NANOPARTICLE APPLICATIONS

• HOW DOES TIO2 ACT LIKE A SELF CLEANING NANOMATERIAL


  When light hits a TiO2 particle, it excites an electron from the valence band to the conduction band which forms a negative electron e- and a positive hole  (h+) pair. (photoexcitation). The energy difference between the conduction and valence band is called the band gap. The electron and hole can react with the water and oxygen molecules surrounding TiO2 on the surface to produce highly oxidative radicals HO· and O2- ·. These can react with organic pollutants breaking them down into less harmful substances such has H2O and CO2
• HOW DOES TIO2 NP REACT UNDER UV RADIATION

  it shows hydrophillic properties, when water drops on the tio2 covered surface, instead of forming droplets, it runs off and takes the dirt with it.
• GIVE 4 EXAMPLES OF TIO2 USED IN SELF CLEANING APPLICATIONS

  1. Buildings – coated windows and exteriors can break down pollution/dirt

  2.Textiles – can resist stains and regrade contaminants

  3. Air and water purification – can break down pollutants in air purifiers and water systems 4. self cleaning pavers - reduce NOX emissions from vehicles
• HOW CAN YOU IMPROVE PHOTOCATALYTIC ACITIVTY UNDER UV LIGHT


  when there is low exposure, doping TiO2 with metals such as iron or gold can increase their activity by narrowing the bad gap between conductance and valence band
• WHY IS GOLD NANOPARTICLES IMPORTANT IN BIOIMAGING

  they show strong absorption/scattering of light and luminescence because of SPR
• HOW DOES DARK FIELD MICROSCOPY WORK

  it enhances the visibility of nanoparticles against a dark background. unlike light field which lights the whole field, this illuminates the sample with light from the side meaning only the scattered light from the sample reaches the detector.
• WHY ARE GOLD NANOPARTICLES USEFUL IN DIAGNOSTICS

  they can attach to antibodies which can be used for targeting cancer cells. when they bind to cancerous cells, they can be shown in dark field microscopy and used in the detection of these cells
• WHY CHOOSE GOLD NANO-RODS OVER NANOSHELLS


  because they can absorb more light efficiently at same wavelengths
• WHAT IS GRAPHENE AND WHAT IS IT MADE OF

  it is made up of a single layer of carbon atoms tightly bound in a hexagonal honeycomb lattice. it is only one atom thick
• NAME 4 PROPERTIES OF GRAPHENE


  1. Lightweight and thin – only one atom thick

  2. High strength – 200x stronger than steel

  3. Transparency – almost transparent

  4. Conductivity – good heat and electrical conductor  
• APPLICATIONS OF GRAPHENE:


  
  

  1. Technology – touchscreens, light panels + solar cells = transparency and conductivity

  2. Biomedical – bioengineering applications = strength + flexibility

  3. Composites – added to other materials to make composites to enhance strength

  4.other application - water purification, textiles
• WHAT IS GRAPHITE


  stacked layers of graphene sheets
• WHAT IS A CARBON NANOTUBE


  cylindrical structures made entirely of carbon
• WHAT ARE THE 2 TYPES

  single walled, double walled, multi walled
• PROPERTIES OF NANOCARBONS:

  1. High tensile strength

  2. Electrical and thermal conductors

  3. High surface area
• WHAT IS A FULLERENE

  it is made up entirely of carbon where the atoms are linked to form a spherical shape
• WHAT IS THE MOST COMMON EXAMPLE OF FULLERENE

  C60 Fullerene - Buckminster fullerene. it is composed of 60 carbons double bonded to form 12 pentagons and 20 hexagons and resembles a football
• PROPERTIES OF FULLERENE: 


  1. High electron affinity

  2. Excellent charge transport  
• APPLICATIONS OF FULLERENE:


  1.  Photovoltaic devices – enhances solar cells – good electron transfer

  2.  Electronics and optics – good charge carriers

  3. Health + environment – drug delivery/catalysts/filters
• WHAT IS MAGNETIC ACTUATION


  the ability to control magnetic nanomaterials by using magnetic field. can change their conditions without physically touching them
• WHAT ARE THE 3 CLASSES OF MAGNETIC REPONSIVE COMPOSITE MATERIALS

  1. Deformation – ability for nanomaterial to change shape – rotate, bend and stretch – when magnetic field applied

  2. Magnetic guidance – the ability to move these materials to specific sites – useful in biomedical applications in drug delivery

  3. Thermo-responsive activation – some magnetic materials can be used to trigger  changes in temp-sensitive polymers through magnetic induction
• WHAT IS MAGNETIC HYPERTHERMIA 


  it is a cancer treatment that uses heat to target and kill cancer cells. it involves gently heating tissues to around 40-43 degrees which is enough to damage/kill cancerous cells without harming healthy cells
• WHY USE MAGNETIC NPs


  they can be directed to accumulate specifically in the tumour tissue. these are tiny enough to interact with the cancer cells
• HOW DOES IT WORK?

  once the magnetic NPs is targeted at cancer cell, an external magnetic field is applied. this causes the NP to generate heat and because the NP is accumulated at tumour site only, the heat is localised and does not affect healthy cells
• ADVANTAGES OF MAGNETIC HYPERTHERMIA


  non-invasive and can be controlled externally making it safe and does not affect healthy tissues like chemotherapy
• MAGNETIC NANOFIBRES AND GELS

  uses