http://www.cnr.it/ontology/cnr/individuo/prodotto/ID194391

On the relation between hierarchical morphology and mechanical properties of a colloidal 2D gel system (Articolo in rivista)

Type

Prodotto della ricerca (Classe)
Articolo in rivista (Classe)

Label

On the relation between hierarchical morphology and mechanical properties of a colloidal 2D gel system (Articolo in rivista) (literal)

Anno

2012-01-01T00:00:00+01:00 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#doi

10.1016/j.colsurfa.2012.01.001 (literal)

Alternative label

Davide Orsi, Giacomo Baldi, Pietro Cicuta, Luigi Cristofolini (2012)
On the relation between hierarchical morphology and mechanical properties of a colloidal 2D gel system
in Colloids and surfaces. A, Physicochemical and engineering aspects (Print); Elsevier BV, Amsterdam (Paesi Bassi)
(literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori

Davide Orsi, Giacomo Baldi, Pietro Cicuta, Luigi Cristofolini (literal)

Pagina inizio

71 (literal)

Pagina fine

77 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#url

http://www.sciencedirect.com/science/article/pii/S0927775712000064 (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume

413 (literal)

Rivista

Colloids and surfaces. A, Physicochemical and engineering aspects (Rivista)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#pagineTotali

7 (literal)

Note

ISI Web of Science (WOS) (literal)

Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni

Physics Department, University of Parma, Italy IMEM-CNR, Parma, Italy Cavendish Laboratory, University of Cambridge, UK (literal)

Titolo

On the relation between hierarchical morphology and mechanical properties of a colloidal 2D gel system (literal)

Abstract

We study a bidimensional gel system formed by a Langmuir film of gold nanoparticles. Its morphology is thoroughly characterized by AFM, SEM, and ellipsometric imaging techniques and shows a complex structure with features on a hierarchy of different sizes following a Levy distribution. The mechanical response arising after the gel point is investigated by Interfacial Shear Rheometry. The film is found to be mainly elastic, with the mechanical moduli scaling as a power law of the reduced concentration, in the same way as the fluctuation time which was measured in a recent X-ray Photon Correlation Spectroscopy experiment. The frequency dependence of the moduli is well described in the framework of the Soft Glass Rheology model (SGR) [Sollich et al. Phys Rev Lett 78, 2020 (1997)]. In this theory a power law distribution of relaxation times is postulated, whose exponent is experimentally determined for the present case. Such a distribution may reflect - in the dynamics - the hierarchical nature of the morphology of the film evidenced by microscopy. A mastercurve can be built, extending time-temperature to a time-concentration superposition principle as in [Cicuta et al. Phys Rev Lett 90, 116103(2003)]. This allows to describe the mechanical response over a frequency range slightly larger than that experimentally accessible. Besides the SGR component, a viscous term is always present, whose origin is investigated also taking into account samples with different preparation histories. (literal)

Editore