in 1960, the u.s. national bureau of standards adopted the prefix "nano-" for "a...

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

http://en.wikipedia.org/wiki/File:Feynman_at_Los_Alamos.jpg

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

Raman spectroscopy

Light & NANOtech

Stokes shift

Light & NANOtech

Raman spectroscopy

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


Applications in Microbiology


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.


Electrostatic force microscopy


Magnetic force microscope (MFM)


Scanning tunneling microscope (STM)


Scanning tunneling microscope (STM) It operates in tow modes1. constant height mode 2. constant current mode


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.


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.


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?

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

in 1960, the u.s. national bureau of standards adopted the prefix "nano-" for "a...

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