Nanotechnology and new materials

Nanotechnology and new materials

1. Chemical elements in nanotechnology

   • Nanoparticles
     • These are materials that include substances whose dimensions are less than 100 nanometers.
     • Dimention
       • Zero-dimensional (0D)
       • Depending of the shape
       • One-dimensional (1D)
       • Two-dimensional (2D)
       • Three-dimensional (3D)
     • Clasification
       • Depending on morphology, size and chemical properties
       • NP based on carbon
         • Fullerenes
         • Carbon nanotubes
       • NP metallic
         • Are mainly metals
           • They have a wide band of absorption in the visible zone of the electromagnetic solar spectrum
             • They are widely used for scanning electron microscope sampling to boost the electronic current
       • NP ceramics
         • Are inorganic non-metalic solid
           • Synthesized by heat and cooled succesively
             • Shape
               • Amorphous forms
               • Hollow
               • Porous
               • Dense
               • Polycrystalline
             • Applications
               • Catalysis
               • Photocatalysis
               • Phorodegradation of dyes
               • Image application
       • NP semiconductors
         • Have metallic and non-metallic properties
           • Applications
             • Photocatalysis
             • Photo-optics
             • Electronic devices
       • NP polymeric
         • They are know as polymer nonoparticles
           • Their base is usually organic
             • Have forms of nanospheres or nano capsules
       • NP based on lipids
         • Contain half of the lipids and the other half of (metallic) nanoparticles
           • They are spherical, whithin a diameter ranging from 10 to 1000 nm
             • Are used in medical applications

2. Allotropic forms of carbon

   • Allotropes
     • Crystalline
       • Graphite
         • First form of carbon
         • Forms hexagonal crystals
           • Its atoms has hybridization sp2
             • Forms three covalent bonds
               • Layers are held by weak Van der Waals forces
                 • Conducts electrycity
                   • It's is use on pensil's tips
       • Diamond
         • Second form of carbon
         • Doesn't conduct electricity
           • It has an covalent bonds
             • It hybridization is sp3
               • It is the hardest substance
                 • It melting point is close to 4000°
                   • It is use in ornaments
                     • 4 Cs: carat cut, color, and clarity
       • Fullerenes
         • Third form of carbon
         • Non-polar
           • High physical strength
             • Soluble in organic solvents
               • Buckminsterfullerene C60 is the most common and first to discover fullerene
                 • There are larger, like C70, C84, C180, C240 and C540
                   • They are normally electrical insulators, but when crystallized with alkali metals, the resultant compound can be conducting or even superconducting
         • Nanotubes
           • Discovered unintentionally by Sumio Iijima.
             • Molecular size structures
               • Their structure comes from a rolled-up sheet of graphene
                 • The solubility in usual organic solvents is reduced.
                   • The structure of the nanotubes is very resistant.
                     • It can withsand a tension up to 20 times higher than that of the best steels.
                       • There are two types of nanotubes:
                         • Single-walled CNT
                         • Multi-walled CNT
     • Different form of the same type of elements in the same physical state
     • Amorphous
       • -Multi-walled CNT
         • -its structural nuclei will vary in size.
           • -Dull or with metallic and greyish flashes
             • Charcoal
               • It is the product of the combustion of plant masses and wood
             • Coal
             • Coke
               • It is the product of the combustion of plant masses and wood
             • Soot
               • Black carbon
                 • Depending on the percentage of carbon, several types of amorphous carbons are generated

3. Characteristics of nanomaterials and classification

   • Nanomaterials
     • Are compounds having sizes less than 1 um in at least one dimension and are often restricted in size from 1 to 100 nm
     • Properties
       • Physical properties
         • Size
           • Form
             • Specific surface
               • Ratio between width and height
                 • Degree of adhesion between molecules
                   • Smoothness or roughness of their surface
                     • Dissolution capacity
       • Chemical properties
         • Molecular structure
           • Composition
             • Chemical purity of the surface of the aggregate
               • Behavior in the presence of water molecules or oils
       • Optic properties
         • Some nanomaterials absorb light in a variable range of wavelengths
           • Depending on the size and the shape of the nanoparticles in suspension
       • Magnetic properties
         • Are iron, nickel, and cobalt
           • Agglomerated gold is not magnetic, but at nanometric sizes it becomes magnetic, and depending on the size the magnetic properties vary
     • Characteristics
       • Structural characteristics
         • High surface energy
           • Spatial confinement
             • Reduced imperfections

4. Applications of nanotechnology

   • The scientific community has reached a concensus that nanotechnology will bring about the industrial revolution of the XXI century
     • Areas where nanotechnology is used
       • Material and Processes for Daily Use
         • It has been posible to obtain more resistant, lightweight, durable materials, with better reactivity and conductivity, among many other properties
           • Transparent nanofilms on lents surface computer screens and cameras
             • Windows or other waterproof surfaces or other debris, resistant to UV radiation or simply resistant to scratches
       • Electronics
         • Nanotechnology
           • Minimize the electric consumption
             • Increase their portability
               • Generate chips with large storage capacity
                 • Development of ultra-screens whit quantum-dots, that produce more vibrant colors and save electricity
                   • Flexible electronic devices
       • Medicine and health
         • Nanomedicine
           • The application of nanotechnology for diagnosis treatment and prevention of disease
             • Nanomaterials in medical use
               • Liposomes
               • Nanocrystals
               • Emulsions
               • Iron carbohydrate complexes
               • Development of Nano-vehicles than can transport drugs directly to the targger cells
       • Energy
         • The nanofluids
           • Increases the performance and durability of collectors in solar cells, electronic devices or automotive radiators.
             • Are used in the development of catalysts for the efficient production of biofuels
       • Enviroment
         • Development of nanoparticles that clean water through chemical reactions that convert pollutants into inert molecules
       • Benefits of nanotechnology

5. Benefits and risks of its applications

   • Risks of nanotechnology
     • Throughout the manufacturing process of nanoparticles and nanofibers
       • Could bring risks to health and the enviroment
         • National Nanotechnology Initiative (NNI)
           • Commited to fostering the development of a community of experts in ethical, legal, and social issues related to nanotechnology, as well as considering the potential benefits and risk of advances in research and providing perspectives on new research direction
     • During the end of the products
       • They could attack cells of healthy people or animals indiscriminately