A kinetic analysis methodology to elucidate the roles of metal, support and solvent for the hydrogenation of 4-phenyl-2-butanone over Pt/TiO2

The rate and, more importantly, selectivity (ketone vs aromatic ring) of the hydrogenation of 4-phenyl-2-butanone over a Pt/TiO2 catalyst have been shown to vary with solvent. In this study, a fundamental kinetic model for this multi-phase reaction has been developed incorporating statistical analysis methods to strengthen the foundations of mechanistically sound kinetic models. A 2-site model was determined to be most appropriate, describing aromatic hydrogenation (postulated to be over a platinum site) and ketone hydrogenation (postulated to be at the platinum–titania interface). Solvent choice has little impact on the ketone hydrogenation rate constant but strongly impacts aromatic hydrogenation due to solvent-catalyst interaction. Reaction selectivity is also correlated to a fitted product adsorption constant parameter. The kinetic analysis method shown has demonstrated the role of solvents in influencing reactant adsorption and reaction selectivity.

A novel scalable manufacturing process for the production of hydrogel-forming microneedle arrays

A novel manufacturing process for fabricating microneedle arrays (MN) has been designed and evaluated. The prototype is able to successfully produce 14 × 14 MN arrays and is easily capable of scale-up, enabling the transition from laboratory to industry and subsequent commercialisation. The method requires the custom design of metal MN master templates to produce silicone MN moulds using an injection moulding process. The MN arrays produced using this novel method was compared with centrifugation, the traditional method of producing aqueous hydrogel-forming MN arrays. The results proved that there was negligible difference between either methods, with each producing MN arrays with comparable quality. Both types of MN arrays can be successfully inserted in a skin simulant. In both cases the insertion depth was approximately 60% of the needle length and the height reduction after insertion was in both cases approximately 3%.

Rapid, simple method for determining the porosity of mesoporous TiO2 films using a quartz crystal microbalance (QCM)

Two different mesoporous films of TiO2 were coated onto a QCM disc and fired at 450o C for 30 min. The first film was derived from a sol-gel paste that was popular in the early days of dye-sensitised solar cell, i.e. dssc, research, a TiO2(sg) film. The other was a commercial colloidal paste used to make examples of the current dssc cell; a TiO2(ds) film. A QCM was used to determine the mass of the TiO2 film deposited on each disc and the increase in the mass of the film when immersed in water/glycerol solutions with wt% values spanning the range 0-70%. The results of this work reveal that with both TiO2 mesoporous films the solution fills the film's pores and acts as a rigid mass, thereby allowing the porosity of each film to be calculated as: 59.1% and 71.6% for the TiO2(sg) and TiO2(ds) films, respectively. These results, coupled with surface area data, allowed the pore radii of the two films to be calculated as: 9.6 and 17.8 nm, respectively. This method is then simplified further, to just a few frequency measurements in water and only air to reveal the same porosity values. The value of the latter ‘one point’ method for making porosity measurements is discussed briefly.

Facile Synthesis of Anatase TiO2 Quantum-Dot/Graphene-Nanosheet Composites with Enhanced Electrochemical Performance for Lithium-Ion Batteries

A facile method to synthesize well-dispersed TiO₂ quantum dots on graphene nanosheets (TiO₂-QDs/GNs) in a water-in-oil (W/O) emulsion system is reported. The TiO₂/graphene composites display high performance as an anode material for lithium-ion batteries (LIBs), such as having high reversible lithium storage capacity, high Coulombic efficiency, excellent cycling stability, and high rate capability. The excellent electrochemical performance and special structure of the composites thus offer a way to prepare novel graphene-based electrode materials for high-energy-density and high-power LIBs.