Filtration of nanosized particles with different shape on oil coated fibres

Boskovic, Lucija; Agranovski, Igor E.; Braddock, Roger David

doi:10.1016/j.jaerosci.2007.09.003

Cited by 41 publications

(25 citation statements)

References 11 publications

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“…As shown in Figure 5, the thermal environment can cause the melting and coagulation of nanoparticles deposited onto filter fibers. As the structural changes due to natural-product nanoparticles increases the porosity of an air filter, the filtration efficiency and filter pressure drop decreases (Podgórski et al 2006;Boskovic et al 2007).…”

Section: Discussionmentioning

confidence: 99%

Effects of Surrounding Temperature on Antimicrobial Air Filters Coated with Sophora flavescens Nanoparticles

Sim

Lee

Nho

et al. 2014

Aerosol Science and Technology

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Bioaerosols, such as bacterial and fungal cells and their spores, are components of indoor airborne particulate matter and have been associated with human health problems as well as various environmental issues. Natural antimicrobial products have been used in air filters for bioaerosol control. However, natural products may lose some function due to their sensitivity to environmental factors such as temperature and humidity. In this study, we investigated the effects of temperature on antimicrobial fiber filters coated with nanoparticles of a natural product, namely, Sophora flavescens extract. Inactivation efficiency decreased with increasing temperature and treatment time. A quantitative chemical analysis of the filters revealed that the quantities of antimicrobial compounds decreased noticeably, with a consequent decrease in antimicrobial activity. In addition, the S. flavescens nanoparticles on the filter fiber surface melted gradually as treatment time increased at temperatures >100• C. This change in nanoparticle morphology in turn affected the pressure and filtration efficiency of filters, both of which decreased with increasing temperature and treatment time. These results could provide a scientific basis for the improvement of indoor air-quality control using antimicrobial air filters coated with S. flavescens nanoparticles.

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Section: Discussionmentioning

confidence: 99%

Effects of Surrounding Temperature on Antimicrobial Air Filters Coated with Sophora flavescens Nanoparticles

Sim

Lee

Nho

et al. 2014

Aerosol Science and Technology

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“…Moreover it assumes that the structure of the filter medium is homogeneous -all fibers with identical diameters are evenly arranged in a plane perpendicular to the direction of aerosol flow. There are some evidence in the literature of the subject that such a description is satisfactory for structurally homogeneous filters composed of identical fibers (Heim et al, 2005;Boskovic et al, 2007;Yun et al, 2007). Notwithstanding, it fails in the case of real polydisperse fibrous filters made of fibers with different diameters, as clearly seen in Fig.…”

Section: Theoretical Descriptionmentioning

confidence: 99%

Separation of Nanoparticles from Air Using Melt-Blown Filtering Media

Jackiewicz

Werner

2015

Aerosol Air Qual. Res.

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Over the last few years, expectations have grown for the development of appropriate materials for separation of nanoparticles of different morphologies from air. Therefore, the objective of this work was to conduct a broad study of the process of filtration of polydisperse nanoaerosols in materials of our design and production. They were made using the modified melt-blown technology, a very promising technique that allows to produce large amounts of fibers with a wide range of diameters which when properly formed in mats or cores can be used in various filtering products, such as protective masks, car filters. The filtration efficiency for KCl solid nanoparticles and DEHS (di-ethyl-hexyl-sebacat) liquid nanoparticles in three polypropylene filters of different morphologies have been established. The obtained results show how the aerosol face velocity and the morphology of the nonwoven media affect the filtration efficiency and pressure drop. It turned out that fibrous filters of our own production can separate particles with very small diameters from the air. As the effectiveness of the separation grew with a decrease in diameter of filter fibers, a filter composed of nanoscale fibers proved to be the most effective. An increase in aerosol flow velocity through the filter negatively affected its filtering effectiveness. The observation of data for cubical KCl and spherical DEHS particles, showed no differences in filtering effectiveness, which proves that for the tested diameter range the morphology of particles removed from air does not play a significant role, as it does for larger particles. The results obtained from the filtration of polydisperse nanoaerosols were successfully interpreted using our Partially Segregated Flow Model which takes into account the polydisperse distribution of fiber diameters in the filter. What is more, it shows that the application of the classical theory of filtration significantly overvalues the results obtained in our experiments.

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“…However, some recent studies indicate that the filtration efficiency of nano-sized particles can be significantly reduced due to thermal rebound effect. The thermal rebound effect is widely defined by two concepts: critical velocity and kinetic energy 38) . It has been stated that with the reduction of the particle size below a certain point, the mean thermal velocity due to Brownian motion exceeds the capture velocity, and consequently increases the likelihood of particle detachment from the filter surface 23) .…”

Section: Filtration Efficiency Affecting Factorsmentioning

confidence: 99%

“…Thus, it is expected that the filtration efficiency drops considerably at higher face velocity. Boskovic et al tested the filtration efficiency at various velocities ranging from 5 to 20 cm/s -1 for different shapes of particles (sphere, semi rounded and cubic) 38,53) . The measured particle size was in the range of 50-300 nm.…”

Section: Face Velocity and Airflow Ratementioning

confidence: 99%

Performance of Mechanical Filters and Respirators for Capturing Nanoparticles ―Limitations and Future Direction

et al. 2010

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There is an increasing concern about the health hazard posed to workers exposed to inhalation of nanoparticles. Inhaling nanoparticles posses an occupational hazard due to elevated amount emitted to the atmosphere and working environment. Nanoparticles have potential toxic properties: the high particle surface area, number concentration, and surface reactivity. Inhalation, the most common route of nanoparticle exposure, has been shown to cause adverse effects on pulmonary functions and the deposited particles in the lung can be translocated to the blood system by passing through the pulmonary protection barriers. Filtration is the simplest and most common method of aerosol control. It is widely used in mechanical ventilation and respiratory protection. However, concerns have been raised regarding the effectiveness of the filters for capturing nanoparticles. This paper reviews the literature on the filtration performance of mechanical filters and respirators against nanoparticles. It includes the discussion about filtration mechanisms, theoretical models, affecting factors of the filtration efficiency, and testing protocols for respirator and filter certification.

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Filtration of nanosized particles with different shape on oil coated fibres

Cited by 41 publications

References 11 publications

Effects of Surrounding Temperature on Antimicrobial Air Filters Coated with Sophora flavescens Nanoparticles

Effects of Surrounding Temperature on Antimicrobial Air Filters Coated with Sophora flavescens Nanoparticles

Separation of Nanoparticles from Air Using Melt-Blown Filtering Media

Performance of Mechanical Filters and Respirators for Capturing Nanoparticles ―Limitations and Future Direction

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