Capillary suspensions are unique materials, in which the rheological properties can be tuned by controlling the particle network through capillary interactions. To gain insights into the influence of particle properties on the network formation and accompanying gel strength for water-absorbing, biopolymeric particles, protein particles of two different sizes and water absorption capacities (WACs) were prepared. Utilizing SESANS, we describe a novel approach towards detecting changes in water distribution between and within particles. While effects of WAC seemed to be overpowered by concurrent variations in surface roughness, a larger particle size or lower roughness led to a lower initial gel strength and a subsequent much larger relative increase in gel strength upon water addition. Even though similar maximum gel strengths were obtained, indicating that particle properties had a comparably small influence once capillary forces dominated the systems, particle size played a critical role for network collapse with increasing particle clustering at larger water volumes. The results pinpoint subsequent knowledge gaps in the existing literature and demonstrate the tunability of biopolymer-based capillary suspensions over a wide gel strength range by adjustment of particle properties. These insights offer exciting opportunities for application of capillary-force controlled systems in the food, pharmaceutical and cosmetic industries.

Granular segregation is a common, yet still puzzling, phenomenon encountered in many natural and engineering processes. Here, we experimentally investigate the effect of particles cohesion on segregation in dry monodisperse and bidisperse systems using a rotating drum mixer. Chemical silanization, glass surface functionalization via a Silane coupling agent, is used to produce cohesive dry glass particles. The cohesive force between the particles is controlled by varying the reaction duration of the silanization process, and is measured using an in-house device specifically designed for this study. The effects of the cohesive force on flow and segregation are then explored and discussed. For monosized particulate systems, while cohesionless particles perfectly mix when tumbled, highly cohesive particles segregate. For bidisperse mixtures of particles, an adequate cohesion-tuning reduces segregation and enhances mixing. Based on these results, a simple scheme is proposed to describe the system’s mixing behaviour with important implications for the control of segregation or mixing in particulate industrial processes.

MercuryDPM is a particle-simulation software developed open-source by a global network of researchers. It was designed ab initio to simulate realistic geometries and materials, thus it contains several unique features not found in any other particle simulation software. These features have been discussed in a companion paper published in the DEM7 conference proceedings; here we present several challenging setups implemented in MercuryDPM . Via these setups, we demonstrate the unique capability of the code to simulate and analyse highly complex geotechnical and industrial applications. The setups implemented include complex geometries such as (i) a screw conveyor, (ii) steady-state inflow conditions for chute flows, (iii) a confined conveyor belt to simulate a steady-state breaking wave, and (iii) a quasi-2D cylindrical slice to efficiently study shear flows. MercuryDPM is also parallel, which we showcase via a multi-million particle simulations of a rotating drum. We further demonstrate how to simulate complex particle interactions, including: (i) deformable, charged clay particles; and (ii) liquid bridges and liquid migration in wet particulates, (iii) non-spherical particles implemented via superquadrics. Finally, we show how to analyse and complex systems using the unique micro-macro mapping (coarse-graining) tool MercuryCG.