Preparation and characterisation of porous poly(2,5benzimidazole) (ABPBI) membranes using surfactants as templates for polymer electrolyte membrane fuel cells

The first instance synthesis of porous poly(2,5benzimidazole) (ABPBI) membranes using sodium dodecyl sulfate (SDS) surfactants as templates is reported. The membranes were characterised by SEM, TGA, DSC and tensile tests. The tensile test results revealed that the porous ABPBI membranes exhibited unique mechanical properties compared with the original ABPBI membrane. Moreover, the porous ABPBI membranes showed high proton conductivity at 180 °C with high thermal stability when compared with the original ABPBI. A maximum conductivity of 2.23 × 10⁻² S cm⁻¹ of the porous ABPBI membranes was achieved at 180 °C in dry conditions, double the 1.1 × 10⁻² S cm⁻¹ obtained in the case of the ABPBI membrane. The porous ABPBI membrane demonstrated excellent properties on mechanical strengths, thermal stability and electrochemical performance when compared with those of the original ABPBI membrane, suggestive of a promising polymer electrolyte for fuel cells at high temperature.     

Maleic Acid Ozonation: Reactor Modeling and Rate Constants Determination

This work is related to ozone treatment of organic wastes, a gas-liquid reaction. A model has been developed that accounts for mass transfer from the gas to the liquid and for the kinetics of chemical reactions. The theoretical approach of the model firstly refers to the film theory enhanced by a new parameter, the depletion factor. This method allows the part of the reaction occurring within the film and that occurring within the bulk to be distinguished. In relation with the first part of the model, the second part allows the overall behavior of a gas-liquid reactor with time to be described. The model is validated by a set of experiments on maleic acid ozonation in a semi-batch reactor.     

Oxidative degradation of phthalic acid using TiO<Subscript>2</Subscript> photocatalyst

TiO₂ is one of the well-known multipurpose material for different applications such as gas sensors, catalysis, solar cells, optoelectronic devices, etc. TiO₂ is widely used as photocatalyst due to interest optical and electrical properties. In the present work, TiO₂ photocatalyst is used to study the degradation of phthalic acid under ultraviolet light illumination. The prepared TiO₂ photocatalyst is characterized by different characterization techniques such as X-ray diffraction, Raman spectroscopy, scanning electron microscopy. The end result shows that the degradation percentage of phthalic acid using TiO₂ photocatalyst has reached 41.93% after 320 min. under ultraviolet light illumination. The amount of mineralization of phthalic acid is confirmed by chemical oxygen demand measurements.     

Carbon Nanotubes Based Nafion Composite Membranes for Fuel Cell Applications

Carbon nanotubes (CNTs) containing Nafion composite membranes were prepared via melt‐blending at 250 °C. Using three different types of CNTs such as pure CNTs (pCNTs), oxidised CNTs (oCNTs) and amine functionalised CNTs (fCNTs); the effect of CNTs surface oxidation as well as functionalisation in composite membranes was investigated by focussing on three aspects: thermo‐mechanical stability, thermal degradation and proton conductivity. The oCNTs‐containing Nafion composite membrane exhibited concurrent improvement in most of the properties as compared to that of pure Nafion or other CNTs‐containing Nafion composite membranes.     

Si nanotubes and nanospheres with two-dimensional polycrystalline walls

We report on the characteristics of a new class of Si-based nanotubes and spherical nanoparticles synthesized by the dc-arc plasma method in a mixture of argon and hydrogen. These two nanostructures share common properties: they are hollow and possess very thin, highly polycrystalline and mainly oxidized walls. In particular, we get several hints indicating that their walls could constitute only one single Si oxidized layer. Moreover, we find that only the less oxidized nanotubes exhibit locally atomic ordered, snakeskin-like areas which possess a hexagonal arrangement which can be interpreted either as an sp(2) or sp(3) hybridized Si or Si-H layer. Their ability to not react with oxygen seems to suggest the presence of sp(2) configuration or the formation of silicon-hydrogen bonding.     

A Model-Integrated, Guideline-Driven, Clinical Decision-Support System

Using evidence-based guidelines to standardize the care of patients with complex medical problems is a difficult challenge. In acute care settings, such as intensive care units, the inherent problems of stabilizing and improving vital patient parameters is complicated by the division of responsibilities among different healthcare team members. Computerized support for implementing such guidelines has tremendous potential. The use of model-integrated techniques for specifying and implementing guidelines as coordinated asynchronous processes is a promising new methodology for providing advanced clinical decision support. Combined with visual dashboards, which show the status of the implemented guidelines, a new approach to computer-supported care is possible. The Vanderbilt Medical Center is applying these techniques to the management of sepsis.     

Grafting of Amine-Functionalized Multiwall Carbon Nanotubes with Free Acid Anhydride in Carboxylic Acid Modified Epoxy

The novel approach was developed for grafting of amine-functionalized multiwall carbon nanotubes with carboxylic acid, modified epoxy resin containing free acid anhydride group, which gives enhanced grafting. The amine-functionalized multiwall carbon nanotubes was dispersed in benzyl alcohol by sonication at 60°C and incorporated with modified epoxy. The amine functioned Multiwall carbon nanotubes were controlled loading of carboxylic acid, modified epoxy resin-grafted with amine-functionalized multiwalll carbon nanotube polymer composites. These were characterized by FTIR, SEM. TEM and NMR analysis. The improved mechanical properties observed for low amounts of MWCNT loading due to uniform dispersion.     

Cross-linked PEEK-WC proton exchange membrane for fuel cell

The low cost proton exchange membrane was prepared by cross-linking water soluble sulfonated-sulfinated poly(oxa-p-phenylene-3,3-phthalido-p-phenylene-oxa-p-phenylene-oxy-phenylene) (SsPEEK-WC). The prepared cross-linked membrane became insoluble in water, and exhibited high proton conductivity, 2.9 × 10⁻² S/cm at room temperature. The proton conductivity was comparable with that of Nafion^® 117 membrane (6.2 × 10⁻² S/cm). The methanol permeability of the cross-linked membrane was 1.6 × 10⁻⁷ cm²/s, much lower than that of Nafion^® 117 membrane.