J O U R N A L O F
C H E M I S T R Y
MaterialsFeatureArticle
Science and technology of nanomaterials: current status and future
prospects
C. N. R. Rao*a,b
and A. K. Cheethama
a
Materials Research Laboratory, University of California, Santa Barbara, CA 93106, USA.
E-mail: cnrrao@jncasr.ac.in
b
Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific
Research, Jakkur, Bangalore, 560 064, India
Received 8th June 2001, Accepted 7th August 2001
First published as an Advance Article on the web 10th October 2001
The science and technology of nanomaterials has created
great excitement and expectations in the last few years.
By its very nature, the subject is of immense academic
interest, having to do with very tiny objects in the nano-
meter regime. There has already been much progress in
the synthesis, assembly and fabrication of nanomaterials,
and, equally importantly, in the potential applications of
these materials in a wide variety of technologies. The
next decade is likely to witness major strides in the
preparation, characterization and exploitation of nano-
particles, nanotubes and other nanounits, and their
assemblies. In addition, there will be progress in the
discovery and commercialization of nanotechnologies
and devices. These new technologies are bound to have
an impact on the chemical, energy, electronics and space
industries. They will also have applications in medicine
and health care, drug and gene delivery being important
areas. This article examines the important facets of
nanomaterials research, highlighting the current trends
and future directions. Since synthesis, structure, pro-
perties and simulation are important ingredients of
nanoscience, materials chemists have a major role to
play.
Introduction
Nanotechnology is the term used to describe the creation and
exploitation of materials with structural features in between
those of atoms and bulk materials, with at least one dimension
in the nanometer range (1 nm ~ 1029
m). Table 1 lists typical
nanomaterials of different dimensionalities. The properties of
materials with nanometric dimensions are significantly differ-
ent from those of atoms or bulk materials. Suitable control of
the properties of nanometer-scale structures can lead to new
science as well as new products, devices and technologies. The
underlying theme of nanotechnology is miniaturization, the
importance of which was pointed out by Feynman1
as early as
1959 in his often-cited lecture entitled ``There is plenty of room
at the bottom''. The challenge is to beat Moore's law2
and
accommodate 1000 CDs in a wristwatch.3
There has been explosive growth of nanoscience and
technology in the last decade, primarily because of the
availability of new methods of synthesizing nanomaterials, as
well as tools for characterization and manipulation (Table 2).
Several innovative methods for the synthesis of nanoparticles
and nanotubes, and their assemblies, are now available. There
is a better understanding of the size-dependent electrical, optical
and magnetic properties of individual nanostructures of
semiconductors, metals and other materials. Besides the
established techniques of electron microscopy, crystallography
and spectroscopy, scanning probe microscopies have provided
powerful tools for the study of nanostructures. Novel methods
of fabricating patterned nanostructures, as well as new device
and fabrication concepts, are constantly being discovered.
Nanostructures have also been ideal for computer simulation
and modelling, their size being sufficiently small to accom-
modate considerable rigour in treatment. In computations on
nanomaterials,4
one deals with a spatial scaling from 1 A° to
Table 1 Typical nanomaterials
Size (approx.) Materials
(a) Nanocrystals and clusters (quantum dots) diameter 1­10 nm Metals, semiconductors, magnetic materials
Other nanoparticles diameter 1­100 nm Ceramic oxides
(b) Nanowires diameter 1­100 nm Metals, semiconductors, oxides, sulfides, nitrides
Nanotubes diameter 1­100 nm Carbon, layered metal chalcogenides
(c) 2-Dimensional arrays (of nano particles) several nm2
­mm2
Metals, semiconductors, magnetic materials
Surfaces and thin films thickness 1­1000 nm Various materials
(d) 3-Dimensional structures (superlattices) Several nm in all three dimensions Metals, semiconductors, magnetic materials
Table 2 Different methods of synthesis and investigation of nanomaterials
Scale (approx.) Synthetic methods Structural tools Theory and simulation
0.1­10 nm Covalent synthesis Vibrational spectroscopy Electronic structure
NMR
Diffraction methods
Scanning probe microscopies (SPM)
v1­100 nm Self-assembly techniques SEM, TEM, SPM Molecular dynamics and mechanics
100 nm­1 mm Processing, modifications SEM, TEM Coarse-grained models, hopping etc.
DOI: 10.1039/b105058n J. Mater. Chem., 2001, 11, 2887­2894 2887
This journal is # The Royal Society of Chemistry 2001
1 mm and temporal scaling from 1 fs to 1 s, the limit of accuracy
going beyond 1 kcal mol21
. There are many examples which
demonstrate the current achievements and paradigm shifts in
this area; STM images of quantum dots (e.g., a germanium
pyramid on a silicon surface) and of the quantum corral of 48
Fe atoms placed in a circle of 7.3 nm radius being familiar ones.
Ordered arrays or superlattices of nanocrystals of metals and
semiconductors have been prepared by several workers.
Nanostructured polymers formed by the ordered self-assembly
of triblock copolymers and nanostructured high-strength
materials (e.g., Cu/Cr nanolayers) are other examples. Proto-
type circuits involving nanoparticles and nanotubes for
nanoelectronic devices have been fabricated. Quantum com-
puting6
has made a good start and appropriate quantum
algorithms have been developed.
Not everything in nanoscience is new; many existing
technologies employ nanoscale processes, catalysis and photo-
graphy being well-known examples. Our capability to synthe-
size, organize and tailor-make materials at the nanoscale is,
however, of very recent origin. The immediate goals of the
science and technology of nanomaterials must be to fully
master the synthesis of isolated nanostructures (building
blocks) and their ensembles and assemblies with the desired
properties, to explore and establish nanodevice concepts and
systems architecture, to generate new classes of high-perform-
ance materials, including biologically-inspired systems, to
connect nanoscience to molecular electronics and biology,
and to improve known investigative methods while discovering
better tools for the characterization of nanostructures.4,5
Some
of the potential applications of nanotechnology which will have
the greatest societal and economic impact are in the production
of novel materials and devices, in nanoelectronics and com-
puter technology, as well as in medicine and health care. These
wide-ranging applications may indeed usher in a new direction
in manufacturing and in the electronics, space, chemical and
energy industries.
In this article, we will present the important highlights in the
field of nanomaterials related to their synthesis and assembly,
experimental tools for their investigation, modelling and simu-
lation, and their potential applications. We have endeavoured
to make the article concise and illustrative rather than ency-
clopedic, and have cited key, representative references to help
describe the present status of the subject.
Synthesis and assembly
The synthesis of nanomaterials spans inorganic, organic and
biological systems, all with control of size, shape and structure.
Assembling the nanostructures into ordered arrays is often
necessary to render them functional and operational. It is by a
combination of novel nanobuilding units and strategies for
assembling them that nanostructured materials and devices
with new capabilities can be generated. In the last decade,
nanoparticles (powders) of ceramic materials have been
produced on a large scale by employing both physical and
chemical methods. In addition, there has also been consider-
able progress in the preparation of nanocrystals of metals,
semiconductors and magnetic materials by employing colloid
chemical methods.7­10
Nearly monodisperse nanocrystals of
materials with narrow size distributions have been prepared by
several workers, with control of the shape in some instances. To
illustrate this aspect, transmission electron microscopy (TEM)
images of CdSe nanorods are shown in Fig. 1. The availability
of such nanocrystals has enabled better studies of size-
dependent properties such as size-controlled light emission
properties of semiconductor nanocrystals, the nonmetallic gap
in metal nanocrystals, size-dependent Coulomb blockade
and the associated scaling laws. Fig. 2 and 3 illustrate some
typical size-dependent properties of materials. Size-dependent
properties have been exploited for biological tagging, for
example using semiconductor nanocrystals as fluorescent bio-
logical labels.11
There is a qualitative change in some facets of
synthesis, the preparation of thin films being one such. For
example, it is now possible to carry out atomic layer-by-layer
deposition of films, thereby affording new heterostructures and
metastable phases.12
Since the discovery of carbon nanotubes,13
much has been
achieved in the synthesis of multiwalled and single-walled
nanotubes and bundles of aligned nanotubes.14
Fig. 4 shows an
electron microscopy image of aligned multiwalled nanotubes.
Carbon nanotubes have been doped with nitrogen and boron.
Especially noteworthy is the recent synthesis of Y-junction
carbon nanotubes (Fig. 5), which can act as vital components
in nanoelectronics15
since, unlike ordinary nanotubes which
can be metallic or insulating, kinks or bends will act as metal­
insulator junctions. Nanotubes of other inorganic materials, in
particular those of layered metal chalcogenides (e.g. MoS2,
Fig. 1 TEM images of CdSe quantum rods: (a), (b) low-resolution
images of quantum rods of different aspect ratios; (c) 3-dimensional
orientation. (Reproduced by permission from ref. 10, X. Peng,
L. Manna, W. Yang, J. Wickham, E. Scher, A. Kadavanich and
A. P. Alivisatos, Nature, 2000, 404, 59. Copyright Nature 2000.)
Fig. 2 Size-dependence of the wavelength of the absorption threshold
in semiconductors. (Reproduced by permission from A. Henglein, Ber.
Bunsen-Ges. Phys. Chem., 1995, 99, 903. Copyright VCH 1995.)
2888 J. Mater. Chem., 2001, 11, 2887­2894
WS2, MoSe2, NbS2), have been synthesized.14,16,17
These
materials are likely to possess interesting and useful properties.
Nanowires of metals, semiconductors, oxides, nitrides, sulfides
and other materials have been prepared by various meth-
ods.14,18
In the area of polymers, the engineering of new
polymeric structures by using dendrimers and block copoly-
mers deserves special mention19
(see Fig. 6, for example).
Nanosized polymers of different shapes could have many
applications.
The construction of ordered arrays of nanostructures by
employing organic self-assembly techniques provides alter-
native strategies for the production of nanodevices. Two- and
three-dimensional arrays of nanocrystals of semiconductors,
metals and magnetic materials have been assembled by using
suitable organic reagents.20
Strain-directed assembly of nano-
particle arrays (e.g., of semiconductors) provides the means to
introduce functionality into the substrate that is coupled to that
on the surface.21
Fig. 7 shows a TEM image of Pd nanocrystals
containing 1415 atoms. By varying the spacer length (or crystal
size), arrays of metal nanocrystals can be made to undergo a
metal­non-metal transition of the Mott­Hubbard type.8
Monodisperse FePt nanoparticles and ferromagnetic FePt
nanocrystal superlattices have been described recently22
(Fig. 8). Spin-dependent tunnelling has been observed in self-
assembled cobalt nanocrystal superlattices.22
Nanocrystals of
uniform size suitably coated with a polymer are found to
assemble to form giant nanocrystals with magic nuclearity.23
It
is noteworthy that self-assembly of objects of varying sizes (nm
to mm) occurs through weak interactions.24
Single crystals of
single-walled carbon nanotubes (Fig. 9) have been formed by
self-assembly.25
Lithography-induced self-assembly (LISA) is
likely to open up new possibilities in the near future.26
The area of nanoporous solids has witnessed many major
advances. There has been a constant quest for crystalline solids
with giant pores and several have been synthesized recently.27
It
has become possible to control pore size in zeolites and other
nanoporous materials, and the shape-selective catalysis
afforded by nanoporous solids continues to motivate much
of the work in this area. Since the discovery of mesoporous
MCM 41 by Mobil chemists, a variety of mesoporous inorganic
solids with pore diameters in the 2­20 nm range have been
prepared and characterized.28
Mesoporous fibers and spheres
of silica and other materials have also been prepared. A variety
of inorganic, organic and organic­inorganic hybrid open-
framework materials with different pore architectures have
been synthesized in the last few years, particularly noteworthy
being the large variety of open-framework metal phosphates.29
Equally interesting are the macroporous solids (pore diameters
100­1000 nm) prepared by templating crystalline arrays of
silica or polymer spheres.30
Many new nanostructured systems will undoubtedly be built
in the next few years using a variety of nanobuilding units, and
there is considerable scope for the discovery of newer and
better methods of synthesis, assembly and processing. Robotic
self-assembly of nanostructures may be employed more com-
monly. It is also likely that in the next few years, more effective
interfaces with biology will emerge. There is already evidence to
show that DNA-directed assembly has the potential for
nanofabrication.31
DNA chips and microarrays have imminent
applications in diagnostics and genetic research. Preparation of
nanoparticles of therapeutic drugs would directly help in drug
targeting. Similarly, gene delivery may become possible
through the use of nanoparticles of lipid/polymer­DNA
complexes.
Experimental tools
As mentioned earlier, the rapid pace of progress in the area of
nanomaterials has been made possible in part because of
improved methods of measurement, characterization and
manipulation. While standard methods of measurement and
characterization are routinely employed for investigation, the
increasing use of scanning probe microscopies (spatial resolu-
tion 1 nm), combined with high-resolution electron micro-
scopy, has enabled direct images of structures to be obtained
and aided the study of properties. Thus, scanning tunnelling
spectroscopy provides important information on electronic
structure and properties. Scanning probe microscopies are now
employed at low temperatures, under vaccum or in a magnetic
field. Computer-controlled scanning probe microscopy is
useful for nanostructure manipulation in real time, and
nanomanipulators are being used with scanning and transmis-
sion electron microscopes.32
Newer versions of nanomanipu-
lators will have to be developed by using technologies such as
nanoelectromechanical systems (NEMS).32
Techniques such as magnetic force microscopy and surface
force microscopy are of great value in specific situations. While
magnetic force microscopy directly images magnetic domains,
magnetic resonance microscopes can detect nuclear or electron
spin resonance with submicron spatial resolution. Near field
scanning optical microscopy allows optical access to sub-
wavelength scales (50­100 nm) by breaking the diffraction
limit.33
Nanomechanics performed in the atomic force microscope
enables the study of single molecules, and is valuable in
understanding folding and related problems in biological
Fig. 3 (a) Size-dependence of the nonmetallic gap (local density of
states) with the volume of metal nanocrystals. (Reproduced by
permission from C. P. Vinod, G. U. Kulkarni and C. N. R. Rao,
Chem. Phys. Lett., 1998, 289, 329. Copyright Elsevier 1998.) (b) Size-
dependence of the charging capacity (Coulomb blockade) in metal
nano crystals. (Reproduced by permission from P. J. Thomas,
G. U. Kulkarni and C. N. R. Rao, Chem. Phys. Lett., 2000, 321,
163. Copyright Elsevier 2000.)
J. Mater. Chem., 2001, 11, 2887­2894 2889
molecules. In order to circumvent the limitations of scanning
probe microscopy, cantilever probes have been developed to
enable high-speed nanometer scale imaging.34
Clearly, there is
much scope for the development of miniaturized instruments
for the study of individual molecules and nanounits.
Optical tweezers provide an elegant means to investigate the
dynamics of particles and molecules.35
Thus, force measure-
ment of complementary DNA binding provides a selective and
sensitive sensor.35
Microfabricated chips for DNA analysis and polymerase
Fig. 5 TEM image of a Y-junction nanotube. (Reproduced by
permission from ref. 15, B. C. Satishkumar, P. J. Thomas,
A. Govindaraj and C. N. R. Rao, Appl. Phys. Lett., 2000, 77, 2530.
Copyright AIP 2000.)
Fig. 4 TEM images of aligned multi-walled carbon nanotubes; (a), (b) and (d) show nanotubes in different orientations, (c) shows several bunbles.
(Reproduced by permission from C. N. R. Rao, A. Govindaraj, R. Sen and B. C. Satishkumar, Mater. Res. Innovations, 1998, 2, 128. Copyright
Springer 1998.)
Fig. 6 Supramolecular nanostructure formed by the self-assembly of
triblock copolymers. (Reproduced by permission from ref. 19,
S. I. Stupp, V. LeBouheur, K. Walker, L. S. Li, K. E. Huggins,
M. Keser and A. Amstuz, Science, 1997, 276, 384. Copyright AAAS
1997.)
2890 J. Mater. Chem., 2001, 11, 2887­2894
chain reactions have been developed.36
It would be of great
benefit if appropriate tools for 3-D imaging and microscopy as
well as for chemical analysis of materials in nanometric
dimensions become available.
Simulation and modelling
A variety of computational techniques have been employed to
simulate and model nanomaterials. Since the relaxation times
can vary anywhere between picoseconds to hours, it becomes
necessary to employ Langevin dynamics besides molecular
dynamics in the calculations. Simulation of nanodevices as a
whole, through the optimization of the various components
and functions, is challenging, as in the simulation of large
systems and coupled phenomena. There are many instances
where simulation and modelling have yielded impressive
results, nanoscale lubrication being one such example
(Fig. 10). Simulation of the molecular dynamics of DNA has
met with some success37
and quantum dots and nanotubes have
been modelled satisfactorily.38,39
Nevertheless, first principles
calculations of nanomaterials can be problematic if the clusters
are too large to treat by Hartree­Fock methods and too small
for density functional theory.
Applications
By employing sol­gels and aerogels, high-surface area inor-
ganic oxide materials with improved absorption and other
properties are being produced. The preparation of super-
adsorbents for toxic chemicals is becoming possible by these
methods.40
Consolidated nanocomposites and nanostructures
will yield ultrahigh-strength, tough structural materials, strong
ductile cements and novel magnets. Significant developments
will occur in the sintering of nanophase ceramic materials and
in textiles and plastics containing dispersed nanoparticles, the
latter being useful in the design of miniature lithium-ion
batteries; nanostructured electrode materials would improve
Fig. 7 TEM image of a two-dimensional array of Pd1415 nanocrystals
(diameter 3.2 nm). (Reproduced from ref. 8, C. N. R. Rao,
G. U. Kulkarni, P. J. Thomas and P. P. Edwards, Chem. Soc. Rev.,
2000, 29, 27.)
Fig. 8 (A) TEM image of a 3-D assembly of Fe50Pt50 nanocrystals
(diameter 6 nm). (B) TEM image after replacing the capping oleic acid
with hexanoic acid. (C) High-resolution scanning electron microscopy
(HRSEM) image of 180 nm thick Fe52Pt48 nanocrystals (diameter
4 nm). (D) HRTEM image of Fe52Pt48 nanocrystals. (Reproduced by
permission from ref. 22a, S. Sun, C. B. Murray, D. Weller, L. Folks and
A. Moser, Science, 2000, 287, 1989. Copyright AAAS 2000.)
Fig. 9 (A) HRTEM image of a single-walled nanotube crystal
(diameter 37 nm). (B) and (C) Lattice resolution of the crystal.
(Reproduced by permission from ref. 25, R. R. Schlittler, J. W. Seo,
J. K. Gimzewski, C. Durkan, M. S. M. Saifullah and M. E. Welland,
Science, 2001, 292, 1136. Copyright AAAS 2001.)
Fig. 10 Snapshot of squalane under shear flow confined between two
walls with tethered butane chains. (Reproduced by permission from
A. Gupta , H. D. Cochran and P. T. Cummins, J. Chem. Phys., 1997,
107, 10327. Copyright AIP 1997.)
J. Mater. Chem., 2001, 11, 2887­2894 2891
the capacity and performance of Li-ion batteries. Nanostruc-
tured tin oxide also appears to attain higher reversible
capacities.41
Shipway et al.42
have recently reviewed nano-
particle-based applications.
Both known and new types of nano-, meso- and macro-
porous materials will be put to use for inorganic synthesis and
industrial catalysis. Porous films (e.g. mesoporous silica) can be
used as molecular sieving membranes and in catalysis. The
chemical industry may indeed get involved to a greater extent in
the design of catalysts containing different types of nanometric
particles, since nanoscale catalysis could provide greater
selectivity. Nanocatalysis by gold illustrates how nanoparticles
can have entirely different catalytic properties. Electron
transfer in nanostructures can also be exploited for applica-
tions. There is a good possibility that nanomaterials such as
carbon nanotubes will be used for storage of hydrogen and
other gases.14,43
It has been reported that carbon nanotubes
can store hydrogen up to ca. 4 wt% or more and that the stored
hydrogen is released easily without fatigue, but some doubts
have been raised about these findings.43
Nanoporous polymers
are useful for water purification, while MoS2 nanotubes and
fullerenes are good solid lubricants.
The techniques of nanoimprint-lithography and soft litho-
graphy are sufficiently developed44
and a combination of
self-assembly with patterning tools could enable new nano-
lithographic patterns to be obtained.45
Examples of nano-
imprint lithography and the LISA process are shown in Fig. 11.
Thin-film electrets patterned with trapped charge provides
another method of patterning which may be useful in
high-density charge-based data storage and high-resolution
printing.46
Carbon nanotubes are being used as tips in scanning
microscopes and also as efficient field emitters for possible
use in display devices. Nanotubes have been shown to act as
field-effect transistors, as illustrated in Fig. 12. Newer proper-
ties of nanotubes continue to be discovered. For example,
nanotubes have been found to exhibit optical limiting proper-
ties.14
Modulated chemical doping of individual nanotubes
yields an intramolecular wire electronic device,47
and magnetic
clusters deposited on single-walled nanotubes exhibit the
Kondo effect.48
Colloidal gold particles attached to DNA strands can be
employed to assay specific complementary DNAs.49
The
technology of DNA microchip arrays, involving lithographic
patterning, which has been used effectively for mapping genetic
information in DNA and RNA, is bound to see further
improvement. Similarly, drug and gene delivery will be
rendered more effective with the use of nanoparticles and
nanocapsules. New miniaturized devices could become useful
not only in drug delivery,50
but also in diagnostics and other
applications. Molecular motors, such as the protein F1-AT
phase, are already known, but it may become practical to
power an inorganic nanodevice with such a biological motor.51
Other areas in biology where nanomaterials can have an impact
are in the monitoring of the environment and living systems by
the use of nanosensors and in the improvement of prosthetics
used to repair or replace parts of the human body. Water-based
ferrofluids, prepared by using organic templates, are useful as
coloured magnetic inks. Soft materials can also be used for
nanofabrication.52
The most important and far-reaching applications of
nanomaterials will be in nanodevices and nanoelectronics.
There are already significant advances in these areas to justify
greater expectations. Typical of the advances to date are the
demonstration of single electron memory, Coulomb blockade
and quantum effects, scanning probe tips in arrays, logic
elements and sensors. The number of applications for semi-
conductor nanostructures, in particular those of the group III­
V nitrides (e.g. InGaN) as LEDs and laser diodes,53
are
impressive, and quantum dots and wires of these materials will
have a great number of uses. In Fig. 13, the essential features
of nanodevice fabrication are shown schematically. A note-
worthy development is the possible design of defect-free
molecular electronics involving chemically fabricated systems,
wherein an electronically addressable molecular switch oper-
ates.54
Electron transport studies have been carried out on
Fig. 11 (a) SEM micrograph of a top view of holes (10 nm diameter,
40 nm period) imprinted into poly(methyl methacrylate) (PMMA)
(60 nm deep). (Reproduced by permission from S.-Y. Chou,
P. R. Krauss, W. Zhang, L Guo and L. Zhuong, J. Vac. Sci. Technol.,
B, 1997, 15, 2897. Copyright Slack 1997.) (b) AFM image of a PMMA/
LISA pillar array formed under a square pattern. (Reproduced by
permission from ref. 26, S.-Y. Chou and L. Zhang, J. Vac. Sci.
Technol., B, 1999, 17, 3197. Copyright Slack 1999.)
Fig. 12 Current­potential characteristics at different gate voltages of a
field-effect transistor based on a single-walled nanotube. (Reproduced
by permission from S. J. Tans, A. R. M. Vercsheuren and C. Dekker,
Nature, 1998, 393, 49. Copyright Nature 1998.)
2892 J. Mater. Chem., 2001, 11, 2887­2894
molecular-scale systems employing advanced microfabrication
and self-assembly techniques.55
Nanocircuits and nanocomputers making use of carbon
nanotubes have already been described.14
Recently, metallic
and semiconducting properties of multi-walled nanotubes have
been engineered by stepwise burning of layers or by tailoring
the chirality.56
Such strategies directly help in the use of
nanotubes in nanocircuitry. Use of Y-junction nanotubes may
help to make further advances in this direction.
Resonant tunnelling devices in nanoelectronics deserve
special mention, since they have already demonstrated success
in multivalued logic and memory circuits. Functional devices
based on quantum confinement would be of use in photonic
switching and optical communications.
It is altogether likely that chips for chemical analysis,
nanorobotic systems, spintronic memory based on magnetic
semiconductors and a variety of other technologies will become
realities in the next few years. Our ability to carry out studies
of nanometer-scale objects will be effectively improved by
integrating nanometer-scale control electronics into micro/
nanomachines.
Concluding remarks
The preceding discussion of the current status and future
prospects of the science and technology of nanomaterials
should suffice to demonstrate the great vitality of the subject
and the immense opportunities it offers. It is a truly inter-
disciplinary area, encompassing physics, chemistry, biology,
materials science and engineering. Interaction amongst
scientists with different backgrounds will undoubtedly create
new science, and in particular new materials, with unforeseen
technological possibilities. While there is already considerable
effort being devoted to nanotechnology in various academic
and industrial laboratories, there is certainly a need to establish
dedicated centres with the required infrastructure and experi-
mental facilities. The subject has caused excitement in the
advanced as well as the developing nations, and is one where
international cooperation would be fruitful. What is also
noteworthy is that nanotechnology will benefit not only the
electronics industry, but also the chemical and space industries,
as well as medicine and health care. Materials chemists have a
major role to play in developing the various facets of
nanoscience, such as design, synthesis, assembly and catalysis.
They can also make valuable contributions to theory,
modelling and computer simulation.
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