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Porous tablets of crystalline calcium carbonate via sintering of amorphous nanoparticles

Porous tablets of crystalline calcium carbonate via sintering of amorphous nanoparticles

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GEBAUER, Denis, Xing-Min LIU, Baroz AZIZ, Niklas HEDIN, Zhe ZHAO, 2013. Porous tablets of crystalline calcium carbonate via sintering of amorphous nanoparticles. In: CrystEngComm. 15(6), pp. 1257-1263. ISSN 1466-8033. eISSN 1466-8033

@article{Gebauer2013Porou-21236, title={Porous tablets of crystalline calcium carbonate via sintering of amorphous nanoparticles}, year={2013}, doi={10.1039/C2CE26604K}, number={6}, volume={15}, issn={1466-8033}, journal={CrystEngComm}, pages={1257--1263}, author={Gebauer, Denis and Liu, Xing-Min and Aziz, Baroz and Hedin, Niklas and Zhao, Zhe} }

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:bibo="http://purl.org/ontology/bibo/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:xsd="http://www.w3.org/2001/XMLSchema#" > <rdf:Description rdf:about="https://kops.uni-konstanz.de/rdf/resource/123456789/21236"> <dc:creator>Hedin, Niklas</dc:creator> <dc:creator>Aziz, Baroz</dc:creator> <dcterms:issued>2013</dcterms:issued> <dc:language>eng</dc:language> <dc:creator>Liu, Xing-Min</dc:creator> <dcterms:available rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2013-01-22T08:49:35Z</dcterms:available> <dc:contributor>Liu, Xing-Min</dc:contributor> <dc:creator>Gebauer, Denis</dc:creator> <dc:creator>Zhao, Zhe</dc:creator> <dcterms:bibliographicCitation>CrystEngComm ; 15 (2013), 6. - S. 1257-1263</dcterms:bibliographicCitation> <dcterms:title>Porous tablets of crystalline calcium carbonate via sintering of amorphous nanoparticles</dcterms:title> <dcterms:abstract xml:lang="eng">Porous tablets of crystalline calcium carbonate were formed upon sintering of a precursor powder of amorphous calcium carbonate (ACC) under compressive stress (20 MPa) at relatively low temperatures (120–400 °C), induced by pulsed direct currents. Infrared spectroscopy ascertained the amorphous nature of the precursor powders. At temperatures of 120–350 °C and rates of temperature increase of 20–100 °C min−1, the nanoparticles of ACC transformed into crystallites of mainly aragonite, which is generally difficult to achieve using wet-chemicals under kinetic control. The amorphous precursor particles (10 nm) transformed into crystallites (30–50 nm) during sintering. Consistently, the specific surface areas of 140–160 m2 g−1 for the precursor particles were reduced to 10–20 m2 g−1 for the porous tablets. The porous network within the tablets consisted of fused aragonite and vaterite particles in a ratio of 80:20. The fraction of aragonite to vaterite was invariant to the temperature and rate of temperature change used. The particle size increased only to a small amount on an increased rate of temperature change. At temperatures above 400 °C, porous tablets of calcite formed. The later transformation was under thermodynamic control, and led to a minor reduction of the specific surface area. The size of the crystallites remained small and the transformation to calcite appeared to be a solid-state transformation. Porous, template- and binder-free tablets of calcium carbonate could find applications in for example, biology or water treatment.</dcterms:abstract> <dc:contributor>Zhao, Zhe</dc:contributor> <bibo:uri rdf:resource="http://kops.uni-konstanz.de/handle/123456789/21236"/> <dc:date rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">2013-01-22T08:49:35Z</dc:date> <dcterms:rights rdf:resource="http://nbn-resolving.org/urn:nbn:de:bsz:352-20140905103605204-4002607-1"/> <dc:contributor>Hedin, Niklas</dc:contributor> <dc:contributor>Gebauer, Denis</dc:contributor> <dc:contributor>Aziz, Baroz</dc:contributor> <dc:rights>deposit-license</dc:rights> </rdf:Description> </rdf:RDF>

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

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