Browsing by Keyword "Nanoparticle"
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Item The effect of nanosilica (SiO2) and nanoalumina (Al2O3) reinforced polyester nanocomposites on aerosol nanoparticle emissions into the environment during automated drilling(2017-05) Starost, Kristof; Frijns, Evelien; Van Laer, Jo; Faisal, Nadimul; Egizabal, Ainhoa; Elizetxea, Cristina; Nelissen, Inge; Blázquez, María; Njuguna, James; Biomateriales; POLIMEROSThe aim of this study is to investigate the effect nanosilica and nanoalumina has on nanoparticle release from industrial nanocomposites due to drilling for hazard reduction whilst simultaneously obtaining the necessary mechanical performance. This study is therefore specifically designed such that all background noise is eliminated in the measurements range of 0.01 particles/cm3 and ±10% at 106 particles/cm3. The impact nano-sized SiO2 and Al2O3 reinforced polyester has on nanoparticle aerosols generated due to drilling is investigated. Real-time measurement was conducted within a specially designed controlled test chamber using a condensation particle counter (CPC) and a scanning mobility particle sizer spectrometer (SMPS). The results show that the polyester nanocomposite samples displayed statistically significant differences and an increase in nanoparticle number concentration by up to 228% compared to virgin polyester. It is shown that the nanofillers adhered to the polyester matrix showing a higher concentration of larger particles released (between 20 – 100 nm). The increase in nanoparticle reinforcement weight concentration and resulting nanoparticle release vary considerably between the nanosilica and nanoalumina samples due to the nanofillers presence. This study indicates a future opportunity to safer by design strategy that reduces number of particles released concentration and sizes without compromising desired mechanical properties for engineered polymers and composites.Item MECHANICAL IMPROVEMENT OF HARDENING AND TEMPERING STEEL WITH THE ADDITION OF SiC AND TiCN NANOPARTICLES IN THE STEEL MELT(2022-07) Callejo, Lorena M.; Pérez, Iñaki; Callejo-Piedra, Lorena M.; Pérez-Bilbao, Iñaki; CIRMETAL; Tecnalia Research & InnovationNovel processing technologies have allowed the reinforcement of several steel grades and alloys through the fine dispersion of different types of particles. However, the addition of ceramic particles in the steel melt causes agglomeration and coarsening phenomena. For this reason, little research has been carried out to add ceramic particles in steel in the traditional steelmaking process. Here we report a hardened and tempered steel grade that is reinforced for the first time through the addition of ceramic nanoparticles, such as TiCN and SiC, into the steel melt at laboratory scale. The results obtained from the tensile tests and hardness measurements reveal the mechanical behaviour of the steel grade is enhanced after the addition of the nanoparticles.Item Removal of TiO 2 nanoparticles from water by low pressure pilot plant filtration(2018-03-15) Olabarrieta, Josune; Monzón, Oihane; Belaustegui, Yolanda; Alvarez, Jon-Iñaki; Zorita, Saioa; VALORIZACIÓN DE RESIDUOS; ADAPTACIÓN AL CAMBIO CLIMÁTICORising use of nanoparticles in manufacturing as well as in commercial products bring issues related to environmental release and human exposure. A large amount of TiO2 nanoparticles will eventually reach wastewater treatment plants. Low pressure membrane filtration has been suggested as a feasible treatment of water streams. This study investigated first at laboratory scale the influence of: i) membrane material, ii) pore size and iii) water chemistry on nTiO2 removal. TiO2 retention was governed by the cake layer formation mechanism and significant retention of nanoparticles was observed even for filters having considerably larger pores than nTiO2. PVDF showed a great potential for nTiO2 rejection. Additionally, filtration pilot plant experiments were carried out using PVDF membranes (0.03 and 0.4 μm pore size). The release of nTiO2 in the pilot scale filtration system was always above the instrumental detection limit (> 1.5 μg/L) and in most cases below 100 μg/L regardless of the pore size and applied conditions. The nTiO2 membrane breakthrough predominantly occurred in the first few minutes after backwashes and ceased when the cake layer was formed. Ultrafiltration and microfiltration were comparable with rejection of nTiO2 above 95% at similar permeate flow rates. Nevertheless, ultrafiltration is more promising than microfiltration because it allowed longer operation times between backwash cycles.Item TiO2 nanoparticle addition into molten steel: From lab scale to Industrial scale(Trans Tech Publications Ltd., 2014) Kaltzakorta, Idurre; Callejo, Lorena M.; Idoyaga, ZuriñeIn this work, the design of a new technology for nanoparticle addition into molten steel that improves the mechanical properties of the material, as well as the upscale of the process, was pursued. The process was scaled from laboratory to industrial level starting from first experiments carried out in pure iron bath, in order to analyze the behavior of nanoparticles in molten metal environment, and finishing with the addition of nanoparticles into microalloyed steel bath as industrial trials. The first steps of the research were performed in the levitation furnace at Tecnalia R&I installations that can cast samples up to 1 kg, continuing with a high vacuum furnace with a capacity up to 35 Kg. By the end of the investigation, the process was scaled up to industrial level at Gerdau facilities.