This document provides an overview of nanomaterials classification. It discusses how nanomaterials can be classified based on origin, size and dimension, and chemical composition. Specifically, it describes: - Zero-dimensional nanomaterials which have all dimensions at the nanoscale, such as nanospheres. - One-dimensional nanomaterials which are confined to the nanoscale in two dimensions, forming structures like nanofibers. - Two-dimensional nanomaterials which are confined to the nanoscale in one dimension, exhibiting plate-like shapes. - Three-dimensional nanomaterials which are not confined to the nanoscale in any dimension. It also discusses organic nanoparticles like dendrimers and liposomes, inorganic

1. BIONANOTECHNOLOGY
UNIT I
CLASSIFICATION OF NANOMATERIALS
ABARNA M P
II – M.Sc.,BIOTECHNOLOGY
21PBT810

5. NANOMATERIAL
• Nanomaterials – The materials possessing, at
minimum, one external dimension measuring
1-100 nm (1nm = 10-9 meter).
• Material properties change as their size
approaches the atomic scale.
• This is due to the surface area to volume ratio
increasing, resulting in the material’s surface
atoms dominating the material performance.

6. • This feature enables nanoparticles to possess
unexpected optical, physical and chemical
properties as they are small enough to confine
their electrons and produce quantum effects.
• Nanoparticles can be classified based on the
following criteria – Origin, Size and chemical
composition.

9. • Based on Origin –
Natural, Anthropogenic
• Based on Size and
dimension – 0D, 1D, 2D
and 3D.
• Based on Chemical
composition
 Organic nanoparticles
 Inorganic nanoparticles
 Carbon-based
nanoparticles

10. BASED ON SIZE AND DIMENSION
• According to Siegel, nanostructured materials
are classified as: zero-dimensional (0D), one-
dimensional (1D), two-dimensional (2D) and
three-dimensional (3D) nanomaterials.
• (i) Zero-dimensional nanomaterials: All
dimensions (x, y, z) are at nanoscale, i.e., no
dimensions are greater than 100 nm. It
includes nanospheres and nanoclusters.

11. • (ii) One-dimensional nanomaterials: Two
dimensions (x, y) are at nanoscale and the
other is outside the nanoscale. This leads to
needle shaped nanomaterials. It includes
nanofibres, nanotubes, nanorods, and
nanowires.
• (iii) Two-dimensional nanomaterials: One
dimension (x) is at nanoscale and the other
two are outside the nanoscale. The 2D
nanomaterials exhibit plate-like shapes. It
includes nanofilms, nanolayers and
nanocoatings with nanometre thickness.

12. • (iv) Three-dimensional nanomaterials: These are the
nanomaterials that are not confined to the nanoscale
in any dimension.
• These materials have three arbitrary dimensions above
100 nm.
• The bulk (3D) nanomaterials are composed of a
multiple arrangement of nanosize crystals in different
orientations.
• It includes dispersions of nanoparticles, bundles of
nanowires and nanotubes as well as multi-nanolayers
(polycrystals) in which the 0D, 1D and 2D structural
elements are in close contact with each other and form
interfaces.

13. BASED ON CHEMICAL COMPOSITION
• Based on the nature i.e., chemical
composition, the nanomaterials are
classified as –
• Organic Np’s (Dendrimers, Miscelles,
Liposomes, Ferritin polymers)
• Inorganic Np’s (Metal and Metal oxides)
• Carbon-based Np’s (Fullerene, Graphene,
Nanotubes, nanofibres)

14. ORGANIC NANOPARTICLES
• Small particles made of aggregated molecules
or polymers.
• Biocompatible, Biodegradable, non-toxic.
• Widely used in the biomedical field for drug
delivery for eg., Targeted drug delivery.
• Low stability, reproducibility and drug
entrapment issues.
• Eg: Dendrimers, Miscelles, Liposomes, Ferritin
polymers

15. DENDRIMERS
• Dendrimers - repetitively branched molecules.
• Greek word ‘dendron’ meaning ‘tree’.
• These nanomaterials are nanosized polymers
built from branched units.
• The surface of a dendrimer has numerous chain
ends, which can perform specific chemical
functions.
• Dendrimers are used in molecular recognition,
nanosensing, light harvesting, and opto-
electrochemical devices.
• They may be useful for drug delivery.

17. LIPOSOMES
• Unique class of organic nanoparticles – Successful
nanoparticle platform for biomedical application.
• Consists of biodegradable phospholipids which
self-assemble into a lipid bilayer around an
aqueous core upon hydration.
• The versatility of liposome can incorporate both
hydrophobic and hydrophilic molecules, like
antigenic proteins and peptides, within the lipid
bilayer and aqueous core, respectively.
• Advantage of liposomal nanoparticle – tunability
of the lipid bilayer, which can further be
functionalized with targeting ligands or antigens,
allowing for vaccine applications in biomedical
imaging and drug delivery.

18. FERRITIN
• Self-assembly nanoparticle-based vaccine
platform for infectious diseases is ferritin –
produced in majority of living organisms.
• Composed of 24 alpha helix subunits of 3-
folds axis symmetry and self-assembles into
nanoparticles with improved thermal and
chemical stability.

20. INORGANIC NANOPARTICLE
• Metal and Metal oxides based nanoparticles
are generally called as inorganic nanoparticle.
• Have a smaller particle size, improved stability,
controlled tunability, enhanced permeability,
high drug loadings and a triggered release
profile which is ideal for antigen delivery as a
vaccine.

21. METAL BASED NANOPARTICLE
• Nanoparticles synthesized from metals.
• All the metals can be synthesized into
nanoparticles.
• Commonly used metals for nanoparticle
synthesis – Aluminium (Al), Cadmium (Cd),
Cobalt (Co), Copper (Cu), Gold (Au), Iron (Fe),
Silver (Ag) and Zinc (Zn).

22. GOLD NANOPARTICLE
• Gold nanoparticles (Au NP’s) used in variety of
applications including computing devices,
catalysis, sensing probes and drug delivery.
• Due to its low toxicity and its chemical
diversity for accommodating different
compositions, sizes, shapes and surface
functionalization, Au Np’s are ideal for vaccine
application.

23. METAL OXIDE NANOPARTICLE
• Synthesized to modify the properties of their
respective metal based nanoparticle.
• Nanoparticles of iron (Fe) instantly oxidizes to
iron oxide (Fe2O3) in the presence of O2 at room
temperature – increases its reactivity compared
to Fe Np’s.
• Have increased reactivity and efficiency.
• Commonly synthesized Metal oxide Np’s are
Aluminium oxide, Cerium oxide, Iron oxide,
Magnetite, Silicon dioxide, Titanium oxide etc.

24. IRON OXIDE NANOPARTICLE
• Commonly associated with Magentic
resonance imaging (MRI) – to image a wide
variety of diseases
• Recently, Iron oxide Np’s are used as adjuvants
for vaccine.

25. CARBON-BASED NANOPARTICLE
• Nanoparticles that are completely made of
carbon.
• Takes the form of hollow spheres, ellipsoids or
tubes. The spherical and ellipsoidal forms are
referred as fullerenes, while cylindrical forms are
called nanotubes.
• Fullerene
• Graphene
• Carbon nanotubes
• Carbon nanofibres
• Carbon nanowires
• Carbon nanocones

26. GRAPHENE
• First isolated by A.K. Geim and K.S. Novoselov at
the University of Manchester in 2004.
• Nobel Prize in 2010.
• Crystalline allotrope of carbon with two-
dimensional, atomic scale, hexagonal pattern.
• Here each carbon atom forms four bonds, three s
bonds (sp2 hybridized) with its three neighbours
and one p bond oriented out of plane.
• It is the basic structural element of other
allotropes like graphite, fullerene, nanotubes,
nanocones, etc. hence called mother of all carbon
nanomaterials

28. PROPERTIES
• It is nearly transparent.
• It is 200 times stronger than steel by weight
due to its tightly packed carbon atoms.
• It conducts heat and electricity with great
efficiency due to presence of p electrons.
• Nowadays, it is commonly used in
semiconductors, batteries, electronics,
composite industries, and many more.

29. FULLERENE
• First fullerene was discovered by Harold Kroto,
Richard Smalley and Robert Curl in 1985 by using
a laser to vaporise graphite rods in an
atmosphere of helium gas.
• Graphene sheets rolled into tubes or spheres. It
is a cage like molecule composed of 60 carbon
atoms (C60) joined together by single and double
bonds to form a hollow sphere with 20 hexagonal
and 12 pentagonal faces (a design that resembles
a football).
• It was named as buckminsterfullerene or
buckyball after the name of American architect
Buckminster Fuller, the inventor of the geodesic
dome.

31. APPLICATIONS
• The recent research has suggested that fullerence has
many uses, including medical applications,
superconductors, fiber-optics, etc. Some of the
important applications are listed as follows:
• Fullerenes (C60) and their derivatives have potential
antiviral activity, and may be used for the treatment of
HIV-infection.
• They have potential medicinal applications as they can
bind specific antibiotics and target certain types of
cancer cells such as melanoma.
• They are used as biological antioxidants.
• They are also used as potential photosensitizers in
photodynamic therapy and catalysts for hydrogenation.
• Fullerenes incorporated with sulphides of tungsten and
molybdenum exhibit excellent solid-lubricant
properties.

32. NANOTUBES
• Elongated form of fullerenes (or) cylinders of one
or more layers of graphene (lattice).
• First identified in 1991 by Iijima Sumio of Japan.
• A tube-shaped material, made up of carbon,
having a diameter ranging from < 1 nm to 50 nm.
• Carbon nanotubes show a unique combination of
stiffness, strength, and tenacity compared to
other fibre materials.
• Thermal and electrical conductivity are also very
high as comparable to other conductive
materials.

33. • Carbon nanotubes may be
categorized as follows:
• Single-wall nanotubes
(SWNT): These may be
zigzag, armchair and chiral
depending on the manner in
which the grapheme sheets
are rolled.
• Multi-wall nanotubes
(MWNT): It consists of
several single walled
nanotubes with different
diameters.

34. APPLICATIONS
• Carbon nanotube technology can be used for a wide
range of new and existing applications, which are as
follows:
• Nanotubes can potentially replace indium tin oxide in
solar cells to generate photocurrent.
• SWNTs are used in transistors and solar panels.
• MWNTs are used in lithium ion batteries to enhance
cycle life.
• Parallel CNTs have been used to create loudspeakers.
• CNTs can serve as a multifunctional coating material.
• CNTs can be used to produce nanowires.
• CNTs are also used for applications in energy storage,
automotive parts, boat hulls, water filters, thin-film
electronics coatings, ultra-capacitors, biosensors for
harmful gases, extra strong fibers, etc.

35. NANOWIRES
• The structures have the diameters of the
order of a nanometre and an unconstrained
length.
• Also called quantum wires because at this
scale they have different quantum mechanical
effects.
• There are different types of nanowires. For
example: carbon nanowires, molecular
nanowires, metallic nanowires, etc.

36. APPLICATIONS
• They are useful in digital computing.
• These are used for the preparation of active
electronic components like p-n junction, logic
gates, etc.
• They have potential applications in high-
density data storage.
• Silver chloride nanowires are used as
photocatalysts to decompose organic
molecules in polluted water.

37. REFERNCES
• Engineering Chemistry with Laboratory
Experiments, R. K. Mohapatra, PHI, Delhi, 2015.
• Chemical Modification of Solid Surfaces by the
Use of Additive, Chapter-2, R. K. Mohapatra and
D. Das (edt.), Bentham Science, Singapore, 2020.
• Nanotechnology – Principles and practices by
Sulabha K. Kulkarni (3rd edition)

38. THANK YOU