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What is NANO?
In 1960, the U.S. National Bureau of Standards adopted the prefix "nano-" for "a billionth".
Millimicrometer (millimicron)mµµµ
What is NANO?
What is NANO?
The nanoscopic scale is sometimes marked as the point where the properties of a material change; above this point, the properties of a material are caused by 'bulk' or 'volume' effects.
What is NANO?
What is NANO?
Iron has ferromagnetism properties .
What is NANO?
IONs have superparamagnetic properties.
'surface area effects' become more apparent
What is NANO?
Matter with at least one dimension sized from 1 to 100 nanometres.
What is Nano-Materials?
10
Nanosheets
Nano-Materials
11
Nanoneedles
Nano-Materials
12
Nanoparticles
Nano-Materials
National Nanotechnology Initiative (INN)The manipulation of matter with at least one
dimension sized from 1 to 100 nanometres.
What is Nanotechnology?
Richard SmalleyNanotechnology is the art and science of
building stuff that does stuff at the nanometer scale.
What is Nanotechnology?
Richard FeynmanAmerican Physical Society meeting at
Caltech on December 29, 1959.There's Plenty of Room
at the Bottom .
History
Possibility of direct manipulation of individual atoms as a more powerful form of synthetic chemistry than those used at the time.
Molecular Nanotechnology
History
K. Eric DrexlerGray goo Ecophagy
History
Iran Nanotechnology Initiative Council (INIC)
History
That Bit of Chemistry and Physics You Just Have to Know
Bonding atoms with electrons
Covalent Bond
That Bit of Chemistry and Physics You Just Have to Know
Light & NANOtech
Turning on the light
PhotonLight is made up of itsy-bitsy particles, too
small for anybody to see.
Light & NANOtech
Isaac Newton
light is essentially a stream of particles
Light & NANOtech
Wave theory light had properties similar to a wavelike
electric field traveling with a wavelike magnetic field.
Light & NANOtech
light can behave in both ways — as a particle and a wave — it depends on the situation. To describe light traveling from one place to another, we call on ideas from the wave model. When you talk about light interacting with matter on the atomic level, Albert’s photons come into play — and into nano-research.
Light & NANOtech
Wavelength
Light & NANOtech
Light frequencyHertz (Hz) per second.
Light & NANOtech
C = f * λC (Light velocity): 299 792 458 metres per
second ≈ 3 × 108 m/s
f: frequency in cycles per secondλ: Wavelength in meter
Light & NANOtech
Light & NANOtech
Wavenumber (spatial frequency)The number of waves that exist over a
specified distance (cm)
Light & NANOtech
Kicking out a photon
Light & NANOtech
At the atomic level, all excited atoms are emitting photons.
Light & NANOtech
A wire designed to let its atoms heat up till they generate light.
Light & NANOtech
Studying things that small requires special, deviously clever instruments that measure certain properties of matter — for example, spectrometers
Light & NANOtech
Infrared (IR) spectroscopy
Light & NANOtech
Infrared (IR) spectroscopy
Light & NANOtech
Infrared (IR) spectroscopy
Light & NANOtech
Infrared (IR) spectroscopy
Light & NANOtech
Infrared (IR) spectroscopy
Light & NANOtech
Raman spectroscopy
Light & NANOtech
Raman spectroscopy
Light & NANOtech
Stokes shift
Light & NANOtech
Raman spectroscopy
Light & NANOtech
Raman spectroscopy
Light & NANOtech
Vibrational microscopy
Light & NANOtech
Vibrational microscopy
Light & NANOtech
Vibrational microscopy
Light & NANOtech
Vibrational microscopy
Light & NANOtech
Applications in Biology and Medicine Diseased tissue research Identify chemical differences in plant leaf
material Identify bacteria using chemical imaging Analysis of biomaterial interactions Characterize ingredient or coating distribution in
tablets Identify counterfeit medications Monitor solvent diffusion and active ingredient
dissolution in blends or granules
Vibrational microscopy
Applications in Microbiology
Vibrational microscopy
Ultra Violet-Visible spectroscopyThe electrons in each type of atom can only
absorb light of certain frequencies.The spectrometer measures that frequency of
light that passes through the sample.
Light & NANOtech
• Ultra Violet-Visible spectroscopyUV-Vis spectroscopy plays a role in the
creation of nanosensors that can detect a material and identify its composition by bonding with it (also called capturing), which changes the nanosensor’s properties in specific ways that tell the tale.
Light & NANOtech
Atomic force microscope (AFM)
Seeing Molecules with Microscopy
Atomic force microscope (AFM) is providing a topographic image.
Seeing Molecules with Microscopy
Electrostatic force microscopy
Seeing Molecules with Microscopy
Magnetic force microscope (MFM)
Seeing Molecules with Microscopy
Scanning tunneling microscope (STM)
Seeing Molecules with Microscopy
Scanning tunneling microscope (STM)
Seeing Molecules with Microscopy
Scanning tunneling microscope (STM) It operates in tow modes1. constant height mode 2. constant current mode
Seeing Molecules with Microscopy
Ernst Abbe
Electron microscope
The ability to resolve detail in an object was limited approximately by the wavelength of the light used in imaging, which limits the resolution of an optical microscope to a few hundred nanometers.
Ernst Abbe
Developments into ultraviolet (UV) microscopes, led by Köhler and Rohr, allowed for an increase in resolving power of about a factor of two.
However this required more expensive quartz optical components, due to the absorption of UV by glass.
At this point it was believed that obtaining an image with sub-micrometre information was simply impossible due to this wavelength constraint.
Köhler and Rohr
A wide range of magnifications is possible, from about 10 times (about equivalent to that of a powerful hand-lens) to more than 500,000 times, about 250 times the magnification limit of the best light microscopes.
The types of signals produced by a SEM include secondary electrons (SE), back-scattered electrons (BSE), characteristic X-rays, light.
Secondary electron detectors are standard equipment in all SEMs, but it is rare that a single machine would have detectors for all possible signals.
Scanning electron microscope (SEM)
Back-scattered electrons (BSE) are beam electrons that are reflected from the sample by elastic scattering.
BSE are often used in analytical SEM along with the spectra made from the characteristic X-rays, because the intensity of the BSE signal is strongly related to the atomic number (Z) of the specimen.
BSE images can provide information about the distribution of different elements in the sample.
Scanning electron microscope (SEM)
Characteristic X-rays are emitted when the electron beam removes an inner shell electron from the sample, causing a higher-energy electron to fill the shell and release energy.
Scanning electron microscope (SEM)
All samples must also be of an appropriate size to fit in the specimen chamber and are generally mounted rigidly on a specimen holder called a specimen stub.
Sample preparation
For conventional imaging in the SEM, specimens must be electrically conductive, at least at the surface, and electrically grounded to prevent the accumulation of electrostatic charge at the surface.
Sample preparation
Fixation: glutaraldehyde sometimes in combination with formaldehyde
Biological samples
Post-fixation: osmium tetroxide?Dehydration: Because air-drying causes
collapse and shrinkage, this is commonly achieved by replacement of water in the cells with organic solvents such as ethanol or acetone, EtOH, 30, 50, 70, 90 & 100%.
Biological samples
Temperature-sensitive materials such as ice Cryo-fixationCryo-stage Low-temperature scanning electron
microscopy
cryo-microscopy
cryo-microscopy
Sputter coater
Sputter coating
What is sputtering?
What is sputtering?
What is sputtering?
What is sputtering?
Magnetron sputtering
Higher magnification results from reducing the size of the raster on the specimen
Magnification
Topography: surface features such as textureMorphology: shape, size, and arrangements
of the particles that compose the object’s surface
Composition: elements that make up the sample (This can be determined by measuring the X-rays produced when the electron beam hits the sample.)
SEM
Bouncing electrons off a sample is only one technique; you can also shoot electrons through
It’s a kind of nanoscale slide projector: Instead of shining a light through a photographic image (which allows certain parts of the light through), the TEM sends a beam of electrons through a sample.
Transmission electron microscope (TEM)
Max Knoll and Ernst Ruska in 1931
The first TEM