Dynamics of particle entrainment for glass particles suspended in various fluids

The frictional properties of two sliding surfaces are often influenced by a fluid lubricant's ability to separate and facilitate movement. When particles are present, their entrainment between surfaces can alter friction, either increasing or decreasing it compared to fluid lubrication alone. Understanding the frictional regimes and the dynamics driving particle entrainment in suspensions is thus critical. This study investigates the tribological properties of glass particles suspended in various fluid matrices. We examined suspensions with varying particle concentrations, fluid viscosities, fluid hydrophobicity, and particle hydrophobicity. Our findings reveal that particle lubrication dominates under the following conditions: (I) high particle concentrations, (II) high fluid viscosities, (III) strong particle – surface interactions, and (IV) weak fluid – particle interactions. These insights are crucial for applications in food science, biomedical industries, and pharmaceuticals, where controlling particle friction is essential for optimizing consumer satisfaction and ensuring the performance and safety of lubricants in medical devices.