polymeric nanocomposites

1. Nanotechnology is the understanding and control of matter at dimensions of roughly 1 to
100 nanometers, where unique phenomena enable novel applications.
1. What Is Nanotechnology?

2. 2. Nanotechnology is very, very small.
Gold (Au) is shiny and yellow at the macroscale. However, when the gold particles are 25 nm in size, they
appear red. The smaller particles interact differently with light, so the gold particles appear a different color.
Depending on the size and shape of the particles, gold can appear red, yellow or blue.

3. 3. Why Is This Length Scale So Important?
Wavelike (quantum mechanical) properties of electrons inside matter and atomic interactions
are influenced by materials variations on the nanometer (nm) scale.
By creating nanometer-scale structures, it is
possible to control the fundamental properties of materials,
such as
• their melting temperature,
• magnetic properties,
• charge capacity, and
• even their color,
without changing the materials' chemical compositions.

4. 4. What Does Nano Really Mean?

5. 5. Uniqueness of Nanostructured Materials

6. 6. Polymer Nanomaterials
Nanomaterials can be classified into nanostructured materials and
nanophase/nanoparticle materials.
Nanostructured materials: usually refer to condensed bulk materials that are made of
grains (agglomerates), with grain sizes in the nanometer size range
Nanophase/'nanoparticle : usually the dispersive nanoparticles. The nanometer size
covers a wide range, from 1 nm to as large as 100 to 200 nm.
The introduction of inorganic nanoparticles as additives into polymer systems has resulted in
polymer nanocomposites (PNs) exhibiting multifunctional, high-performance polymer
characteristics.
Polymer nanocomposites, or the more inclusive term, polymer nanostructured materials (PNMs),
represent a radical alternative to these traditional filled polymers or polymer compositions.

7. 7. Current Polymer Nanocomposite Technology

8. 8. Different Types of Nanoparticles
The most commonly used nanoparticles in the
literature:
• Montmorillonite organoclays (MMT)
• Carbon nanofibers (CNFs)
• Polyhedral oligomeric silsesquioxane (POSS®)
• Carbon nanotubes [multiwall (MWNTs), small-diameter
(SDNTs),
and single-wall (SWNTs)]
• Nanosilica (N-silica)
• Nanoaluminum oxide (A1203)
• Nanotitanium oxide (TiC^)
• Others

9. 9. Montmorillonite nanoclays

10. 10. Montmorillonite nanoclays

11. 11. Importance of organic treatment.
Since layered silicates are hydrophilic materials, they must be made organophilic (or
hydrophobic) to become compatible with the polymer.
– Without organic treatment, layered silicates only disperse in very polar polymers.
– Organic treatment is typically done via ion exchange between inorganic alkali cations on the
clay surface and the desired organic cation.

12. 12. Dispersing nanoclay.

13. 13. Different mechanisms for dispersing nanoclays
Fig 2.7 Fig 2.8
Fig 2.9