semicohesive

Semicohesive is an adjective used to describe materials, interfaces, or systems that exhibit partial internal bonding or cohesive forces, positioning them between fully cohesive and non-cohesive states. In materials science and granular physics, semicohesive behavior arises when bonding is present but limited, such as moisture-induced capillary bridges between particles, partial crosslinking in polymers, or weak van der Waals interactions. This leads to intermediate mechanical properties, including finite yield strength and partial resistance to fracture, with failure modes that may combine cohesive failure within a material and adhesive failure at interfaces.

Because there is no universal standard definition, the term is often used informally or as a conceptual descriptor. Researchers might model semicohesive systems with a cohesion parameter ranging from zero (non-cohesive) to one (fully cohesive), or employ mixed-friction and capillary models to capture both particle-particle and particle-substrate interactions.

Applications and contexts include wet granular media, pharmaceutical powders, soils with partial moisture, and composites with soft, partially bonded networks. Understanding semicohesive behavior helps in predicting flow, compaction, and failure, particularly where environmental conditions alter bonding, such as humidity or temperature.

Related concepts include cohesion, adhesion, capillarity, and cohesive fracture. The term remains informal in some disciplines, and precise use can vary by field.