Chemiluminescence history

Analytical Chemiluminescence. Naval Air Warfare Center Weapons Division NA WCWPNS, China Lake. Chemiluminescence history. http //www.nawcwpns.navy.mil/clmf/chemilume.html Chemiluminescence. 

The quality of the polymer, its photo-oxidation and thermo-oxidation history expressed in concentration of hydroperoxides, carbonyl groups or of other oxidized structures and terminal groups. The rate of an oxidative attack may then be related to the average molar mass and to its distribution, and to the ratio of amorphous/crystalline structures. Polymers cannot be simply ordered according to the intensity of light emission at a given temperature. The chemiluminescence-time patterns are related with the rate of sample oxidation, but they may differ from one to the next polymer. 

The subsequent history of C2H and C4H3 is not important for the oxidation scheme once the chain system develops. Nevertheless, the oxidation of C2H could lead to chemiluminescent reactions that form CH and C2, the species responsible for the blue-green appearance of hydrocarbon flames. These species may be formed by the following steps [40, 40a, 40b] ... 

The history of chemiluminescence from polymers is relatively short. In 1961 Ashby [3] reported that light was emitted from polymers heated in air. Because of the relationship between light and oxidation the term oxylumines-cence was used. Ashby saw the possibility of using chemiluminescence as a tool for testing the stability of polymers and studied the role of oxygen concentration and the effect of antioxidants. A few years later, Schard and... 

I am, however, only one of many who have seen the extraordinary possibilities offered by harpooning reactions. For example, Dudley Herschbach began his life as a dynamicist by studying that type of reaction. One should also add that my father himself was part of a continuous progression. What drew him to sodium reactions was that Fritz Haber had been studying an unexplained chemiluminescence from them. This was in Berlin and my father was in Haber s Institute as a young researcher. The history, as is usual in science, constitutes an unbroken chain. 

Under nitrogen, the emission of chemiluminescence from polymer samples corresponds to the initial concentration of peroxy radicals (POO") and it is proportional to the hydroperoxide content formed during the processing of the material, this being related to its thermal oxidation history. Under these conditions, Rt = 0. Hence, Equation 3.2 can be simplified as follows [26] ... 

The reciprocal of the square root of the chemiluminescence intensity versus time gives a linear relationship as published by Kihara and Hosoda [26]. In the region where the plot gives a straight line, the slope is the value of fkhfj. This parameter is named CL-decay rate and may be used to evaluate the thermal history of different polymers. 

The origin of chemiluminescence in polyolefins has been profoundly analyzed and it has contributed to the better understanding of their complex mechanism of thermooxidation The thermal oxidation of polyethylenes with different manufacturing histories has been compared, which allowed to establish a relationship between CL and some structural characteristics of the polymers. Modification of their stability in the presence of antioxidants, or other additives such as the activity of nano- and micron particles of pigments has been evaluated. 

Qualitative aspects of photochemistry were known long before the development of chemistry as a science. For example, the history of chemical luminescence (or chemiluminescence) goes back to 1603 when Vincenzo Cascariolo, an alchemist... 

Demonstrations of scientific phenomena have a long and honourable history and the more dramatic pyrotechnic examples of chemical reactions are deservedly popular. However the gentle glow from variously coloured chemiluminescing solutions has a unique appeal. Sufficient intensity is sometimes obtainable for the demonstrations to be visible in daylight, but their appearance in all the colours of the spectrum in a totally darkened room is a memorable sight. 

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