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Surface-clean Au nanoparticles (NPs) confined in films of ionic liquids (ILs) can be easily fabricated by sputtering deposition. A silicon wafer coated with films of both hydrophobic (bis((trifluoromethyl)sulfonyl)amide, NTf) and hydrophilic (tetrafluoroborate, BF) imidazolium-based ILs forms an 'ionic carpet-like' structure that can be easily decorated with Au NPs of 5.1 and 6.5 nm mean diameter, respectively. The depth profile distribution of the Au NPs depends on the arrangement of the IL, which is controlled mainly by the anion volume. Higher concentrations of Au NPs are found closer to the IL surface for the system containing a larger anion (NTf) whereas Au NPs are located deeper in the IL for the system containing a smaller anion (BF). The Au NPs are well distributed over the IL/Si support and are strictly confined in a single layer of the IL. This method is among the most simple and versatile for the generation of liquid layers containing surface-clean, stable and confined Au NPs.

The present study has investigated the influence of the filtration step of the liquid-liquid extraction (LLE) on the quantitative analysis of di-n-butyl phthalate (DnBP) in the wastewater treatment system of the University of Caxias do Sul (WWTS-UCS). During five months, five wastewater samples from the inflow and outflow points were collected and submitted to LLE with and without the filtration step. The organic extracts were analyzed by Gas Chromatography with Flame Ionization Detection (GC/FID). The DnBP removal in the filtered samples was 36%, and the median DnBP concentration at the outflow point was 17.45 μg/mL. For the unfiltered samples, the DnBP removal was 39%, and the median DnBP concentration at the outflow point was 21.45 μg/mL. According to these results, an important fraction of the contaminant is retained in the LLE filtration step leading to considerable errors in the quantification of the target compounds.

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In this work a simple gravimetric method was described for the study of di-(2-ethylhexyl) phthalate (DEHP) in wastewater samples from the inflow and outflow points of the sewage treatment plant (ETE) at the University of Caxias do Sul (UCS). The organic phase of the sample was precipitated by adding concentrated HCl. The precipitate was filtered in glass columns packed with treated cotton. After drying, the columns containing the precipitate were carefully weighted and extracted with n-hexane. After solvent evaporation, the organic extract was re-diluted and analyzed by Gas Chromatography with Flame Ionization Detection (GC/FID). The average rate of DEHP removal was 27.50%. The median DEHP concentration was 6.01 µg mL -1 at the outflow point. This DEHP concentration is well above the maximum concentration level reported in the literature.

A procura de novas tecnologias de dispositivos de armazenamento de energia e a melhoria das já existentes devido à diversificação da rede energética e à eficiência energética, incentivam a investigação e o trabalho na área da condutividade eléctrica. As experiências com electrólitos líquidos iónicos resultaram num aumento da condutividade, e no melhor desempenho em gamas definidas. Mostrando ser um caminho para uma nova geração de baterias e condensadores.

Thermal management system is a relevant aspect for Li-ion batteries, mainly for electric vehicles. For this reason, several cooling methods have been proposed along the years, considering effect of both thermal conduction and convection. This study reviews the main methods applied for cooling Li-ion batteries: the use of phase change materials PCMs, air-forced and liquid cooling. Cell Arrangements are also presented due to the effect of temperature distribution. Finally, a discussion on the use of flow boiling as a mechanism of heat transfer in Li-ion batteries is presented.