A unified model for temperature dependent electrical conduction in polymer electrolytes

The observed temperature dependence of electrical conduction in polymer electrolytes is usually fitted with two separated equations: an Arrhenius equation at low temperatures and Vogel-Tamman-Fulcher (VTF) at high temperatures. We report here a derivation of a single equation to explain the variation of electrical conduction in polymer electrolytes at all temperature ranges. Our single equation is in agreement with the experimental dataComment: 13 pages, 2 figure

Zinc Oxide Nanoparticles Prepared By a Simple Heating: Effect of Polymer Addition and Polymer Absence on the Morphology

Zinc oxide (ZnO) nanoparticles were prepared by a simple heating of precursors in a furnace at temperatures of below 1000°C in an air environment. If zinc nitrate was used as precursor, polymer (e.g., polyethylene glycol (PEG)) must be added into the precursor to produce ZnO in nanometer size. The absence of polymer led to the presence of several micrometer-sized flakes. In addition, the heating temperatures must be higher than 500°C to completely decompose the organic material in final product. However, if zinc acetate was used as precursor, nanometer-sized ZnO having a high crystallinity can be obtained even when the polymer was absent. Interestingly, we also found that heating at low temperatures (e.g. 400°C) resulted in ZnO nanorods with an elongation ratio of around 5. This method is rapid, economically efficient, and readily scalable for industrial applications

Luminescent Polymer Electrolyte Composites Using Silica Coated-Y2O3:Eu as Fillers

Luminescent polymer electrolyte composites composed of silica coated Y2O3:Eu in polyethylene glycol (PEG) matrix has been produced by initially synthesizing silica coated Y2O3:Eu and mixing with polyethylene glycol in a lithium salt solution. High luminescence intensity at round 600 nm contributed by electron transitions in Eu3+ (5D0 → 7F0, 5D0 → 7F1, and 5D0 → 7F3 transitions) were observed. The measured electrical conductivity was comparable to that reported for polymer electrolyte composites prepared using passive fillers (non luminescent). This approach is therefore promising for production of high intensity luminescent polymer electrolyte composites for use in development of hybrid battery/display

Luminescent Polymer Electrolyte Composites Using Silica Coated-Y2O3:Eu as Fillers

Luminescent polymer electrolyte composites composed of silica coated Y2O3:Eu in polyethylene glycol (PEG) matrix has been produced by initially synthesizing silica coated Y2O3:Eu and mixing with polyethylene glycol in a lithium salt solution. High luminescence intensity at round 600 nm contributed by electron transitions in Eu3+ (5D0 → 7F0, 5D0 → 7F1, and 5D0 → 7F3 transitions) were observed. The measured electrical conductivity was comparable to that reported for polymer electrolyte composites prepared using passive fillers (non luminescent). This approach is therefore promising for production of high intensity luminescent polymer electrolyte composites for use in development of hybrid battery/display

Zinc Oxide Nanoparticles Prepared by a Simple Heating: Effect of Polymer Addition and Polymer Absence on the Morphology

Zinc oxide (ZnO) nanoparticles were prepared by a simple heating of precursors in a furnace at temperatures of below 1000°C in an air environment. If zinc nitrate was used as precursor, polymer (e.g., polyethylene glycol (PEG)) must be added into the precursor to produce ZnO in nanometer size. The absence of polymer led to the presence of several micrometer-sized flakes. In addition, the heating temperatures must be higher than 500°C to completely decompose the organic material in final product. However, if zinc acetate was used as precursor, nanometer-sized ZnO having a high crystallinity can be obtained even when the polymer was absent. Interestingly, we also found that heating at low temperatures (e.g. 400°C) resulted in ZnO nanorods with an elongation ratio of around 5. This method is rapid, economically efficient, and readily scalable for industrial applications

Preparation of size-controlled tungsten oxide nanoparticles and evaluation of their adsorption performance

The present study investigated the effects of particle size on the adsorption performance of tungsten oxide nanoparticles. Nanoparticles 18–73 nm in diameter were prepared by evaporation of bulk tungsten oxide particles using a flame spray process. Annealing plasma-made tungsten oxide nanoparticles produced particles with diameters of 7–19 nm. The mechanismof nanoparticle formation for each synthetic route was examined. The low-cost, solid-fed flame process readily produced highly crystalline tungsten oxide nanoparticles with controllable size and a remarkably high adsorption capability. These nanoparticles are comparable to those prepared using the more expensive plasma process

Simple Fabrication of Carbon Nanotubes From Ethanol Using an Ultrasonic Spray Pyrolysis

Carbon nanotubes of diameter (20–100 nm) are synthesized by pyrolyzing a sprayed solution of Fe(C5H5)2 and C2H5OH in an Ar atmosphere at relatively low temperatures (around 800 oC). The tubular structures consist of highly crystalline nested graphene cylinders (<200 concentric tubes). Tube diameter can be controlled by varying the furnace temperature, carrier gas flow rate and the Fe:C ratio within the precursor solution. This low cost route for the synthesis of carbon nanotubes is advantageous due the low pyrolytic temperature, safety, processable in atmospheric pressure, and scalable

Synthesis of uniformly porous NiO/ZrO2 particles

Porous NiO–ZrO2 particles were successfully synthesized using a spray-drying method with polystyrene latex (PSL: 400 nm) as a template and starting materials that included NiO powder (7 nm) and ZrO2 sol (1.2 nm). Porous particles with an average diameter of 4.5 µm and nearly spherical, narrow pores with an average size of ∼300 nm were obtained from the precursor at a pH of 3.7. The Brunauer, Emmett and Teller (BET) surface area of the prepared particles was relatively high—about 27 m2/g. When the solution pH was increased to 9.7, the particle morphology became completely spherical, indicating that the morphology of prepared particles can be controlled by adjusting the pH. Calcinations at 900 and 1200 °C were carried out to estimate the thermal stability of the prepared particles, which had shrinkage of less than 36%. The existence of these pores means that various applications, such as electrodes and catalysts, will be possible for the prepared particles

Particle dynamics simulation of nanoparticle formation in a flame reactor using a polydispersed submicron-sized solid precursor

Formation of nanoparticles from polydispersed, non-spherical submicron-sized particles via a gas-phase route in a flame reactor was investigated using tungsten oxide particles as a model material. Nanoparticles were formed by the evaporation of non-spherical powder, followed by nucleation, coagulation and surface condensation. The effects of both the flame temperature profile and the carrier gas flow rate on particles formation were studied numerically, and the results were validated by experimental data. The simulation was initiated by the use of computational fluid dynamics (CFD) to obtain the temperature distribution in the flame reactor. Then, evaporation of the feed material was modeled, taking into account both the polydispersity and the shape of the non-spherical particles. A nodal method was selected to solve the general dynamics equation (GDE), which included nucleation, coagulation, and surface condensation terms, for the prediction of particle dynamics. Results of the simulation were consistent with the experimental data, indicating that the selected model adequately predicts the final particle size distribution. Keywords Tungsten oxide; Evaporation; A gas-phase route; Non-spherical particle