Quiz1 Flashcards
Use for nano materials (14st)
- Photovoltaic materials (Solar cells)
- Hydrogen production, conversion, storage and use
- Catalysis for cleaning of automotive and industry emissions
- Electrocatalysis, e.g. fuel cells
- Batteries
- Catalysis for reduced energy consumption in industrial processes
- Sensors for improved energy efficiency in industrial processes
- Smart windows and isolation materials for energy-efficient buildings
- Efficient lighting solutions (white LEDs)
- Superstrength nanomaterials
- Thermoelectric structures and materials
- Water cleaning
- Gasification/liquefaction of coal and biomass
- CO2 fixation
Sustainability
optimizing in the long run:
“Sustainable Development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.”
fick sin internationella spridning i samband med FN-rapporten “Vår gemensamma framtid” (1987), kallad Brundtlandrapporten. (Gro Brundtland)
Size of 1 nm
10^-9 m
What is “real” nano technology
Building from bottom and up, atom by atom
Envisioned by Richard P. Feynman 1959
N2 fundamental concepts (3st)
- Large or small, materials properties perspective
- Simple to complex, unit perspective
- Nanotechnology, a long term view
Colloidal Lithography
material + coating a) particles b) gold coating c) remove particles d) hole between the gold e) add more gold f) remove the first gold+coating g) hole between gold again h) remove the last gold there are now nano-pilars exactly where the particles where to begin with.
Top 10 challanges facing humanity:
- (Mis)information, AI
- Energy
- Environment
- Food and Water
- Economic Disparity
- Conflicts
- Health
- Education
- Democracy and Rights
- Population
Peak oil chrash mat:
Nano science must be prepared to meet the needs after peak oil.
Energy:
Strictly conserved
dE = work
Arebete = kraft*sträcka
Fundamental energy forces of physics: (4st)
- GRAVITY
- ELECTROMAGNETIZM
- WEAK INTERACTION (or Weak Nuclear Force)
- STRONG INTERACTION (or Strong Nuclear Force)
Energy formulas:
ΔE = W + Q ΔE = W + Q + E Ep = mgh Ek=1/2mv^2 Ep + Ek = Etotal
E = mc^2
Units of energy
J kg*m2/s-2 N*m C*V 1 calorie (cal) = 4.184 J
How much is 1 kWh?
• 100 ml of oil • (~ 900 kcal) • move a small car(1200 kg), to the top of the Eiffel Tower (321 meters) • 2 days work
1 donat is how many laptop batteries
10 laptop batteries à 45Wh = 450 Wh
1 donat
= 400 kilocalories
= 1.7 megajoules
= 460 watt hours
Human daily energy consumption:
2400cal ca = 100W
The brain takes 20% = 20W
Moore’s law
Doubles every 18 months
London horse to car:
1900 to 1913
Pre nano-technology
Surface science
Gibbs free energy:
dG ≡ −SdT +VdP +γdA
Surface vs Bulk energy
Surface: More energy, less tightly bound
Bulk: Less energy, more tightly bound
Surface area:
- The surface area decreases for rounder shapes.
* The surface-area-to-volume ratio decreases with increasing volume.
Thin films may be:
- Lower in density (compared to bulk material)
- With different defect structure compared to bulk
- Strongly affected by surface and interface effects
- Under stress
- Ultra thin films (< 10-20 nm): quasi 2D materials
Steps in thin film growth:
- Separation of particles from the source
- (heating, high voltage, sputtering)
- Transport
- Condensation (deposition) on substrate
Skillnad mellan droppe och tunn film:
Stor droppe:
Diameter större än träffyta
Liten droppe:
Diameter typ samma som träffyta
Tunn film
Diameter mindre än träffyta
Mycket yta och lite bulk
The three different growth modes:
- Island growth (Volmer – Weber)
- Layer-by-layer growth (Frank – van der Merwe)
- Stranski – Krastanov (mixed growth)
Defects in film:
- 0D or point defects
- 1D or line defects (dislocations)
- 2D and 3D (grain boundaries, crystal twins, twists, stacking faults, voids)
“Lutande bägare” formel:
gamma=dW/dA
Vapor deposition: (3st)
- Physical Vapor Deposition (PVD)
- Chemical Vapor Deposition (CVD)
- Molecular Beam Epitaxy (MBE)
Biomimetics
application of methods and systems found in nature
to the study and design of engineering systems and
modern technology
Nature often have the solutions, but not always!
Hydrophilic and hydrophobic
Lotus flower
A hydrophobic material becomes more hydrophobic if you make the surface uneaven on nano level. Less surface to conect to on top.
Large contact angles
A hydrophilic material becomes more hydrophilic though. Goes down into the spaces in between (?)
Contact angle: Young equation
cos theta = vinkel för ytan (180)
/ vinkel mellan droppe och yta
Nanofabrication
“Nanofabrication is the design and manufacture of objects with
dimensions measured in nanometers”
Top down methods:
- Lithography (VIS, UV, e-beam, ion beam)
- Scanning probe – based manipulations
- Nano-imprint/soft lithography
Bottom up methods:
- Chemical vapor growth
- Self assembly: colloidal chemistry
The steps:
• Identify (choose) the repeating block (precursor)
• Identify (recognize) the governing interaction
• Apply active control (mass and energy supply)
Different Lithography
Top down
- Visible-light
- UV
- e-beam
The Abbe diffraction limit:
d = lambda / 2(n sin theta)
Etching:
Top down
Refers to the removal of material by bombardment of ions
Sputtering:
bombardment of the target by energetic particles.
GC vs HOPG
GC:
• Isotropic
• Big round holes
HOPG:
• Anisotropic
• Shallow “half hexagon” holes
Characterisation: (4st)
- Transmission Electron Microscope (TEM)
- Scanning Tunneling microscopy (STM)
- Scanning Electron Microscope (SEM)
- Atomic force microscopy (AFM)
Carbon particles of different dimentions:
0D: Fullurene, bucky ball
1D: Nano-tube
2D: graphene
3D: Graphite and Dimond etc
C-nanofabrication:
• Nano pattering of bulk materials
• Growth of nanocarbons
(Fullerenes, Nanotubes, Graphene)
Examples of nanoC Applications:
- Composite materials
- Electrodes
- Sensors and Electronics
Dimonds:
- Optics
- Transparency
- Hardnes (strong 3D bond)
Graphite:
- Week bond between layers
- Very strong bond i 2D
- Copletely black (not transparent, and low reflectivenes, anisotropy)
Buckminster fullurene:
- Football
- Organic solar cells
- Grows longer with more atoms
Nanotube:
- Diameter 1.3nm!
* Root or top growth
Graphene:
- Highest conductivity
- Zig-zag edge or armchair edge
- metallic or semi conduct
- Hamburger structure or Swiss roll
- Tubes within tubes
Super black material:
- Solar tech
* Stelth tech
Due to the high intercrystalline volume fraction:
unique: • mechanical • magnetic • electrical • corrosive properties.
Preparation routes:
- Mechanical alloying
- Gas-condensation
- Rapid solidification
- Sol gel process
- Electroplating
- Severe plastic deformation
- Field assisted sintering
I-lines and U-lines
I-lines share nodes, stable
U-lines are lines that does not share nodes, not as stable
10nm
Amount of intercrystaline (grain surface) and crystaline (grain interior) meet
Thermal Stability:
Grain growth occurs when the
impurity/solute grain boundary
concentration is reduced after
precipitation sets in.
Coincidence Site Lattice (CSL)
SUM eq or less than 29:
special properties like low energy
Grain Boundary Engineering
Increased corrosion resistance at special grain boundaries and I-lines.
Intergranular Crack Arrest
(a) Conventional crystalline material
(b) Nanocrystalline coating
(c) Grain-shape modified coating
Soft and Hard Magnetic Materials
• Soft magnetic materials
– easy to magnetize and demagnetize
– high initial permeability µ (slope of B-H cuve)
– low coercivity
• Hard magnetic materials – hard to magnetize and demagnetize – very large remanence – can be made into permanent magnets – high coercivity (pinning of domain walls)
Coatings
• APS, EB-PVD, SPS
• Thermal spray
- Gas turbines, aero-engine parts
• Cutting tools
