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1.
An important safety aspect of the workplace environment concerns the severity of its air pollution with nanoparticles (NP;
<100 nm) and ultrafine particles (UFP; <300 nm). Depending on their size and chemical nature, exposure to these particles
through inhalation can be hazardous because of their intrinsic ability to deposit in the deep lung regions and the possibility
to subsequently pass into the blood stream. Recommended safety measures in the nanomaterials industry are pragmatic, aiming
at exposure minimization in general, and advocating continuous control by monitoring both the workplace air pollution level
and the personal exposure to airborne NPs. This article describes the design and operation of the Aerasense NP monitor that
enables intelligence gathering in particular with respect to airborne particles in the 10–300 nm size range. The NP monitor
provides real time information about their number concentration, average size, and surface areas per unit volume of inhaled
air that deposit in the various compartments of the respiratory tract. The monitor’s functionality relies on electrical charging
of airborne particles and subsequent measurements of the total particle charge concentration under various conditions. Information
obtained with the NP monitor in a typical workplace environment has been compared with simultaneously recorded data from a
Scanning Mobility Particle Sizer (SMPS) capable of measuring the particle size distribution in the 11–1086 nm size range.
When the toxicological properties of the engineered and/or released particles in the workplace are known, personal exposure
monitoring allows a risk assessment to be made for a worker during each workday, when the workplace-produced particles can
be distinguished from other (ambient) particles. 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.
R. M. Nielsen S. Murphy C. Strebel M. Johansson I. Chorkendorff J. H. Nielsen 《Journal of nanoparticle research》2010,12(4):1249-1262
We have investigated the morphology of mass selected ruthenium nanoparticles produced with a magnetron-sputter gas-aggregation
source. The nanoparticles are mass selected using a quadrupole mass filter, resulting in narrow size distributions and average
diameters between 2 and 15 nm. The particles are imaged in situ by scanning electron microscopy and scanning tunneling microscopy
(STM) as well as ex-situ using transmission electron microscopy (TEM). For each distribution of mass selected nanoparticles,
the height determined by STM and the width determined by TEM are seen to be similar throughout the mass range investigated.
The particles are found to have a well-defined morphology for diameters below approximately 6 nm. Larger nanoparticles are
less well-defined having rough surfaces, unlike the equilibrium morphology determined from the Wulff construction. The morphology
of the particles is, in general, believed to be determined by the conditions inside the gas-aggregation source and the morphology
is retained as the particles are soft-landed on the substrate. 相似文献
4.
Kyung O. Yu Christin M. Grabinski Amanda M. Schrand Richard C. Murdock Wei Wang Baohua Gu John J. Schlager Saber M. Hussain 《Journal of nanoparticle research》2009,11(1):15-24
The present study was designed to examine the uptake, localization, and the cytotoxic effects of well-dispersed amorphous
silica nanoparticles in mouse keratinocytes (HEL-30). Mouse keratinocytes were exposed for 24 h to various concentrations
of amorphous silica nanoparticles in homogeneous suspensions of average size distribution (30, 48, 118, and 535 nm SiO2) and then assessed for uptake and biochemical changes. Results of transmission electron microscopy revealed all sizes of
silica were taken up into the cells and localized into the cytoplasm. The lactate dehydrogenase (LDH) assay shows LDH leakage
was dose- and size-dependent with exposure to 30 and 48 nm nanoparticles. However, no LDH leakage was observed for either
118 or 535 nm nanoparticles. The mitochondrial viability assay (MTT) showed significant toxicity for 30 and 48 nm at high
concentrations (100 μg/mL) compared to the 118 and 535 nm particles. Further studies were carried out to investigate if cellular
reduced GSH and mitochondria membrane potential are involved in the mechanism of SiO2 toxicity. The redox potential of cells (GSH) was reduced significantly at concentrations of 50, 100, and 200 μg/mL at 30 nm
nanoparticle exposures. However, silica nanoparticles larger than 30 nm showed no changes in GSH levels. Reactive oxygen species
(ROS) formation did not show any significant change between controls and the exposed cells. In summary, amorphous silica nanoparticles
below 100 nm induced cytotoxicity suggest size of the particles is critical to produce biological effects. 相似文献
5.
Mariko Ono-Ogasawara Fumio Serita Mitsutoshi Takaya 《Journal of nanoparticle research》2009,11(7):1651-1659
As the production of engineered nanomaterials quantitatively expands, the chance that workers involved in the manufacturing
process will be exposed to nanoparticles also increases. A risk management system is needed for workplaces in the nanomaterial
industry based on the precautionary principle. One of the problems in the risk management system is difficulty of exposure
assessment. In this article, examples of exposure assessment in nanomaterial industries are reviewed with a focus on distinguishing
engineered nanomaterial particles from background nanoparticles in workplace atmosphere. An approach by JNIOSH (Japan National
Institute of Occupational Safety and Health) to quantitatively measure exposure to carbonaceous nanomaterials is also introduced.
In addition to real-time measurements and qualitative analysis by electron microscopy, quantitative chemical analysis is necessary
for quantitatively assessing exposure to nanomaterials. Chemical analysis is suitable for quantitative exposure measurement
especially at facilities with high levels of background NPs. 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.
Chuen-Jinn Tsai Cheng-Yu Huang Sheng-Chieh Chen Chi-En Ho Cheng-Hsiung Huang Chun-Wan Chen Cheng-Ping Chang Su-Jung Tsai Michael J. Ellenbecker 《Journal of nanoparticle research》2011,13(9):4161-4172
In this study, nanoparticle (NP, diameter < 100 nm) and respirable particles measurements were conducted at three different
nanopowder workplaces, including the mixing area of a nano-SiO2-epoxy molding compound plant (primary diameter: 15 nm), bagging areas of a nano-carbon black (nano-CB) (primary diameter:
32 nm) and a nano-CaCO3 (primary diameter: 94 nm) manufacturing plant. Chemical analysis of respirable particle mass (RPM) and NPs was performed
to quantify the content of manufactured nanoparticles in the collected samples. Nanopowder products obtained from the plants
were used in the laboratory dustiness testing using a rotating drum tester to obtain particle mass and number distributions.
The obtained laboratory data were then used to elucidate the field data. Both field and laboratory data showed that NP number
and mass concentrations of manufactured materials were close to the background level. Number concentration was elevated only
for particles with the electrical mobility diameter >100 nm during bagging or feeding processes, unless there were combustion-related
incidental sources existed. Large fraction of nanomaterials was found in the RPM due to agglomeration of nanomaterials or
attachment of nanomaterials to the larger particles. From this study, it is concluded that RPM concentration measurements
are necessary for the exposure assessment of nanoparticles in workplaces. 相似文献
8.
Production and handling of manufactured nanoparticles (MNP) may result in unwanted worker exposure. The size distribution
and structure of MNP in the breathing zone of workers will differ from the primary MNP produced. Homogeneous coagulation,
scavenging by background aerosols, and surface deposition losses are determinants of this change during transport from source
to the breathing zone, and to a degree depending on the relative time scale of these processes. Modeling and experimental
studies suggest that in MNP production scenarios, workers are most likely exposed to MNP agglomerates or MNP attached to other
particles. Surfaces can become contaminated by MNP, which constitute potential secondary sources of airborne MNP-containing
particles. Dustiness testing can provide insight into the state of agglomeration of particles released during handling of
bulk MNP powder. Test results, supported by field data, suggest that the particles released from powder handling occur in
distinct size modes and that the smallest mode can be expected to have a geometric mean diameter >100 nm. The dominating presence
of MNP agglomerates or MNP attached to background particles in the air during production and use of MNP implies that size
alone cannot, in general, be used to demonstrate presence or absence of MNP in the breathing zone of workers. The entire respirable
size fraction should be assessed for risk from inhalation exposure to MNP. 相似文献
9.
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
10.
Electrochemical method for the synthesis of silver nanoparticles 总被引:1,自引:0,他引:1
Rashid A. Khaydarov Renat R. Khaydarov Olga Gapurova Yuri Estrin Thomas Scheper 《Journal of nanoparticle research》2009,11(5):1193-1200
The article deals with a novel electrochemical method of preparing long-lived silver nanoparticles suspended in aqueous solution
as well as silver powders. The method does not involve the use of any chemical stabilising agents. The morphology of the silver
nanoparticles obtained was studied using transmission electron microscopy, scanning electron microscopy, atomic force microscopy
and dynamic light scattering measurements. Silver nanoparticles suspended in water solution that were produced by the present
technique are nearly spherical and their size distribution lies in the range of 2 to 20 nm, the average size being about 7 nm.
Silver nanoparticles synthesised by the proposed method were sufficiently stable for more than 7 years even under ambient
conditions. Silver crystal growth on the surface of the cathode in the electrochemical process used was shown to result in
micron-sized structures consisting of agglomerated silver nanoparticles with the sizes below 40 nm. 相似文献
11.
Michael P. Beck Yanhui Yuan Pramod Warrier Amyn S. Teja 《Journal of nanoparticle research》2009,11(5):1129-1136
We present new data for the thermal conductivity enhancement in seven nanofluids containing 8–282 nm diameter alumina nanoparticles
in water or ethylene glycol. Our results show that the thermal conductivity enhancement in these nanofluids decreases as the
particle size decreases below about 50 nm. This finding is consistent with a decrease in the thermal conductivity of alumina
nanoparticles with decreasing particle size, which can be attributed to phonon scattering at the solid–liquid interface. The
limiting value of the enhancement for nanofluids containing large particles is greater than that predicted by the Maxwell
equation, but is predicted well by the volume fraction weighted geometric mean of the bulk thermal conductivities of the solid
and liquid. This observation was used to develop a simple relationship for the thermal conductivity of alumina nanofluids
in both water and ethylene glycol. 相似文献
12.
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
13.
Harald Hagendorfer Christiane Lorenz Ralf Kaegi Brian Sinnet Robert Gehrig Natalie V. Goetz Martin Scheringer Christian Ludwig Andrea Ulrich 《Journal of nanoparticle research》2010,12(7):2481-2494
This study describes methods developed for reliable quantification of size- and element-specific release of engineered nanoparticles
(ENP) from consumer spray products. A modified glove box setup was designed to allow controlled spray experiments in a particle-minimized
environment. Time dependence of the particle size distribution in a size range of 10–500 nm and ENP release rates were studied
using a scanning mobility particle sizer (SMPS). In parallel, the aerosol was transferred to a size-calibrated electrostatic
TEM sampler. The deposited particles were investigated using electron microscopy techniques in combination with image processing
software. This approach enables the chemical and morphological characterization as well as quantification of released nanoparticles
from a spray product. The differentiation of solid ENP from the released nano-sized droplets was achieved by applying a thermo-desorbing
unit. After optimization, the setup was applied to investigate different spray situations using both pump and gas propellant
spray dispensers for a commercially available water-based nano-silver spray. The pump spray situation showed no measurable
nanoparticle release, whereas in the case of the gas spray, a significant release was observed. From the results it can be
assumed that the homogeneously distributed ENP from the original dispersion grow in size and change morphology during and
after the spray process but still exist as nanometer particles of size <100 nm. Furthermore, it seems that the release of
ENP correlates with the generated aerosol droplet size distribution produced by the spray vessel type used. This is the first
study presenting results concerning the release of ENP from spray products. 相似文献
14.
A. Kotoulas M. Gjoka K. Simeonidis I. Tsiaoussis M. Angelakeris O. Kalogirou C. Dendrinou-Samara 《Journal of nanoparticle research》2011,13(5):1897-1908
The controllable synthesis of relatively large nickel nanoparticles via thermal decomposition of nickel acetate tetrahydrate
in oleylamine in the presence of 1-adamantane carboxylic acid (ACA) and trioctylphosphine oxide (TOPO) is reported. High crystalline
hcp nanoparticles of different sizes have been prepared at 290 °C, whereas at relative lower temperatures fcc are favored.
The particle size was varying between 50 and 150 nm by properly adjusting the proportion of the capping ligands. TOPO-to-ACA
ratio was also found to have an influence on the magnetic properties through the potential formation of a NiO shell. Pure
hcp Ni nanoparticles over 50 nm in size served as models to illuminate the magnetic behavior of this metastable hexagonal
Ni phase. Contrary to the net ferromagnetic characteristics of fcc Ni nanoparticles in the same size range, hexagonal structured
particles exhibit superparamagnetic behavior at room temperature and a weak ferromagnetic contribution below 15 K. 相似文献
15.
Aniket S. Wadajkar Bhanuprasanth Koppolu Maham Rahimi Kytai T. Nguyen 《Journal of nanoparticle research》2009,11(6):1375-1382
The objective of this research project is to investigate the biocompatibility of N-isopropylacrylamide (NIPAAm) monomers and poly(N-isopropylacrylamide) (PNIPAAm) nanoparticles in vitro. PNIPAAm nanoparticles of different sizes were synthesized and characterized
by transmission electron microscopy and dynamic light scattering. Cytotoxicity studies using MTS assays were conducted on
fibroblasts, smooth muscle cells, and endothelial cells. In addition, the concentration of NIPAAm monomers remaining on PNIPAAm
nanoparticles was determined using bromination and spectrophotometry. The cytotoxicity results did not show a significant
difference in cell survival when cells were exposed to different particle sizes (100, 300, and 500 nm). Dose studies showed
that all three cell types exposed to 100 nm PNIPAAm nanoparticles at concentrations less than or equal to 5 mg/mL were compatible,
while cells exposed to NIPAAm monomers exhibited toxicity even at very low concentrations. We also found that 1 mg/mL concentration
of 100 nm PNIPAAm nanoparticles was cytocompatible for 4 days, whereas NIPAAm monomers were cytotoxic after 24 h of exposure.
Photomicrographs showed altered morphology in cells exposed to NIPAAm monomers, while cells exposed to PNIPAAm nanoparticles
maintained their normal morphology. Finally, a very low concentration of NIPAAm monomers remained on the PNIPAAm nanoparticles
after synthesis and dialysis. Our results demonstrate that NIPAAm monomers are cytotoxic, whereas PNIPAAm nanoparticles are
compatible at 5 mg/mL concentration or below for fibrobasts, smooth muscle cells, and endothelial cells. 相似文献
16.
Yi-Hsin Lien Tzong-Ming Wu Jhao-Huei Wu Jiunn-Wang Liao 《Journal of nanoparticle research》2011,13(10):5065-5075
The nanoparticles containing thermosensitive and magnetic properties were investigated for their potential use as a novel
drug carrier for targeted and controlled release drug delivery system. These thermosensitive and magnetic nanoparticles were
prepared by grafting thermosensitive poly (N-isopropylacrylamide) (PNIPAM) on the surface of silica (SiO2)-coated Fe3O4 nanoparticles with the particle size of 18.8 ± 1.6 nm. Adsorption and desorption behavior of bovine serum albumin (BSA) on
the surface of PNIPAM-grafted SiO2/Fe3O4 nanoparticles was studied, and the results indicated that these nanoparticles were able to absorb protein at temperature
above the lower critical solution temperature (LCST) and to be desorbed below the LCST. Cytotoxicity studies conducted on
Chinese hamster ovary (CHO-K1) cells using methyl tetrazolium (MTT) assays revealed that cell viability of 1 mg/mL PNIPAM-grafted
nanoparticles was slightly decreased after 24 h of incubation as compared to the lower concentration of nanoparticles. Furthermore,
the concentration of 0.5 mg/mL PNIPAM-grafted nanoparticles was totally biocompatible for 48 h, but had low cytotoxicity after
72 h of incubation. These PNIPAM-grafted nanoparticles did not induce morphological change in their cellularity after exposure
for 24 and 108 h. These results demonstrate that PNIPAM-grafted nanoparticles are biocompatible and have potential use as
drug carriers. 相似文献
17.
Zi-Chun Zhu Qing-Sheng Wu Ping Chen Xiao-Hong Yang 《Journal of nanoparticle research》2011,13(10):5347-5353
In this article, a new synthetic method of nanoparticles with fresh Chinese gooseberry juice (CGJ) as bio-template was developed.
One-step synthesis of highly water-soluble silver nanoparticles at room temperature without using any harmful reducing agents
and special capping agent was fulfilled with this method. In the process, the products were obtained by adding AgNO3 to CGJ, which was used as reducing agent, capping agent, and the bio-template. The products of silver nanoparticles with
diameter of 10–30 nm have strong water solubility and excellent antibiotic function. With the same concentration 0.047 μg mL−1, the antibacterial effect of water-soluble silver particles by fresh CGJ was 53%, whereas only 27% for silver nanoparticles
synthesized using the template method of fresh onion inner squama coat (OISC). The excellent water solubility of the products
would enable them have better applications in the bio-medical field. The synthetic method would also have potential application
in preparing other highly water-soluble particles, because of its simple apparatus, high yield, mild conditions, and facile
operation. 相似文献
18.
Gorazd Hribar Andrej Žnidaršič Marjan Bele Uroš Maver Simon Caserman Miran Gaberšček Vladka Gaberc-Porekar 《Journal of nanoparticle research》2011,13(7):3019-3032
The authors’ intention was to prepare nanometer-sized zinc-phosphate nanoparticles that would be capable of binding histidine-rich
TNF-α analogs onto their surface via a coordinative bond. Zinc-phosphate nanoparticles with a size of around 60 nm were prepared
by a wet precipitation method and characterized using SEM, EDX, XRD, and DLS. First, BSA was bound as a testing protein, afterward
two TNF-α analogs with decreased activity were bound to the described nanoparticles. The efficiency of binding and the existence
of coordinative bond were confirmed with SDS-PAGE analysis. During binding, particle storage, and release experiments, the
prepared TNF-α analogs retained their biological activity—hence the epitopes necessary for formation of antibodies stayed
intact. The particle size did not change within a period of 2 weeks. No significant agglomeration was observed, the particles
could be quickly dispersed in ultrasound. The present nanoparticles and the general approach of coordinative binding are widely
applicable for natural and engineered histidine-rich proteins. The nanoparticles bearing appropriate TNF-α analogs could also
be potentially used for active immunotherapy to tackle the chronic inflammatory diseases associated with pathogenically elevated
levels of TNF-α. 相似文献
19.
Uğur Tamer İsmail H. Boyacı Erhan Temur Adem Zengin İlker Dincer Yalçın Elerman 《Journal of nanoparticle research》2011,13(8):3167-3176
The preparation and application of rod-shaped core–shell structured Fe3O4–Au nanoparticles for immunomagnetic separation and sensing were described for the first time with this study. To synthesize
magnetic gold nanorod particles, the seed-mediated synthetic method was carried out and the resulting nanoparticles were characterized
with transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV–Vis), energy-dispersive X-ray (EDX), and
X-ray diffraction (XRD). Magnetic properties of the nanoparticles were also examined. Characterization of the magnetic gold
nanorod particles has proven that the resulting nanoparticles were composed of Fe3O4 core and the gold shell. The rod-shaped gold-coated iron nanoparticles have an average diameter of 16 ± 2 nm and an average
length of about 50 ± 5 nm (corresponding aspect ratio of 3). The saturation magnetization value for the magnetic gold nanorod
particles was found to be 37 emu/g at 300 K. Rapid and room temperature reaction synthesis of magnetic gold nanorod particles
and subsequent surface modification with E. coli antibodies provide immunomagnetic separation and SERS application. The analytical performance of the SERS-based homogenous
sandwich immunoassay system with respect to linear range, detection limit, and response time is also presented. 相似文献
20.
Veeranarayanan S Poulose AC Mohamed S Aravind A Nagaoka Y Yoshida Y Maekawa T Kumar DS 《Journal of fluorescence》2012,22(2):537-548
The use of fluorescent nanomaterials has gained great importance in the field of medical imaging. Many traditional imaging
technologies have been reported utilizing dyes in the past. These methods face drawbacks due to non-specific accumulation
and photobleaching of dyes. We studied the uptake and internalization of two different sized (30 nm and 100 nm) FITC labeled
silica nanoparticles in Human umbilical vein endothelial cell line. These nanomaterials show high biocompatability and are
highly photostable inside live cells for increased period of time in comparison to the dye alone. To our knowledge, we report
for the first time the use of 30 nm fluorescent silica nanoparticles as efficient endothelial tags along with the well studied
100 nm particles. We also have emphasized the good photostability of these materials in live cells. 相似文献