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DEMONSTRATIONS
1. Oxygen
Sensing: As described by Kneas et al, we will demonstrate the oxygen
quenching of [Ru(byp)3]Cl2 in oxygen-saturated,
air-saturated and degassed solutions. This will show a qualitative
detection of oxygen amounts in the solutions mentioned above based on
luminescence quenching.
2. Chemiluminescent
Oscillator: We will demonstrate an oscillating chemiluminescence
experiment by interacting luminol, a chemiluminescent substance, with a
known chemical oscillator as described by Prypsztein. This oscillator
system involves the Cu2+ catalyzed reaction between hydrogen
peroxide and potassium thiocyanate.
3. Light
Emission of Electrodes: We will show electroluminescence obtained upon
the application of electrical potential to [Ru(byp)3]2+/tri-n-propylamine
solution as described by
Bolton
et al.
4. Chemiluminescence
of Tris(2,2’-bipyridyl)ruthenium(II) ([Ru(byp)3]2+):
In this demonstration, students will have the opportunity to observe the
chemiluminescence formed as a result of the reduction of [Ru(byp)3]2+
by magnesium via electron transfer.
5. Rayleigh
Light Scattering: This demonstration will let students to observe and
manipulate the optical path of a polarized laser through optically active
and inactive media. This will allow students to see the differences in the
light patterns occurring due to Rayleigh scattering in these media.
HANDS
ON
1. Blue
Skies and Red Sunsets: In this activity students will observe how
light is scattered in a medium
producing colors and they will make an analogy of this with scattering of
sunlight in the atmosphere producing the blue sky and red sunset.
This activity is adopted from eo.ucar.edu/educators/activities/WrkshpBook.pdf
2. Fluorescence
upon Host-Guest Interaction: Students will perform a demonstration by
themselves by using prepared solutions which contain a host (hydroxypropyl-b-cyclodextrin)
and a guest molecule (8-anilino-1-naphthalenesulfonic acid). They will
observe a fluorescence enhancement from the guest molecule upon mixing of
two solutions.
3.
Diffraction
Grating: Students will use laser pointers to explore the diffraction
of light by a CD (dispersive element). Detailed information on this
demonstration was given in the literature.
4. As
explained by O’Hara et al.,
students will be encouraged to participate in several class activities
such as:
(a) extraction of chlorophyll from spinach to observe its properties when
interacting with different light sources (incandescent and UV)
(b) interaction with several luminescent materials including paints,
stickers, markers, toys, dollar bills, etc.
(c) crushing of wintergreen-flavored candy in a plastic bag to observe the
light emission (triboluminescence)
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