Article abstract
Nature Materials 7, 556 - 561 (2008)
Published online: 22 June 2008 | doi:10.1038/nmat2219
Subject Categories: Glasses | Colloids
Direct observation of a local structural mechanism for dynamic arrest
C. Patrick Royall1,2, Stephen R. Williams3, Takehiro Ohtsuka2 & Hajime Tanaka2
Abstract
The mechanism by which a liquid may become arrested, forming a glass or gel, is a long-standing problem of materials science. In particular, long-lived (energetically) locally favoured structures (LFSs), the geometry of which may prevent the system relaxing to its equilibrium state, have long been thought to play a key role in dynamical arrest. Here, we propose a definition of LFSs which we identify with a novel topological method and directly measure with experiments on a colloidal liquid–gel transition. The population of LFSs is a strong function of (effective) temperature in the ergodic liquid phase, rising sharply approaching dynamical arrest, and indeed forms a percolating network that becomes the 'arms' of the gel. Owing to the LFSs, the gel is unable to reach equilibrium, crystal–gas coexistence. Our results provide direct experimental observation of a link between local structure and dynamical arrest, and open a new perspective on a wide range of metastable materials.
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
Correspondence to: C. Patrick Royall1,2 e-mail: paddy.royall@bristol.ac.uk
Correspondence to: Hajime Tanaka2 e-mail: tanaka@iis.u-tokyo.ac.jp
MORE ARTICLES LIKE THIS
These links to content published by NPG are automatically generated.
NEWS AND VIEWS
Penetrating insights into pore formationNature Structural Biology News and Views (01 Feb 1997)
Disordered materials One liquid, two glassesNature Materials News and Views (01 Nov 2002)
See all 4 matches for News And ViewsRESEARCH
Equilibrium cluster formation in concentrated protein solutions and colloidsNature Letters to Editor (25 Nov 2004)
See all 18 matches for Research
