Linked Life Data

11783646

Source:http://linkedlifedata.com/resource/pubmed/id/11783646

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2002-1-9
pubmed:abstractText
For long-term performance assessment of nuclear waste repositories knowledge concerning interactions of actinides with mineral surfaces is imperative. The mobility and bioavailability of released radionuclides is strongly dependent on sorption/desorption processes onto mineral surfaces. Therefore it is necessary to characterize the surface species formed and to elucidate the reaction mechanisms involved. The high fluorescence spectroscopic sensitivity of Cm(III) has attracted our interest regarding the complexation process of Cm(III) onto smectite and kaolinite as a model system for the sorption of trivalent actinides in the trace concentration range. We conclude that at low pH Cm(III) is sorbed onto kaolinite and smectite as an outer-sphere complex and retains its complete primary hydration sphere. With increasing pH inner-sphere adsorption onto kaolinite and smectite occurs via the aluminol edge sites. The same evolution of the Cm(III)-clay surface species as a function of pH was observed for both minerals. Starting at a pH > or = 5 we observe the formation of a [triple bond]Al-O-Cm2+(H2O)5 surface complex, which is replaced by a second species at higher pH. The second surface complex may be a monodentate [triple bond]Al-O-Cm+(OH)(H2O)4 species or bidentate [triple bond](Al-O)2-Cm+(H2O)5 species. The Cm(III)/clay surface complexes are characterized bytheir emission spectra (peak maxima at 598.8 and 603.3 nm) and their fluorescence lifetime (both 110 +/- 7 micros). An important result in view of the mobility and bioavailability of radionuclides is that no incorporation of Cm(III) into the bulk clay structure was observed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0013-936X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3691-4
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Time-resolved laser fluorescence spectroscopy study of the sorption of Cm(III) onto smectite and kaolinite.
pubmed:affiliation
Forschungszentrum Rossendorf, Institut für Radiochemie, Dresden, Germany. T.stumpf@fz-rossendorf.de
pubmed:publicationType
Journal Article