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Titolo:
Influencing crystallization damage in porous materials through the use of surfactants: Experimental results using sodium dodecyl sulfate and cetyldimethylbenzylammonium chloride
Autore:
Rodriguez-Navarro, C; Doehne, E; Sebastian, E;
Indirizzi:
Univ Granada, Dept Mineral & Petrol, Granada 18002, Spain Univ Granada Granada Spain 18002 Mineral & Petrol, Granada 18002, Spain Getty Conservat Inst, Los Angeles, CA 90049 USA Getty Conservat Inst Los Angeles CA USA 90049 , Los Angeles, CA 90049 USA
Titolo Testata:
LANGMUIR
fascicolo: 3, volume: 16, anno: 2000,
pagine: 947 - 954
SICI:
0743-7463(20000208)16:3<947:ICDIPM>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
CRITICAL MICELLE CONCENTRATION; CARBONATE MINERALS; CALCIUM; ADSORPTION; GROWTH; STONE; SUPERSATURATION; INTERFACE; DIHYDRATE; DROPLETS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
67
Recensione:
Indirizzi per estratti:
Indirizzo: Rodriguez-Navarro, C Univ Granada, Dept Mineral & Petrol, Fuente Nueva S-N, Granada 18002, Spain Univ Granada Fuente Nueva S-N Granada Spain 18002 in
Citazione:
C. Rodriguez-Navarro et al., "Influencing crystallization damage in porous materials through the use of surfactants: Experimental results using sodium dodecyl sulfate and cetyldimethylbenzylammonium chloride", LANGMUIR, 16(3), 2000, pp. 947-954

Abstract

The interactions of two ionic surfactants on the decay of ornamental stone(porous limestone) by salt crystallization, a common and damaging weathering process, were studied. Conductivity and/or surface tension measurements allowed calculations of the critical micellar concentration (cmc) of sodiumdodecyl sulfate (SDS) and cetyldimethylbenzylammonium chloride (CDBAC) in distilled water and saturated sodium sulfate solution (both with and without the addition of calcite), total surfactant adsorption onto calcite (Gamma(tot)), and the area (A(s)) which a surfactant molecule occupies at the liquid-air interface. In aqueous calcite suspensions SDS shows a strong cme reduction due to Ca2+ binding to the micelles that undergo sphere-to-rod transition at SDS concentrations > cmc, while calcium dodecyl sulfate (Ca(DS)(2)) precipitation contributes to a reduction of DS- concentration in the bulk solution. Adsorption of DS- on calcite is promoted in the saturated saline solution where Gamma(tot) reaches values of 1 x 10(-2) mmol m(-2). CDBA(+) is preferentially adsorbed onto calcite in water (Gamma(tot) = 1.89 x 10(-3) mmol m(-2)) while adsorption on calcite in saturated sodium sulfate solution is limited (Gamma(tot) = 2.18 x 10(-4) mmol m(-2)) due to competitionwith Na+ for calcite adsorption sites. Limited CDBA(+) adsorption onto calcite, and significantA(s) reduction in the saline solution, results in sphere-to-rod (or disk) micelle shape transition. The previous results togetherwith in situ, high magnification environmental scanning electron microscopy (ESEM) studies and macroscale salt crystallization tests revealed that: (a) the adsorption behavior of DS- induces crystallization of mirabilite at high supersaturation, resulting in nonequilibrium crystal shapes that promote significant damage to the stone; (b) rodlike and/or disc-shaped CDBA(+) micelles enhance solute solubilization and transport to mirabilite nuclei growth sites, inducing crystallization of euhedral crystals formed at low supersaturation and distributed homogeneously throughout the stone pore system. While CDBAC initially reduces stone damage by salt crystallization, it can ultimately result in enhanced damage when in contact with water due to mechanical weakening of the stone and rehydration of previously dehydrated mirabilite crystals within the stone pores. The implications of these results in the conservation of ornamental stone are discussed.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/04/20 alle ore 21:42:32