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1.
Gold and gold–silver core-shell nanoparticle constructs with defined size based on DNA hybridization
Andrea Steinbrück Andrea Csaki Kathrin Ritter Martin Leich J. Michael K?hler Wolfgang Fritzsche 《Journal of nanoparticle research》2009,11(3):623-633
Nanoparticles represent versatile building blocks in material science and nanotechnology. Thereby, the defined assembly of
nanostructures (13 and 56 nm in diameter, respectively) is of significant importance. Short DNA sequences can be bound to
the nanoparticle surface thus enabling highly specific DNA hybridization-driven events that direct the formation of nanoparticle
constructs.
In this paper, examples for the defined formation of gold nanoparticle constructs are demonstrated. In addition, gold–silver
core-shell nanoparticles are introduced as further building blocks for the hybridization-controlled formation of nanoparticle
constructs. 相似文献
2.
Manuj Nahar Ignacio F. Gallardo Kristofer L. Gleason Michael F. Becker John W. Keto Desiderio Kovar 《Journal of nanoparticle research》2011,13(8):3455-3464
A continuous aerosol process has been studied for producing nanoparticles of oxides that were decorated with smaller metallic
nanoparticles and are free of organic stabilizers. To produce the oxide carrier nanoparticles, an aerosol of 3–6 μm oxide
particles was ablated using a pulsed excimer laser. The resulting oxide nanoparticle aerosol was then mixed with 1.5–2.0 μm
metallic particles and this mixed aerosol was exposed to the laser for a second time. The metallic micron-sized particles
were ablated during this second exposure, and the resulting nanoparticles deposited on the surface of the oxide nanoparticles
producing an aerosol of 10–60 nm oxide nanoparticles that were decorated with smaller 1–5 nm metallic nanoparticles. The metal
and oxide nanoparticle sizes were varied by changing the laser fluence and gas type in the aerosol. The flexibility of this
approach was demonstrated by producing metal-decorated oxide nanoparticles using two oxides, SiO2 and TiO2, and two metals, Au and Ag. 相似文献
3.
The study of energy transfer mechanism from different capping agents to intrinsic luminescent vacancy centres of zinc sulphide
(ZnS) has been reported in the present work. Nanoparticles of capped and uncapped ZnS are prepared by co-precipitation reaction.
These nanoparticles are sterically stabilized using organic polymers—poly vinyl pyrrolidone, 2-mercaptoethanol and thioglycerol.
Monodispersed nanoparticles were observed under TEM for both capped and uncapped ZnS nanopowders. However, for uncapped ZnS
nanopowders, tendency for formation of nanorod like structure exists. Size of ZnS crystallites was calculated from X-ray diffraction
pattern. The primary crystallite size estimated from X-ray diffraction pattern is 1.95–2.20 nm for capped nanostructures and
2.2 nm for uncapped nanostructures. FTIR spectra were conducted to confirm capping. Zeta potential measurements have been
done to check the stability of dispersed nanoparticles. Band gap measurement was done by UV–visible spectrophotometer. Excitation
and emission spectra are also performed in order to compare optical properties in various samples. Increase in emission intensity
and band gap has been observed by adding different capping agents in comparison to uncapped ZnS nanoparticles. The results
show that in capped ZnS nanoparticles the mechanism of energy transfer from capping layer to photoluminescent vacancy centres
is more pronounced. 相似文献
4.
We report a straightforward approach to prepare multifunctional manganese–gold nanoparticles by attaching Mn(II) ions onto
the surface of 20 nm citrate-capped gold nanoparticles. In vitro MRI measurements made in agarose gel phantoms exhibited high
relaxivity (18.26 ± 1.04 mmol−1 s−1). Controlled incubation of the nanoparticles with mesenchymal stem cells (MSCs) was used to study cellular uptake of these
particles and this process appeared to be controlled by the size of the nanoparticle aggregates in the extracellular solution.
SEM images of live MSCs showed an increased concentration of particles near the cell membrane and a distribution of the size
of particles within the cells. Survivability for MSCs in contact with Mn–Au NPs was greater than 97% over the 3-day period
and up to the 1 mM Mn used in this study. The high relaxivity and low cell mortality are suggestive of an enhanced positive
contrast agent for in vitro or in vivo applications. 相似文献
5.
Filip Ilie 《Journal of nanoparticle research》2012,14(3):752
Nanoparticles have been widely used in polishing slurry such as chemical mechanical polishing (CMP) process. The movement
of nanoparticles in polishing slurry and the interaction between nanoparticles and solid surface are very important to obtain
an atomic smooth surface in CMP process. Polishing slurry contains abrasive nanoparticles (with the size range of about 10–100 nm)
and chemical reagents. Abrasive nanoparticles and hydrodynamic pressure are considered to cause the polishing effect. Nanoparticles
behavior in the slurry with power-law viscosity shows great effect on the wafer surface in polishing process. CMP is now a
standard process of integrated circuit manufacturing at nanoscale. Various models can dynamically predict the evolution of
surface topography for any time point during CMP. To research, using a combination of individual nanoscale friction measurements
for CMP of SiO2, in an analytical model, to sum these effects, and the results scale CMP experiments, can guide the research and validate
the model. CMP endpoint measurements, such as those from motor current traces, enable verification of model predictions, relating
to friction and wear in CMP and surface topography evolution for different types of CMP processes and patterned chips. In
this article, we explore models of the microscopic frictional force based on the surface topography and present both experimental
and theoretical studies on the movement of nanoparticles in polishing slurry and collision between nanoparticles, as well
as between the particles and solid surfaces in time of process CMP. Experimental results have proved that the nanoparticle
size and slurry properties have great effects on the polishing results. The effects of the nanoparticle size and the slurry
film thickness are also discussed. 相似文献
6.
Marcus Koch Silke Kiefer Christian Cavelius Annette Kraegeloh 《Journal of nanoparticle research》2012,14(2):646-11
For a detailed analysis of the biological effects of silver nanoparticles, discrimination between effects related to the nano-scale
size of the particles and effects of released silver ions is required. Silver ions are either present in the initial particle
dispersion or released by the nanoparticles over time. The aim of this study is to monitor the free silver ion activity {Ag+} in the presence of silver nanoparticles using a silver ion selective electrode. Therefore, silver in the form of silver
nanoparticles, 4.2 ± 1.4 nm and 2–30 nm in size, or silver nitrate was added to cell culture media in the absence or presence
of A549 cells as a model for human type II alveolar epithelial cells. The free silver ion activity measured after the addition
of silver nanoparticles was determined by the initial ionic silver content. The p {Ag+} values indicated that the cell culture media decrease the free silver ion activity due to binding of silver ions by constituents
of the media. In the presence of A549 cells, the free silver ion activity was further reduced. The morphology of A549 cells,
cultivated in DME medium containing 9.1% (v/v) FBS, was affected by adding AgNO3 at concentrations of ≥30 μM after 24 h. In comparison, silver nanoparticles up to a concentration of 200 μM Ag did not affect
cellular morphology. Our experiments indicate that the effect of silver nanoparticles is mainly mediated by silver ions. An
effect of silver on cellular morphology was observed at p {Ag+} ≤ 9.2. 相似文献
7.
Zero valent iron nanoparticles are of increasing interest in clean water treatment applications due to their reactivity toward
organic contaminants and their potential to degrade a variety of compounds. This study focuses on the effect of organophosphate
stabilizers on nanoparticle characteristics, including particle size distribution and zeta potential, when the stabilizer
is present during nanoparticle synthesis. Particle size distributions from DLS were obtained as a function of stabilizer type
and iron precursor (FeSO4·7H2O or FeCl3), and nanoparticles from 2 to 200 nm were produced. Three different organophosphate stabilizer compounds were compared in
their ability to control nanoparticle size, and the size distributions obtained for particle volume demonstrated differences
caused by the three stabilizers. A range of stabilizer-to-iron (0.05–0.9) and borohydride-to-iron (0.5–8) molar ratios were
tested to determine the effect of concentration on nanoparticle size distribution and zeta potential. The combination of ferrous
sulfate and ATMP or DTPMP phosphonate stabilizer produced stabilized nanoparticle suspensions, and the stabilizers tested
resulted in varying particle size distributions. In general, higher stabilizer concentrations resulted in smaller nanoparticles,
and excess borohydride did not decrease nanoparticle size. Zeta potential measurements were largely consistent with particle
size distribution data and indicated the stability of the suspensions. Probe sonication, as a nanoparticle resuspension method,
was minimally successful in several different organic solvents. 相似文献
8.
S. Zolghadri A. A. Saboury A. Golestani A. Divsalar S. Rezaei-Zarchi A. A. Moosavi-Movahedi 《Journal of nanoparticle research》2009,11(7):1751-1758
The binding of silver nanoparticles to bovine hemoglobin (BHb) was studied by fluorescence, UV–Visible, and circular dichroism
(CD) spectroscopic techniques at different temperatures of 20, 37, and 42 °C. The absorption spectrum of soret band, in the
presence of silver nanoparticle, showed a significant spectral change, which indicated the heme groups of BHb were directly
attacked and degraded by silver nanoparticle. The fluorescence data explained that the nanoparticle binding to BHb occurred
at a single binding site, which demonstrated a dynamic quenching procedure. Nanoparticles could reduce the fluorescence of
tryptophanyl residues of BHb to a lesser extent. Circular dichroism studies demonstrated a conformational change of BHb in
the presence of silver nanoparticles. The helicity of BHb was reduced by increasing silver nanoparticle concentration at different
temperatures. Thermodynamic analysis of the protein interaction by silver nanoparticles suggested that the binding process
is only entropy driven. 相似文献
9.
M. L. Singla Rajeev Sehrawat Nidhi Rana Kulvir Singh 《Journal of nanoparticle research》2011,13(5):2109-2116
Emeraldine base (EB) polymer–ZnO nanoparticles composite films has been synthesized by solution casting technique on ITO-coated
glass substrate and characterized by XRD, FTIR and TEM for their structure and morphology. Dielectric behaviour of these composite
films has been investigated in the very low frequency region to medium frequency region (1 kHz–1 MHz). The dielectric constant
of the composite with 30% nanoparticles is almost one-tenth of the pure EB. The dielectric value becomes constant in the frequency
region greater than 400 kHz. The change in dielectric behaviour of the composite is explained on the basis of multilayered
interface formed between the ZnO nanoparticles and emeraldine chains. Nanoparticles have high energy surface which is responsible
for the decrease of free volume for the orientation of polymer chains consequently decrease in dielectric constant of the
composite. TEM images shows about 10 nm ZnO particles embedded in the emeraldine matrix. From the XRD data it has been observed
that the lattice parameters of ZnO have been modified due to the alignment of polymer chains along the basal planes of the
nanoparticles. The shift of N=Q=N and N–B–N vibration bands to higher wave number in IR indicates that interaction between
emeraldine chain and nanoparticles which provides stability to emeraldine matrix. 相似文献
10.
Steven Yueh-Hsiu Wu Ching-Li Tseng Feng-Huei Lin 《Journal of nanoparticle research》2010,12(4):1173-1185
In this study, a magnetic iron-doped calcium sulfide (Fe–CaS) nanoparticle was newly developed and studied for the purpose
of hyperthermia due to its promising magnetic property, adequate biodegradation rate, and relatively good biocompatibility.
Fe–CaS nanoparticles were synthesized by a wet chemical co-precipitation process with heat treatment in a N2 atmosphere, and were subsequently cooled in N2 and exposed to air at a low temperature. The crystal structure of the Fe–CaS nanoparticles was similar to that of the CaS,
which was identified by an X-ray diffractometer (XRD). The particle size was less than 40 nm based on a Debye–Scherrer equation
and transmission electron microscope (TEM) examination. Magnetic properties obtained from the SQUID magnetometer demonstrated
that the synthesized CaS was a diamagnetic property. Once the Fe ions were doped, the synthesized Fe–CaS converted into paramagnetism
which showed no hysteresis loop. Having been heated above 600 °C in N2, the Fe–CaS showed a promising magnetic property to produce enough energy to increase the temperature for hyperthermia. 10 mg/ml
of the Fe–CaS was able to generate heat to elevate the media temperature over 42.5 °C within 6 min. The area of the hysteresis
loop increased with the increasing of the treated temperature, especially at 800 °C for 1 h. This is because more Fe ions
replaced Ca ions in the lattice at the higher heat treatment temperature. The heat production was also increasing with the
increasing of heat treatment temperature, which resulted in an adequate specific absorption ratio (SAR) value, which was found
to be 45.47 W/g at 37 °C under an alternative magnetic field of f = 750 KHz, H = 10 Oe. The in vitro biocompatibility test of the synthesized Fe–CaS nanoparticles examined by the LDH assay showed no cytotoxicity
to 3T3 fibroblast. The result of in vitro cell hyperthermia shows that under magnetic field the Fe–CaS nanoparticles were
able to generate heat and kill the CT-26 cancer cells significantly. We believe that the developed Fe–CaS nanoparticles have
great potential as thermo-seeds for cancer hyperthermia in the near future. 相似文献
11.
Takashi Ogi Norizoh Saitoh Toshiyuki Nomura Yasuhiro Konishi 《Journal of nanoparticle research》2010,12(7):2531-2539
Biosynthesis of spherical gold nanoparticles and gold nanoplates was achieved at room temperature and pH 2.8 when cell extract
from the metal-reducing bacterium Shewanella algae was used as both a reducing and shape-controlling agent. Cell extract, prepared by sonicating a suspension of S. algae cells, was capable of reducing 1 mol/m3 aqueous AuCl4
− ions into elemental gold within 10 min when H2 gas was provided as an electron donor. The time interval lapsed since the beginning of the bioreductive reaction was found
to be an important factor in controlling the morphology of biogenic gold nanoparticles. After 1 h, there was a large population
of well-dispersed, spherical gold nanoparticles with a mean size of 9.6 nm. Gold nanoplates with an edge length of 100 nm
appeared after 6 h, and 60% of the total nanoparticle population was due to gold nanoplates with an edge length of 100–200 nm
after 24 h. The yield of gold nanoplates prepared with S. algae extract was four times higher than that prepared with resting cells of S. algae. The resulting biogenic gold nanoparticle suspensions showed a large variation in color, ranging from pale pink to purple
due to changes in nanoparticle morphology. 相似文献
12.
N. G. Semaltianos S. Logothetidis W. Perrie S. Romani R. J. Potter S. P. Edwardson P. French M. Sharp G. Dearden K. G. Watkins 《Journal of nanoparticle research》2010,12(2):573-580
Silicon nanoparticles were generated by femtosecond laser [387 nm, 180 fs, 1 kHz, pulse energy = 3.5 μJ (fluence = 0.8 J/cm2)] ablation of silicon in deionized water. Nanoparticles with diameters from ~5 up to ~200 nm were observed to be formed in
the colloidal solution. Their size distribution follows log-normal function with statistical median diameter of ≈20 nm. Longer
ablation time leads to a narrowing of the nanoparticle size distribution due to the interaction of the ablating laser beam
with the produced nanoparticles. Raman spectroscopy measurements confirm that the nanoparticles exhibit phonon quantum confinement
effects and indicate that under the present conditions of ablation they are partially amorphous. 相似文献
13.
B. Zümreoglu-Karan 《Journal of nanoparticle research》2009,11(5):1099-1105
Preparation of gold nanoparticles, particularly gold nanorods, by wet chemistry processes involves gold seeds, an Au(III)
salt, structure directing surfactants, and metal ion additives in the growth solution into which a weak reducing agent is
added. The most commonly employed weak reducing agent is l-ascorbic acid (vitamin C) which is known to reduce many metal ions in the solution phase and form complexes with relatively
low stability constants. A purple-gray gold–ascorbate compound, obtained from the reaction of sodium tetrachloroaurate(III)
with sodium ascorbate, is now reported. The compound possesses the expected structural features of vitamin C–metal complexes
as verified by its 13C CP-MAS NMR spectrum. A discussion is also presented on the possibility of gold–ascorbate complexation operating in gold
nanoparticle formation. 相似文献
14.
H. Takele S. Jebril T. Strunskus V. Zaporojchenko R. Adelung F. Faupel 《Applied Physics A: Materials Science & Processing》2008,92(2):345-350
Nanocomposites consisting of Au and Ag nanoparticles embedded in Teflon AF 1600 (Teflon) and Nylon 6 (Nylon) matrices were
prepared by a simultaneous vapor phase deposition of both the polymer and the metal. The composite films were deposited between
two Au-Pd alloy electrodes prepared by sputtering onto kapton foil substrates enabling further electrical measurements. The
electrical properties of the composites are strongly influenced by the metal filling factor and changes in the microstructure.
At first, the dependence of the resistivity of the composites consisting of various Ag and Au nanoparticle concentrations
was investigated. The resistivity is characterized by a threshold region with a critical metal filling factor. Changes in
the microstructure, in particular, can occur as a result of an induced electric field in between the metal nanoparticles and
a heat treatment. The I–V characteristics of Teflon AF composites for different Au concentrations were studied thoroughly.
An increase in the slope of the I–V curve up to a certain voltage (breakdown voltage) was observed. This phenomenon is accompanied
by the field induced tunneling of the charge carriers which enhances the conductivity. The change in conductivity was also
analyzed for Nylon nanocomposites with various Au concentrations in the temperature range 20–180 °C. The observed temperature
dependence is explained by activated electron tunneling between metal nanoparticles and by rearrangements in the microstructure
(e.g. coalescence of metal nanoparticles).
PACS 78.67.-n; 78.67.Bf 相似文献
15.
A review of the antibacterial effects of silver nanomaterials and potential implications for human health and the environment 总被引:6,自引:0,他引:6
Here, we present a review of the antibacterial effects of silver nanomaterials, including proposed antibacterial mechanisms
and possible toxicity to higher organisms. For purpose of this review, silver nanomaterials include silver nanoparticles,
stabilized silver salts, silver–dendrimer, polymer and metal oxide composites, and silver-impregnated zeolite and activated
carbon materials. While there is some evidence that silver nanoparticles can directly damage bacteria cell membranes, silver
nanomaterials appear to exert bacteriocidal activity predominantly through release of silver ions followed (individually or
in combination) by increased membrane permeability, loss of the proton motive force, inducing de-energization of the cells
and efflux of phosphate, leakage of cellular content, and disruption DNA replication. Eukaryotic cells could be similarly
impacted by most of these mechanisms and, indeed, a small but growing body of literature supports this concern. Most antimicrobial
studies are performed in simple aquatic media or cell culture media without proper characterization of silver nanomaterial
stability (aggregation, dissolution, and re-precipitation). Silver nanoparticle stability is governed by particle size, shape,
and capping agents as well as solution pH, ionic strength, specific ions and ligands, and organic macromolecules—all of which
influence silver nanoparticle stability and bioavailability. Although none of the studies reviewed definitively proved any
immediate impacts to human health or the environment by a silver nanomaterial containing product, the entirety of the science
reviewed suggests some caution and further research are warranted given the already widespread and rapidly growing use of
silver nanomaterials. 相似文献
16.
Improvement of electrical conductivity of poly ethylene oxide (PEO)–LiI polymer electrolytes is necessary for their use in
solid state lithium ion battery. In this study a new kind of PEO–LiI-based polymer electrolytes embedded with CdO nanoparticles
with improved electrical conductivity has been prepared and characterized. The electron microscopic studies confirm that CdO
nanoparticles of average size 2.5 nm are dispersed in the PEO matrix. The glass transition temperature of the PEO–LiI electrolyte
decreases with the introduction of CdO nanoparticle in the polymer matrix. X-ray diffraction, electron microscopic, and differential
scanning calorimetry studies show that the amorphous phase of PEO increases with the introduction of CdO nanoparticle and
that the increase in amorphous phase is maximum for 0.10 wt% CdO doping. The electrical conductivity of the sample with 0.10 wt%
CdO increases by three orders in magnitude than that of the PEO–LiI electrolyte. The electrical conductivity of PEO–LiI electrolyte
embedded with CdO nanoparticle exhibits VTF behavior with reciprocal temperature indicating a strong coupling between the
ionic and the polymer chain segmental motions. 相似文献
17.
Csaba László Sajti Svea Petersen Ana Menéndez-Manjón Stephan Barcikowski 《Applied Physics A: Materials Science & Processing》2010,101(2):259-264
In-situ functionalization of gold nanoparticles with fluorophore-tagged oligonucleotides is studied by comparing femtosecond
laser ablation in stationary liquid and in biomolecule flow. Femtosecond laser pulses induce significant degradation to sensitive
biomolecules when ablating gold in a stationary solution of oligonucleotides. Contrary, in-situ conjugation of nanoparticles
in biomolecule flow considerably reduces the degree of degradation studied by gel electrophoresis and UV–Vis spectrometry.
Ablating gold with 100 μJ femtosecond laser pulses DNA sequence does not degrade, while the degree of fluorophore tag degradation
was 84% in stationary solution compared to 5% for 1 mL/min liquid flow. It is concluded that femtosecond laser-induced degradation
of biomolecules is triggered by absorption of nanoparticle conjugates suspended in the colloid and not by ablation of the
target. Quenching of nanoparticle size appears from 0.5 μM biomolecule concentration for 0.3 μg/s nanoparticle productivity
indicating the successful surface functionalization. Finally, increasing the liquid flow rate from stationary to 450 mL/min
enhances nanoparticle productivity from 0.2 μg/s to 1.5 μg/s, as increasing liquid flow allows removal of light absorbing
nanoparticles from the ablation zone, avoiding attenuation of subsequent laser photons. 相似文献
18.
Sultana Ferdous Marios A. Ioannidis Dale Henneke 《Journal of nanoparticle research》2011,13(12):6579-6589
The pendant drop technique was used to characterize the adsorption behavior of n-dodecane-1-thiol and n-hexane-1-thiol-capped gold nanoparticles at the hexane–water interface. The adsorption process was studied by analyzing the
dynamic interfacial tension versus nanoparticle concentration, both at early times and at later stages (i.e., immediately
after the interface between the fluids is made and once equilibrium has been established). A series of gold colloids were
made using nanoparticles ranging in size from 1.60 to 2.85 nm dissolved in hexane for the interfacial tension analysis. Following
free diffusion of nanoparticles from the bulk hexane phase, adsorption leads to ordering and rearrangement of the nanoparticles
at the interface and formation of a dense monolayer. With increasing interfacial coverage, the diffusion-controlled adsorption
for the nanoparticles at the interface was found to change to an interaction-controlled assembly and the presence of an adsorption
barrier was experimentally verified. At the same bulk concentration, different sizes of n-dodecane-1-thiol nanoparticles showed different absorption behavior at the interface, in agreement with the findings of Kutuzov
et al. (Phys Chem Chem Phys 9:6351–6358, 2007). The experiments additionally demonstrated the important role played by the capping agent. At the same concentration, gold
nanoparticles stabilized by n-hexane-1-thiol exhibited greater surface activity than gold nanoparticles of the same size stabilized by n-dodecane-1-thiol. These findings contribute to the design of useful supra-colloidal structures by the self-assembly of alkane-thiol-capped
gold nanoparticles at liquid–liquid interfaces. 相似文献
19.
Manish Hudlikar Shreeram Joglekar Mayur Dhaygude Kisan Kodam 《Journal of nanoparticle research》2012,14(5):865
A low-cost, green synthesis of ZnS nanoparticles is reported using 0.3 % latex solution prepared from Jatropha curcas L. ZnS nanoparticles were characterized by X-ray diffraction, selected area electron diffraction, transmission electron microscopy,
energy dispersive analysis of X-rays, UV–vis optical absorption and photoluminescence techniques. Fourier Transform Infrared
Spectroscopy was performed to find the role of cyclic peptides namely curcacycline A (an octapeptide), curcacycline B (a nonapeptide)
and curcain (an enzyme) as a possible reducing and stabilizing agents present in the latex of J. curcas L. The average size of ZnS nanoparticles was found to be 10 nm. Latex of J. curcas L. itself acts as a source of sulphide (S−2) ions that are donated to Zn ions under present experimental conditions. Source of sulphide (S−2) ions is still unclear, but we speculate that cysteine or thiol residues present in enzyme curcain may be donating these
sulphide (S−2) ions. 相似文献
20.
Candace S.-J. Tsai Manuel E. Echevarría-Vega Georgios A. Sotiriou Christopher Santeufemio Daniel Schmidt Philip Demokritou Michael Ellenbecker 《Journal of nanoparticle research》2012,14(5):812
Applying engineering controls to airborne engineered nanoparticles (ENPs) is critical to prevent environmental releases and
worker exposure. This study evaluated the effectiveness of two air sampling and six air cleaning fabric filters at collecting
ENPs using industrially relevant flame-made engineered nanoparticles generated using a versatile engineered nanomaterial generation
system (VENGES), recently designed and constructed at Harvard University. VENGES has the ability to generate metal and metal
oxide exposure atmospheres while controlling important particle properties such as primary particle size, aerosol size distribution,
and agglomeration state. For this study, amorphous SiO2 ENPs with a 15.4 nm primary particle size were generated and diluted with HEPA-filtered air. The aerosol was passed through
the filter samples at two different filtration face velocities (2.3 and 3.5 m/min). Particle concentrations as a function
of particle size were measured upstream and downstream of the filters using a specially designed filter test system to evaluate
filtration efficiency. Real time instruments (FMPS and APS) were used to measure particle concentration for diameters from
5 to 20,000 nm. Membrane-coated fabric filters were found to have enhanced nanoparticle collection efficiency by 20–46 % points
compared to non-coated fabric and could provide collection efficiency above 95 %. 相似文献