Coagulating

Coagulating refers to the process of coagulation, in which a dispersed phase, such as a suspension of particles or a liquid colloid, transitions into a more solid or gel-like state through aggregation or network formation. This transformation often involves the destabilization of particles that would otherwise repel each other, allowing attractive forces to promote clumping into larger masses.

In colloid science and civil engineering, coagulation is typically induced by adding coagulants that neutralize surface charges on suspended particles, reducing electrostatic repulsion. This destabilization enables particles to collide and stick together, forming microflocs that can be removed by sedimentation or filtration. The subsequent step, flocculation, gently aggregates these microflocs into larger flocs. Common coagulants include metal salts such as aluminum and iron salts, as well as polymeric coagulants. Factors that influence coagulation include pH, ionic strength, temperature, particle size, and mixing intensity.

In biological systems, coagulation most frequently refers to blood coagulation (hemostasis). This is a cascade of proteolytic reactions that converts soluble fibrinogen into insoluble fibrin, forming a fibrous mesh that, together with platelets, produces a stable clot to stem bleeding. Regulation is tight, with anticoagulant pathways ensuring clot formation is localized and temporary; dysregulation can lead to excessive clotting (thrombosis) or bleeding disorders.

In food science, coagulation describes protein gelation that occurs upon heating, acidification, or enzymatic action. Milk coagulates to form curds in cheese production, while eggs and other proteins coagulate under heat to change texture and structure. Coagulation thus spans disciplines from environmental engineering to medicine and culinary arts, denoting a fundamental change from dispersed to solidified states.