Gelation as arrested phase separation in short-ranged attractive colloid-polymer mixtures

We present further evidence that gelation is an arrested phase separation in attractive colloid–polymer mixtures, based on a method combining confocal microscopy experiments with numerical simulations recently established in Lu et al (2008 Nature 453, 499). Our results are independent of the form of the interparticle attractive potential and therefore should apply broadly to any attractive particle system with short-ranged, isotropic attractions. We also give additional characterization of the gel states in terms of their structure, inhomogeneous character and local density.