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Photoreduction of nitrogen trifluoride with controlled release of radicals
Author(s) -
Liu Xingang,
Zhang Jiahui,
Zhang Renxi,
Hou Huiqi,
Chen Shanping,
Zhang Yi
Publication year - 2014
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4136
Subject(s) - radical , chemistry , photochemistry , degradation (telecommunications) , reaction rate constant , irradiation , excited state , nitrogen , photodissociation , oxygen , kinetics , organic chemistry , telecommunications , physics , quantum mechanics , computer science , nuclear physics
BACKGROUND With the rapid growth of the semiconductor and thin film transistor liquid crystal display manufacturing industries, large quantities of the potent greenhouse gas nitrogen trifluoride ( NF 3 ) is in demand. But perfluorocarbons are very stable compounds because of their molecular structures. Therefore, in the atmosphere, NF 3 is difficult to oxidize by O 3 , NO , NO 2 , and OH radicals, except by excited oxygen atoms O( 1 D ) that can react with it to form NF 2 or other products. In this study the possible degradation process of NF 3 in the ‘controlled release of radicals’ reactor is discussed.RESULTS Under the conditions of 5 mmHg partial pressure of NF 3 and 600 mmHg total pressure with buffer gas of argon, NF 3 was photodegraded in an in situ reactor with a ‘controlled release of radicals’ system. The results indicated that reductive double bonds and allyl radicals, slowly released from polyisoprene irradiated by a UV lamp emitting 185 and 253.7 nm of light, could contribute to the NF 3 degradation in the CRR system. The NF 3 degradation efficiency, significantly affected by O 2 and almost independent of N 2 , reached 96% with a kinetic rate constant k ≈ 1.77 × 10 −4 s −1 after 300 min of ultraviolet irradiation.CONCLUSION According to the experimental results, a potential way of continuous photoreduction of NF 3 was found , since excited double bonds and allyl radicals are consequently released by irradiating the surface of the polymer matrix. The considerable degradation reaction constant of NF 3 and no fluoride byproducts in gas make it possible for industry application. © 2013 Society of Chemical Industry