More on the microstructural characterization of dense particle gels

A systematic study of the microstructure of densely packed coagulated colloidal particle gels is important for understanding their macroscopic, in particular, mechanical properties. It was previously shown that heterogeneous gels exhibit higher elastic properties and yield strengths than their homogeneous counterparts at the same solids loading. This was explained by the newly developed straight path method.¹ However, this macroscopic behaviour can be also explained by classical and conceptually simpler methods of spatial statistics, in particular, the pair-correlation function and the related K-function. Additionally, the structural differences of homogeneous and heterogeneous gels can be described by the contact distributions, which characterize the pore space and are of relevance for certain transport properties. The understanding of the structural differences is completed by presenting a benchmark model, which is in some sense ‘between’ the homogeneous and heterogeneous case.