Colloidal gels and glasses inside a computer

Condensed Matter lunchtime seminar

Colloidal gels and glasses inside a computer

  • Event time: 1:00pm
  • Event date: 10th September 2001
  • Speaker: Antonio Puertas (University of Edinburgh)
  • Location: Room 2511,

Event details

Gelation has been observed experimentally for colloidal systems with short range attraction [1], and a recent theoretical work [2] rationalizes it within Mode Coupling Theory (MCT), therefore, as a glass transition. In this talk, I will present results on gelation from molecular dynamics simulations. At moderate and high densities, the gel transition is observed at decreasing interaction strength for increasing colloidal packing fraction. The position of this line relative to the crystallization or liquid-gas de-mixing will be discussed. Gelation is studied according to the predictions from MCT, and compared with the glass transition occurring at high density and low interaction strength. Bond formation has been identified as the driving mechanism leading to the gel transition, while steric hindrance is responsible for the glass transition. At high density and interaction strength, where the gel and glass transition lines merge, singular points may appear. This possibility will be discussed according to the simulation findings.

[1] W.C.K. Poon et al., Faraday Discuss. vol. 112, 143 (1999).

[2] K. Dawson et al., Phys. Rev. E vol. 63 011401 (2001).

This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..

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