Electrical Engineering Materials Dr. Md. Sherajul Islam Associate Professor Department of Electrical and Electronics Engineering Khulna University of Engineering & Technology Khulna, Bangladesh

LECTURE - 6 Nanotechnology and Nanomaterials

Nanotechnology The art and science of manipulating and rearranging individual atoms and molecules to create useful materials, devices, and systems The design, characterization, and application of structures, devices, and systems by controlled manipulation of size and shape of materials at the nanometer scale (atomic, molecular, and macromolecular scale)

Nanoscale? A sheet of paper is about 100,000 nanometers thick, a human hair is around 80,000- 100,000 nanometers wide

1.1.2- What is nanomaterial? Is defined as any material that has unique or novel properties, due to the nanoscale ( nano metre- scale) structuring. These are formed by incorporation or structuring of nanoparticles. They are subdivided into nanocrystals, nanopowders, and nanotubes: A sequence of nanoscale of C60 atoms arranged in a long thin cylindrical structure.

1.1.2- What is nanomaterial? carbon nanotubes

Noble metal nanocrystals with cyclic penta-twinned structures 1.1.2- What is nanomaterial? Noble metal nanocrystals with cyclic penta-twinned structures

1.1.2- What is nanomaterial? Naonpowder

Types of nanomaterials Nanomaterials can… occur naturally be produced by human activity either as a product of another activity on purpose (engineered) Our focus: engineered nanomaterials as these are designed and integrated into products because of the specific characteristics of the nanomaterial Date, location

Classes of nanomaterials Date, location

NanoZnO – One Chemistry, Many Shapes Courtesy of Prof. Z.L. Wang, Georgia Tech

Why are nanomaterials used? At nano-scale, the material properties change - melting point, fluorescence, electrical conductivity, and chemical reactivity Surface size is larger so a greater amount of the material comes into contact with surrounding materials and increases reactivity Nanomaterial properties can be ‘tuned’ by varying the size of the particle (e.g. changing the fluorescence colour so a particle can be identified) Their complexity offers a variety of functions to products

Examples of nanomaterials in products Amorphous silica fume (nano-silica) in Ultra High Performance Concrete – this silica is normally thought to have the same human risk factors as non‐nano non‐toxic silica dust Nano platinum or palladium in vehicle catalytic converters - higher surface area to volume of particle gives increased reactivity and therefore increased efficiency Crystalline silica fume is used as an additive in paints or coatings, giving e.g. self-cleaning characteristics – it has a needle-like structure and sharp edges so is very toxic and is known to cause silicosis upon occupational exposure

Nanotechnology spans many Areas Information Technology Information Technology Information Technology Information Technology Information Technology Information Technology Information Technology Information Technology Information Technology Information Technology Information Technology Information Technology Mechanical Eng. & Robotics Mechanical Eng. & Robotics Mechanical Eng. & Robotics Mechanical Eng. & Robotics Mechanical Eng. & Robotics Mechanical Engineering / Robotics Mechanical Eng. & Robotics Mechanical Eng. & Robotics Mechanical Eng. & Robotics Mechanical Eng. & Robotics Biotechnology Biotechnology Biotechnology Biotechnology Biotechnology Biotechnology Biotechnology Biotechnology Transportation Transportation Transportation Transportation Advance Materials & Textiles Advance Materials & Textiles Advance Materials & Textiles Advance Materials & Textiles Advance Materials & Textiles NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY NANOTECHNOLOGY National Security & Defense National Security & Defense National Security & Defense National Security & Defense National Security & Defense National Security & Defense Energy & Environment Energy & Environment Energy & Environment Energy & Environment Energy & Environment Energy & Environment Energy & Environment Energy & Environment Energy & Environment Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Food and Agriculture Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Medicine / Health Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace Aerospace

2- Applications of Nanotechnology: 2.1 General Applications Examples Application Diagnostics, Drug delivery, Tissue engineering, Cryonics Medicine Memory storage, Novel semiconductor devices, Novel optoelectronic devices, Displays, Quantum computers Information and communication Aerospace, Catalysis, Catalysis, Construction Vehicle manufacturers Heavy Industry Foods, Household, Optics, Textiles, Cosmetics, Sports Consumer goods Environment

energy of vibrating electron = (any integer) x hf 2.2- Environmental Applications Check http://www.nanowerk.com/products/product.php?id=160 for more details Examples Application Photocatalyst consisting of silica Nanosprings coated with a combination of titanium dioxide Carbon capture Pollutants sensors that able to detect lower limits with low cost Sensors Heavy metal decontaminant removes heavy metals such as lead, cadmium, nickel, zinc, copper, manganese and cobalt in a neutral pH environment without using any form of sulphur. Remediation (decontamination, oil spill management) Veolia Water Solutions & Technologies' ceramic membrane modules, utilizing the CeraMem technology platform, can be supplied with a variety of inorganic microfiltration and ultrafiltration membranes. Wastewater treatment Heat distribution e.g. ceramic-like  materials  that provide sufficient reliability and durability of the entire structure Energy Drinking water purification So how does this explain the spectrum of blackbody radiation? Planck said that an electron vibrating with a frequency f could only have an energy of 1 hf, 2 hf, 3 hf, 4 hf, ... ; that is, energy of vibrating electron = (any integer) x hf But the electron has to have at least one quantum of energy if it is going to vibrate. If it doesn't have at least an energy of 1hf, it will not vibrate at all and can't produce any light. "A ha!" said Planck: at high frequencies the amount of energy in a quantum, hf, is so large that the high-frequency vibrations can never get going! This is why the blackbody spectrum always becomes small at the left-hand (high