| Autor: |
Rouwhorst J; Institute of Physics, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands., Ness C; Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK.; School of Engineering, University of Edinburgh, Edinburgh, EH9 3FB, UK., Stoyanov S; Unilever R&D Vlaardingen, Olivier van Noortlaan 120, Vlaardingen, 3133 AT, The Netherlands., Zaccone A; Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK. az302@cam.ac.uk.; Department of Physics 'A. Pontremoli'', University of Milan, via Celoria 16, Milan, 20133, Italy. az302@cam.ac.uk.; Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK. az302@cam.ac.uk., Schall P; Institute of Physics, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands. P.Schall@uva.nl. |
| Abstrakt: |
The dynamical arrest of attractive colloidal particles into out-of-equilibrium structures, known as gelation, is central to biophysics, materials science, nanotechnology, and food and cosmetic applications, but a complete understanding is lacking. In particular, for intermediate particle density and attraction, the structure formation process remains unclear. Here, we show that the gelation of short-range attractive particles is governed by a nonequilibrium percolation process. We combine experiments on critical Casimir colloidal suspensions, numerical simulations, and analytical modeling with a master kinetic equation to show that cluster sizes and correlation lengths diverge with exponents ~1.6 and 0.8, respectively, consistent with percolation theory, while detailed balance in the particle attachment and detachment processes is broken. Cluster masses exhibit power-law distributions with exponents -3/2 and -5/2 before and after percolation, as predicted by solutions to the master kinetic equation. These results revealing a nonequilibrium continuous phase transition unify the structural arrest and yielding into related frameworks. |
