Thermoplastic polyurethane (TPU) doped with multi-walled carbon nanotubes (MWCNTs) at 1, 3, 5, and 7 wt% has been studied. The effect of MWCNTs on thermal, viscoelastic, and electric properties in the TPU matrix was characterized by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and by impedance spectroscopy. The results show that the thermal, electrical, and viscoelastic properties, such as the glass transition temperature, shifted towards high temperatures.
View Article and Find Full Text PDFThe performance of a pilot-scale boron-doped diamond (BDD) reactor through a numerical analysis of reaction rate parameters and enhanced mass transfer has been investigated. The main objective of this research is to evaluate the efficiency of the reactor in mineralizing and degrading caffeine as an emerging contaminant. Based on the kinetic mechanisms and mass transport correlations reported in the literature, two reaction rate kinetic models for caffeine degradation are proposed and analyzed.
View Article and Find Full Text PDFThe impacts on the morphological, electrical and hardness properties of thermoplastic polyurethane (TPU) plates using multi-walled carbon nanotubes (MWCNTs) as reinforcing fillers have been investigated, using MWCNT loadings between 1 and 7 wt%. Plates of the TPU/MWCNT nanocomposites were fabricated by compression molding from extruded pellets. An X-ray diffraction analysis showed that the incorporation of MWCNTs into the TPU polymer matrix increases the ordered range of the soft and hard segments.
View Article and Find Full Text PDFThis work proposes a novel approach for the coupling of ozonation and Fenton processes using a new prototype of a high rotation bubble reactor (HRBR), which improves utilization of the ozone and hydrogen peroxide through bubble generation and axial and radial dispersion of the flow. The HRBR integrates the rotor and the diffuser in the same device facilitating the generation and dispersion of the ozone bubbles inside the reaction tank. Thus, the mass transfer to the liquid phase is enhanced.
View Article and Find Full Text PDFWO/TiO is a composite photocatalyst that is being widely used in heterogeneous photocatalysis because it presents better photocatalytic properties than TiO. For example, the probability of recombination of the electron/hole pairs is diminished and a more range of the solar spectrum is used for its excitation. However, this depend of variables such as tungsten oxide concentration, calcination temperature and synthesis method.
View Article and Find Full Text PDFThe present work reports the use of a flotation cell as a prospective reactor for ozonation and the intensification of ozonation (catalytic ozonation and photocatalytic ozonation). The effect of the pH, ozone concentration and loading catalyst was investigated. The performance of the flotation cell was compared with that of conventional reactors used in ozonation through the ozone utilized index (OUI), which was proposed in this work and relates the amount of ozone supplied to the system per milligram of degraded pollutant.
View Article and Find Full Text PDFEmerging contaminants (EC) are an imminent risk due to potential toxicity to aquatic ecosystems and human beings. This type of contaminants is found in low concentrations and usually present incomplete or inefficient removal by conventional treatments, which entail its permanence and constant increase. Advanced Oxidation Processes (AOP) are an alternative for the elimination of dangerous and resistant substances in wastewater.
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