A dispersion comprising (a) a continuous liquid phase and (b) a solid phase of epoxypolymer particles dispersed in the continuous liquid phase where the polymer is formed from monomers that are insoluble in the continuous phase a chemical agent is present within the polymer particles and the dispersion is not a Pickering dispersion and optionally the polymer molecules that form the polymer particles contain hydrophilic groups that hydrate on exposure to water in a manner that renders the particles permeable and that allows the chemical agent to diffuse out, and optionally at least one non-cross-linkable mobile chemical such that the extraction of this chemical from the dispersed phase renders it porous in a manner that allows the chemical agent to diffuse out.
