Saturday 28 July 2012

Failed experiment

The reason for the failure of the first experiment was due to difficulty in finding the right experiment procedure. I tried out once, however, it failed badly, lasting only about 1 to 3 secs. Therefore, a new experiment was thought of.

The references

I also made other references of the journals of the food science in the National Library, from the  Lee Kong Chian Reference Library.

The process of doing experiment

The different starch and the egg

When testing for the thickening measuring the length after 6 hours


Wheat Starch

tapioca starch

corn starch

potato starch

testing for the difference between sugar and salt (the mixture)
This is the table for the egg cartoon, a description of what is the content in the egg cartoon.

Egg cartoon 1
Tapioca
 2 teaspoon salt
Wheat
1 teaspoon sugar
tapioca
1 teaspoon sugar
potato
1 teaspoon sugar
corn
1 teaspoon sugar
Potato
2 teaspoon salt
Wheat
2teaspoon sugar
Tapioca
2teaspoon sugar
potato
2teaspoon sugar
corn
2teaspoon sugar
Egg cartoon 2
egg
2teaspoon sugar
egg
 2 teaspoon salt

corn
 2 teaspoon salt
wheat
 2 teaspoon salt
Egg
1 teaspoon sugar
Egg
1teaspoon salt



The structure molecule of Luminol chemiluminesce


The background research


When two molecules react chemically so that there is a release of energy (an exothermic reaction), that energy sometimes manifests itself not as heat but as light. This occurs because the energy excites the product molecules into which it has been funneled. A molecule in this excited state either relaxes to the ground state, with the direct emission of light, or transfers its energy to a second molecule, which becomes the light emitter. This process is referred to as chemiluminescence. The originally green, now multicolored, commercially made "light sticks" (often in the form of bracelets and necklaces) work in this way, utilizing the (exothermic) reaction of hydrogen peroxide with an oxalate ester . This oxidation reaction produces two molecules of carbon dioxide (CO ), and the released energy is transferred to a fluorescent dye molecule, usually an anthracene derivative. Light sticks were developed by the U.S. Navy as an inconspicuous and easily shielded illumination tool for special operations forces dropped behind enemy lines. Besides their use as children's toys, they are also used extensively as a navigation aid by divers searching in muddy water.

These light sticks glow as a result of the energy released by a chemical reaction.
Chemiluminescence is also found in fireflies. The male firefly uses the reaction of a luciferin substrate and the enzyme luciferase with oxygen, with adenosine triphosphate (ATP) as an energy source, to create the illumination it uses to attract a mate. Because the detection of very minute amounts of light is possible, chemiluminescence and bioluminescence have become the basis of many sensitive analytical and bioanalytical techniques or assays used to quantify particular compounds in samples. Indeed, the use of these techniques is broad enough to justify the existence of a journal devoted to them, the Journal of Bioluminescence and Chemiluminescence.
In 1669 Hennig Brand, a German alchemist, was attempting to recover, by means of intense heat, the gold he hoped was lurking in human urine. The waxy white substance that he did retrieve, which glowed green when exposed to air, was in fact elemental phosphorus.
The emission of light observed by Brand was actually chemiluminescence. The light arises from PO molecules in an excited state. This excited state of PO is brought about by the reaction between PO and ozone, which are both intermediates in the fundamental reaction between oxygen in air and P vapor evaporating from the solid white phosphorus. It is unfortunate that the chemiluminescent glow of phosphorus gave rise to the term


"phosphorescence." Scientifically, phosphorescence is a process whereby absorbed photons are emitted at a later time, as exemplified by the glow of a watch face in the dark after its earlier exposure to light.
Luminol (3-aminophthalhydrazide) is used in a commercially available portable device called the Luminox that measures minute concentrations (parts per billion) of the pollutant nitrogen dioxide in air. Luminol is also used frequently in laboratory demonstrations of the chemiluminescence phenomenon. Luminol-mediated chemiluminescence is the result of an oxidation reaction. The oxidation proceeds in two steps, which ultimately lead to the production of the aminophthalate anion in an excited state and the elimination of water and molecular nitrogen. The formation of the strong triple bond (N≡N) is a major factor in the release of energy in the form of light.
Probably the simplest chemiluminescent reaction (and one that has been studied extensively) is the reaction between nitric oxide , NO, and ozone, O . The reaction (with about 10% efficiency) yields nitrogen dioxide in an excited state (NO *)
NO + O = NO * + O 2
NO * = NO + h ν
The reaction was developed in the early 1970s as a specific and instantaneous method to detect nitric oxide in the exhaust of automobiles. This use of chemiluminescence rapidly led to application of the same phenomenon to monitor the presence of NO in the atmosphere. Both applications continue in use. Ozone can easily be produced by passing dry air or oxygen through an electric discharge. The ozone-containing stream and the sample to be evaluated are mixed in a dark chamber adjacent to a photomultiplier tube, and the chemiluminescence signal that is produced is amplified. These devices are capable of monitoring NO levels ranging from parts per trillion to thousands of parts per million; an individual instrument can sometimes measure concentrations extending across six orders of magnitude.
The familiar yellow glow from a natural gas or wood-burning flame is not the result of chemiluminescence, but is due to bright, red-hot particles of carbon soot. The blue, green, and other colors produced when metals are put into flame can indeed be ascribed to chemiluminescence; in these instances the luminescence is accompanied by heat production.
According to information provided by the Harbor Branch Oceanographic Institution in Ft. Pierce, Florida, more than 90 percent of organisms living in the oceans at depths from 200 to 1,000 meters (656 to 3,281 feet) use chemiluminescence for activities such as attracting prey and avoiding predators. Light from the sky is quite weak at those depths; a fish that emits a dim glow from its lower parts could become invisible from below, while a fish without this capability would appear as a dark shadow.
Donald H. Stedman




Planning Process of the the experiment


Planning for the experiment
Area of experiment- measuring the duration of phosphorescence can last when exposed under Uv rays.
w       Find UV light/ Uv lamp to provide the UV rays needed.
w       Measuring the duration the glow-in-the-dark can last in the dark after being exposed to UV light.
w       Find the phosphorescence material
w       Find the difference between flouroescence and phosphorescence
Area of experiment –measuring if the amount of chemical in the light stick would allow it to last longer
w       Find the chemical in the light stick
w       Find the ratio of the chemical needed and the effect of each of them when combined.




Proposal for the chemiluminescence


A
Observations made

I observed that light stick in the chemiluminescence enables the light stick to last longer than glow-in-the-dark that phosphorescence is present in.
B
Research Question

Does Chemiluminescence last longer than phosphorescence exposed under Ultraviolet
 Rays?
C
Hypothesis statement

 Chemiluminescence last longer than phosphorescence exposed under Ultraviolet rays.


D
A short summary of research done on the area of investigation

Research shows that phosphorescence exposed under Ultraviolet rays last longer than phosphorescence under normal light. Chemiluminescence occurs due to chemical reaction while phosphorescence occurs only when it absorbs the radiation, and then it re-emits
the radiation at lower intensity for up to several hours after the original excitation.
Phosphorescence
 Phosphorescence occurs when energy in light waves is absorbed by a phosphorescent material and later released in the form of light, at a very slow rate. This slow release of light energy is what causes the glow-in-the-dark sticker to continue glowing over a period of time.

When ultraviolet light is absorbed by the phosphorescent material, electrons in the atom become"excited". These electrons will eventually
return to their normal energy levels, gradually. It is during this gradual process of electron state "degradation", that the material is seen to glow.
Chemiluminescence- present in light sticks
Lightsticks or glowsticks are used by trick-or-treaters, divers, campers, and for decoration and fun! A lightstick is a plastic tube with a glass vial inside of it. In order to activate a lightstick, you bend the plastic stick, which breaks the glass vial. This allows the chemicals that were inside the glass to mix with the chemicals in the plastic tube. Once these substances contact each other, a reaction starts taking place. The reaction releases light, causing the stick to glow!
Chemiluminescence is the production of light from a chemical reaction. Two chemicals react to form an excited (high-energy) intermediate, which breaks down releasing some of its energy as photons of light (see glossary for all terms in bold) to reach its ground state

E
Bibliography (Please refer to RS Students’ Handbook in RS Folder on Inet regarding APA Style Format)