Incollection,
Gel-forming patchy colloids and network glass formers: Thermodynamic and Dynamic analogies
Abstract Book of the XXIII IUPAP International Conference on Statistical Physics, Genova, Italy, (9-13 July 2007)
Abstract
I will discuss thermodynamic and dynamic properties of simple
models of particles with
patchy interactions. Results provide, simultaneously, a description
of network-forming liquids like water and silica
as well as of Pine-colloids, the new generation of molecular
colloids.
We show that the possibility of controlling the number of bonded
nearest neighbors interactions has interesting consequences on the
thermodynamic of the system:
(i) It reduces the region of the phase diagram where liquid-gas
coexistence is observed\\
(ii) it offers the possibility of generating liquid states (i.e.
states with temperature lower than the liquid-gas critical
temperature) with a vanishing occupied packing fraction, a case can
not be realized with spherically interacting particles;\\
(iii) it opens up the region of stability of the liquid phase,
favoring the establishment of homogeneous disordered materials at
small packing fraction, which can be named accordingly stable
equilibrium gels or network glasses.
Finally, I will show how combining the Wertheim theory for
associated liquids and the Flory-Stockmayer
theory for chemical gels it is possible to provide a parameter-free
description of the self-assembly process
in patchy particles, when the average functionality (average
number of patches per particle) is small.
