Transcript Applications of nanoparticles in Chemistry

THE APPLICATIONS OF
NANOPARTICLES IN CHEMISTRY
AND RELATED SCIENCES
BY
BENEDICT ISEROM ITA
PROFESSOR OF PHYSICAL/THEORETICAL CHEMISTRY AND COORDINATOR,
NANOSIENCE AND NANOTECHNOLOGY RESEARCH GROUP CHEMISTRY
DEPARTMENT, UNIVERSITY OF CALABAR, CALABAR, NIGERIA AND COVENANT
UNIVERSITY, OTA, OGUN STATE (email:
[email protected]; [email protected];
[email protected])
Abstract
• In this paper, we
explore the applications of
nanoparticles in chemistry and other related sciences
like technology and medicine. Nanoparticles are
defined as tiny objects each of nanometric dimensions
1 – 100nm and exhibit very useful and interesting
properties different from their bulk counterpart.
Chemistry ingenuity enables them to be applied as
catalysts, as magnetic materials, as anti-corrosion
agents etc. In technology, they are mainly used in
fabrication of equipment parts, as building materials
and in electronic devices etc. and in medicine they
have very wide applications. The most interesting
applications being in the treatments of various
diseases, etc. There is hardly any area of human
endeavor that has nothing to do with nanoparticles
Introduction
We shall discuss:
1) Definition of nanomaterials
2) Types of nanomaterials and their dimensions: nanoparticle
nanotubes/nanowires/nanoplates
nanofibres
nanofilms
3) Syntheses of nanoparticles
4) Applications of nanoparticles in chemistry
5) Applications of nanoparticles in technology
6) Applications of nanoparticles in biology and medicine
7) Advantages of nanotechnology and nanomaterials
8) Summary and Conclusion
9) References
Continuation
1) Definition of nanomaterials
A material is a substance that things can be
made from. For instance, building materials
will include things like bricks, sand, glass,
metals, etc. A substance is a type of solid,
liquid or gas that has particular quantities. A
nanomaterial is therefore a substance that
has small objects of nanometer (10-9
m) sizes.
Continuation
Nanomaterials have unique properties: They
have very high magneto resistance
They have lower melting point, high solid
state phase transition pressure, lower Debye
temperature and high self diffusion coefficient
They have high catalytic activity and lower
ferroelectric phase transition temperature
Continuation
2) Types of nanomaterials and their dimensions
In the physical sciences, a particle is a small
localized object to which can be ascribed several
properties such as volume or mass. In chemistry, a
particle is a small object that behaves as a whole unit
in terms of its transport and properties. Particles are
further classified according to size: in terms of
diameter, coarse particles cover a range 2,500nm to
10,000 nm. Fine particles are sized above 100nm to
less than 2,500nm and ultrafine particles or
nanoparticles are sized between 1nm to 100nm
Continuation
Nanomaterials
may
be
zero-dimensional
(e.g.,
nanoparticles),
one-dimensional
(e.g.,
nanorods,
nanotubes, nanowires, nanoplates, nanoflowers, nanofilms,
etc) or two-dimensional (e.g., thin films or stacks of thin
films). A zero-dimensional structure is the simplest building
block that may be used for nanomaterials design. These
materials have dimensions less than 100nm and are
synonymously labeled as nanoparticles or nanoclusters.
Any nanomaterial that is crystalline should be referred to as
a nanocrystal. However, this term is normally reserved for
those materials that are single-crystalline. Polycrystalline
nanomaterials could be termed nanopolycrystal. A term
used by me for the first time, in a paper published in 2000
in Acta Chimica Hungarica-Models in Chemistry.
Continuation
A special case of nanocrystal that is composed
of a semiconductor ( a solid substance that
conducts electricity better than insulators or
non-conductors but not as good as
conductors) is known as a quantum dot and
has dimension between 1nm to 30nm.
Quantum dots are very useful as sensors,
lasers, and light emitting diodes (LEDs).
Continuation
Therefore, when the size or dimension of a material is
continuously reduced from a large or macroscopic size, such
as a metre or centimetre, to a very small size, the properties
remain the same at first, then small changes begin to occur,
until finally when the size drops below 100 nm, dramatic
changes in properties can occur.
If one dimension is reduced to the nanorange while the other
dimensions remain large, then we obtain a structure known as
quantum well.
If two dimensions are so reduced and one remains large, the
resulting structure is referred to as a quantum wire.
The extreme case of this process of size reduction in which all
three dimensions reach the low nanometer range is called a
quantum dot.
Continuation
Bulk
Well
Wire
Dot
Continuation
• The above structures show progressive
generation of rectangular structures. Below is
the progressive generation of curvilinear
structures
Bulk
Well
Wire
Dot
Continuation
• The semiconductors like PbS, GaAs, CdS etc.,
can be synthesized in the nanometer level and
they are referred to as semiconductor
quantum dots. Their properties like band gap,
luminescence etc., always differ from their
bulk counterpart.
These quantum structures are useful in the
fabrication of high efficiency solar cells,
infrared detectors, quantum dot lasers etc.
3) Some methods of synthesizing
nanomaterials
Although the basic chemistry of the synthesis of
nanomaterials is fairly well understood, the synthesis of
complex nanomaterials continues to be a problem of
importance, since these materials are found to exhibit new
phenomena and find novel applications. A variety of
methods has been employed for the synthesis of complex
metal oxides and many of these methods give the products
in form of fine particulates. There are two general
approaches to the synthesis of nanomaterials and the
fabrication of nanostructures. They are (a) Top-down
approach, that is the miniaturization of the components as
articulated by Feynman, who stated in the 1959 Nobel
lecture that “there is plenty of room at the bottom” and (b)
Bottom-top approach akin to that of Jean-Marie Lehn in
1995. It involves the self-assembly of molecular
components, where each nanostructured component
becomes part of a superstructure. We elaborate on these
methods below:
(a)Top-down approach
This involves slicing or successive cutting of a
bulk material to get nanosized particle. The
advantages are;
1) Mechanical force is used to produce
nanosized particles
2) It could be used to produce nanosized
particles on large scale
The disadvantages of the method are:
Continuation
1) polydispersity, formation of variable
nanosized particles
2) surface
dislocations
occur
during
attrition/slicing/ball milling
3) morphology control of nanoparticles is
very difficult
Continuation
b) Bottom-top approach
This approach refers to the build up of a material
from the bottom; atom by atom, molecule by
molecule or cluster by cluster.
Advantages:
1) produces nanostructures with less defects and
more homogeneous chemical composition
2) size and shape of nanoparticles can be controlled
3) good quality nanoparticles can be prepared for
applications in functional devices
4) Applications of nanoparticles in
Chemistry
The knowledge of chemistry is very useful in
nanoparticles applications. One important
applications of nanoparticles in chemistry is in
catalysis. For instance, titanium-doped
zirconia, aluminum-doped zirconia and
potassium-doped zirconia are used as
effective catalysts in nanosized form for the
transesterification of soybean with methanol
for the production of biodiesel. The list of
nanosized particles as catalysts in biodiesel
production is inexhaustible
Continuation
There are also several reports of nanosized
particles used as gas sensors for atmospheric
pollutants in the literature. In our laboratory, we
are exploring the use of iridium-doped indium
oxides as gas sensors for atmospheric pollutants
due to the absorbing capability of iridium.
Titanium oxide nanoparticle coating is being
utilized for the corrosion protection of mild steel
in high temperature environments. Nickel and
iron oxide nanoparticles are recently being used
in concrete mixing matrix to increase the
compressive strength of cement as well as
decrease its setting time.
Continuation
• Zirconia-based nanoparticles are attractive for a
variety of applications, such as solid-oxide fuel
cells, oxygen sensors etc. We have also found
lanthanum oxide capable of enhancing the
decomposition of hydrogen peroxide in our
laboratory, for effective oxygen production. MgO
nanoparticles are also recognized as adsorbent
for air purification, toxic waste remediation, etc.
Scientists in America are investigating the thermal
behavior of metal nanoparticles in geochemical
materials in order to obtain a new tool to define
the thermal history of nanoparticle-bearing
geochemical and planetary materials.
5) Applications of nanoparticles in
technology
Technology has a quite different meaning from an
apparently similar word, technique. Technique is the
method of doing or performing, with skill acquired by
experience, something that has already been established.
Technology can be defined as the ability of taking
advantage of the progress of science to create novel
opportunities for practical applications. Technology is the
main driving force for the progress of mankind since it
provides a wealth of novel materials, devices, and
machines capable of improving the quality of life.
Unfortunately, however, technology can also be exploited
for negative purposes, for example, violence, war, and
terrorism. In this paper, we only discuss nanoparticles in
positive aspects of technology for the benefit of mankind.
Continuation
Nanotechnology could be referred to as the applications of
nanoparticles in technology. Thus, nanotechnology pertains
to the synthesis, characterization and manipulation of
matter on an atomic and molecular scale for the
fabrications of useful devices and machines. One of the
most important objectives of nanotechnology is a further
miniaturization of information processing devices. Present
computers are based on the miniaturization of electronic
circuits by scientists. Efforts are underway to design and
construct “molecular computers’ much smaller and much
powerful than the presently used silicon-based computers.
In fact, IBM one time announced that it was replacing
silicon wafers with nanoparticles of lanthanum strontium
manganate as the memory device of its computers. They
stated that lanthanum strontium manganate had a better
speed and more storage capacity and was cheaper that
silicon wafer.
Continuation
• Nanotechnology can generate products with many
unique characteristics that can improve the current
construction materials: lighter and stronger structural
composites, low maintenance coatings, better
cementitious materials, lower thermal transfer rate of
fire retardant and insulation, better sound absorption
of acoustic absorbers and better reflectivity of glass,
etc. Concrete is a macro-material strongly influenced
by its nano-properties. The addition of nano-silica to
cement based materials can control the degradation of
calcium-silicate hydrate reaction caused by calcium
leaching in water, blocking water penetration and
leading to improvements in durability.
Continuation
• Also, nano-sensors have a great potential to be used
in concrete structures for quality control and
durability monitoring (i.e. to measure concrete
density and viscosity, to monitor concrete curing and
to measure shrinkage or temperature, moisture,
chlorine concentration, pH, carbon dioxide, stresses,
reinforcement corrosion or vibration). Carbon nanotubes increase the compressive strength of cement
motar specimens and change their electrical
properties which can be used for health monitoring
and damage detection.
Continuation
• The addition of copper nanoparticles reduces the
surface unevenness of steel, limits the number of
stress carriers and hence fatigue cracking, leading
to increased safety, less need for monitoring and
more efficient materials for construction.
Vanadium and molybdenum nanoparticles
improve the delay fracture problems associated
with high strength bolts, reducing the effects of
hydrogen embrittlement and improving the steel
micro-structure. The addition of nanoparticles of
magnesium and calcium leads to an increase in
weld toughness. Wood is composed of nanotubes
or “nanofibrils”
Continuation
• Lignocellulosic surfaces at the nanoscale could open
new opportunities for such things as self-sterilizing
surfaces, internal self-repair, biodiesel production,
and electronic lignocellulosic devices, providing
feedback for product performance and
environmental conditions during service. Highly
water repellent coatings incorporating silica and
alumina nanoparticles and hydrophobic polymers are
proper to be used for wood. Fire-protective glass is
obtained using fumed silica nanoparticles as a clear
interlayer sandwiched between two glass panels
which turns into a rigid and opaque fire shield when
heated.
Continuation
• Nanotechnology is applied to paints in order to prevent
the corrosion under insulation since it is hydrophobic
and repels water from the metal pipe and can also
protect metal from salt-water attack. Nanotechnology
is now being applied in sports such as soccer, football
and baseball. Materials for new athletic shoes may be
made from nanoparticles in order to make the shoe
lighter ( and the athlete faster). Baseball bats made of
carbon nanotubes are already in the market. In
agriculture, the applications of nanotechnology have
the potential to change the entire agriculture sector
and food industry chain from production to
conservation, processing, packaging, transportation,
and even waste management.
Continuation
• In aerospace industries, nanoparticles have
made it possible to create lighter and stronger
materials for aircraft manufacture, leading to
increased performance. Spacecraft will also
benefit, where weight is a major factor.
Nanotechnology will help to reduce the size of
equipment and thereby decrease fuel
consumption required to get it airborne
6) Applications of nanoparticles in
biology and medicine
• One area of applications of nanoparticles in
biology and medicine is in treatments of
various health problems. Malaria, for instance,
is a serious menace to countries in the tropics
– Africa, Asia, etc. because it is geographically
specific, affecting mostly children and
pregnant women as well as having greater
morbidity and mortality than any other
infectious diseases of the world. Currently, the
only hope in chemotherapy of malaria lies
within the artemisinin class of antimalarial
Continuation
drugs. The widespread resistant malaria parasites
(plasmodium spp) to most common antimalarials, and
cross-resistance to structurally unrelated drugs, emphasize
the need for a new therapeutic targets. Raising the
immunocompetence of individuals in malaria endemic
areas by vaccination could significantly lower the death
tolls due to clinically severe malaria. A viable malaria
vaccine could be regarded as the most cost effective and
best practical method of reducing the high human and
economic toll of this devastating disease. Scientists are now
engaged in the use of water-soluble cationic nanoparticle
of N, N, N-trimethylchitosan as having a desirable qualities
for the intending antigen delivery. Thus, it is regarded as a
nanocarrier for malaria vaccine. The biological activities of
the nanocarrier is also under investigation. In another
development, acinetobacter baumanii (Ab) is found to be a
frequent cause of hospital acquired pneumonia and also
has increased in incidence as the causative agent of severe
disease in troops wounded in Afghanistan and Iraq.
Continuation
• Ab clinical isolates are frequently extremely resistant
to antimicrobials, significantly complicating the
capacity to treat infections due to this pathogen.
Hence, the development of innovative therapeutics
targeting mechanisms to which the bacteria are
unlikely to evolve resistance becomes urgently
needed. Scientists have examined the capacity of
nitric oxide-releasing nanoparticle (NO-np) to treat
wounds infected with Ab and found it very effective.
Foot ulcers are one of the main complications in
diabetes mellius, with 15% life time risk in all diabetic
patients. Patients with diabetes display aberrant
angiogenesis in various organs, with insufficient
activity occurring in impaired wound healing
including ulcers
Continuation
Nanotechnology but is also used in treating diabetic
wound. Angiogenesis induced with the peptide DNA
nanoparticles helps in the treatment. Also, silver
nanoparticles are found to be effective in wound
healing in animals and are promising for future
applications in human. Silver nanoparticles exert
positive effects through their antimicrobial properties,
reduction in wound inflammation, and modulation of
fibrogenic cytokines. Solid lipid nanopartcles (SLN) are
the forefront of the rapidly developing field of
nanotechnology with several potential applications in
drug delivery and research. Due to their unique size
dependent properties, lipid nanoparticles offer exiting
possibilities to develop new therapeutics. The ability to
incorporate drugs into nanocarriers offers a new
prototype in drug delivery that could be used for drug
targeting. Hence, SLN hold great promise for reaching
the goal of controlled and site specific drug delivery.
Continuation
• In the treatment of cancer, scientists have resorted to
nanophotothermolysis with pulsed lasers and
absorbing nanoparticles like gold nanospheres,
nanorods or carbon nanotubes, attached to specific
targets. This technique is a great potential for selective
damage to cancer cells, bacteria and viruses. In
another development, various nanomaterials such as
fullerenes, dendrimers, silver and gold nanoparticles
have shown anti-HIV effects in vitro and in vivo.
Generally, it has been found that metal nanoparticles
can be effective antiviral agents against HIV-1, hepatitis
B virus, respiratory syncytial virus, herpes simplex virus
type 1, monkeypox virus, influenza virus and Tacaribe
virus. Furthermore, laboratory studies in mice have
shown that using nanoparticles to target the delivery
of clot busting drug can reduce dosage of the drug
needed, which may reduce possible side effects, such
as internal bleeding
Continuation
• The clot busting drug was attached to a cluster
of nanoparticles that break apart in regions of
turbulent blood flow. Researchers are
developing polymer nanoparticles that get to
inflamed tissues such as arterial plaque and
then dissolve, releasing drugs, in the presence
of hydrogen peroxide that is present in the
inflamed tissue. Also, nanoparticles containing
iron oxide could be directed by a magnetic
field, to stents. This could allow drugs to be
delivered directly to stents placed in arteries.
Continuation
• In another development, a method being developed by
scientists to tackle autoimmune diseases uses
nanoparticles to deliver antigens for a particular
disease into the blood stream. The antigens reset the
immune system, stopping white blood cells from
attacking healthy cells to prevent aging. This method
has already been tested in the laboratory on mice with
a disease similar to multiple sclerosis with promising
result. Another method is being developed to fight
aging using mesoporous nanoparticles with coating
that releases the contents of the nanoparticles when
an enzyme found in aging cell is present. Skin creams
that uses proteins derived from stem cells could
prevent aging of the skin. These proteins are
encapsulated in liposome nanoparticles which merge
with the membranes of the skin cells to allow delivery
of the proteins
Continuation
• Researchers have also developed nanoparticles that
can slip through mucus coating surfaces such as lung
tissue. This could provide the capability to coat lung
tissue with therapeutic drugs. Medical implants
made of porous plastic, coated with carbon
nanotubes are also very useful. Therapeutic drugs,
which are attached to the nanotubes can be released
into the blood stream, for example, when a change in
the blood chemistry signals a problem. NASA is
developing these implants, called “biocapsule”, to
protect astronauts from the effects of radiation,
however, the implants may also be useful for
releasing insulin for diabetes patients or for
delivering chemotherapy drugs directly to tumors
Continuation
• In dentistry, nanofillers used include
nanoparticles of aluminosilicate powder.
Orthodontic nanorobots are also developed to
directly manipulate the periodontal tissues,
allowing rapid and painless tooth straightening,
rotating and vertical repositioning within
minutes. Titanium and silver nanoparticles are
being introduced into dental composites, to
introduce antimicrobial properties and enhance
biocompatibility of the composites
7) Advantages of nanotechnology
and nanomaterials
1. IMPROVED TRANSPORTATION
Today, most airplanes are made from metal despite the fact that
diamond has a strength-to-weight ratio over 50 times that of aerospace
aluminum
Diamond is expensive, it is not possible to make it in the required
shapes, and it shatters. Nanotechnology will let us inexpensively make
shatterproof diamond in exactly the shapes we want.
Nanotechnology will dramatically reduce the costs and increase the
capabilities of space ships and space flight
The strength-to-weight ratio and the cost of components are absolutely
critical to the performance and economy of space ships: with
nanotechnology, both of these parameters will be improved
Nanotechnology will also provide extremely powerful computers
with which to guide both those ships and a wide range of other activities
in space
Continuation
2. ATOM COMPUTERS
Today, computer chips are made using lithography -- literally, "stone
writing"
If the computer hardware revolution is to continue at its current pace, in a
decade or so we'll have to move beyond lithography to some new post
lithographic manufacturing technology. Ultimately, each logic element will
be made from just a few atoms
Designs for computer gates with less than 1,000 atoms have already been
proposed - but each atom in such a small device has to be in exactly the
right place
To economically build and interconnect trillions upon trillions of such small
and precise devices in a complex three dimensional pattern we'll need a
manufacturing technology well beyond today's lithography: we'll need
nanotechnology.
With it, we should be able to build mass storage devices that can store
more than a hundred billion billion bytes in a volume the size of a sugar
cube;
RAM that can store a mere billion billion bytes in such a volume; and
massively parallel computers of the same size that can deliver a billion
billion instructions per second will require nanotechnology
Continuation
• 3. SOLAR ENERGY
Nanotechnology will cut costs both of the
solar cells and the equipment needed to
deploy them, making solar power economical
In this application we need not make new
or technically superior solar cells: making
inexpensively what we already know how to
make expensively would move solar power
into the mainstream
Continuation
• 4. MEDICAL USES
It is not modern medicine that does the healing, but
the cells themselves: we are but onlookers
If we had surgical tools that were molecular both in
their size and precision, we could develop a medical
technology that for the first time would let us
directly heal the injuries at the molecular and cellular
level that are the root causes of disease and ill health
With the precision of drugs combined with the
intelligent guidance of the surgeon's scalpel, we can
expect a quantum leap in our medical capabilities
Continuation
• 5. Other Advantages
Less Pollution
The problem with past technologies is that
they pollute the environment in cases where
we humans would die in years.
A good example of a bad polluting invention
would be the automobile. The automobile
runs on gas and the gas fumes destroyes the
ozone layer. Nanotechnology can circumvent
this problem
Summary
• Physics : The construction of specific
molecules is governed by the physical forces
between the individual atoms composing
them
Nanotechnology will involve the
continued design of novel molecules for
specific purposes
•
Researchers need to understand
how quantum physics affects the behavior of
matter below a certain scale
Summary continues
• Chemistry : The interaction of different
molecules is governed by chemical forces
•
Nanotechnology will involve the
controlled interaction of different molecules,
often in solution
•
Understanding how different
materials interact with each other is a crucial
part of designing new nanomaterials to
achieve a given purpose
Summary continues
• Biology : A major focus of nanotechnology is
the creation of small devices capable of
processing information and performing tasks
on the nanoscale
The process by which information
encoded in DNA is used to build
proteins, which then go on to perform
complex tasks including the building of more
complex structures, offers one possible
template
Summary continues
• Computer Science : Moore’s Law and its
corollaries, affect the price performance,
speed, and capacity of almost every
component of the computer
•
Communication industries have
improved exponentially in the use of
nanotechnology over the last several decades
accompanied by steady miniaturization of
components
Summary continues
• Electrical Engineering : To operate
independently, nanodevices will need a steady
supply of power
Moving power into and out of devices at
that scale represents a unique challenge
Within the field of information technology,
control of electric signals is also vital to
transistor switches and memory storage
A great deal of research is also going into
developing nanotechnologies that can
generate and manage power more efficiently
Summary continues
• Mechanical Engineering : Even at the
nanolevel, issues such as load bearing, wear,
material fatigue, and lubrication still apply.
Detailed knowledge of how to actually build
devices that do what we want them to do with
an acceptable level of confidence
will be a critical component of future research
8) Conclusion
• The applications of nanoparticles in chemistry,
technology and medicine can not be exhausted in
this lecture. Series of lectures may be required to
deal sufficiently with this interesting topic. I have
tried my best to define a nanoparticle and will
like to mention that nanoparticles are currently
being utilized in all fields of human endeavor
including their usefulness in clothing, cosmetics,
sporting, structural materials, speech recognition,
general agricultural sciences, wound healing and
dressing, sunglasses, sunscreens, catalysis,
biodiesel production, HIV/AIDS treatment, cancer
treatment, dentistry, malaria treatment, etc.
Continuation
• In biomedical research, nanoparticles (NPs)
can improve solubility, they can be used as
carriers for hydrophobic drugs (e.g.,
Abraxane). NPs also give multifunctional
capability, they target tumors, could be used
to reduce toxicity of a therapeutic drug, etc. I
therefore , call on all researchers to begin
focusing their research work on the synthesis,
characterization and applications of
nanoparticles to solve some unsolved
problems
Continuation
• To conduct a successful and advanced
research in nanomaterials, a well equipped
and functional laboratory is required. Few of
the important equipment include (1) X-Ray
Diffractometer (XRD) which gives the ‘finger
print’ of a material as well as the particle-size
of a material using Sherrer’s equation. Also,
using appropriate computer programme such
as Prozski one can determine the structure of
a material from the XRD diffractogram with
the d-values and Miller indices indicated. XRD
can also tell us whether a material is
amorphous or crystalline.
Continuation
Continuation
Continuation
• (2) Scanning Electron Microscope (SEM)
attached to Energy Dispersive Analysis of Xrays (EDAX). The SEM provides the
morphology of a material. Thus, one can
discover the shape of the crystallites in a
material. It can also give us information about
the range of size of the particles, etc. EDAX
gives us information regarding the elemental
composition of the material in percentages,
etc
Below is the SEM
The ED
EDAX of ZnO nanowire
Continuation
• (3) Transmission Electron Microscope (TEM)
coupled with Electron Diffratometer (ED). TEM
also gives us the morphology of the material,
near exact particle size as well as the
crystalline or non-crystalline nature of the
material
• (4) Micromerritics Accusorb instrument for
nitrogen adsorption in accordance with BET
surface area measurement. It gives us specific
surface area of the material
TEM images of (a) C nanoparticles, (b) C-Al(OH)3 coreshell nanoparticles, and (c) Al2O3 hollow spherical
nanoparticles are below
Continuation
• (5) Various magnetometers such as Vibrating
Sample Magnotometer (VSM), Lewis-Coil
Magnetometer (LCM), etc.
• In our department, we have designed a
postgraduate programme in Nanoscience and
Nanotechnology for approval by the
University.
9) References
• During the preparation of this paper, the
following materials were consulted:
• 1) Subramani, K., Pathak, S. and Hosseinkhani
(2012). Recent trends in diabetes treatment
using nanotechnology. Digest Journal of
Nanomaterials and Biostructures. 7 (1), 85 –
95.
• 2) Reich, M., Utsunomiya, S., Kesler, S. E.,
Wang, L., Ewing, R. C. and Becker, U. (2006).
Thermal behavior of metal nanoparticles in
geologic materials. Geology. 34 (12), 1033 –
1036.
Continuation
• 3) Salata, O. V. (2004). Applications of
nanoparticles in biology and medicine. Journal
of Nanotechnology. DOI: 10.1186/1477-31552-3.
• 4) Surendiran, A., Sandhiya, S., Pradhan, S. C.
and Adithan, C. (2009). Novel applications of
nanotechnology in medicine. Indian journal of
Medical Research. 130, 689 – 701.
Continuation
5) Ita, B. I. (2000). Combustion synthesis of
nanocrystalline LaFeO3. ACH-Models in
Chemistry. 137: 671 – 676.
Continuation
6) Ita, B. I., Murugavel, P., Ponnambalam, V. and
Raju, A. R. (2003). Magnetic properties of
lanthanum orthoferrite fine powders prepared
by different chemical routes. Procedure of
Indian Academy of Sciences (Chemical
Science). 115: 519 – 524.
Continuation
7) Ita, B. I., Ekpe, U. J. and Ibok, U. J. (1998). Synthesis of
nanocrystalline-Fe2O3 from iron (III) citrate precursor
using sol – gel method. Journal of Chemical Society of
Nigeria. 23: 19 – 20.
8) Ita, B. I., Ekpe, U. J. and Ibok, U. J. (2000). Synthesis
and electron microscopic study of nanostructured La1xSrxCoO3 (x = 0.0, 0.3, 0.5) systems. Global Journal of
Pure and Applied Sciences. 6: 61 – 65.
Continuation
9) Ita, B. I. (2000). Synthesis and characterization of
nanocrystalline LaMnO3.Journal of Chemical Society
of Nigeria. 25: 58 – 60.
10) Ita, B. I., Ekpe, U. J. and Ibok, U. J. (2000). Synthesis
and characterization of nanocrystalline- Fe2O3 by
combustion method.Global Journal of Pure and
Applied Sciences. 6: 635 – 637.
11) Ita, B. I. (2001). Synthesis and X – ray diffraction
studies of  - Al2O3 using aluminum acetylacetonate
(AAA) precursor via a novel sol – gel method.Global
Journal of Pure and Applied Sciences. 7: 81 – 84.
Continuatiuon
12) Ita, B. I. (2001). Synthesis and characterization of
LaxFe2-xO3 by nebulized spray pyrolysis. Journal of
Chemical Society of Nigeria.26: 112 – 114.
13) Ita, B. I. and Edem, C. A. (2004). Synthesis and
analysis of La0.9MnO3 by combustion method. Global
Journal of Pure and Applied Sciences. 10: 121 – 124.
Continuation
14) Ita, B. I. and Ebenso, E. E. (2005). Novel sol – gel
synthesis of nanopolycrystalline LaCrO3. International
Journal of Science and Technology. 4: 1 – 3.
15) Ita, B. I. (2006). Synthesis and characterization of
Co3O4 spinel. International Journal of Natural and
Applied Sciences. 1: 80 – 82.
16) G. Iniama, P. de la Presa, J. M. Alonso, M. Multigner,
B. I. Ita, R. Cortes-Gil, M. L. Ruiz-Gonzalez, A.
Hernando and J. M. Gonzalez-Calbet (2014).
Unexpected ferromagnetic ordering enhancement with
crystallite size growth observed in La0.5Ca0.5MnO3
nanoparticles. Journal of Applied Physics. 116: 113901
– 113901-8
•
END
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