Dilute gel networks vs. clumpy gels in colloid-polymer mixtures

Abstract: Using Brownian dynamics simulations we study gel-forming colloid-polymer mixtures. The focus of this article lies on the differences of dense and dilute gel networks in terms of structure formation both on a local and a global level. We apply reduction algorithms and observe that dilute networks and dense gels differ in the way structural properties like the thickness of strands emerge. We also analyze the percolation behavior and find that two different regimes of percolation exist which might be responsible for structural differences. In dilute networks we confirm that solidity is mainly a consequence of pentagonal bipyramids forming in the network. In dense gels also tetrahedral structures influence solidity.