Browsing by Author "Starost, Kristof"
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Item Assessment of nanoparticles release into the environment during drilling of carbon nanotubes/epoxy and carbon nanofibres/epoxy nanocomposites(2017-10-15) Starost, Kristof; Frijns, Evelien; Van Laer, Jo; Faisal, Nadimul; Egizabal, Ainhoa; Elizetxea, Cristina; Blazquez, Maria; Nelissen, Inge; Njuguna, James; Elizextea, Cristina; Biomateriales; POLIMEROSThe risk assessment, exposure and understanding of the release of embedded carbon nanotubes (CNTs) and carbon nanofibers (CNFs) from commercial high performance composites during machining processes are yet to be fully evaluated and quantified. In this study, CNTs and CNFs were dispersed in epoxy matrix through calendaring process to form nanocomposites. The automated drilling was carried out in a specially designed drilling chamber that allowed elimination of background noise from the measurements. Emission measurements were taken using condensed particle counter (CPC), scanning mobility particle sizer (SMPS) and DMS50 Fast Particulate Size Spectrometer. In comparison to the neat epoxy, the study results revealed that the nano-filled samples produced an increase of 102% and 227% for the EP/CNF and EP/CNT sample respectively in average particle number concentration emission. The particle mass concentration indicated that the EP/CNT and EP/CNF samples released demands a vital new perspective on CNTs and CNFs embedded within nanocomposite materials to be considered and evaluated for occupational exposure assessment. Importantly, the increased concentration observed at 10 nm aerosol particle sizes measurements strongly suggest that there are independent CNTs being released at this range.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.