Nanostructure and irreversible colloidal behavior of Ca(OH)2 : implications in cultural heritage conservation

Although Ca(OH)2 is one of the oldest art and building material used by mankind, little is known about its nanostructural and colloidal characteristics that play a crucial role in its ultimate performance as a binder in lime mortars and plasters. In particular, it is unknown why hydrated lime putty...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1992. - 21(2005), 24 vom: 22. Nov., Seite 10948-57
1. Verfasser: Rodriguez-Navarro, C (VerfasserIn)
Weitere Verfasser: Ruiz-Agudo, E, Ortega-Huertas, M, Hansen, E
Format: Aufsatz
Sprache:English
Veröffentlicht: 2005
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
LEADER 01000naa a22002652 4500
001 NLM158914708
003 DE-627
005 20231223083118.0
007 tu
008 231223s2005 xx ||||| 00| ||eng c
028 5 2 |a pubmed24n0530.xml 
035 |a (DE-627)NLM158914708 
035 |a (NLM)16285758 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Rodriguez-Navarro, C  |e verfasserin  |4 aut 
245 1 0 |a Nanostructure and irreversible colloidal behavior of Ca(OH)2  |b implications in cultural heritage conservation 
264 1 |c 2005 
336 |a Text  |b txt  |2 rdacontent 
337 |a ohne Hilfsmittel zu benutzen  |b n  |2 rdamedia 
338 |a Band  |b nc  |2 rdacarrier 
500 |a Date Completed 05.04.2007 
500 |a Date Revised 15.11.2005 
500 |a published: Print 
500 |a Citation Status PubMed-not-MEDLINE 
520 |a Although Ca(OH)2 is one of the oldest art and building material used by mankind, little is known about its nanostructural and colloidal characteristics that play a crucial role in its ultimate performance as a binder in lime mortars and plasters. In particular, it is unknown why hydrated lime putty behaves as an irreversible colloid once dried. Such effect dramatically affects the reactivity and rheology of hydrated lime dispersions. Here we show that the irreversible colloidal behavior of Ca(OH)2 dispersions is the result of an oriented aggregation mechanism triggered by drying. Kinetic stability and particle size distribution analysis of oven-dried slaked lime or commercial dry hydrate dispersions exhibit a significant increase in settling speed and particle (cluster) size in comparison to slaked lime putty that has never been dried. Drying-related particle aggregation also leads to a significant reduction in surface area. Electron microscopy analyses show porous, randomly oriented, micron-sized clusters that are dominant in the dispersions both before and after drying. However, oriented aggregation of the primary Ca(OH)2 nanocrystals (approximately 60 nm in size) is also observed. Oriented aggregation occurs both before and during drying, and although limited before drying, it is extensive during drying. Nanocrystals self-assemble in a crystallographically oriented manner either along the 100 or equivalent 110 directions, or along the Ca(OH)2 basal planes, i.e., along [001]. While random aggregation appears to be reversible, oriented aggregation is not. The strong coherent bonding among oriented nanoparticles prevents disaggregation upon redispersion in water. The observed irreversible colloidal behavior associated with drying of Ca(OH)2 dispersions has important implications in heritage conservation, particularly considering that nowadays hydrated lime is often the preferred alternative to portland cement in architectural heritage conservation. Finally, our study demonstrates that, fortuitously, hydrated lime could be one of the first nanomaterials used by mankind 
650 4 |a Journal Article 
700 1 |a Ruiz-Agudo, E  |e verfasserin  |4 aut 
700 1 |a Ortega-Huertas, M  |e verfasserin  |4 aut 
700 1 |a Hansen, E  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1992  |g 21(2005), 24 vom: 22. Nov., Seite 10948-57  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnns 
773 1 8 |g volume:21  |g year:2005  |g number:24  |g day:22  |g month:11  |g pages:10948-57 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 21  |j 2005  |e 24  |b 22  |c 11  |h 10948-57