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Quantification of activated (2,2,6,6-tetramethylpiperIdin-1-yl) oxyl radical

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dc.contributor Aalto University en
dc.contributor Aalto-yliopisto fi
dc.contributor.advisor Pääkkönen, Timo
dc.contributor.advisor Nuopponen, Markus
dc.contributor.author Tummala, Gopi
dc.date.accessioned 2013-10-16T08:05:10Z
dc.date.available 2013-10-16T08:05:10Z
dc.date.issued 2013-09-10
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/11134
dc.description.abstract Cellulose oxidation is a known chemical pretreatment for nanocellulose production. The use of (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl radical (TEMPO) as a catalyst in oxidation of cellulose is well-known. TEMPO is commercially available as a radical and it needs to be activated by some other chemical or method for it to catalyze cel-lulose oxidation. The cost of TEMPO catalyst is very high and any unnecessary use is a direct loss. Hence the chemistry of activation of TEMPO is of very high importance to understand the process and optimize the process variables and chemicals. So far there is no easy method to quantify activated TEMPO. This work aims to find a method to determine the quantity of activated TEMPO and apply the method to other TEMPO based chemical compounds and compare the results. Further this work explores the stoichiometric conversion of radical TEMPO to activated TEMPO. The theoretical section of this thesis will describe the catalysis in brief, provide in-formation on chemistry of nitroxyl radicals in general, describe reactions and appli-cations of TEMPO and provide a brief note on TEMPO derivatives. In the experimental section the three point titration method used for analysis of chlorine compounds was applied here to measure the activated TEMPO. TEMPO solution was activated by chlorine dioxide or hypochlorous acid and titrated imme-diately. ClO2/TEMPO and HOCl/TEMPO ratio was varied to reach the optimum degree of activation in each case. UV-Vis spectrometry was used to verify whether TEMPO was activated completely or not. The effect of chloride ion and 1-propanol on the systems was studied. The method was later applied on TEMPO derivatives to observe the response. It was found that TEMPO reacts with chlorine dioxide and hypochlorous acid very fast. The titration method estimated approximately 50% conversion of TEMPO to nitrosonium ion. The data from UV-Vis spectroscopy indicates the absence of radical TEMPO after activation. It was found that chloride ion has no effect on the titration results. Although the three point titration method was able to quantify TEMPO par-tially using the conditions shown in this thesis, the results attained show that it could however be possible to refine the method for better estimation. en
dc.format.extent 57
dc.language.iso en en
dc.title Quantification of activated (2,2,6,6-tetramethylpiperIdin-1-yl) oxyl radical en
dc.type G2 Pro gradu, diplomityö en
dc.contributor.school Kemian tekniikan korkeakoulu fi
dc.subject.keyword TEMPO en
dc.subject.keyword catalysis en
dc.subject.keyword hypochlorous acid en
dc.subject.keyword chlorine dioxide. en
dc.identifier.urn URN:NBN:fi:aalto-201310167705
dc.programme.major Renewable Materials Engineering fi
dc.programme.mcode KM3002 fi
dc.type.ontasot Diplomityö fi
dc.type.ontasot Master's thesis en
dc.contributor.supervisor Vuorinen, Tapani
dc.programme Master's Programme in Bioproduct Technology fi
dc.location PK fi
local.aalto.openaccess no
local.aalto.digifolder Aalto_90873
dc.rights.accesslevel closedAccess
local.aalto.idinssi 48087
dc.type.publication masterThesis
dc.type.okm G2 Pro gradu, diplomityö

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