Interaction of copper(II) with cellulose pulp ; Vario(II) jonų sąveika su celiuliozės pulpa
In: Chemija, 2002, T. 13, Nr. 2, p. 75-84 ; ISSN 0235-7216, 2002, S. 75-84
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Zugriff:
Cu(II) interaction with cellulose pulp was studied by means of polarography, AAS, and ultraviolet-visible spectrophotometry. The experiments were carried out at room temperature and at selected initial cellulose pulp pH values between 7.0-13.0. The results show a trend of decreasing pH after hydrolysis of the pulp (2 % w/w) as well as after further addition of a Cu(II) salt (0.5 mmol/1; pCu = 3.3). The pCu in solutions with initial pH values from 7.0 to 11.0 remain in the range 3.4-3.9, implying an insignificant complexation of Cu(II). This is almost certainly caused by the relatively low solution pH (5.9-7.4) after pulp hydrolysis and Cu(II) salt addition. When the pH of these solutions was raised to 12.0, the complexing ability of the dissolved cellulose hydrolysis products rised, apparently due to the deprotonation of hydroxyl groups, and pCu reached 13.0-13.5. When the Cu(II) salt was added directly into cellulose pulp slurry at the onset of the hydrolysis step, some of the Cu(II) ions were bound (due to adsorption and/or chemical bonds formation) to the cellulose fibres. The extent of this interaction depended on the initial pH. The bound fraction of the Cu(II) ions represented about 50-70% of the initial Cu(II) at pH 7.0 and about 90-95% at pH 13.0. The pCu in filtered solutions with initial pH values in the range 7.0-11.0 remained in the range 3.9-6.1. When the pH of any of the solutions with the initial pH values between 7.0 and 11.0 was increased to 12.0, the complexing ability rised dramatically, and pCu re- ached 12.9-15.1.
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Interaction of copper(II) with cellulose pulp ; Vario(II) jonų sąveika su celiuliozės pulpa
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Autor/in / Beteiligte Person: | Norkus, Eugenijus ; Vaičiūnienė, Jūratė ; Virbalytė, Dalia ; Vuorinen, Tapani ; Macalady, Donald |
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Zeitschrift: | Chemija, 2002, T. 13, Nr. 2, p. 75-84 ; ISSN 0235-7216, 2002, S. 75-84 |
Veröffentlichung: | 2002 |
Medientyp: | academicJournal |
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