Nanotechnology PDF

NANOTECHNOLOG Y Prepared by: Anlee A. Refuerzo  NANOSCIENCE AND NANOTECHNOLOGY Nanotechnology manipulates and controls matter's sizes, forms, and structure on a 1 to 100 nanometer scale. Source: https://introtonanotechnology.weebly.com/the-nanoscale...

NANOTECHNOLOG Y Prepared by: Anlee A. Refuerzo  NANOSCIENCE AND NANOTECHNOLOGY Nanotechnology manipulates and controls matter's sizes, forms, and structure on a 1 to 100 nanometer scale. Source: https://introtonanotechnology.weebly.com/the-nanoscale.html  Size affects the material's qualities (conductivity, color,  NANOSCIENCE AND NANOTECHNOLOGY Fire discovery: early 400,000 Medical application: 21st years ago century Source: (Photo by National Galleries Of Scotland/Getty Source: © Wiley-VCH Verlag Images) Size, shape, and structure contribute to their distinctive reactivity and strength, making them useful in commercial and home contexts from electronics to biology to imaging to the environment to food packaging (Khan et. al ,2019).  NANOPARTICLES Nanoparticles range from 1 to 100 nanometers. Nanoparticles can have drastically different physical and chemical properties than their bigger counterparts, which are invisible to the human eye. Classifications of Nanomaterial  NANOPARTICLES According to origins  Naturally occurring nanoparticles can be found in volcanic ash, ocean spray, fine sand and dust, and even biological matter (e.g. viruses).  Synthetic nanoparticles (sometimes called anthropogenic nanoparticles) fall into two general categories: “incidental” and “engineered”  NANOPARTICLES According to dimension Zero-dimensional nanomaterials:  Here, all dimensions (x, y, z) are at nanoscale, i.e., no dimensions are greater than 100 nm. One-dimensional nanomaterials:  Here, two dimensions (x, y) are at nanoscale and the other is outside the nanoscale.  This leads to needle shaped nanomaterials.  NANOPARTICLES According to dimension Two-dimensional nanomaterials:  One dimension (x) is nanoscale, but the other two are not.  2D nanomaterials are flat.  It includes nanofilms, nanolayers, and nanocoatings. Three-dimensional nanomaterials:  These nanomaterials have no nanoscale boundaries.  Three random dimensions are greater than 100 nm.  Bulk (3D) nanomaterials are made up of nanoscale crystals with varying orientations.  NANOPARTICLES According to structure Carbon based materials:  These are composed of carbon, taking the form of hollow spheres, ellipsoids or tubes. Metal based materials:  These include quantum dots, nanogold, nanosilver and metal oxides like TiO2.  NANOPARTICLES According to structure Dendrimers:  Dendrimers are repetitively branched molecules.  These nanomaterials are nanosized polymers built from branched units. Composites:  Composites are combination of nanoparticles with other nnanoparticles or with larger, bulk-type materials. NANOPARTICLES CHARACTERISTICS AND ITS EFFECTS  SYNTHESIS OF NANOPARTICLES  Physical methods employ a top-down strategy , beginning with the mechanical fragmentation of a large mass of metal into smaller pieces.  Bottom-up approaches involve the production of nanoparticles from smaller molecules. This technique is primarily based on chemical reduction Visual Illustration of Constructing Nanoparticles SYNTHESIS IF NANOPARTICLES  SYNTHESIS IF NANOPARTICLES (CHEMICAL METHOD) Green synthesis is a chemistry method that is friendly to the environment by using ecological solvents and reducing toxic waste. Chemical synthesis of nanoparticles is usually done in a solution with reducing agents Radiation Induced Synthesis involves irradiating aqueous solutions with gamma rays or accelerated electrons at room temperature.  SYNTHESIS IF NANOPARTICLES (CHEMICAL METHOD) Electrochemical deposition occurs between a metal- containing electrolyte solution and a conductive metal substrate. Micro-emulsion technique involves a droplet (dispersed phase), an immiscible solvent (continuous phase), and a covering surfactant. The desired size and composition of nanoparticles are synthesized in droplets.  SYNTHESIS IF NANOPARTICLES (PHYSICAL METHOD) Laser ablation synthesis deals with generation of nanoparticles using a powerful laser beam. Short laser pulses vaporize metal target spots, which condense as nanoparticles in the solvent. Sputtering produces nanoparticles by bombarding a target metal with high-energy particles. Thermal evaporation is the vaporization of a material by heating to a high enough temperature that atoms or molecules are lost from the surface in a vacuum.  SYNTHESIS IF NANOPARTICLES (PHYSICAL METHOD) Ball milling is a grinding method that grinds nanotubes into extremely fine powders. Nanolithography creates microscopic structures by etching patterns. Most nanolithography methods use light or electrons to create substrate patterns.  EXAMPLE OF NANOPARTICLES Graphene  Graphene is a two-dimensional, atomic-scale hexagonal carbon allotrope.  It is constructed of hexagonal sp2-hybridized carbon.  It is a fundamental structural component of other carbon nanomaterials such as graphite, fullerene, nanotubes, and nanocones.  It is 200 times stronger than steel by weight due to its tightly packed carbon atoms.  EXAMPLE OF NANOPARTICLES METALLIC NANOMATERIAL  Metallic nanoparticles (MNPs) have an inorganic metal or oxide core surrounded by an organic or inorganic shell or oxide.  Various properties like mechanical strengths, high surface area, low melting point, optical properties and magnetic properties. APPLICATION: It is used for several biomedical applications, waste water treatment and photocatalysis.  EXAMPLE OF NANOPARTICLES APPLICATION:  These are commonly found in trans istors, solar cells, diode lasers, LED s, and other electronic devices.  These are also necessary for optica l applications such as amplifiers, an d biological sensors.  Photocatalysis Quantum Dots  These are the semiconductor nanoparticles between 10 and 100 atoms in diameter.  The properties of QDs can vary depending on its shape and size.