintain the same ion track size for all impacting ions, their initial velocity was kept constant at 1.1 cm/ns. Under these conditions the deposited energy density in a single ion track changes as a result of the varying stopping power (dE/dx) of the projectiles in the material. Fourier transform infrared spectroscopy and UV-visible spectroscopy were used to characterize the irradiated targets. Damage cross sections (σ) for different chemical bonds, such as C-S and ring C-C bonds, are extracted from the IR data. For all analyzed IR bands, the values of σ scale roughly with the square of dE/dx (energy density in a single ion track). The absorption of the irradiated samples in the visible and UV region increases as a function of fluence. The rate of increase of absorption at a particular wavelength scales also as (dE/dx)n with n~2. The observed nonlinear dependence of the damage cross sections on the deposited energy density is considered in the light of two models: a statistical model based on the fluctuations of the energy deposited by the primary ions (hit theory) and an activation (thermal spike) model. It is found that the damage cross section is not determined directly by the initial deposited energy density distribution. The best agreement between experiment and theory is obtained when transport of the deposited energy occurs