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Introduction to chemistry

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					 Introduction to Chemistry –
Background for Nanoscience
     and Nanotechnology
         UEET 101
         Prof. Petr Vanýsek
 NIU – Department of Chemistry and
            Biochemistry
        JANUARY 25th, 2011
Introduction to measurements

Distance/size
dynamics of the scale – from the wavelength of
x-rays to astronomic distances.
focus on the “middle” scale size from visible
objects – person, hand (where did inch come
from?), fingernail thickness, hair diameter, mite,
microbe, virus, finally atom and a molecule.
         Wide dynamic range of
              dimensions
Electromagnetic spectrum




 Relevant dimensions:
         kilometers (10+3 m)
         meters
         centimeters (2-1/2 = 1 inch)
         millimeter
         nanometers                              Atom:
         Angstroms (10-10 m) – size of an atom   Electrons going around
                                                 the nucleus
The scale of things
         Units of Measurement
                      SI Units
• There are two types of units:
  – fundamental (or base) units;
  – derived units.
• There are 7 base units in the SI system
     distance (length) is one of them
     the fundamental unit is meter
Some measurements are too small or too large to use the basic unit.
                Therefore, we use prefixes.

                             SI Units

             Selected Prefixes used in SI System
    Why dimensions matter?
Nanomaterials – particles of nanometer size
 Nano-scale materials often have very different
        properties from bulk materials
            e.g. color and reactivity


• 3nm iron particle has 50% of atoms on the surface

• 10nm particle has 20% of atoms on the surface

• 30nm particle has 5% of atoms on the surface
                   Temperature
                          SI Units
• Other important unit is unit for temperature.
  Temperature relates to the state of matter (gas,
  liquid, solid) and is fundamentally important in
  materials science.
      Change of volume with
          temperature
Thermal expansion – volumetric thermal
 expansion.
Mercury thermometer

     Gallium nanothermometer
How to
understand
structures
Space filling
Wire frame
Ball and stick
  Forms of material
CARBON - GRAPHITE
 Forms of material
CARBON - DIAMOND
   Form of material
CARBON - FULLERENE
Fullerenes
Fullerenes
Nanotubes                Carbon nanotube – extremely strong

                         Theoretical tensile strength 300 GPa
                         Highest reported 63 GPa

                         Kevlar 2.7 GPa
                         steel piano wire 2.4 GPa
                         spider silk 1 GPa
                         diamond - up to 60 GPa




Single walled nanotube
           Properties of Matter
             Physical vs. Chemical Properties
• Physical properties can be measure without changing the
  basic identity of the substance (e.g., color, density, melting
  point)
• Chemical properties describe how substances react or
  change to form different substances (e.g., hydrogen burns in
  oxygen)
• Intensive physical properties do not depend on how much
  of the substance is present.
   – Examples: density, temperature, and melting point.
• Extensive physical properties depend on the amount of
  substance present.
   – Examples: mass, volume, pressure.
 Properties of Matter
Physical and Chemical Changes




        2 H2 + O2  2 H2O
           Properties of Matter
          Physical and Chemical Changes
• When a substance undergoes a physical change, its
  physical appearance changes.
  – Ice melts: a solid is converted into a liquid.
• Physical changes do not result in a change of
  composition.
• When a substance changes its composition, it
  undergoes a chemical change:
  – When pure hydrogen and pure oxygen react completely,
    they form pure water. In the flask containing water, there
    is no oxygen or hydrogen left over.
      Why Study Chemistry?
• Chemistry is the study of the properties of
  materials and the changes that materials
  undergo.
• Chemistry is central to our understanding
  of other sciences.
• It is substantial part of nanoscience and
  nanotechnology
        The Study of Chemistry
      The Molecular Perspective of Chemistry
•   Matter is the physical material of the universe.
•   Matter is made up of relatively few elements.
•   On the microscopic level, matter consists of
    atoms and molecules.
•   Atoms combine to form molecules.
•   As we see, molecules may consist of the same
    type of atoms or different types of atoms.
Molecular Perspective of
      Chemistry
                      Matter
• Solution: A uniform mixture of two substances
  such that molecules are separate from each
  other and move around randomly. Usually these
  are liquids. Solutions are usually transparent.

• Colloids: A mixture of much larger particles
  ranging from 20 nm to 100 μm. Milk and paint
  are colloids.

• Grains: Some materials are made up of many
  small crystals called grains. A grain is an
  individual crystal of such a solid. Different grains
  may have the crystal lattice oriented in different
  directions.
Grain Structure in Steel
Diagram – Atom of helium

               Protons
               Electrons
               Neutrons

               Electrons, on the outside,
               are responsible for bonds
        Chemical Bonding
• Covalent bonds
• Ionic bonds
• Metal bonding
How to go about making
materials?

Through chemistry
      Forms of material
CARBON – GRAPHITE - DIAMOND
             Phase diagram for carbon




From: F.P. Bundy, The P,T Phase and Reaction diagram for elemental
Carbon, 1979; J. Geophys. Res. 85 (B12) (1980) 6930.
How to go about making
nanomaterials?
Diamond is hard, has high thermal
          conductivity

  It is desirable material, how to
         make it synthetically
Swiss Diamond® Pan
Now, please turn to your group mates and discuss
the questions.

You have about 10 minutes to do that.

Write down your answers.
Claims and/or facts
+ Pressure Cast Aluminum for non-warping and great thermal
characteristics with no “hot spots.”
+ Reinforced Non-Stick coating using Nano-Composite Technology with
Diamond Crystals.
+ Perfectly flat bottoms for cooking on all major surfaces.
+ Ergonomic Handles- oven safe 500ºF.
+ Dishwasher and Metal Utensil Safe.
+ Patented Non-Stick – Exclusive.
+ Hardest material known to man.
+ Diamonds Make the Difference!
+ Perfect Heat Distribution
The 8” pan cost (mail order) $55

As a chemist, engineer, student, cook, consumer:

1. Discuss each point and decide whether it is a useful or a good
value and design a test how to verify the claim.
2. Discuss what methods have to be mastered to make such a pan.
[Where do you get the diamonds, for example]
  Large diamonds, though not of the
 jewelry quality, can be made at high
              pressures.

    How about small particles with
  properties of diamond, having also
properties on nano-materials (e.g, large
        surface to volume ratio.

 This has been achieved by chemical
       vapor deposition (CVD).
Why make nanodiamonds – hard surface,
good heat conductivity, low
adherence to water.

Ideal technological material for a
household item

                A frying pan.
                       WHAT IS NANO?
                           -2  10 m                    10mm


                               10-3m                   1mm (1,000,000nm)




                                        Microwave
                               10-4m                   0.1mm
 Red blood cells
   (~2-5μm)
                               10-5m                   0.01mm
                                                                  Hair (~60-120μm)




                                        Infrared
                      Virus
                                                       0.001mm, 1μm (1000nm)
                   (10-300nm) 10 m
                                -6




                               10-7m                   0.1μm (100nm)
                                         Ultraviolet


                               10-8m                   0.01μm (10nm)


                   Buckyball   10-9m                   1nm
                    (~1nm)                                                Gold atom
                                          X-ray




     DNA                                                                   (135pm)
                                                                       www.nature.com/physics/
(~2nm diameter)                10-10m                  0.1nm            highlights/6999-1.html
Top-down and bottom-up approach
 The ‘top-down’ approach
 Machining or etching larger blocks and composites to
                  smaller structures




• Compare to
traditional sculpture


• Size of detailed
features depends on
size of tools
          The ‘bottom-up’ approach
     Small molecules or particles pre-designed to
    self assemble into larger, organised structures


e.g. surfactants                Hydrophilic head group
                        oil     “Water loving”




    oil
                                   oil
                water




          oil             oil        Hydrophobic tail
                                     “Water hating”
          Spherical micelle
                     The Periodic Table
1                                                                                                  2
H                                                                                                  He
3    4                                                               5     6     7     8     9     10
Li   Be                                                              B     C     N     O     F     Ne
11   12                                                              13    14    15    16    17    18
Na   Mg                                                              Al    Si    P     S     Cl    Ar
19   20   21   22    23    24    25    26    27    28    29    30    31    32    33    34    35    36
K    Ca   Sc   Ti    V     Cr    Mn    Fe    Co    Ni    Cu    Zn    Ga    Ge    As    Se    Br    Kr
37   38   39   40    41    42    43    44    45    46    47    48    49    50    51    52    53    54
Rb   Sr   Y    Zr    Nb    Mo    Tc    Ru    Rh    Pd    Ag    Cd    In    Sn    Sb    Te    I     Xe
55   56   57   72    73    74    75    76    77    78    79    80    81    82    83    84    85    86
Cs   Ba   La   Hf    Ta    W     Re    Os    Ir    Pt    Au    Hg    Tl    Pb    Bi    Po    At    Rn
87   88   89   104   105   106   107   108   109   110   111   112   113   114   115   116   117   118
Fr   Ra   Ac   Rf    Db    Sg    Bh    Hs    Mt    Ds



               58    59    60    61    62    63    64    65    66    67    68    69    70    71
               Ce    Pr    Nd    Pm    Sm    Eu    Gd    Tb    Dy    Ho    Er    Tm    Yb    Lu
               90    91    92    93    94    95    96    97    98    99    100   101   102   103
               Th    Pa    U     Np    Pu    Am    Cm    Bk    Cf    Es    Fm    Md    No    Lr
Acceptance of nanotechnology