Proposed nano-scale coalescence of cellulose in chemical pulp fibers during technical treatments

Autor: Raili Pönni, Tapani Vuorinen, Eero Kontturi

Publikováno v: BioResources, Vol 7, Iss 4, Pp 6077-6108 (2012)

This review summarizes the proposed mechanisms for irreversible coalescence of cellulose microfibrils within fibers during various common industrial treatments for chemical pulp fibers as well as the methods to evaluate it. It is a phenomenon vital f

Externí odkaz: https://doaj.org/article/5781a4cccd564185b0ad298f7a5a8192

Rate-limiting steps in bromide-free TEMPO-mediated oxidation of cellulose—Quantification of the N-Oxoammonium cation by iodometric titration and UV–vis spectroscopy

Autor: Carlo G. Bertinetto, Markus Nuopponen, Tapani Vuorinen, Timo Pääkkönen, Raili Pönni, Gopi Krishna Tummala

Publikováno v: Applied Catalysis A: General. 505:532-538

A iodometric titration method was introduced to study the conversion of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) to the corresponding N -oxoammonium cation (TEMPO + ) by hypochlorite in the absence and presence of bromide ion. The validity of the

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2554556f43f2eb14e4a8709a15dfbc10
https://doi.org/10.1016/j.apcata.2015.07.024

Activation of TEMPO by ClO2 for oxidation of cellulose by hypochlorite — Fundamental and practical aspects of the catalytic system

Autor: Timo Pääkkönen, Tapani Vuorinen, Jinze Dou, Markus Nuopponen, Raili Pönni

Bromide-free TEMPO-catalyzed oxidation of the primary alcohols by sodium hypochlorite (NaOCl) does not proceed without a prior activation of the catalyst. Here were demonstrate an immediate in situ activation of the catalyst with an equimolar additio

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::73a807d66be4899cf4dbaa8408313e0c
https://aaltodoc.aalto.fi/handle/123456789/27434

Accessibility of hydroxyl groups in birch kraft pulps quantified by deuterium exchange in D2O vapor

Autor: Callum A. S. Hill, Raili Pönni, Lauri Rautkari, Tapani Vuorinen

Publikováno v: Cellulose. 21:1217-1226

Deuterium exchange in a deuterium oxide (D2O) atmosphere (95 % relative humidity), quantified by a dynamic vapor sorption (DVS) apparatus, was applied for assessing the accessibility of hydroxyl groups in birch kraft pulps. Achieving the maximum deut

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::6ff9e14077c385adb0ffbb1356e47c80
https://doi.org/10.1007/s10570-014-0166-x

Effect of xylan in hardwood pulp on the reaction rate of TEMPO-mediated oxidation and the rheology of the final nanofibrillated cellulose gel

Autor: Katarina Dimic-Misic, Tapani Vuorinen, Hannes Orelma, Timo Pääkkönen, Thaddeus Maloney, Raili Pönni

Publikováno v: Pääkkönen, T, Dimic-Misic, K, Orelma, H, Pönni, R, Vuorinen, T & Maloney, T 2016, ' Effect of xylan in hardwood pulp on the reaction rate of TEMPO-mediated oxidation and the rheology of the final nanofibrillated cellulose gel ', Cellulose, vol. 23, no. 1, pp. 277-293 . https://doi.org/10.1007/s10570-015-0824-7

alkali-washed nanofibrillated cellulose (NFC) samples, obtained from hardwood kraft pulp, with different amounts of retained xylan were prepared to study the influence of xylan on the water-retention properties of NFC suspensions. In this study, NFC

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8aa6df2e058572d8c3eb286f59d62ef2
https://cris.vtt.fi/en/publications/932ba567-ff20-4566-bb87-20203fb60846