Pesticide matrix entrapment

Physical Methods. Physical methods are divided into two general approaches. The pesticide is entrapped within a physical structure either at a molecular or micro-domain level or the pesticide in the form of a reservoir is enclosed within a polymeric envelope (2). In the first approach, the pesticide is mixed with the polymer (or other material with high energy density) to form a monohthic structure or matrix. Release is normally through diffusion through the matrix or dissolution and erosion of the matrix. In the second approach, structures are based upon a reservoir of the pesticide enclosed by the polymer, from nano-scale up to centimeter-sized devices. The shapes of these devices are varied and include spherical, such as microcapsules, and laminar or layered structures with the reservoir bounded by permeable membranes. These membranes provide a permeable barrier which controls the release rate. Other mechanisms of release include capsule rupture and erosion of the membrane. 

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