Investigation of the setting reaction in magnesium phosphate ceramics with quasielastic neutron scattering

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F17%3A00474658" target="_blank" >RIV/68378297:_____/17:00474658 - isvavai.cz</a>

Result on the web

<a href="http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.7b01396" target="_blank" >http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.7b01396</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcc.7b01396" target="_blank" >10.1021/acs.jpcc.7b01396</a>

Result language

angličtina

Original language name

Investigation of the setting reaction in magnesium phosphate ceramics with quasielastic neutron scattering

Original language description

Magnesium phosphate ceramics are a class of acid-base cements for bioengineering and civil engineering applications. We report on quasielastic neutron scattering results focusing on the evolution of the state of water in the system during the setting reaction, to shed light on the reaction mechanisms and the nature of the products. In the first few minutes, a consistent fraction of water molecules appears as immobile, and after a transient time, they start to be progressively bound into a reaction product. The kinetics of this last process has been described with an equation combining an Avrami model and a first-order reaction model with apparent activation energies of 18 and 6 kJ/mol, respectively. The results indicate that during the reaction the water molecules experience confinement effects inside a restricted space. The size of the confining volume decreases as the reaction progresses. It is proposed that an amorphous precursor with high surface area, bonding a relevant fraction of water, but also hosting mobile water, forms first. After an induction period, this phase undergoes further transformation into a product, still amorphous, considered as a further precursor of the final crystalline phase. With the reaction being kinetically driven, nonclassical mechanisms of nucleation and growth may lead to the formation of prenucleation clusters developing the first intermediate compound by coalescence. The mutating pH conditions trigger the transformation of the precursors, which likely contain structural motifs of the crystalline phase, similar to those observed in Ca and Zn, phosphate hydrate systems.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20504 - Ceramics

Project

<a href="/en/project/LO1219" target="_blank" >LO1219: Sustainable advanced development of CET</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Physical Chemistry C

ISSN

1932-7447

e-ISSN

—

Volume of the periodical

121

Issue of the periodical within the volume

21

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

11355-11367

UT code for WoS article

000402775200039

EID of the result in the Scopus database

2-s2.0-85020683714