Document Detail


Effects of initial supersaturation on spontaneous precipitation of calcium carbonate in the presence of charged poly-L-amino acids.
MedLine Citation:
PMID:  20060980     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Spontaneous precipitation of calcium carbonate was investigated in two precipitation systems: (1) with initial supersaturation lower than that corresponding to the solubility of amorphous calcium carbonate (ACC), at which vaterite precipitated, and (2) with initial supersaturation higher than that of ACC solubility, at which a mixture of calcite and vaterite was formed. After the addition of an acidic polypeptide, poly-L-glutamic acid (pGlu) or poly-L-aspartic acid (pAsp), into (1) a significant inhibition of nucleation, expressed as an increase in induction time, and growth of vaterite, perceived as a dead zone, was observed. Extent of inhibition decreased in the order: Inh(pAps)>Inh(pGlu)>>Inh(pLys). The addition of a polypeptide into (2) caused the inhibition of precipitation and changed the morphology and polymorphic composition of the precipitate; only vaterite appeared at approximately c(pAsp)=3 ppm, c(pGlu)=6 ppm, or c(pLys)=7 ppm. This finding is explained as a consequence of kinetic constraints through the inhibition of calcite nucleation and stronger binding of acidic polypeptide by the calcite surfaces than by the vaterite surfaces. Laboratory precipitation studies using conditions that resemble those in living organism should be run at an initial supersaturation corresponding to the solubility of ACC as a limiting condition.
Authors:
Branka Njegi?-Dzakula; Giuseppe Falini; Ljerka Brecevi?; Zeljko Skoko; Damir Kralj
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-12-06
Journal Detail:
Title:  Journal of colloid and interface science     Volume:  343     ISSN:  1095-7103     ISO Abbreviation:  J Colloid Interface Sci     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-02-15     Completed Date:  2010-04-26     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0043125     Medline TA:  J Colloid Interface Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  553-63     Citation Subset:  IM    
Copyright Information:
2009 Elsevier Inc. All rights reserved.
Affiliation:
Laboratory for Precipitation Processes, Division of Materials Chemistry, Ruder Boskovi? Institute, P.O. Box 180, HR-10002 Zagreb, Croatia. bnjeg@irb.hr
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Amino Acids / chemistry*
Calcium Carbonate / chemistry*
Chemical Precipitation
Polymers / chemistry*
Spectroscopy, Fourier Transform Infrared
Static Electricity
Chemical
Reg. No./Substance:
0/Amino Acids; 0/Polymers; 471-34-1/Calcium Carbonate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Compact type-I coil planet centrifuge for counter-current chromatography.
Next Document:  Hysteresis during contact angles measurement.