Gel and Glass Transitions in Short-Range Attractive Colloidal Systems - Food Colloids: Self-Assembly and Material Science - page 327

Chapter 22

Gel and Glass Transitions in Short-Range
Attractive Colloidal Systems

Giuseppe Fo, 1,2 Nicolas Dorsaz 1,2 and Cristiano De Michele 3,4

1 INSTITUT ROMAND DE RECHERCHE NUME ´ RIQUE EN
PHYSIQUE DES MATE ´ RIAUX IRRMA, PPH-ECUBLENS, CH-105
LAUSANNE, SWITZERLAND
2 PHYSICS DEPARTMENT, ECOLE POLYTECHNIQUE FE ´ DE ´ RALE
DE LAUSANNE (EPFL), CH-1015 LAUSANNE, SWITZERLAND
3 DIPARTIMENTO DI FISICA AND INSTITUTO NAZIONALE PER
LA FISICA DELLA MATERIA (INFM), UNIVERSITA ` DI ROMA LA
SAPIENZA, PIAZZALE ALDO MORO 2, 00185 ROME, ITALY
4 INSTITUTO NAZIONALE PER LA FISICA DELLA MATERIA
(INFM)—CRS SOFT, UNIVERSITA ` DI ROMA LA SAPIENZA,
PIAZZALE ALDO MORO 2, 00185 ROME, ITALY

22.1 Introduction
In the last few decades, the advances in colloidal science have made possible the
realization of systems that are characterized by interactions tuneable in range
and strength. The size and the shape of the particle can also be finely controlled.
One possibility to deal theoretically with the physical properties of these
systems is to devise a proper effective interparticle potential by integrating
out the solvent (and cosolute) degrees of freedom. 1 Once this step has been
carried out, each colloidal particle can be treated as a 'big' atom and the tools
of statistical mechanics can be applied.
Interactions in atomic systems are characterized by a range that is long
compared to the atomic size and they cannot be adjusted externally. The
possibility of controlling the range of the interaction and the particle size opens
up a whole range of phenomena that are not observed in atomic systems.
Moreover, the larger size of colloidal particles allows scientists to use optical
experimental technique such as light scattering and confocal microscopy to
investigate the structural and dynamic properties.
Hard spheres are a striking example of the possibilities offered by colloidal
systems. A freezing transition was predicted for hard spheres in pioneering
work more than 30 years ago. 2

Some 20 years later, a first-order phase

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