The present invention relates to a coating and coating application comprising a natural carrier for controlled release of a compound, such as for metal protection, a product comprising said coating or coating application, a method of modifying a natural carrier for controlled release, and methods of forming said coating or coating application, wherein the natural carrier is selected from exoskeletons of a Heterokontophyta species.
It is an object of the invention to overcome one or more limitations of the devices of the prior art and at the very least to provide an alternative thereto. The present invention relates to a coating, and likewise a coating application, comprising a natural carrier for controlled release of a compound, such as for metal protection, comprising 1-20 wt.%, preferably 2-19 wt.%, more preferably 3-18 wt.%, even more preferably 4-15 wt.%, such as 5-10 wt.%, of hollow structures, which may also be a halve structure, each structure enclosing an internal space thereof, wherein the hollow structures are selected from exoskeletons of a Heterokontophyta species, wherein the walls of the structure are mainly (e.g. 50-99.5 wt.%, such as 75-99 wt.%) of natural porous silica, wherein both the internal space and the surface of the hollow structure is provided with 0.1-100 vol.%, preferably 0.2-80 vol.%, more preferably 0.5-50 vol.%, even more preferably 1-40 vol.%, such as 5-30 vol.%, of at least one of an organic and inorganic active compound, wherein wt . % and vol.% are based on a total weight of the coating and volume of the hollow