Cyalume

Temperature and reaction rate. A chemical reaction in the Cyalume light sticks produces light as it takes place. 

Bassam Z. Shakhashiri, "Light- sticks," Chemical Demonstrations, A Handbook for Teachers of Chemistry, Vol. 1 (The University of Wisconsin Press, Madison, 1983), pp. 146-152. Cyalume lightsticks are used to demonstrate the effect of temperature on reaction rates. 

Bassam Z. Shakhashiri, Lloyd ) G. Williams, Glen E. Dirreen, and Ann Francis, "Cool-Light Chemiluminescence," /. Chem. Educ., Vol. 58,1981,70-72. Cyalume lightstick chemiluminescence reactions. 

Cyalume sticks are chemiluminescent when you bend the flexible tube enough to break the barrier that separates two substances, the tube glows for several hours until the chemical reactions are completed. A method called enhanced chemiluminescent detection, developed by researchers in Paris, offers a non-radioac-tive way of keeping track of genes and is being used in the international Human Genome Project. 

Lab-on-a-Chip Devices for Chemical Analysis, Fig. 12 (a) Microchip layout. The inlets are 400 pm wide, 800 pm deep, and 10 mm long. The mixing channel is 800 pm wide, 800 pm deep, and 520 mm long. The active area of the photodiode used for chemiluminescence detection is 1 x 1 mm. The photodiode is located at a position 10 mm downstream from the point of confluence of the two inlet streams, (b) Quantum efficiency spectrum of the organic photodiode and the normalized emission spectra for the two chemiluminescent dyes used in the work (cyalume blue and cyalume green). The emission spectra of both dyes overlap the spectral response of the photodiode (Reprinted with permission from [20])... 

The rates of most chemical reactions increase as the temperature rises. For example, dough rises faster at room temperature than when refrigerated, and plants grow more rapidly in warm weather than in cold. We can see the effect of temperature on reaction rate by observing a chemiluminescence reaction (one that produces light), such as that in Cyalume light sticks ( Figure 14.13). 

Figure 8.4 The reaction that makes a Cyalume light stick glow takes place more rapidly in hot water (left) than in ice water (right). The light sticks outside the container are at room temperature. Which pair of sticks would glow for a longer time Explain your reasoning.

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