STS CHAPTER 11 : THE NANO WORLD

nanoscience

The branch of science that deals with the study of phenomena and manipulation of material at the nanoscale

nanotechnology.

The more specific branch that caters to nanoparticles. This is also the understanding and control of matter at the atomic and molecular levels in the range of approximately 1-100 nm. It is further described as "any technology that involves the imaging, measuring, modeling, and manipulating matter at this length scale.”

Richard Feynman

the physicist with a speech “There’s Plenty of Room at the Bottom” that first introduced the idea of manipulating very small particles

Norio Taniguchi

who coined the word nanotechnology. It was initially a description on semiconductor processes such as thin film deposition and ion beam milling that involves characteristic control on the order of a nanometer.

Nanotechnology Consumer Products Inventory (CPI)

this was created as documentation in keeping track of the marketing and distribution of nanaproducts in the market

health and fitness category

in what category of products did nanotechnology dominated on 2013, accounting to 42% . And the most frequently used nanomaterial is the nanoparticle metal silver.

U.S. National Nanotechnology Initiative (NNI).

This was the first official Federal government effort in nanotechnology. It was established by President Bill Clinton and funded for the first time in 2000 and continues up to this date. By far, NNI is the most popular and influential nanotechnology initiative in the world. As a result, US of America leads the countries actively involved in nanotech research. 

Electron microscopy

works by bombarding a sample with a stream of electrons and monitoring either the resulting transmission or scattering effects.

Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM).

two types of electron microscopy

Scanning Electron Microscopy (SEM).

the type of electron microscopy that gives 3D images of particles in the dispersion

Transmission Electron Microscopy (TEM)

2D images are only seen and requires further interpretation. This is capable of delivering much greater resolution other than the other type. 

Ernst Ruska

German engineer that developed the first electron microscope, a TEM, with the assistance of his colleague Max Knolls in 1931.

scanning tunneling microscope

works by applying a voltage bias between an electrical probe tip (tunneling tip) over the surface of a sample. The distance between the tip and sample is measured based on the tunneling current produced by the transport of electrons.

Gerd Binnig and Heinrich Rohrer

shared the development of the first working STM while employed at IBM Zurich Research Laboratories in Switzerland in 1981. This led them to win the Nobel Prize in physics in 1985.

atomic force microscope (AFM)

was developed to overcome the limitation of the STM, which can only work on conducting/semiconducting surfaces. can resolve the image of almost any type of surface like polymers, ceramics, etc, here the tunneling tip is replaced by an atomic scale force sensor (cantilever) which is used to measure the attractive or repulsive forces between the tip and sample.

carbon-based

the most widely used classes of nanomaterials

Carbon-based nanomaterial

Carbon nanotube

Fullerene

Graphene

Inorganic-based nanomaterial

Ag nanoparticle

Gold nanoparticle

Titanium dioxide

Organic-based nanomaterial

Dendrimer

Polymer nanoparticle

Composite-based nanomaterial

Hybrid nanofiber

Metal-organic framework

Fullerenes

are spherical carbon-caged molecules with sixty (C60) or more carbon atoms. The spherical shape could allow this to contain molecules while other chemical groups can be attached to the surface. These measure about 0.7-1.5 nm in diameter. Applications is its use as an antioxidant.

Buckminsterfullerene (C60)

more commonly known as the buckyball. It is a stable molecule that contains 50 to 500 carbon atoms in a ball. It was the first fullerene to be discovered and was named after the American architect, Buckminster Fuller, as it resembled his geodesic dome design.

Carbon nanotubes (CNT)

discovered by Sumio Iijima and have different properties from fullerene-type materials. If the buckyballs are round, this has have a cylindrical shape that has not folded around to create a sphere. The carbon atoms are linked in hexagonal shapes, with each carbon atom covalently bonded to the other three carbon atoms. They are produced ranging from single to tens of nanometers in diameter and several micrometers in length. After being bent and then released, they will spring back to their original shape. They have tensile strength, or breaking strain that is 6-7 times that of steel.

Two types of CNT that are possible

The first one has a cylindrical shape with open ends. Another type has closed ends and formed into pentagons on the end of the nanotube.

Graphene

The most recent form of carbon discovered. It is a flat one-atom thick sheet or a single monolayer of carbon atoms, tightly bound in a hexagonal honeycomb lattice.

• holds the record of being the thinnest compound discovered with one atom thick and the lightest material known to man with 1 m² thick at a weight of around 0.77 mg. It is the strongest compound discovered (around 100-300 times stronger than steel), the best conductor of heat at room temperature, and the best conductor of electricity (150 times more conducting than silicon) It is the only substance that is impermeable to liquid and gas; yet weighs almost nothing

Andre Geim and Sir Kostya Novoselov

isolated a single atomic layer of carbon for the first time. The discovery of graphene is considered so important that the two discoverers won the Nobel Prize for Physics in 2010.

nanobots

capable of. cleaning the blood of toxins generated by bacteria in the experimental stage. About 25 times smaller than the width of a human hair and can travel 35 micrometers per second by moving through blood when powered by ultrasound.

TiO₂

using this in paint transforms airborne toxins into safe residues, which are washed away by rains.

pure silicon

an example of insulator that can also become a good conductor at the new nanoscale.