Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media
Aqueous dissolution of a synthetic chloride-containing Mg2+-Al3+ layered double hydroxide was studied at 298K as a function of pH. Mild acidification (final pH 9 -5) results in incongruent dissolution of Mg2+, exclusively. Formation of an amorphous Al(OH)3 passive layer prevents further Mg2+ leachin...
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_01691317_v51_n3_p366_Jobbagy |
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todo:paper_01691317_v51_n3_p366_Jobbagy2023-10-03T15:06:56Z Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media Jobbágy, M. Regazzoni, A.E. Dissolution kinetics Hydrotalcite Layered double hydroxide Amorphous al3 Aqueous dissolution Aqueous media Congruent dissolutions Dissolution kinetics Final pH Hydrotalcites Kinetic order Layered double hydroxides Nano-size Passive layer PH dependence pH value Proton concentrations Volume kinetics Aluminum Chlorine compounds Leaching Rate constants Dissolution acidification aluminum aqueous solution chloride dissolution hydrotalcite hydroxide magnesium pH reaction kinetics Aqueous dissolution of a synthetic chloride-containing Mg2+-Al3+ layered double hydroxide was studied at 298K as a function of pH. Mild acidification (final pH 9 -5) results in incongruent dissolution of Mg2+, exclusively. Formation of an amorphous Al(OH)3 passive layer prevents further Mg2+ leaching, thus dissolved Mg2+ amounts for only 20% of the solid. At lower pH values, massive dissolution readily takes place in a congruent fashion. Congruent dissolution profiles are accounted for by a contracting volume kinetic law. The pH dependence of the observed rate constant shows that the kinetic order on proton concentration is 0.41, indicating that dissolution is surface controlled. The implications of these findings are discussed. © 2010 Elsevier B.V. Fil:Jobbágy, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_01691317_v51_n3_p366_Jobbagy |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Dissolution kinetics Hydrotalcite Layered double hydroxide Amorphous al3 Aqueous dissolution Aqueous media Congruent dissolutions Dissolution kinetics Final pH Hydrotalcites Kinetic order Layered double hydroxides Nano-size Passive layer PH dependence pH value Proton concentrations Volume kinetics Aluminum Chlorine compounds Leaching Rate constants Dissolution acidification aluminum aqueous solution chloride dissolution hydrotalcite hydroxide magnesium pH reaction kinetics |
| spellingShingle |
Dissolution kinetics Hydrotalcite Layered double hydroxide Amorphous al3 Aqueous dissolution Aqueous media Congruent dissolutions Dissolution kinetics Final pH Hydrotalcites Kinetic order Layered double hydroxides Nano-size Passive layer PH dependence pH value Proton concentrations Volume kinetics Aluminum Chlorine compounds Leaching Rate constants Dissolution acidification aluminum aqueous solution chloride dissolution hydrotalcite hydroxide magnesium pH reaction kinetics Jobbágy, M. Regazzoni, A.E. Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media |
| topic_facet |
Dissolution kinetics Hydrotalcite Layered double hydroxide Amorphous al3 Aqueous dissolution Aqueous media Congruent dissolutions Dissolution kinetics Final pH Hydrotalcites Kinetic order Layered double hydroxides Nano-size Passive layer PH dependence pH value Proton concentrations Volume kinetics Aluminum Chlorine compounds Leaching Rate constants Dissolution acidification aluminum aqueous solution chloride dissolution hydrotalcite hydroxide magnesium pH reaction kinetics |
| description |
Aqueous dissolution of a synthetic chloride-containing Mg2+-Al3+ layered double hydroxide was studied at 298K as a function of pH. Mild acidification (final pH 9 -5) results in incongruent dissolution of Mg2+, exclusively. Formation of an amorphous Al(OH)3 passive layer prevents further Mg2+ leaching, thus dissolved Mg2+ amounts for only 20% of the solid. At lower pH values, massive dissolution readily takes place in a congruent fashion. Congruent dissolution profiles are accounted for by a contracting volume kinetic law. The pH dependence of the observed rate constant shows that the kinetic order on proton concentration is 0.41, indicating that dissolution is surface controlled. The implications of these findings are discussed. © 2010 Elsevier B.V. |
| format |
JOUR |
| author |
Jobbágy, M. Regazzoni, A.E. |
| author_facet |
Jobbágy, M. Regazzoni, A.E. |
| author_sort |
Jobbágy, M. |
| title |
Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media |
| title_short |
Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media |
| title_full |
Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media |
| title_fullStr |
Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media |
| title_full_unstemmed |
Dissolution of nano-size Mg-Al-Cl hydrotalcite in aqueous media |
| title_sort |
dissolution of nano-size mg-al-cl hydrotalcite in aqueous media |
| url |
http://hdl.handle.net/20.500.12110/paper_01691317_v51_n3_p366_Jobbagy |
| work_keys_str_mv |
AT jobbagym dissolutionofnanosizemgalclhydrotalciteinaqueousmedia AT regazzoniae dissolutionofnanosizemgalclhydrotalciteinaqueousmedia |
| _version_ |
1782030243477848064 |