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1.
Jing Wang Christof Asbach Heinz Fissan Tim Hülser Heinz Kaminski Thomas A. J. Kuhlbusch David Y. H. Pui 《Journal of nanoparticle research》2012,14(4):759
Emission into the workplace was measured for the production process of silicon nanoparticles in a pilot-scale facility at
the Institute of Energy and Environmental Technology e.V. (IUTA). The silicon nanoparticles were produced in a hot-wall reactor
and consisted of primary particles around 60 nm in diameter. We employed real-time aerosol instruments to measure particle
number and lung-deposited surface area concentrations and size distribution; airborne particles were also collected for off-line
electron microscopic analysis. Emission of silicon nanoparticles was not detected during the processes of synthesis, collection,
and bagging. This was attributed to the completely closed production system and other safety measures against particle release
which will be discussed briefly. Emission of silicon nanoparticles significantly above the detection limit was only observed
during the cleaning process when the production system was open and manually cleaned. The majority of the detected particles
was in the size range of 100–400 nm and were silicon nanoparticle agglomerates first deposited in the tubing then re-suspended
during the cleaning process. Appropriate personal protection equipment is recommended for safety protection of the workers
during cleaning. 相似文献
2.
As a precautionary measure, it is often recommended that workers take steps to reduce their exposure to airborne nanoparticles
through the use of respiratory protective devices. The purpose of this study was to provide a review and analysis of the research
literature and current recommendations on respirators used for protection against nanoparticles. Key research findings were
that studies with particles as small as 4 nm have shown that conventional single-fiber filtration theory can be used to describe
the filtration performance of respirators and that the most penetrating particle size for respirators equipped with commonly
used electrostatic filter media is in the range of 30–100 nm. Future research needs include human laboratory and workplace
protection factor studies to measure the respirator total inward leakage of nanoparticles. Industrial hygienists and safety
professionals should continue to use traditional respirator selection guidance for workers exposed to nanoparticles. 相似文献
3.
Building activities are recognised to produce coarse particulate matter but less is known about the release of airborne ultrafine
particles (UFPs; those below 100 nm in diameter). For the first time, this study has investigated the release of particles
in the 5–560 nm range from three simulated building activities: the crushing of concrete cubes, the demolition of old concrete
slabs, and the recycling of concrete debris. A fast response differential mobility spectrometer (Cambustion DMS50) was used
to measure particle number concentrations (PNC) and size distributions (PNDs) at a sampling frequency of 10 Hz in a confined
laboratory room providing controlled environment and near–steady background PNCs. The sampling point was intentionally kept
close to the test samples so that the release of new UFPs during these simulated processes can be quantified. Tri–modal particle
size distributions were recorded for all cases, demonstrating different peak diameters in fresh nuclei (<10 nm), nucleation
(10–30 nm) and accumulation (30–300 nm) modes for individual activities. The measured background size distributions showed
modal peaks at about 13 and 49 nm with average background PNCs ~1.47 × 104 cm−3. These background modal peaks shifted towards the larger sizes during the work periods (i.e. actual experiments) and the
total PNCs increased between 2 and 17 times over the background PNCs for different activities. After adjusting for background
concentrations, the net release of PNCs during cube crushing, slab demolition, and ‘dry’ and ‘wet’ recycling events were measured
as ~0.77, 19.1, 22.7 and 1.76 (×104) cm−3, respectively. The PNDs were converted into particle mass concentrations (PMCs). While majority of new PNC release was below
100 nm (i.e. UFPs), the bulk of new PMC emissions were constituted by the particles over 100 nm; ~95, 79, 73 and 90% of total
PNCs, and ~71, 92, 93 and 91% of total PMCs, for cube crushing, slab demolition, dry recycling and wet recycling, respectively.
The results of this study firmly elucidate the release of UFPs and raise a need for further detailed studies and designing
health and safety related exposure guidelines for laboratory workplaces and operational building sites. 相似文献
4.
Chuen-Jinn Tsai Guan-Yu Lin Chun-Nan Liu Chi-En He Chun-Wan Chen 《Journal of nanoparticle research》2012,14(4):777
A standard rotating drum with a modified sampling train (RD), a vortex shaker (VS), and a SSPD (small-scale powder disperser)
were used to investigate the emission characteristics of nano-powders, including nano-titanium dioxide (nano-TiO2, primary diameter: 21 nm), nano-zinc oxide (nano-ZnO, primary diameter: 30–50 nm), and nano-silicon dioxide (nano-SiO2, primary diameter: 10–30 nm). A TSI SMPS (scanning mobility particle sizer), a TSI APS (aerodynamic particle sizer), and
a MSP MOUDI (micro-orifice uniform deposit impactor) were used to measure the number and mass distributions of generated particles.
Significant differences in specific number and mass concentration or distributions were found among different methods and
nano-powders with the most specific number and mass concentration and the smallest particles being generated by the most energetic
SSPD, followed by VS and RD. Near uni-modal number or mass distributions were observed for the SSPD while bi-modal number
or mass distributions existed for nano-powders except nano-SiO2 which also exhibited bimodal mass distributions. The 30-min average results showed that the mass median aerodynamic diameter
(MMAD) and number median diameter (NMD) of the SSPD ranged 1.1–2.1 μm and 166–261 nm, respectively, for all three nano-powders,
which were smaller than those of the VS (MMAD: 3.3–6.0 μm and NMD: 156–462 nm), and the RD (MMAD: 5.2–11.2 μm and NMD: 198–479 nm).
For nano-particles (electric mobility diameter < 100 nm), specific mass concentrations were nearly negligible for all three
nano-powders and test methods. Specific number concentrations of nano-particles were low for the RD tester but were elevated
when more energetic VS and SSPD testers were used. The quantitative size and concentration data obtained in this study is
useful to elucidate the field emission and personal exposure data in the future provided that particle loss in the generation
system is carefully assessed. 相似文献
5.
Zinc oxide (ZnO) and Cu-doped ZnO (CZO) thin films were prepared on borosilicate glass substrates by spray pyrolysis technique.
The X-ray diffraction study revealed that Cu doping caused a reduction in crystallite size. AFM study showed an increase in
roughness with doping. This is attributed to the aggregation of particles to form clusters. From transmission electron microscopy
analysis, the particle size is measured to be in the range 30–65 nm (average particle size 48 nm) for undoped ZnO, whereas
it is in the range 24–56 nm (average particle size 40 nm) for CZO film. The electrical resistivity of the thin films was investigated
in the presence of air as well as N2 mixed air at different temperatures in the range 30–270 °C. The change in resistivity properties was explained on the basis
of conduction phenomena within the grain along with the grain boundaries as well as Cu- and N2-induced defect states. The thermal activation energy of ZnO was found to be in the range 0.04–0.7 eV and dependent on Cu
doping and N2 level in air. 相似文献
6.
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
7.
The particle size distribution, morphology and optical properties of the Au nanoparticle (NP) structures for surface enhanced
Raman signal (SERS) application are investigated in dependence on their preparation conditions. The structures are produced
from relatively thin Au films (10–20 nm) sputtered on fused silica glass substrate and irradiated with several pulses (6 ns)
of laser radiation at 266 nm and at fluencies in the range of 160–412 mJ/cm2. The SEM inspection reveals nearly homogeneously distributed, spherical gold particles. Their initial size distribution of
the range of 20–60 nm broadens towards larger particle diameters with prolonged irradiation. This is accompanied by an increase
in the uncovered surface of the glass substrate and no particle removal is observed. In the absorption profiles of the nanostructures,
the broad peak centred at 546 nm is ascribed to resonant absorption of surface plasmons (SPR). The peak position, halfwidth
and intensity depend on the shape, size and size distribution of the nanostructured particles in agreement with literature.
From peak intensities of the Raman spectra recorded for Rhodamine 6G in the range of 300–1800 cm−1, the relative signal enhancement by factor between 20 and 603 for individual peaks is estimated. The results confirm that
the obtained structures can be applied for SERS measurements and sensing. 相似文献
8.
Derk Brouwer Birgit van Duuren-Stuurman Markus Berges Elzbieta Jankowska Delphine Bard Dave Mark 《Journal of nanoparticle research》2009,11(8):1867-1881
In the past few years, an increasing number of studies on workplace air measurements on manufactured nano-materials and -objects
have been published. Most of the studies had a more explorative character, so a direct interpretation to workers” exposure
for a given exposure situation, activity, or process is not a straight-forward process. In general, the studies use a quite
similar package of devices for near real-time monitoring of particle number- and mass concentration in size ranges <100 nm
up to 10 μm, and the collection of samples for off-line characterization of air samples. Various approaches for addressing
background concentrations and its use to indicate the potential for exposure to nano-objects could be observed. Within the
EU-sponsored NANOSH project, a harmonized approach for measurement strategy, data analysis and reporting was developed. In
addition to time/activity–concentration profiles as reported by most studies, this approach enables a first step to estimate
the potential for exposure to manufactured nano-objects, more quantitatively. The NANOSH data will be collated into a base,
which may form the starting point for a harmonized database facilitating overall analysis in near future, to derive estimates
for exposure for several exposure situations. 相似文献
9.
P. K. Khanna K. Srinivasa Rao K. R. Patil V. N. Singh B. R. Mehta 《Journal of nanoparticle research》2010,12(1):101-109
Surface-capped CdSe and CdTe nano-crystals (NCs) have been synthesized using cadmium acetate, oleic acid and respective tri-octylphosphine
chalcogenide (TOPE; E = Se/Te) in diphenyl ether (DPE). Well-dispersed CdSe particles showed two absorption bands at the region
of 431–34 and 458–60 nm in optical absorption study. A band-edge emission resulted at 515 nm with an excitation energy of
400 nm, in its photoluminescence (PL) spectrum. Similarly, UV–visible absorption study of CdTe revealed an absorption band
at <700 nm. The broadened X-ray diffraction (XRD) pattern showed that at higher reaction temperature cubic CdSe but hexagonal
CdTe can be obtained with crystallite size of <10 nm. Scanning electron microscopy (SEM) and transmission electron microscopy
(TEM) revealed that agglomerated particles are of spherical nature. The inter-planar spacing in CdTe was measured to be 0.406 nm,
a characteristic of (100) lattice plane in hexagonal CdTe. X-ray photoelectron spectroscopy (XPS) showed that CdSe NCs have
better air stability stable than CdTe. Presence of organic moiety around the semiconductor particles was confirmed by infra-red
(IR) spectroscopy. 相似文献
10.
H. G. Silva-Pereyra J. Arenas-Alatorre L. Rodriguez-Fernández A. Crespo-Sosa J. C. Cheang-Wong J. A. Reyes-Esqueda Alicia Oliver 《Journal of nanoparticle research》2010,12(5):1787-1795
Au nanoparticles (NPs) with a size in the 2–12 nm range have been grown in silica by 2 MeV Au-ion implantation and a subsequent
thermal annealing in air. The as-prepared Au NPs were irradiated with 10 MeV Si ions elongating some of them. From transmission
electron microscopy in Z-contrast mode, we observed a narrow size distribution of the minor axis of the deformed NPs, which
presents its higher frequency around 6–7 nm and have a saturation about 9 nm. This final result agrees well with the diameter
of the track formed by Si ions of 10 MeV in silica, supporting the thermal spike model, which would explain the deformation
of the NPs. In this model, the NP melts and creeps along the ion track. Our results show that the NP crystallization is in
the fcc structure. On the other hand, a 200 keV electron irradiation provoked roundness on the previously elongated nanoparticles.
This effect was observed in situ by high-resolution transmission electron microscopy, showing additionally that, during the
roundness process, the fcc structure, as well as its crystalline orientation, remain unchanged. Thus, this study shows how
Au NPs embedded in silica, within this size distribution, keep the fcc bulk structure under both ion and electron irradiations. 相似文献
11.
Kazunori Kadota Takenobu Yamamoto Atsuko Shimosaka Yoshiyuki Shirakawa Jusuke Hidaka Masato Kouzu 《Journal of nanoparticle research》2011,13(12):7209-7218
The mechanism on aggregation of spindle granular particles of calcite was investigated for the carbonation of calcium hydroxide
in aqueous suspension for the purpose of controlling morphology of CaCO3. The experimental carbonation process was carried out in a semi-batch bubble column reactor under different conditions. Although,
fine rhombic nano-particles diameter ranged from 100 to 200 nm were obtained at 291 K, a higher temperature of 300 K provided
spindle granular particles with a length of 1.0–1.5 μm and a width of 0.3–0.5 μm. The average crystallite size was 28 nm for
the fine rhombic nano-particles and 43 nm for the spindle granules. Zeta potential measurement for the spindle granules indicated
that the suspension tended to be aggregated during the carbonation process. The effect of the degree of particle aggregation
on the shape of the obtained calcite particles was studied by Monte Carlo simulations. Our simulation results elucidated the
dependence of aggregation on unit particles, i.e., primary particles, on the experiment carbonation condition where the spindle
granules were formed out of the unit particles under the same condition as the experiments. In addition, the formation mechanism
of the granules was investigated by applying classical nucleation theory to the present simulations. 相似文献
12.
Measuring particle size-dependent physicochemical structure in airborne
single walled carbon nanotube agglomerates 总被引:1,自引:1,他引:1
Andrew D. Maynard Bon Ki Ku Mark Emery Mark Stolzenburg Peter H. McMurry 《Journal of nanoparticle research》2007,9(1):85-92
As-produced single-walled carbon nanotube (SWCNT) material is a complex matrix of carbon nanotubes, bundles of nanotubes (nanoropes),
non-tubular carbon and metal catalyst nanoparticles. The pulmonary toxicity of material released during manufacture and handling
will depend on the partitioning and arrangement of these components within airborne particles. To probe the physicochemical
structure of airborne SWCNT aggregates, a new technique was developed and applied to aerosolized as-produced material. Differential
Mobility Analysis-classified aggregates were analyzed using an Aerosol Particle Mass Monitor, and a structural parameter Γ
(proportional to the square of particle mobility diameter, divided by APM voltage) derived. Using information on the constituent
components of the SWCNT, modal values of Γ were estimated for specific particle compositions and structures, and compared
against measured values. Measured modal values of Γ for 150 nm mobility diameter aggregates suggested they were primarily
composed of non-tubular carbon from one batch of material, and thin nanoropes from a second batch of material – these findings
were confirmed using Transmission Electron Microscopy. Measured modal values of Γ for 31 nm mobility diameter aggregates indicated
that they were comprised predominantly of thin carbon nanoropes with associated nanometer-diameter metal catalyst particles;
there was no indication that either catalyst particles or non-tubular carbon particles were being preferentially released
into the air. These results indicate that the physicochemistry of aerosol particles released while handling as-produced SWCNT
may vary significantly by particle size and production batch, and that evaluations of potential health hazards need to account
for this.
Disclaimer: The mention of any company or product does not constitute an endorsement by the Centers for Disease Control and
Prevention. The findings and conclusions in this paper are those of the authors and do not necessarily represent the views
of the National Institute for Occupational Safety and Health. 相似文献
13.
C. Asbach H. Fissan B. Stahlmecke T. A. J. Kuhlbusch D. Y. H. Pui 《Journal of nanoparticle research》2009,11(1):101-109
Nanoparticle Surface Area Monitor (NSAM, TSI model 3550 and Aerotrak 9000) is an instrument designed to measure airborne surface
area concentrations that would deposit in the alveolar or tracheobronchial region of the lung. It was found that the instrument
can only be reliably used for the size range of nanoparticles between 20 and 100 nm. The upper size range can be extended
to 400 nm, where the minimum in the deposition curves occurs. While the fraction below 20 nm usually contributes only negligibly
to the total surface area and is therefore not critical, a preseparator is needed to remove all particles above 400 nm in
cases where the size distribution extends into the larger size range. Besides limitations in the particle size range, potential
implications of extreme concentrations up to the coagulation limit, particle material (density and composition) and particle
morphology are discussed. While concentration does not seem to pose any major constraints, the effect of different agglomerate
shapes still has to be further investigated. Particle material has a noticeable impact neither on particle charging in NSAM
nor on the deposition curves within the aforementioned size range, but particle hygroscopicity can cause the lung deposition
curves to change significantly which currently cannot be mimicked with the instrument. Besides limitations, possible extensions
are also discussed. It was found that the tendencies of the particle deposition curves of a reference worker for alveolar,
tracheobronchial, total and nasal depositions share the same tendencies in the 20–400 nm size range and that their ratios
are almost constant. This also seems to be the case for different individuals and under different breathing conditions. By
means of appropriate calibration factors NSAM can be used to deliver the lung deposited surface area concentrations in all
these regions, based on a single measurement. 相似文献
14.
The Cu–CdSe–Cu nanowire heterojunctions were fabricated by sequential electrochemical deposition of layers of Cu metal and
CdSe semiconductor within the nano-pores of anodic alumina membrane templates. X-ray diffraction reveals the cubic phase for
Cu and hexagonal phase for CdSe in the electrodeposited Cu–CdSe–Cu nanowire heterojunctions. The composition of the nanowire
heterojunction segments is characterized by energy dispersive X-ray spectroscopy. The morphological study of nanowire heterojunctions
has been made using scanning electron microscope and high resolution transmission microscopy. The nanowire heterojunctions
grown in 100 and 300 nm nano-pore size templates have been found to have optical band gaps of 1.92 and 1.75 eV, respectively.
The absorption spectra of 100 nm nanowire heterojunctions show a blue shift of 0.18 eV. The collective nonlinear current–voltage
(I–V) characteristics of the 300 and 100 nm nanowire heterojunctions show their rectifying and asymmetric behaviour, respectively. 相似文献
15.
Pieter van Broekhuizen Fleur van Broekhuizen Ralf Cornelissen Lucas Reijnders 《Journal of nanoparticle research》2011,13(2):447-462
In the European construction industry in 2009, the use of engineered nanoparticles appears to be confined to a limited number
of products, predominantly coatings, cement and concrete. A survey among representatives of workers and employers from 14
EU countries suggests a high level of ignorance about the availability and use of nanomaterials for the construction industry
and the safety aspects thereof. Barriers for a large-scale acceptance of products containing engineered nanoparticles (nanoproducts)
are high costs, uncertainties about long-term technical material performance, as well as uncertainties about health risks
of nanoproducts. Workplace measurements suggest a modest exposure of construction workers to nanoparticles (NPs) associated
with the use of nanoproducts. The measured particles were within a size range of 20–300 nm, with the median diameter below
53 nm. Positive assignment of this exposure to the nanoproduct or to additional sources of ultrafine particles, like the electrical
equipment used was not possible within the scope of this study and requires further research. Exposures were below the nano
reference values proposed on the basis of a precautionary approach. 相似文献
16.
Brouwer Derk H. van Duuren-Stuurman Birgit Berges Markus Bard Delphine Jankowska Elzbieta Moehlmann Carsten Pelzer Johannes Mark Dave 《Journal of nanoparticle research》2013,15(11):1-14
Workplace exposure to nanoparticles from gas metal arc welding (GMAW) process in an automobile manufacturing factory was investigated using a combination of multiple metrics and a comparison with background particles. The number concentration (NC), lung-deposited surface area concentration (SAC), estimated SAC and mass concentration (MC) of nanoparticles produced from the GMAW process were significantly higher than those of background particles before welding (P < 0.01). A bimodal size distribution by mass for welding particles with two peak values (i.e., 10,000–18,000 and 560–320 nm) and a unimodal size distribution by number with 190.7-nm mode size or 154.9-nm geometric size were observed. Nanoparticles by number comprised 60.7 % of particles, whereas nanoparticles by mass only accounted for 18.2 % of the total particles. The morphology of welding particles was dominated by the formation of chain-like agglomerates of primary particles. The metal composition of these welding particles consisted primarily of Fe, Mn, and Zn. The size distribution, morphology, and elemental compositions of welding particles were significantly different from background particles. Working activities, sampling distances from the source, air velocity, engineering control measures, and background particles in working places had significant influences on concentrations of airborne nanoparticle. In addition, SAC showed a high correlation with NC and a relatively low correlation with MC. These findings indicate that the GMAW process is able to generate significant levels of nanoparticles. It is recommended that a combination of multiple metrics is measured as part of a well-designed sampling strategy for airborne nanoparticles. Key exposure factors, such as particle agglomeration/aggregation, background particles, working activities, temporal and spatial distributions of the particles, air velocity, engineering control measures, should be investigated when measuring workplace exposure to nanoparticles. 相似文献
17.
F. Miomandre F. Chandezon B. Lama J. Besnardière M. Routier A. Brosseau P. Audebert 《Journal of nanoparticle research》2011,13(2):879-886
A direct route to polypyrrole–silica core–shell nanoparticles with diameters in the 150–300 nm range is described to design
new nanocomposites, in which the conducting part is wrapped by an external silica shell in order to obtain finally neutral
conductive nanoparticles. The nanocomposites are characterized by SEM, FTIR, electrochemistry and thermal gravimetric analysis,
demonstrating that the external silica shell actually insulates the conjugated polymer from the outer medium. In a second
step, the nanocomposites are coated with an additional PDMS layer. The electrorheological properties of the ink made by dispersion
of these final nanoparticles in a low dielectric constant fluid are checked in a dielectrophoretic device, in which the motion
of the particles induced by an external electric field can be used to monitor a switch of the light transmission properties
with a low voltage threshold. 相似文献
18.
A. Eremin E. Gurentsov E. Popova K. Priemchenko 《Applied physics. B, Lasers and optics》2011,104(2):285-295
The evidence of the change of the complex refractive index function E(m) of carbon and iron nanoparticles as a function of their size was found from two-color time-resolved laser-induced incandescence
(TiRe-LII) measurements. Growing carbon particles were observed from acetylene pyrolysis behind a shock wave and iron particles
were synthesized by pulse Kr–F excimer laser photo-dissociation of Fe(CO)5. The magnitudes of refractive index function were found through the fitting of two independently measured values of particle
heat up temperature, determined by two-color pyrometry and from the known energy of the laser pulse and the E(m) variation. Small carbon particles of about 1–14 nm in diameter had a low value of E(m)∼0.05–0.07, which tends to increase up to a value of 0.2–0.25 during particle growth up to 20 nm. Similar behavior for iron
particles resulted in E(m) rise from ∼0.1 for particles 1–3 nm in diameter up to ∼0.2 for particles >12 nm in diameter. 相似文献
19.
Nalenthiran Pugazhenthiran Sambandam Anandan Govindarajan Kathiravan Nyayiru Kannaian Udaya Prakash Simon Crawford Muthupandian Ashokkumar 《Journal of nanoparticle research》2009,11(7):1811-1815
A silver resistant Bacillus sp. was isolated through exposure of an aqueous AgNO3 solution to the atmosphere. Silver nanoparticles were synthesized using these airborne bacteria (Bacillus sp.). Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) analyses confirmed that silver nanoparticles
of 5–15 nm in size were deposited in the periplasmic space of the bacterial cells; a preferable cell surface location for
the easy recovery of biogenic nanoparticles. 相似文献
20.
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