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SM ISO690:2012 CEBAN (GÎNSARI), Irina, NASTAS, Raisa, LUPASCU, Tudor, PODDUBNAYA, Olga, PUZIY, Alexander. Determination of surface groups on activated carbons by BOEHM and potentiometric titrations. In: Achievements and perspectives of modern chemistry, 9-11 octombrie 2019, Chişinău. Chisinau, Republic of Moldova: Tipografia Academiei de Ştiinţe a Moldovei, 2019, p. 148. ISBN 978-9975-62-428-2. |
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Achievements and perspectives of modern chemistry 2019 | |||||
Conferința "International Conference "Achievements and perspectives of modern chemistry"" Chişinău, Moldova, 9-11 octombrie 2019 | |||||
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Pag. 148-148 | |||||
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The surface chemistry of activated carbons determines their moisture content, catalytic properties, acid–base character, and adsorption of polar species [1]. It is related to the presence of heteroatoms (oxygen, nitrogen, phosphorus, chlorine, sulfur et al.) other than carbon within the carbonaceous matrix. In this study, activated carbons of local origin (Republic of Moldova) from the apple wood (CA-M) and nut shells (CA-N) were oxidized with nitric acid (sample CA-Mox) and mixture of nitric acid/urea (samples CA-Mox-u and CA-Nox-u) in order to improve their ion-exchange properties. The surface chemistry was characterized by using Boehm and potentiometric titration methods [2, 3]. Additionally, the ash and metals content in studied samples were determined as well as. Obtained results showed that oxidation introduces a variety of functional groups to the surface, making it more heterogeneous (Table and Figure). There are some discrepancies in the obtained results, which may be attributed to the limitations of the Boehm titration method.Table. The quantity and character of functional groups (mmol/g) on the surface of active carbons, determined by the Boehm methodFigure. Distribution of surface groups F(pK) with respect to the protonation constants pK |
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