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dc.contributor.authorGebauer, Denis
dc.contributor.authorLiu, X.
dc.contributor.authorAziz, B.
dc.contributor.authorHedin, N.
dc.contributor.authorZhao, Z.
dc.date.accessioned2017-04-28T13:58:59Z
dc.date.available2017-04-28T13:58:59Z
dc.date.created2017-04-28T09:06:17Z
dc.date.issued2013
dc.identifier.citationGebauer, D. and Liu, X. and Aziz, B. and Hedin, N. and Zhao, Z. 2013. Porous tablets of crystalline calcium carbonate via sintering of amorphous nanoparticles. CrystEngComm. 15 (6): pp. 1257-1263.
dc.identifier.urihttp://hdl.handle.net/20.500.11937/52513
dc.identifier.doi10.1039/c2ce26604k
dc.description.abstract

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. © 2013 The Royal Society of Chemistry.

dc.publisherThe Royal Society of Chemistry
dc.titlePorous tablets of crystalline calcium carbonate via sintering of amorphous nanoparticles
dc.typeJournal Article
dcterms.source.volume15
dcterms.source.number6
dcterms.source.startPage1257
dcterms.source.endPage1263
dcterms.source.issn1466-8033
dcterms.source.titleCrystEngComm
curtin.departmentDepartment of Chemistry
curtin.accessStatusFulltext not available


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