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3220395 
Journal Article 
The inhibition of crystal growth of mirabilite in aqueous solutions in the presence of phosphonates 
Vavouraki, AI; Koutsoukos, PG 
2016 
Yes 
Journal of Crystal Growth
ISSN: 0022-0248 
436 
92-98 
WOS:000368244600015 
The formation of sodium sulfate decahydrate (Mirabilite) has
been known to cause serious damages to structural materials both of modern and of historical
buildings. Methods which can retard or completely suppress the development of mirabilte crystals
are urgently needed especially as remedies or preventive measures for the preservation of the
built cultural heritage. In the present work we present results on the effect of the presence of
phosphonate compounds on the kinetics of crystal growth from aqueous supersaturated solutions at
18 degrees C using the seeded growth technique. The phosphonate compounds tested differed with
respect to the number of ionizable phosphonate groups and with respect to the number of amino
groups in the respective molecules. The crystal growth process was monitored by the temperature
changes during the exothermic crystallization of mirabilite in the stirred supersaturated
solutions. The crystal growth of mirabilite in the presence of: (1-hydroxyethylidene)-1, 1-
diphosphonic acid (HEDP), amino tri (methylene phosphonic acid) (ATMP), hexamethylenediaminetetra
(methylene) phosphonic acid (HTDMP), and diethylene triamine penta(methylene phosphonic acid)
(DETPMP) over a range of concentrations between 0.1-5% w/w resulted in significant decrease of
the rates of mirabilite crystal growth. All phosphonic compounds tested reduced the
crystallization rates up to 60% in comparison with additive-free solutions. The presence of the
test compounds did not cause changes of the mechanism of crystal growth which was surface
diffusion controlled, as shown by the second order dependence of the rates of mirabilite crystal
growth on the relative supersaturation. The excellent fit of the measured rates to a kinetic
Langmuir-type model suggested that the activity of the tested inhibitors could be attributed to
the adsorption and subsequent reduction of the active crystal growth sites of the seed crystals.
In all cases, the inhibitory activity was reduced with increasing solution supersaturation, while
the presence of DETPMP, which showed the best inhibition activity, showed the least reduction of
inhibition with increasing supersaturation. (C) 2015 Elsevier B.V. All rights reserved. 
Sodium sulfate decahydrate; Mirabilite; Crystal growth; Kinetics of; Inhibition of; Phosphonates