Nanoparticle From Wikipedia, th e free encyclopedia (Redirected from Nanopar ti cl es) In nanotechn ology , a particle is def ined as a sm all ob ject that behav es as a whole unit with respect to its tran sport and properties. Particles are furth er classif ied accordin g to diam eter. [1] Coarse particles cover a range between 10,000 and 2,500 nanom eters. Fine particles are sized between 2,500 and 100 nanometers. Ultrafine particles, or nanopar ticles, are between 1 and 100 nanometers in size. The reason for th is double n ame ofth e sam e ob ject i s that, durin g the 1970-80s, wh en the f irst thorough f undam en tal studies with "nanoparticles" were underway in the USA (by Granqv ist and Buhrm an ) [2] an d Japan, (within an ERATO Project) [3] th ey were called "ultraf ine particles" (UFP). However, during the 1990s before th e National Nanotechn olog y Initiativ e was launch ed in th e USA, the n ew n am e, "nanoparticle," h ad becom e fashi onable (see , for ex am ple th e sam e sen ior author's paper 20 years lateraddressin g the same issue, logn orm al distribution of si zes [4 ] ). Nanoparticles m ay or m ay not ex h ibit siz e-relatedpropert i es th at di ffer sign i ficantly from those observed in fi n e particles or bulk m aterials. [5][6] Although the size of m ost m olecules would f it into the above outline, individual m olecules are usuall y not referred to as nanoparticles. Nanocl u sters h av e at least one dim ension between 1 an d 10 n anom eters and a n arrow siz e distributi on. Nanopowd ers [7] are agg l om erates ofultraf ine particles, nanoparticles, or nan oclusters. Nanom eter- si zed sing l e crystals, or single-dom ain ultraf ine particles, are often referred to as n anocrystals. Nanopar ti cl e rese arch i s cu rren tl y an area ofintense scientif ic interest due to a wide v ariety ofpoten ti al appl i cati on s in biom edical , optical an d e l ectron i c fields. [8][9][10][11] Th e National Nanotechn ology Initiative has led to generous public f unding for nan oparti cle resear ch in the UnitedStates. Contents 1 Backgroun d2 Unif ormi ty 3 Properties 4 Synthesis 4.1 Sol-g el 5 Colloids 6 Mo rphol ogy 7 Characteriz ation 8 Function alization 8.1 Surface coating f or biolog ical application s 9 Safety 10 Laser a ppl i cation s 11 Medicinal application s 12 See also 13 References 14 Extern al links
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NanoparticleFrom Wikipedia, the f ree encyclopedia
(Redirected f rom Nanoparticles)
In nanotechnology, a particle is def ined as a small ob ject that behaves as a whole unit with respect to its transport
and properties. Particles are f urther classif ied according to diameter.[1] Coarse particles cover a range between
10,000 and 2,500 nanometers. Fine particles are sized between 2,500 and 100 nanometers. Ultraf ine particles, or
nanoparticles, are between 1 and 100 nanometers in size. The reason f or this double name of the same ob ject is
that, during the 1970-80s, when the f irst thorough f undamental studies with "nanoparticles" were underway in the
USA (by Granqvist and Buhrman)[2] and Japan, (within an ERATO Project)[3] they were called "ultraf ine particle
(UFP). However, during the 1990s bef ore the National Nanotechnology Initiative was launched in the USA, the
new name, "nanoparticle," had become f ashionable (see, f or exam ple the same senior author's paper 20 years late
addressing the same issue, lognormal distribution of sizes [4]). Nanoparticles may or may not exhibit size-related
properties that dif f er signif icantly f rom those observed in f ine particles or bulk materials.[5][6] Although the size of
most molecules would f it into the above outline, individual molecules are usually not ref erred to as nanoparticles.
Nanoclusters have at least one dimension between 1 and 10 nanometers and a narrow size distribution. Nanopowders[7] are agglomerates of ultraf ine particles, nanoparticles, or nanoclusters. Nanometer-sized single
crystals, or single-domain ultraf ine particles, are of ten ref erred to as nanocrystals.
Nanoparticle research is currently an area of intense scientif ic interest due to a wide variety of potential application
in biomedical, optical and electronic f ields.[8][9][10][11]
The National Nanotechnology Initiative has led to generous public f unding f or nanoparticle research in the United
TEM (a, b, and c) images of prepared mesoporous silica
nanoparticles with mean outer diameter: (a) 20nm, (b) 45nm, and (c)
80nm. SEM (d) image corresponding to (b). The insets are a high
magnification of mesoporous silica particle. [12]
IUPAC def inition
Background
Although, in general, nanoparticles are
considered a discovery of modern science,
they actually have a very long history.
Nanoparticles were used by artisans as f ar
back as the 9th century in Mesopotamia
f or generating a glittering ef f ect on the
surf ace of pots[citation needed ].
Even these days, pottery f rom the Middle
Ages and Renaissance of ten retain a
distinct gold- or copper-colored metallic
glitter. This luster is caused by a metallic
f ilm that was applied to the transparent
surf ace of a glazing. The luster can still be
visible if the f ilm has resisted atmospheric
oxidation and other weathering.
The luster originated within the f ilm itself ,
which contained silver and copper
nanoparticles dispersed homogeneously in
the glassy matrix of the ceramic
glaze. These nanoparticles were
created by the artisans by adding
copper and silver salts and oxides
together with vinegar, ochre, and clay on the surf ace of previously-
glazed pottery. The object was
then placed into a kiln and heated
to about 600 °C in a reducing
atmosphere.
In the heat the glaze would sof ten,
causing the copper and silver ions
to migrate into the outer layers of
the glaze. There the reducingatmosphere reduced the ions back
to metals, which then came
together f orming the nanoparticles
that give the colour and optical ef f ects.
Luster technique showed that ancient craf tsmen had a rather sophisticated em pirical knowledge of materials. The
technique originated in the Islamic world. As Muslims were not allowed to use gold in artistic representations, they
had to f ind a way to create a similar ef f ect without using real gold. The solution they f ound was using luster.[16]
Particle of any shape with dimensions in the 1 × 10
–9
and 1 × 10
–7
m range.
N ote 1: Modified from definitions of nanoparticle and nanogel in [refs., [13][14]]
N ote 2: The basis of the 100-nm limit is the fact that novel properties thatdifferentiate particles from the bulk material typically develop at a critical
length scale of under 100 nm.
N ote 3: Because other phenomena (transparency or turbidity, ultrafiltration,stable dispersion, etc.) that extend the upper limit are occasionally considered,the use of the prefix nano is accepted for dimensions smaller than 500 nm,
provided reference to the definition is indicated.
N ote 4: Tubes and fibers with only two dimensions below 100 nm are also
Michael Faraday provided the f irst description, in scientif ic terms, of the optical properties of nanometer-scale
metals in his classic 1857 paper. In a subsequent paper, the author (Turner) points out that: "It is well known that
when thin leaves of gold or silver are mounted upon glass and heated to a tem perature that is well below a red hea
(~500 °C), a remarkable change of properties takes place, whereby the continuity of the metallic f ilm is destroyed
The result is that white light is now f reely transmitted, ref lection is correspondingly diminished, while the electrical
resistivity is enormously increased." [17][18][19]
Unif ormity
The chemical processing and synthesis of high-perf ormance technological com ponents f or the private, industrial,
and military sectors requires the use of high-purity ceramics, polymers, glass-ceramics, and material com posites. I
condensed bodies f ormed f rom f ine powders, the irregular particle sizes and shapes in a typical powder of ten lead
to non-unif orm packing morphologies that result in packing density variations in the powder com pact.
Uncontrolled agglomeration of powders due to attractive van der Waals f orces can also give rise to in
microstructural inhomogeneities. Dif f erential stresses that develop as a result of non-unif orm drying shrinkage are
directly related to the rate at which the solvent can be removed, and thus highly dependent upon the distribution of
porosity. Such stresses have been associated with a plastic-to-brittle transition in consolidated bodies, and can yieto crack propagation in the unf ired body if not relieved. [20] [21] [22]
In addition, any f luctuations in packing density in the com pact as it is prepared f or the kiln are of ten am plif ied durin
the sintering process, yielding inhomogeneous densif ication. Some pores and other structural def ects associated
with density variations have been shown to play a detrimental role in the sintering process by growing and thus
limiting end-point densities. Dif f erential stresses arising f rom inhomogeneous densif ication have also been shown to
result in the propagation of internal cracks, thus becoming the strength-controlling f laws. [23][24] [25]
Inert gas evaporation and inert gas deposition [2][3] are f ree many of these def ects due to the distillation (cf .
purif ication) nature of the process and having enough time to f orm single cr ystal particles, however even their non-aggreated deposits have lognormal size distribution, which is typical with nanoparticles.[3] The reason why modern
gas evaporation techniques can produce a relatively narrow size distribution is that aggregation can be avoided.[3]
However, even in this case, random residence times in the growth zone, due to the com bination of drif t and
dif f usion, result in a size distribution appearing lognormal.[4]
It would, theref ore, appear desirable to process a material in such a way that it is physically unif orm with regard to
the distribution of com ponents and porosity, rather than using particle size distributions that will maximize the green
density. The containment of a unif ormly dispersed assem bly of strongly interacting particles in suspension requires
total control over interparticle f orces. Monodisperse nanoparticles and colloids provide this potential. [26]
Monodisperse powders of colloidal silica, f or exam ple, may theref ore be stabilized suf f iciently to ensure a high
degree of order in the colloidal crystal or polycrystalline colloidal solid that results f rom aggregation. The degree o
order appears to be limited by the time and space allowed f or longer-range correlations to be established. Such
def ective polycrystalline colloidal structures would appear to be the basic elements of submicrometer colloidal
materials science and, theref ore, provide the f irst step in developing a more rigorous understanding of the
mechanisms involved in microstructural evolution in high perf ormance materials and com ponents. [27] [28]
Clay nanoparticles when incorporated into polymer matrices increase reinf orcement, leading to stronger plastics,
verif iable by a higher glass transition tem perature and other mechanical property tests. These nanoparticles are
hard, and im part their properties to the polymer (plastic). Nanoparticles have also been attached to textile f ibers in
order to create smart and f unctional clothing.[38]
Metal, dielectric, and semiconductor nanoparticles have been f ormed, as well as hybrid structures (e.g., core–shel
nanoparticles).[39] Nanoparticles made of semiconducting material may also be labeled quantum dots if they are
small enough (typically sub 10 nm) that quantization of electronic energy levels occurs. Such nanoscale particles arused in biomedical applications as drug carriers or imaging agents.
Semi-solid and sof t nanoparticles have been manuf actured. A prototy pe nanoparticle of semi-solid nature is the
liposome. Various types of liposome nanoparticles are currently used clinically as delivery systems f or anticancer
drugs and vaccines.
Nanoparticles with one half hydrophilic and the other half hydrophobic are termed Janus particles and are
particularly ef f ective f or stabilizing emulsions. They can self -assem ble at water/oil interf aces and act as solid
surf actants.
Synthesis
There are several methods f or creating nanoparticles, including both attrition and pyrolysis. In attrition, macro- or
micro-scale particles are ground in a ball mill, a planetary ball mill, or other size-reducing mechanism. The resulting
particles are air classif ied to recover nanoparticles. In pyrolysis, a vaporous precursor (liquid or gas) is f orced
through an orif ice at high pressure and burned. The resulting solid (a version of soot) is air classif ied to recover
oxide particles f rom by-product gases. Pyrolysis of ten results in aggregates and agglomerates rather than single
primary particles.
A thermal plasma can also deliver the energy necessar y to cause vaporization of small micrometer-size particles.The thermal plasma tem peratures are in the order of 10,000 K, so that solid powder easily evaporates.
Nanoparticles are f ormed upon cooling while exiting the plasma region. The main ty pes of the thermal plasma
torches used to produce nanoparticles are dc plasma jet, dc arc plasma, and radio f requency (RF) induction
plasmas. In the arc plasma reactors, the energy necessary f or evaporation and reaction is provided by an electric
arc f ormed between the anode and the cathode. For exam ple, silica sand can be vaporized with an arc plasma at
atmospheric pressure. The resulting mixture of plasma gas and silica vapour can be rapidly cooled by quenching
with oxygen, thus ensuring the quality of the f umed silica produced.
In RF induction plasma torches, energy coupling to the plasma is accom plished through the electromagnetic f ield
generated by the induction coil. The plasma gas does not come in contact with electrodes, thus eliminating possible
sources of contamination and allowing the operation of such plasma torches with a wide range of gases including
inert, reducing, oxidizing, and other corrosive atmospheres. The working f requency is ty pically between 200 kHz
and 40 MHz. Laborator y units run at power levels in the order of 30–50 kW, whereas the large-scale industrial
units have been tested at power levels up to 1 MW. As the residence time of the in jected f eed droplets in the
plasma is very short, it is im portant that the droplet sizes are small enough in order to obtain com plete evaporation
The RF plasma method has been used to synthesize dif f erent nanoparticle materials, f or exam ple synthesis of
various ceramic nanoparticles such as oxides, carbours/carbides, and nitrides of Ti and Si (see Induction plasma
Inert-gas condensation is f requently used to make nanoparticles f rom metals with low melting points. The metal is
vaporized in a vacuum cham ber and then supercooled with an inert gas stream. The supercooled metal vapor
condenses into nanometer-size particles, which can be entrained in the inert gas stream and deposited on a
substrate or studied in situ.
Nanoparticles can also be f ormed using radiation chemistry. Radiolysis f rom gamma rays can create strongly activ
f ree radicals in solution. This relatively sim ple technique uses a minimumnum ber of chemicals. These including
water, a soluble metallic salt, a radical scavenger (of ten a secondary alcohol), and a surf actant (organic capping
agent). High gamma doses on the order of 104 Gray are required. In this process, reducing radicals will drop
metallic ions down to the zero-valence state. A scavenger chemical will pref erentially interact with oxidizing radica
to prevent the re-oxidation of the metal. Once in the zero-valence state, metal atoms begin to coalesce into
particles. A chemical surf actant surrounds the particle during f ormation and regulates its growth. In suf f icient
concentrations, the surf actant molecules stay attached to the particle. This prevents it f rom dissociating or f orming
clusters with other particles. Formation of nanoparticles using the radiolysis method allows f or tailoring of particle
size and shape by adjusting precursor concentrations and gamma dose.[40]
Sol-gel
The sol-gel process is a wet-chemical technique (also known as chemical solution deposition) widely used recently
in the f ields of materials science and ceramic engineering. Such methods are used primarily f or the f abrication of
materials (typically a metal oxide) starting f rom a chemical solution (sol, short f or solution), which acts as the
precursor f or an integrated network (or gel) of either discrete particles or network polymers. [41]
Ty pical precursors are metal alkoxides and metal chlorides, which undergo hydrolysis and polycondensation
reactions to f orm either a network "elastic solid" or a colloidal suspension (or dispersion) – a system com posed of
discrete (of ten amorphous) submicrometer particles dispersed to various degrees in a host f luid. Formation of a
metal oxide involves connecting the metal centers with oxo (M-O-M) or hydroxo (M-OH-M) bridges, theref ore
generating metal-oxo or metal-hydroxo polymers in solution. Thus, the sol evolves toward the f ormation of a gel-like diphasic system containing both a liquid phase and solid phase whose morphologies range f rom discrete
particles to continuous polymer networks.[42]
In the case of the colloid, the volume f raction of particles (or particle density) may be so low that a signif icant
amount of f luid may need to be removed initially f or the gel-like properties to be recognized. This can be
accom plished in any num ber of ways. The most sim ple method is to allow time f or sedimentation to occur, and the
pour of f the remaining liquid. Centrif ugation can also be used to accelerate the process of phase separation.
Removal of the remaining liquid (solvent) phase requires a dr ying process, which is typically accom panied by a
signif icant amount of shrinkage and densif ication. The rate at which the solvent can be removed is ultimately
determined by the distribution of porosity in the gel. The ultimate microstructure of the f inal com ponent will clearly
be strongly inf luenced by changes im plemented during this phase of processing. Af terward, a thermal treatment, or
f iring process, is of ten necessary in order to f avor f urther polycondensationand enhance mechanical properties an
structural stability via f inal sintering, densif ication, and grain growth. One of the distinct advantages of using this
methodology as opposed to the more traditional processing techniques is that densif ication is of ten achieved at a
much lower tem perature.
The precursor sol can be either deposited on a substrate to f orm a f ilm (e.g., by dip-coating or spin-coating), cast
into a suitable container with the desired shape (e.g., to obtain a monolithic ceramics, glasses, f ibers, mem branes,
aerogels), or used to synthesize powders (e.g., microspheres, nanospheres). The sol-gel approach is a cheap and
low-tem perature technique that allows f or the f ine control of the product’s chemical com position. Even small
quantities of dopants, such as organic dyes and rare earth metals, can be introduced in the sol and end up unif orm
dispersed in the f inal product. It can be used in ceramics processing and manuf acturing as an investment casting
material, or as a means of producing ver y thin f ilms of metal oxides f or various purposes. Sol-gel derived materials
have diverse applications in optics, electronics, energy, space, (bio)sensors, medicine (e.g., controlled drug releas
and separation (e.g., chromatography) technology.[43][44]
Colloids
The term colloid is used primarily to describe a broad range of solid–liquid (and/or liquid– liquid) mixtures, all of
which containing distinct solid (and/or liquid) particles that are dispersed to various degrees in a liquid medium. Th
term is specif ic to the size of the individual particles, which are larger than atomic dimensions but small enough to
exhibit Brownian motion. If the particles are large enough then their dynamic behavior in any given period of time i
suspension would be governed by f orces of gravity and sedimentation. But, if they are small enough to be colloids
then their irregular motion in suspension can be attributed to the collective bom bardment of a myriad of thermally
agitated molecules in the liquid suspending medium, as described originally by Albert Einstein in his dissertation.
Einstein proved the existence of water molecules by concluding that this erratic particle behavior could adequately
be described using the theory of Brownian motion, with sedimentation being a possible long-term result. This criticsize range (or particle diameter) ty pically ranges f rom nanometers (10−9 m) to micrometers (10−6 m).[45]
Morphology
Scientists have taken to naming their particles af ter the real-
world shapes that they might represent. Nanospheres,[46]
nanoreef s,[47] nanoboxes [48] and more have appeared in
the literature. These morphologies sometimes arise
spontaneously as an ef f ect of a tem plating or directing agent present in the synthesis such as miscellar emulsions or
anodized alumina pores, or f rom the innate crystallographic
growth patterns of the materials themselves.[49] Some of
these morphologies may serve a purpose, such as long
carbon nanotubes used to bridge an electrical junction, or
just a scientif ic curiosity like the stars shown at right.
Amorphous particles usually adopt a spherical shape (due
to their microstructural isotropy), whereas the shape of
anisotropic microcrystalline whiskers corresponds to their particular crystal habit. At the small end of the size range,
nanoparticles are of ten ref erred to as clusters. Spheres, rods, f ibers, and cups are just a f ew of the shapes that hav
been grown. The study of f ine particles is called micromeritics.
Characterization
Nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and
applications. Characterization is done by using a variety of dif f erent techniques, mainly drawn f rom materials
science. Common techniques are electron microscopy (TEM, SEM), atomic f orce microscopy (AFM), dynamic
spectrometry (MALDI-TOF), ultraviolet-visible spectroscopy, dual polarisation interf erometry and nuclear
magnetic resonance (NMR).
While the theory has been known f or over a century (see Robert Brown), the technology f or Nanoparticle trackin
analysis (NTA) allows direct tracking of the Brownian motion; this method. theref ore, allows the sizing of individua
nanoparticles in solution.
Functionalization
The surf ace coating of nanoparticles is crucial to determining their properties. In particular, the surf ace coating can
regulate stability, solubility, and targeting. A coating that is multivalent or polymeric conf ers high stability.
Functionalized nanomaterial-based catalysts can be used f or catalysis of many known organic reactions.
Surf ace coating f or biological applications
For biological applications, the surf ace coating should be polar to give high aqueous solubility and preventnanoparticle aggregation. In serum or on the cell surf ace, highly charged coatings promote non-specif ic binding,
whereas polyethylene glycol linked to terminal hydroxyl or methoxy groups repel non-specif ic interactions.[50][51]
Nanoparticles can be linked to biological molecules that can act as address tags, to direct the nanoparticles to
specif ic sites within the body,[52] specif ic organelles within the cell,[53] or to f ollow specif ically the movement of
individual protein or RNA molecules in living cells.[54] Common address tags are monoclonal antibodies, aptamers
streptavidin or peptides. These targeting agents should ideally be covalently linked to the nanoparticle and should b
present in a controlled num ber per nanoparticle. Multivalent nanoparticles, bearing multiple targeting groups, can
cluster receptors, which can activate cellular signaling pathways, and give stronger anchoring. Monovalent
nanoparticles, bearing a single binding site,[55][56][57] avoid clustering and so are pref erable f or tracking the
behavior of individual proteins.
See also Nanomedicine#Nanoparticle targeting
Red blood cell coatings can help nanoparticles evade the immune system.[58]
Saf ety
S ee also: Nanotoxicology, Fine particles, and Regulation o f nanotechnolog y
Nanoparticles present possible dangers, both medically and environmentally.[59][60] Most of these are due to the
high surf ace to volume ratio, which can make the particles very reactive or catalytic.[61] They are also able to pass
through cell mem branes in organisms, and their interactions with biological systems are relatively unknown.[62] A
recent study looking at the ef f ects of ZnO nanoparticles on human immune cells has f ound varying levels of
susceptibility to cytotoxicity.[63] There are concerns that pharmaceutical com panies, seeking regulatory approval f
nano-ref ormulations of existing medicines, are relying on saf ety data produced during clinical studies of the earlier,
pre-ref ormulation version of the medicine. This could result in regulatory bodies, such as the FDA, missing new sid
ef f ects that are specif ic to the nano-ref ormulation.[64]
Whether cosmetics and sunscreens containing nanomaterials pose health risks remains largely unknown at this
stage.[65] However considerable research has demonstrated that zinc nanoparticles are not absorbed into the
bloodstream in vivo.[66] Diesel nanoparticles have been f ound to damage the cardiovascular system in a mouse
model.[67]
Concern has also been raised over the health ef f ects of respirable nanoparticles f rom certain com bustion
processes.[68] As of 2013 the Environmental Protection Agency was investigating the saf ety of the f ollowing
nanoparticles:[69]
Carbon Nanotubes: Carbon materials have a wide range of uses, ranging f rom com posites f or use in vehicle
and sports equipment to integrated circuits f or electronic com ponents. The interactions between
nanomaterials such as carbon nanotubes and natural organic matter strongly inf luence both their aggregation
and deposition, which strongly af f ects their transport, transf ormation, and exposure in aquatic environments
In past research, carbon nanotubes exhibited some toxicological im pacts that will be evaluated in various
environmental settings in current EPA chemical saf ety research. EPA research will provide data, models, te
methods, and best practices to discover the acute health ef f ects of carbon nanotubes and identif y methods t
predict them.[69]
Cerium oxide: Nanoscale cerium oxide is used in electronics, biomedical supplies, energy, and f uel additive
Many applications of engineered cerium oxide nanoparticles naturally disperse themselves into the
environment, which increases the risk of exposure. There is ongoing exposure to new diesel emissions using
f uel additives containing CeO2 nanoparticles, and the environmental and public health im pacts of this new
technology are unknown. EPA’s chemical saf ety research is assessing the environmental, ecological, and
health im plications of nanotechnology-enabled diesel f uel additives.[69]
Titanium dioxide: Nano titanium dioxide is currently used in many products. Depending on the ty pe of
particle, it may be f ound in sunscreens, cosmetics, and paints and coatings. It is also being investigated f or
use in removing contaminants f rom drinking water.[69]
Nano Silver: Nano silver is being incorporated into textiles and other materials to eliminate bacteria and odof rom clothing, f ood packaging, and other items where antimicrobial properties are desirable. In collaboratio
with the U.S. Consumer Product Saf ety Commission, EPA is studying certain products to see whether they
transf er nano-size silver particles in real-world scenarios. EPA is researching this topic to better understand
how much nano-silver children come in contact with in their environments.[69]
Iron: While nano-scale iron is being investigated f or many uses, including “smart f luids” f or uses such as
optics polishing and as a better-absorbed iron nutrient supplement, one of its more prominent current uses i
to remove contamination f rom groundwater. This use, supported by EPA research, is being piloted at a
num ber of sites across the country.[69]
Laser applications
The use of nanoparticle distributions in laser dye-doped poly(methyl methacrylate) (PMMA) laser gain media was
demonstrated in 2003 and it has been shown to im prove conversion ef f iciencies and to decrease laser beam
divergence.[70] Researchers attribute the reduction in beam divergence to im proved dn/dT characteristics of the
organic-inorganic dye-doped nanocom posite. The optimumcom position reported by these researchers is 30% w/
3. ^ a b c d Ch. Hayashi, Ryozi Uyeda, A. Tasaki. (1997). U ltr a- f ine particles: ex plor ator y science and technolog y
(1997 Translation o f the Ja pan r e port o f the related ER ATO Pr o ject 1981–86 ). Noyes Publications.
4. ^
a
b
L.B. K iss, J. Söderlund, G.A. Niklasson, C.G. Granqvist (1999). "New approach to the origin of lognormalsize distributions of nanoparticles". N anotechnolog y 10: 25–28. Bibcode:1999Nanot..10...25K
11. ^ Taylor, R, Otanicar, T, Herukerrupu, Y, Bremond, F, Rosengarten, G, Hawkes, E, Jiang, X and Coulombe, S2013, 'Feasibility of nanofluid-based optical filters
(http://researchbank.rmit.edu.au/eserv/rmit:20882/n2006040764.pdf)', A pplied Optics, vol. 52, no. 7, pp. 1413-
1422
12. ^ A.B.D. Nandiyanto; S.-G K im; F. Iskandar; and K . Okuyama 2009 447–453
13. ^ Alan D. MacNaught, Andrew R. Wilkinson, ed. (1997). Com pendium o f Chemical Terminology: IU PAC
Recommendations (2nd ed.). Blackwell Science. ISBN 0865426848.
14. ^ Pure and Ap plied Chemistr y 79: 1801. 2007.
15. ^ "Terminology for biorelated polymers and applications (IUPAC Recommendations 2012)"
(http://pac.iupac.org/publications/pac/pdf/2012/pdf/8402x0377.pdf). Pur e and Applied Chemistr y 84 (2): 377–41
tr ans par ent_nano fluid s?ev=pr f _ pub), A pplied Optics, 52(24):6041-6050
30. ^ Buffat, Ph.; Borel, J.-P. (1976). "Size effect on the melting temperature of gold particles". Ph ysical Review A 1(6): 2287. Bibcode:1976PhRvA..13.2287B (http://adsabs.harvard.edu/abs/1976PhRvA..13.2287B).
43. ^ Klein, L. (1994). Sol-Gel O ptics: Processing and Ap plications (http://books.google.com/?
id=wH11Y4UuJNQC&printsec=frontcover). Springer Verlag. ISBN 0-7923-9424-0.
44. ^ Robert Corriu, Nguyên Trong Anh (2009). Molecular Chemistr y o f Sol-Gel Der ived N anomaterials
(http://books.google.com/?id=TMr5XeZXlL0C&pg=PA75). John Wiley and Sons. ISB N 0-470-72117-0.
45. ^ Pais, A. (2005). Subtle is the Lord: The Science and the Li fe o f Alber t Einstein (http://books.google.com/?
id=U2mO4nUunuwC&printsec=frontcover). Oxford University Press. ISBN 0-19-280672-6.
46. ^ Agam, M. A.; Guo, Q (2007). "Electron Beam Modification of Polymer Nanospheres". Jour nal o f N anoscienceand N anotechnolog y 7 (10): 3615–9. doi:10.1166/ jnn.2007.814 (http://dx.doi.org/10.1166%2Fjnn.2007.814).
(//www.ncbi.nlm.nih.gov/pubmed/18425138). | di spl ayaut hor s= suggested (help)
58. ^ http://physicsworld.com/cws/article/news/46344 Nanoparticles play at being red blood cells
59. ^ Mnyusiwalla, Anisa; Daar, A bdallah S; Singer, Peter A (2003). "Mind the gap : science and ethics in
nanotechnology". N anotechnolog y 14 (3): R9. Bibcode:2003Nanot..14R...9M(http://adsabs.harvard.edu/abs/2003Nanot..14R...9M). doi:10.1088/0957-4484/14/3/201
63. ^ Hanley, C; Thurber, A; Hanna, C; Punnoose, A; Zhang, J; Wingett, DG (2009). "The Influences of Cell Type an
ZnO Nanoparticle Size on Immune Cell Cytotoxicity and Cytokine Induction". N anoscale Res Lett 4 (12): 1409–2Bibcode:2009NRL.....4.1409H (http://adsabs.harvard.edu/abs/2009NRL... ..4.1409H). doi:10.1007/s11671-009-
Nanohedron.com (http://www.nanohedron.com) images of nanoparticlesAcquisition, evaluation and public orientated presentation of societal relevant data and f indings f or
Applications of Nanoparticles (http://www.understandingnano.com/nanoparticles.html)
International Journal of Nanoparticles (http://www.inderscience.com/browse/index.php? journalCODE=i jnp
Journal of Nanoparticle Research (http://www.springer.com/11051)
Nanoparticle Conf erences and Meetings (http://nanoparticles.org/meetings/)
Lectures on All Phases of Nanoparticle Science and Technology (http://nanoparticles.org/primers/)ENPRA – Risk Assessment of Engineered NanoParticles (http://www.enpra.eu/) EC FP7 Pro ject led by th
Institute of Occupational Medicine
SAFENANO (http://www.saf enano.org/) at the Institute of Occupational Medicine
Nanoparticles: An occupational hygiene review (http://www.hse.gov.uk/research/rrpdf /rr274.pdf ) by RJ
Aitken and others. Health and Saf ety Executive Research Report 274/2004
EMERGNANO: A review of com pleted and near com pleted environment, health and saf ety research on
nanomaterials and nanotechnology (http://www.iom-world.org/pubs/IOM_TM0901.pdf ) by RJ Aitken and