Photoreduction of nitrogen trifluoride with controlled release of radicals. Issue 3 (29th July 2013)

• Record Type: Journal Article
• Authors: Liu, Xingang; Zhang, Jiahui; Zhang, Renxi; Hou, Huiqi; Chen, Shanping; Zhang, Yi
• Is Part Of: Journal of chemical technology & biotechnology. Volume 89:Issue 3(2014:Mar.)
• Page Start: 436
• Page End: 447
• Publication Date: 2013-07-29
• Subjects: Biotechnology -- Periodicals; Chemistry, Technical -- Periodicals; Chemical engineering -- Periodicals; Industries -- Environmental aspects -- Periodicals; 660
• DOI: 10.1002/jctb.4136
• Languages: English
• ISSNs: 0268-2575

Abstract

<abstract abstract-type="main" id="jctb4136-abs-0001"> <title>Abstract</title> <sec id="jctb4136-sec-0001" sec-type="section"> <title>BACKGROUND</title> <p id="jctb4136-para-0001"> <bold>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<sub>3</sub>) is in demand. But perfluorocarbons are very stable compounds because of their molecular structures. Therefore, in the atmosphere, NF<sub>3</sub> is difficult to oxidize by O<sub>3</sub>, NO, NO<sub>2</sub>, and OH radicals, except by excited oxygen atoms O(<sup>1</sup><italic>D</italic>) that can react with it to form NF<sub>2</sub> or other products. In this study the possible degradation process of NF<sub>3</sub> in the 'controlled release of radicals' reactor is discussed.</bold> </p> </sec> <sec id="jctb4136-sec-0002" sec-type="section"> <title>RESULTS</title> <p id="jctb4136-para-0002"> <bold>Under the conditions of 5 mmHg partial pressure of NF<sub>3</sub> and 600 mmHg total pressure with buffer gas of argon, NF<sub>3</sub> was photodegraded in an <italic>in situ</italic> 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<sub>3</sub> degradation in the CRR system. The NF<sub>3</sub> degradation efficiency, significantly affected by O<sub>2</sub> and almost independent of N<sub>2</sub>, reached 96% with a kinetic rate constant <italic>k</italic> ≈ 1.77 × 10<sup>−4</sup> s<sup>−1</sup> after 300 min of ultraviolet irradiation.</bold> </p> </sec> <sec id="jctb4136-sec-0003" sec-type="section"> <title>CONCLUSION</title> <p id="jctb4136-para-0003"> <bold>According to the experimental results, a potential way of continuous photoreduction of NF<sub>3</sub> was found<sub>, </sub> 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<sub>3</sub> and no fluoride byproducts in gas make it possible for industry application. © 2013 Society of Chemical Industry</bold> </p> </sec> </abstract>