Freon 114

Freons (Freon 11, trichloromonofluoromethane Freon 12, dichlorofluoro-methane) are used as propellants in sprays. Three patients have been reported allergic to Freon 11, one of them also reacted to Freon 12. All three showed positive reactions to ethyl chloride as well one had an eczematous eruption on the skin after spraying for a biopsy (Van Ketel 1976 a). 

Because Franklin and Wilkins were hardly speaking to each other, Franklin left King s College in 1953 for Birkbeck College, also in London, where she finished her DNA work and became head of the team studying tobacco mosaic virus. Franklin died of ovarian cancer on April 16, 1958, at the age of 37. see also Deoxyribonucleic Acid (DNA) Double Helix Pauling, Linus Watson, James Dewey. 

Chemistry Industry (2003). Rosalind Franklin The Woman behind the DNA Helix Chemistry b Industry 8 (April 21) 13. 

Lynne Osman (2003). Rosalind Franklin and the Double Helix. Physics Today 56 (March) 42. 

Harvey, Joy, and Ogilvie, Marilyn B. (2000). Rosalind Elsie Franklin (1920-1958). In The Biographical Dictionary of Women in Science Pioneering Lives from Ancient Times to the Mid-20th Century, Vol. 1, ed. Marilyn Ogilvie and Joy Harvey. New York and London Routledge. 

Julian, M. M. (1983). Rosalind Franklin, from Coal to DNA to Plant Viruses. Journal of Chemical Education 60 660-662. 

INQUIRY EXAMPLE 1 Our refrigeration engineers wish to locate references on the Prandtl Number for Freon 23. 

SEARCH STRATEGY AND RESULTS On page A23 of the Materials Directory, you will find Freon 23 with the 

INQUIRY EXAMPLE 2 Our chief chemist wishes to find specific heat references for Lactic Acid. 

SEARCH STRATEGY AND RESULTS On page A29 of the Materials Directory, only property f Is listed for Lactic Acid, substance number 221-0101. Since property code f is viscosity, do not look further in this volume for specific heat. However, if you go to Book 1, page 254, in the Basic Edition of the Retrieval Guide (Plenum, 1967), you will find that papers have been coded for specific heat. Continue the search in the Basic Edition, where in Book 2, page 223, under the same substance number 221-0101 you will find six entries with four different TPRC numbers 1252, 4676, 12862, and 13331. Finally, in Book 3 in the Basic Edition you can find the complete bibliographic citations for papers 1252, 4676, 12862, and 13331. (Books 1, 2, and 3 of the Basic Edition correspond directly to Parts A, B, and C of this six-volume Supplement I.) 

INQUIRY EXAMPLE 3 Our technical staff would like references on the specific heat of Dextrose. 

Purcell [20] was the first to suggest an adsorption open tubular capillary column with molecular sieves (see Fig. 1-5 [20]). The copper column (23 m x 1 mm) with roughened walls coated with pulverized molecular sieve 5A was used for separation of 

Column 22 m X 1 mm adsorbent molecular sieve 5A deposited on the inner wall  

The preparation of capillary columns with porous polymers was first described by Hollis [21] in 1973. The styrene-divinylbenzene polymers were synthesized in situ inside the capillary. An example of the gas chromatographic separation possible on such columns is shown in Fig. 1-6 [21]. These columns were usable for hydrocarbon separations (note the separation by carbon number) but polar molecules such as alcohols have the tailing peaks characteristic of adsorption. In Hollis opinion, this is probably due to the same forces as are seen with a metal capillary column using apolar squalane without a tailing reducer [21]. 

Mention should be made of using a capillary column for separation of polar compounds on organic natural adsorbents. Fig. 1-7 [22] shows the separation of naturally occurring organic acids on a natural polymer, i.e., cells of Staphylococcus aureus. The use of such adsorbents holds good promise. 

Petitjean and LeftauK [23], Schwartz [24], and others also contributed to the eeirly development of capillary gas-solid chromatography, and subsequent important contributions to this kind of chromatography were made by Liberti, Bruner, Cartoni, and co-workers [25 — 29] as well as llkova and Mistryukov [30], 

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Chloroform is a potent volatile anaesthetic, but is little used due to its potential hepato-toxicity. It is used principally for the manufacture of chlorofluorohydrocarbon refrigerants ( Arctons and Freons ) and certain polymers. 

C. Manufactured by the action of HF on CCI4 using SbClj as a catalyst. Known commercially as Freon-12 or Arcton-12. Widely used as a refrigerant and aerosol propellant. It is much less toxic than carbon tetrachloride. 

Many condensable vapours have been used as refrigerants, but the main ones are the chlorofluorocarbons (Freons ), ammonia and carbon dioxide. 

Figure Bl.16.2. X-band TREPR spectra obtained at 0.1 ps after 308 mn photolysis of a fliiorinated peroxide dimer in Freon 113 at room temperature. Part A is the A/E RPM spectrum obtained upon direct photolysis part B is the E/A RPM spectrum obtained upon triplet sensitization of this reaction using benzophenone.

Materials of this type have been sold by Du Pont Co. under the Freon E and Krytox trademarks. Perfluorinated materials stmcturaEy similar to those in equation 11 have been prepared by Ausimont by the low temperature irradiation of either hexafluoropropylene or tetrafluoroethylene with oxygen followed by heating and/or irradiation and have been sold as Fomblin Hquids (52). An isomeric polyether, Demnum, prepared by the oligomerization of 2,2,3,3-tetrafluorooxetane followed by fluorination has been commercialized by Daikin (eq. 12). 

Fig. 15. Schematic of the interfacial polymerization process. The microporous film is first impregnated with an aqueous amine solution. The film is then treated with a multivalent cross-linking agent dissolved in a water-immiscible organic fluid, such as hexane or Freon-113. An extremely thin polymer film...

Surface cleanliness of the substrate is important for all thermal spray processes. Degreasing, which formerly often reHed on freons or chlorinated... 

Off-Gas Treatment. Before the advent of the shear, the gases released from the spent fuel were mixed with the entire dissolver off-gas flow. Newer shear designs contain the fission gases and provide the opportunity for more efficient treatment. The gaseous fission products krypton and xenon are chemically inert and are released into the off-gas system as soon as the fuel cladding is breached. Efficient recovery of these isotopes requires capture at the point of release, before dilution with large quantities of air. Two processes have been developed, a cryogenic distillation and a Freon absorption. 

Portable fire extinguishers are classified according to appHcabiHty Class A for soHd combustibles Class B for flammable Hquids Class C for electrical fires that require a nonconducting agent and Class D for combustible metals. Water frequently is used for Class A extinguishers bicarbonates for Class B and Class BC carbon dioxide or Freon for Class C ammonium phosphate for Class ABC and powdered salt, sodium chloride, for Class D. 

A more concentrated solution of HOBr can be prepared by filtration of one of the above solutions and distillation in vacuum. Or the mercuric oxide reaction can be carried out in Freon 11 without water, yielding a solution of bromine monoxide which is filtered and hydrolyzed. Hypobromous acid is slightly ionized its dissociation constant at 25°C is 2 x 10 . ... 

Freon SMT CleaningHgent product brochure, E. I. du Pont de Nemours Co., Inc., June 1988. 

Agglomeration-Based Fine Coal Cleaning. Most recently a search for nonaqueous collectors or reagents for fine coal cleaning has been undertaken. A number of Hquids have been tested and found to be suitable as agglomeration agents. These include heavy oil. Freon, pentane, hexane, heptane, 2-methylbutane, methyl chloride, and Hquid carbon dioxide. 

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