▎ 摘　　要

NOVELTY - The method involves providing a polyol blend comprising a polyol resin, and an electromagnetic absorber (EMA) additive; and providing an isocyanate resin selected such that blending the isocyanate resin with the polyol blend results in an EMA spray foam. USE - Method for preparing and depositing electromagnetic absorber spray foam on electronic equipment. ADVANTAGE - The EMA particle additives can be surface-modified with components for preventing agglomeration, binding to polyurethane, imparting flame-retardancy. The carbon coating is used to reduce surface tension between particles and the polyol resin. The hydrophobic polymer shell or small molecule shell also prevents agglomeration. The particles include magnetic iron oxide nanoparticle cores surrounded by a shell, which can prevent oxidation and agglomeration of the iron oxide particles while preserving their electromagnetic properties. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: i. a device, which comprises a first compartment containing an isocyanate resin, and a second compartment containing a polyol blend comprising a polyol resin; and an electromagnetic absorber (EMA) additive; and ii. a composition, which comprises a polyurethane spray foam, and an electromagnetic (EMA) additive blended into the polyurethane spray foam.