Journal of Nano Research Vol. 7

Abstract: An experimental investigation into the evaporation of sessile nanofluid droplets is reported in this paper. The effect of nano-particle addition on the evaporative behaviour is studied using ethanol and Titanium Oxide nano-particles. The results show that a distinct ‘stick-slip’ pinning behaviour is observed when nano-particles are added to the base liquid. Increasing the nano-particle concentration was found to enhance the ‘stick-slip’ behaviour. This behaviour is attributed to the effects of evaporatively driven particle accumulation near the contact line. This in turn leads to an increase in localised viscosity, and an enhancement of contact line pinning.

Abstract: . The Pd0.97Zr0.03, Pd0.97Ce0.03 and Pd0.97Ce0.015 Zr0.015 alloys were produced and studied in the present paper with respect to the hydrogen diffusivity and solubility. These alloys in the conditions as melted and cold worked, heat treated and also internally oxidized were submitted to hydrogen permeation tests. It was observed that the hydrogen diffusivity is strongly affected by the internal oxidation due to nano-oxides formation in the samples. On the other hand, the hydrogen solubility increases with introduction of defects as dislocations and vacancies introduced by cold working as well as the precipitates due to the internal oxidation. The nature, size and distribution of the precipitates and their influence on the hydrogen permeation parameters are discussed in this work.

Abstract: Nanostructured manganese dioxide films were obtained by electrosynthesis using 0.02-0.15 M KMnO4 solutions. The diffusion-controlled deposition mechanism is based on the reduction of anionic MnO4- at the cathode surface. The method allowed the fabrication of porous films for application in electrochemical supercapacitors (ES). It was shown that film porosity is beneficial for the charge transfer during deposition, crack prevention in thick films and electrolyte diffusion in fabricated ES electrodes. Porous nanostructured films showed good capacitive behavior in the 0.1 M Na2SO4 electrolyte in a voltage window of 1V. The specific capacitance decreased with increasing scan rate due to the diffusion limitation in the porous manganese dioxide electrodes