Swift heavy ion (SHI) irradiation effects on ionic conduction in the PVA-H3PO4 polymer electrolyte films have been investigated due to its variety of applications in electrochemical devices. Polymer electrolytes films are irradiated with 50 MeV Li3+ ions having five different fluences viz. 5x1010, 1011, 5x1011, 1012 and 5x1012 ions/cm2. It is observed that irradiation of the polymer electrolyte films with swift heavy ions shows enhancement in conductivity at lower fluences and decrease in conductivity at higher fluences. It appears that below the critical fluence, swift heavy ion irradiation increases the diffusivity of Li+ ion in the polymer electrolyte which provides larger pathways for ionic transport throughout the system. The temperature dependence of electrical conductivity variation has been used to compute the activation energy involved in conduction process.

In this study, we use novel thermal deposition techniques to synthesize films of poly(vinlyidene fluoride), or PVDF, containing nanoparticles of the ceramic titanium dioxide (TiO2). This ferroelectric polymer has shown promise as a capacitor dielectric material, and possible enhanced electrical properties when combined with ceramic nanoparticles. Characterization of these composite films has been performed including chemical structure and microstructure using SFM, XPS, and EDS techniques. Measurements of film parameters such as dielectric constant and breakdown voltage have also been performed, and the dispersion of the ceramic particles within the films has been characterized

Proton dissociation and transfer are investigated with ab initio molecular dynamics (AIMD) simulations of carbon nanotubes (CNT) functionalized with perfluorosulfonic acid (-CF2SO3H) groups with 3 H2O/–SO3H. The CNT systems were constructed both with and without fluorine atoms covalently bound to the inner walls to determine the effects of the presence of fluorine on proton dissociation, hydration, and stabilization. The results of the AIMD trajectories show that decreasing the separation of sulfonic acid groups increases the propensity for proton dissociation. The simulations also revealed that the dissociated proton was preferentially stabilized as a hydrated hydronium (H3O+) cation in the CNT systems with the fluorine. This feature is attributed to the fluorine atoms providing a localized negative charge that promotes hydrogen bonding of the water molecules coordinated to the central hydronium ion. The hydrated H3O+ ion differed from a traditional Eigen cation (H9O4+) as it donated hydrogen bonds to sulfonate oxygen atoms, as well as water molecules.

Ionic transport in electrolyte membranes limits performance in both battery and fuel cell membranes. The problems have been well known for years, sometimes decades, but empirical progress in solving them has been slow. The focus here is on studies to improve understanding of transport mechanisms, which despite extensive study, remain in dispute in several important cases. For lithium transport in polymer membranes, I will review simulation work by ourselves and others, and contend that the original qualitative picture by Ratner and coworkers is confirmed in many respects by recent work. It means, however, that the fundamental difficulty is that the transport is controlled by torsion forces in the hydrocarbon backbone which are extremely difficult to manipulate experimentally. Turning to possibly promising additives, I review recent work on proton and lithium transport in ionic liquids, on which promising experimental results have been reported. The data, both from simulation and experiment, indicate nontrivial collective effects in the transport properties which need to be sorted out to control these systems. In the case of proton transport, we report results suggesting that high mobilities occur in acid-ionic mixtures with a common anion in mixtures near phase separation.

Significant conductive polymer-based composites consisting of immiscible semi-crystalline polymers PP and PVDF, at different volume ratios loaded with a certain concentration of CB were prepared by blending and sequent hot-pressing technology. The distributing status of CB in the polymers was evaluated through the micrographs of the composite. The percolation threshold of this kind of composite is much lower than those of the individual polymers. Even more, the composite at 1/1 volume ratio of PP and PVDF displays the best conductivity among different ratios at a certain concentration of CB, and it displays an outstanding PTC effect more than five orders of magnitude, and synchronously an enhanced dielectric permittivity about 24.9 at 100 Hz. These inimitable properties may owe to the formation of PP/PVDF co-continuous phases and a double-percolation effect in the composite. The novel polymer-based composite with ultra-low percolation threshold, enhanced PTC effect, as well as the significant dielectric permittivity is promising a potential application.

Surface scratches in a series of controlled epoxy networks (CEN) were measured using a combination of instrumented indentation protocols and laser scanning confocal microscopy. Identical epoxy chemistry with increasing molecular weight between crosslinks provided different viscoelastic relaxation behaviors with the same modulus at ambient conditions. The glass transition temperatures (Tg)ranged between 70°C and 117°C. The high Tg CEN exhibited the lowest penetration depth and the highest elastic recovery. The results are analyzed with respect to the macroscale bulk properties and underlying molecular architecture of the CEN materials.

Perfluorosulfonic acid membrane (Nafion®-117) was first surface modified with atmospheric pressure UV photo-oxidation or low-pressure vacuum UV photo-oxidation downstream from an Ar microwave plasma, and then graft polymerized with acrylic acid. X-ray photoelectron spectroscopy (XPS) was used to analyze the modified Nafion surface and poly(acrylic acid) grafted to the modified surface.

Interconnected microcellular polymeric monoliths having unexpected high mechanical strength have been prepared using the High Internal Phase Emulsion methodology. Direct concentrated emulsions of aqueous 5-amino-1-vinyl-[1,2,3,4]tetrazole mixed with low molar (5 %) fractions of N,N'-methylenebisacrylamide (MBA) as cross-linking agent were prepared using dodecane as dispersed phase and a mixture of hydrophilic surfactants. “Reverse” polyHIPE materials were obtained after radical copolymerization, solvent extraction and drying. Their morphology, chemical composition and physico-chemical behaviour are discussed.

A small-angle neutron scattering (SANS) investigation of saturated aqueous proton exchange membranes is presented. Our membranes were synthesized by radiation-induced grafting of poly(ethylene-alt-tetrafluoroethylene) (ETFE) with styrene in the presence of crosslinker (divinylbenzene, DVB) and the polystyrene was sulfonated subsequently. The contrast variation method was used to understand the relationship between morphology, water uptake, and proton conductivity. We find that the membranes are separated into two phases, mostly following the morphology already defined in the semi-crystalline ETFE base film. The amorphous phase hosts the water and swells upon hydration, swelling being inversely proportional to the degree of crosslinking. Proton conductivity and volumetric fraction of water are related by a power law, indicating a percolated and most likely random network of finely dispersed aqueous pores in the hydrophilic domains.