Year 11 Chemistry - Nanotechnology

what is nanotechnology

the study and applcation of extremely small materials to be used in multiple disciplines

what marked the start of the nanotechnology “era”

when Norio Taniguchi developed a scanning tunnelling microscope

who first discussed the idea of nanotechnolgy

Richard Feynman in 1959

what is an ancient use of nanoscale materials

using gold and silver particles to stain glass

how large is 1nm

1 billionth of a metre

what defines a nanoparticle

a particle with 1 of it’s 3 dimensions being less than 100nm

why is a nanotube considered a nanoparticle

a nanotbe is a tubular molecule composed of carbon atoms, but it is a nanoparticle because although it’s longer than 100nm, it has a width of only 3nm

what shape are typical nanoparticles

a rough sphere

is nanoparticle sa:v ratio high or low

it is very high because of how small they are

define a nanomaterial

any material with a compostition based on nanoparticles

what are the 3 microscopes which can see at a nanoscale

optical microscope, electron microscopes and scanning probe microsopes

describe an optical microscope

it can magnify over 2000x

can see a cell in minimal detail

light wavelengths limit it’s use due to their large size relative to nanoparticles

objects less than 300nm are distorted by them

describe electron microscopes

focuses a beam of electrons on a sampe and their scattering produces an image

can magnify of 500,000x

what are the 2 types of scanning probe microscopes

atomic force microscope and magnetic force microscope

describe the atomic force microscope

a probe, an atom wide, drags across the material surface and rises and falls across the atoms

a laser records these movements and it is computed to produce a 3D images of atoms

describe a magnetic force microscope

the probe senses changes in magnetic strucutre of the surface of the material at the atomic level which is computed to produce an image

what can scanning probe microscopes also do

they can snag and move individual atoms using the probe, which allowed the beginning of building materials atom by atom

give an example of nanotechnology in health and medicine

gold nanoparticles are used as probes for detection of targeted nucleic acid sequences and potential disease treatment

give an example of nanotechnology in material sciences

nanoscale additives to body armour can provide lightweight ballistic energy defelction and resist wrinkles and bacteria growth

give an example of nanotechnology in electronics

nanoparticle copper suspensions are a safer, cheaper and more reliable option than lead based solder for fusing electronics

give an example of nanotechnology in water quality

nanoparticles of titnaium dioxide can break down common organic contaminents like fertiliser and manure

give an example of nanotechnology in environmental applications

nanofabric paper towel made from potassium magnesium oxide wires can absorb 20x it’s weight in oil

what is the quantum effect in relation to nanotechnology

it describes the physics of electron properties in solids with great reduction in particle size

it can effect optical, electrical and megnetic behaviours

at nanoscale, material act differently than they do at macroscale

give an example of the quantum effect

on the macroscale copper is a salmon pink, but on the nanoscale it becomes transparent

how does surface area affect nanoparticles

because of their large surface area ot volume ratio, nanoparticles can be more chemically reactive and affect strength + electrical properties

what is colloidial gold

a suspension consisting of gold nanoparticles suspended within a solvent

it is used for the properties of the gold nanoparticles including optic, thermal and electronic

what is a gold bullion

gold refined to a high standard of elemental purity, kept as bars, coins or ingots

what are the 2 methods of building nanomaterials

bottom up and top down

describe the top down method

it is the breaking down of bulk materials into nanoparticles

an example is wet ball milling

describe the bottom up method

the building of nanomaterials from the bottom, atom by atom or molecule by molecule

creates less waste and is more economical

an example is hydrothermal synthesis

what is a semiconductor

a material which, at room temperature, conducts electricity better than an insulator but worse than a conductor

which factors affect semiconductivity and how

temperature → low = worse, high = better

metal purity → pure = worse, impure = better

light → excites valence electrons

what are quantum dots

tiny particles, 2-10nm wide, made of roughly 50 atoms which emit colour based on size

smaller = more blue

larger = more red

name some uses of quantum dots

LCD screens

solar cells

lasers

microscopy

medical imaging

name some health risks of nanotechnology

small size may cause lung damage

they may kill healthy bacteria

they could unpredictably speed up chemical reactions

name some environmental risks of nanotechnology

harming crops and land

killing human food sources

can impact reproduction, growth and development of animals

what is an allotrope with an example

a different structural form of the same element , which display different properties

e.g. carbon can exist as diamond and graphite

what is graphene

a sheet of carbon atoms arranged hexagonally, and is 1 atom thick

what are the properties of graphene

lightweight

very strong

flexible

super conductor of electricity

what are uses of graphene based on it’s properties

biolelectric sensory devices

replace steel in aircraft

optical electronics

what are the differences between composite graphene and nanotubes

graphene is a sheet of carbon whereas nanotubes are tubes of carbon

composite graphene is graphene mixed with a composite material

graphene in a composite is much stornger (uses less carbon to achieve same stength)

why is graphene stronger when a composite than nanotubes

because graphene makes stronger bonds with the composite polymer molecules

e.g. in a resin the graphene has a larger s.a. to attach with than a nanotube does

compare and contrast nanosunscreen and normal sunscreen

both use zinc oxide and titanium dioxide

nanosunscreen uses nanoparticles, normal uses macroparticles

what are some properties of nanosunscreen

leave sno white residue

easily absorbed by skin

long lasting

greater protection

what are the concerns with nanosunscreen

minerals may enter bloodstream

can cause irritation

could enter lungs or digestive system

what is a free radical in relations to nanotechnolgoy

an atom or molecule with at least 1 unpaired valence electron, making them highly reactive

nanoparticles have been shown to trigger production of free radicals in the body

how are nanoparticles regulated in australia

we have a working definition of what a naoparticle is

each field of use, e.g. cosmetics, has different regulations based on what it’s application is and the material

new regulations are always being made along with new discoveries

what are some unique uses of nanotechnology

we can make tennis balls boucnier and retain their bounciness for longer

we can reduce flammability of foam in furniture using carbon nanofibres by up to 35%

incorporating silica into fabrics can make them repel water and stain causing liquids