CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The instant application claims priority to Brunei patent application BN/N/2016/0016 filed on February 9, 2016. The pending Brunei patent application BN/N/2016/0016 is hereby incorporated by reference in its entireties for all of its teachings.

FIELD OF THE INVENTION

[0002] The present technology is generally related to a corrosion control system and method of metallic surface, above all metal structures in the atmospheric environment. More particularly, it relates to an anti-corrosion electrolyte coating system and methods to protect steel surface of ground and off-shore facilities from rusting, wherein the steel surface is exposed to the atmospheric environment and coated by a transparent, ionically conductive, and dried layer or film.

BACKGROUND

[0003] Most metals are prone to corrosion in an oxidizing atmosphere forming compounds such as oxides, hydroxides and sulphides. Rusting of iron or steel takes place, when iron or steel is exposed to oxygen in presence of water in the atmospheric environment. Due to rusting, the metal is degraded forming ferric rust, a red-brown compound, which is a sign of electrochemical oxidation of the underlying metal.

[0004] The corrosive attack on a metal occurs at the surface of the metal. Therefore, modification of the metal surface or its environment can change the rate of reaction leading to the corrosion protection of the metals. Thus based on metal surface modification or some change in metal surface, a number of methods have been developed for reducing the surface reaction. A few known methods includes removing oxidizing agent by boiler water treatment; prevention of surface reaction by cathodic or anodic protection; inhibition of surface reaction by use of chemical inhibitor or pH Control; protective coating or organic, metallic or non-metallic layer by paint, claddings, electroplating, galvanizing, metal spraying, anodizing, or conversion coating. Modification of the metal or surface conditions are also frequently being used to prevent the metals from corrosions.

[0005] The above methods help in slowing down rate of oxidation reaction of metal on the metal surface. Such methods are frequently used in industries at large scale such as paint, chemical, electroplating, anodizing, galvanising, and corrosion resistant alloy production industry.

[0006] Cathodic protection as mentioned above is one of the most popular methods for protecting metal structures below the surface and above the ground in the atmospheric environment as well. This technology is very familiar and many in the oil and gas industries have also adopted this method to protect their tanks, vessels and even offshore platforms. Not only that, those in the shipping business, pipelined manufacturers or even construction companies dealing with reinforced concretes and pilings or any metallic/ steel structures that are directly in contact with electrolytes would also be benefited from this old and refined technology.

[0007] C. L. I. Systems, Inc. (U.S.A.) developed an apparatus as a protective anode and cathodic corrosion protection system for corrosion that protects surface of a metal structure exposed to the atmosphere. This corrosion protection apparatus provided effective corrosion protection of a metal structure exposed to the atmosphere and protected by coating.

[0008] US Patent 5954938A (Masahiro Takahashi etc.) also discloses a cathodic corrosion protection method and apparatus for metal structure. It describes an anode mounted on a coated surface of a metal structure exposed to the atmosphere. The anode is further connected to a solar power battery and metal structure being cathode. The current flowing between the anode and the cathode becomes an uninterrupted source of electron for the oxidized metal of the metal structure due to oxygen thereby preventing the metal structure from atmospheric corrosion. However, its uses water film as an electrolyte on the painted metal surface.

[0009] The above cited art disclose use of water film on the painted surface while the present invention discloses using electrolyte on the surface so that cathodic protection works even in dry environment.

[0010] The present invention discloses a novel electrolyte used as coating composition comprising sulfonated group graft fluoropolymer resin. The electrolyte is used to coat a thin layer on the painted metal surface e.g. steel surface, above the ground and offshore facilities, wherein the thin layer which is dried, transparent, and ionically conductive becomes a good source of constant supply of electrolyte above the ground and at atmospheric conditions.

OBJECTS OF THE INVENTION

[0011] Accordingly, one object of the present invention is to provide a cathodic protection system and method to prevent metal surface of metal structures installed above the ground from rusting in the atmospheric corrosion.

[0012] A related object of the present invention is to provide a composition used for forming a dried thin film on the metal surface of a metal structure exposed to the atmospheric environment.

[0013] A further object of the present invention is applying a protective layer on the painted metal surface providing constant supply of ionically conductive electrolyte.

[0014] A further object of the present invention is to provide an electrolyte in the form of a coating liquid having good ionic conductivity, resistivity, and anti-cracking properties. [0015] A further object of the present invention is to provide a method of applying an electrolyte composition to increase anti-corrosion protection with self-cleaning property to help prolonging aesthetic desired coloring of conventional painted layer.

[0016] Further object of the present invention is to provide an electrolyte coating having resistivity much less than the resistivity of the conventional paint.

[0017] Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present disclosure.

SUMMARY OF THE INVENTION

[0018] The present invention discloses a corrosion control system comprising an anode, an electrolyte connected to the anode by an conductive adhesive, a power source e.g. DC power source, and a metal structure to be protected from corrosion, or rusting due to environment or atmospheric factors. The electrolyte used in the present system further comprises a highly ionically conductive & hydrophilic fluoropolymer resin having anti-cracking properties. In one aspect the fluoropolymer resin is used in the form of coating liquid.

[0019] The coating liquid can be applied easily onto the metal structure above the ground just like ordinary paints and functions well as an electrolyte of the cathodic protection. The coating liquid applied on the metal surface leads to the realization of the cathodic protection of the ground metal structures. In one aspect the metal structure can be a steel structure.

[0020] In accordance to one aspect of the present invention, there is provided a system to protect the metal surface of metal structures from atmospheric corrosion. The system of the present invention comprises a material used to paint the metal surface of the metal structure above the ground in the atmosphere, an electrolyte coating composition used to form a dried film having thickness from about 0.5 microns to about 20 microns on the painted metal surface, an anode material mounted on the dried film, and a power supply system coupled to the anode and the metal surface acting as cathode to supply constant voltage to the anode and cathode. In one embodiment the metal structure can be a steel surface which is protected by a paint layer further covered by the electrolyte coating.

[0021 ] In another aspect, an anti-corrosion electrolyte coating system for metal structures, preferably steel structures exposed to the atmospheric environment is provided. One of the embodiments of the present system comprises a dried thin layer of an electrolyte composition on a painted metal surface comprising a homogenous mixture of a graft polymer A| _ds having low density of sulfonate (S03-) group, and polymer A _Ms having high density of sulfonate (S03-) group, wherein the sulfonate group (S03-) weight % of the dried layer is > about 900 units equivalent, and the dried layer constantly supplies ionically conductive electrolyte to the metal structure above ground and at atmospheric conditions, an anode material mounted on the dried layer using a conductive glue or adhesive, and a power supply system coupled to the anode and the metal surface acting as a cathode to supply constant voltage to the anode and cathode i.e. metal structure.

[0022] In yet another aspect of the present invention, a method is disclosed for the protection of metal structures above the ground from atmospheric corrosion comprising of removing impurities from exterior surface of the metal structure; coating the exterior surface with a conventional paint to form a conventional coating; applying a layer of sulfonated graft polytetrafluoroethylene, or sulfonated graft polyvinylidene difluoride on the conventional coating, and drying the layer to form a dried film having thickness from about 0.5 microns to about 20 microns; coupling a power supply system to an anode mounted on the dried film, and to the metal structure; wherein the dried film continuously supplies ionically conductive electrolyte above the ground and at atmospheric conditions, and the metal acts as cathode, wherein the metal structures acts as cathode. In one embodiment, the conventional coating comprises an organic paint easily available in the industry [0023] The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION

[0024] FIG. 1 is a perspective view of the anti-corrosion electrolyte coating system with a defective part of metal structure.

[0025] FIG. 2 is a flow diagram of a process of applying an electrolyte coating composition on metal surface in accordance to present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Various embodiments are described hereinafter. It should be noted that the specific embodiments are not intended as an exhaustive description or as a limitation to the broader aspects discussed herein. One aspect described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced with any other embodiment(s).

[0027] As used herein, "about" will be understood by persons of ordinary skill in the art and will vary to some extent depending upon the context in which it is used. If there are uses of the term which are not clear to persons of ordinary skill in the art, given the context in which it is used, "about" will mean up to plus or minus 10% of the particular term.

[0028] The use of the terms "a" and "an" and "the" and similar referents in the context of describing the elements (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the embodiments and does not pose a limitation on the scope of the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0029] The term "including" is used to mean "including but not limited to." "Including" and "including but not limited to" are used interchangeably.

[0030] The term "Polymer A" refers to an aliphatic or aromatic sulfonic group grafted fluoropolymer having electrolyte properties.

[0031] The term "Polymer A| _ds " refers to "Polymer A" having low density sulfonate group graft polymer.

[0032] The term "Polymer A _Ms " refers to "Polymer A" having high density sulfonate group graft polymer.

[0033] The phrase "Electrolyte Composition" refers to a homogenous mixture of Polymer Aids and Polymer A _Ms which is used for electrolyte coating of a metal structure exposed to the atmospheric environment, wherein the metal structure can be painted or non- painted surface.

[0034] The phrase "Dried Film" refers to a thin, transparent, ionically conductive, and dry layer made of the electrolyte coating compositing. The phrase "Dried Film" and "Dried Layer" can interchangeably be used in the present disclosure while describing the claimed invention. [0035] Ratios, concentrations, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited.

[0036] In one aspect, the present invention comprises at least four indispensable elements that include but not limited to an anode, an electrolyte, a DC power source, and the metal structure itself is a protected material like cathodic protection system. In one embodiment, the electrolyte which is a highly ionic conductive and hydrophilic fluoro-resin provided in the form of coating liquid. The electrolyte used herein also exhibits excellent anti-cracking properties in the atmosphere.

[0037] In one aspect of the present invention, the coating liquid can be applied easily onto the metal surface above the ground just like ordinary paints and functions well as an electrolyte of the cathodic protection. Such coating liquid applied on the metal surface can lead to the realization of the cathodic protection of the ground metal.

[0038] In accordance to one aspect of the present invention, the system disclosed herein is made of some essential components that include, but not limited to a conventional coating or paint material, a sulfonate group graft fluoropolymer resin, a metal structure to be prevented from atmospheric corrosion, anodic materials, battery or power source, and wires. The conventional paint or coating material is used to coat the metal surface of the metal structure to prevent the metal structure from rusting caused due to atmospheric factors. The exterior surface of the metal structure is coated by an organic paint well known in the market. The painted surface of the metal is further covered by an electrolyte coating wherein the metal structure is above the ground in the atmosphere. The corrosion control system of metal surface above the ground in atmospheric environment is further described with the help of FIG. 1. [0039] In accordance to the present invention, FIG. 1 is a perspective view of the anti- corrosion electrolyte coating system 100 having a defective part 1 18 of metal structure 102 to be protected from corrosion or rusting caused by the atmospheric factors. The metal structure 102, preferably a steel structure, which exterior surface 1 16 is first coated with an organic paint 104 or similar conventional coating layer 104. The painted metal surface 104 is further coated by an electrolyte liquid e.g. fluoro-polymer resin, to form a dried thin film 106 having thickness from about 0.5 microns to about 20 microns. An anode108 mounted on to the dried film 106 is connected, by wire 1 12, to a DC power source 1 10 having an operation voltage from about 5V to about 20V, preferably from about 6V to 12V.

[0040] In some embodiments, the metal surface 1 16 is covered by at least two layers more precisely, a primer to get firm adhesion and the top coat to get weathering durability.

[0041] In a preferred embodiment the topcoat of the metal surface 1 16 is a topcoat comprises an organic paint. The paint is applied to accelerate the corrosion and experimentally compare the results. The electrolyte coating 106 plays a crucial role in the present corrosion control system and method. The electrolyte coating 106 helps obtain sufficient ionic or electronic conductivity and hydrophilicity with this thin quasi- transparent coating layer 106.

[0042] The anode materials composed of ionically conductive yet chemically stable substance is mounted 108 onto some part of the electrolyte coating layer 106 to provide proton to this layer constantly. The DC power supply 1 10 should be connected to the anode materials and the metal substrate itself as cathode to provide DC current for this corrosion control system. In one embodiment a glue or adhesive is used to connect the anode 108 and the electrolyte film 106. The glue or adhesive used herein is a conductive substance so that current can flow between the anode 108 and the electrolyte film 106. [0043] The anode material mounted 108 on the dried film 106 is selected from the group consisting of but not limited to carbon, stainless steel, or noble metal. The anode material 106 is fixed on the dried film 106 either directly or indirectly by adhesive or other suitable methods known in the art. The power supply system 1 10 is coupled to the anode 108 and the metal surface 102 for supplying the constant voltage to the anode 108 and cathode 102.

[0044] In accordance to one aspect of the present invention, resistivity of the electrolyte coating 106 plays a vital role to obtain improved cathodic protection system. The resistivity of the electrolyte coating 106 should be less than the resistivity of the conventional paint 104 so that the improved cathodic protection system 100 can work to achieve the key objects of the present invention. In some embodiments the resistivity of the electrolyte coating film 106 ranges from about 1 E5 to about 1 E6 ohm cm, whereas the anti-corrosion paint has resistivity of about 1 E10 to about 1 E13 ohm cm. In one embodiment, the electrolyte coating composition is made by mixing or blending two kinds of sulfonic group graft fluoropolymers i.e. Polymer A| _ds and Polymer A _Ms , until a homogenous solution of the polymer A is formed.

[0045] The metal structure 102 itself acts as a cathode 102 and is connected to the power source 1 10. In some embodiments, when the electrolyte coated surface 106 becomes wet due to rainfall or splashing of sea water, the water on the surface will spread on the surface widely and will contribute the increase of ionic conductivity even in the wet conditioning.

[0046] In case, some part of paint 104 is scratched, corrosion progresses in the water spot 1 14 without cathodic protection. However, in a cathodic protection system 100, dried filml 06 supplies positive voltage to the water and it functions as an anode for the water spot 1 14. The scratched surface or defective part 1 18 of metal is supplied negative voltage, consequently the surface of metal is protected by the cathodic protection mechanism. [0047] The water 1 14 remaining in defective part 1 18 triggers corrosion of metal surface 1 16 in an ordinary case but in the present system 100 the ionically conductive electrolyte coating film 106 surrounding the water provides enough proton as an excellent cation exchange resin to prevent the corrosion of the metal surface 1 16.

[0048] In one embodiment, the electrolyte coating comprises a fluoro-polymer resin that can be made by mixing of two types of sulfonic group graft fluoropolymers i.e. polymer Ai _d s and polymer A _Ms , until a homogenous solution of the polymer A is formed. The first type of the fluoropolymer comprises low density sulfonic group graft fluoropolymer i.e. polymer A| _ds and the second type is a high density sulfonic group graft polymer i.e. Polymer A _Ms . In some embodiments the polymer A| _ds and A _Ms are mixed in 4:1 ratio to achieve the desired level of sulfonic group units in the homogenous solution.

[0049] In some embodiments the Polymer A can be selected from, but not limited to sulfonic group graft polytetrafluoroethylene (PTFE), or sulfonic group graft polyvinyldiene fluoride (PVdF). In a preferred embodiment the homogenous solution can be made of sulfonate group graft polytetrafluoroethylene (PTFE). The homogenous solution of the electrolyte coating composition is used to coat the painted surface 104 of the metal structure 102 to create a thin layer having thickness from about 0.5 microns to about 20 microns. The thin film or layer 106 may be made by uniform distribution of the electrolyte composition on the painted metal surface 104 in a manner so as to sulfonic group weight% of the dried film or layer is greater than or equal to 900 units equivalent preferably greater than or equal to 1024 units equivalent.

[0050] In one embodiment, the anode material 108 is mounted on the dried film 106 is selected from the group consisting of but not limited to carbon, stainless steel, or noble metal. The anode material 108 is fixed on the dried film 106 by a conductive adhesive or other methods known in the art. The power supply system coupled to the anode and the metal surface acting as cathode for supply of uninterrupted voltage to the anode and cathode. [0051] In another aspect, a system is provided to prevent metal structures from atmospheric corrosion, wherein the electrolyte coating composition having sulfonate moiety used to form an electrolyte coating layer on the painted metal surface. In some embodiments, the electrolyte coating is a polymeric transparent film that can retain colors of the painted metal surface of the metal structure above the ground structures.

[0052] In some embodiments, the electrolyte coating is a dried film having thickness from about 0.1 microns to about 50 microns, preferably from about 0.3 microns to about 30 microns, more preferably from about 0.5 microns to about 20 microns.

[0053] In some embodiments, the electrolyte coating is an electronically conductive film having thickness from about 0.1 microns to about 50 microns, preferably from about 0.3 microns to about 30 microns, more preferably from about 0.5 microns to about 20 microns.

[0054] In a preferred embodiment the electrolyte coating is an ionically conductive film having thickness from about 0.1 microns to about 50 microns, preferably from about 0.3 microns to about 30 microns, more preferably from about 0.5 microns to about 20 microns.

[0055] In accordance to one aspect of the present invention, the electrolyte coating is applied on the coated metal surface using an aqueous fluoropolymer resin having good ionically conductivity and anti-cracking properties. The aqueous fluoropolymer resin is prepared by mixing low density sulfonate group grafted PTFE (A| _ds ) with high density sulfonate group grafted PTFE (A _hc is) based on a pre-calculated amount until homogenous solution is obtained. In some embodiments, the polymer A| _ds is added in an amount of from about 0.01 % to about 99 % by weight of the total weight of the homogenous solution. This includes embodiments in which the amount is from about 10 % to about 99 %, from about 20 % to about 95 %, from about 30% to about 92 %, from about 40% to about 90 %, from about 50 % to about 80 %, from about 60% to about 75 %, from about 65% to about 80%, from about 70% to 85% of the total weight of the homogenous solution of polytetrafluoroethylene and ranges between any two of these values or less than any one of these values.

[0056] In some embodiments, the polymer A _Ms may constitute from about 0.01 wt%, about 2 wt%, about 5 wt%, about 7 wt%, about 10 wt%, about 20 wt%, about 30 wt%, about 40wt%, about 50 wt%, about 60 wt%, about 70 wt%, about 80 wt%, about 90.0 wt%, about 95.0 wt%, about 99.0 wt% of the homogenous solution of the fluoropolymer, and ranges between any two of these values or less than any one of these values. However, other amounts are possible. The particular amount depends upon the desired properties of the homogenous solution to meet constant supply of the electrolyte. In a preferred embodiment, the homogenous solution includes about 80% of the A| _ds polymer and about 20 wt% of the A _Ms polymer.

[0057] In some embodiments of the present invention the sulfonate (S03-) group weight % of the dried film or dried layer or dried electrolyte coating is > 900 units equivalent so as to have adequate ionic conductivity in the electrolyte coating. In one aspect, provided is an anti-corrosion electrolyte coating system to protect a metal structure exposed to the atmospheric environment comprising the sulfonate group grafted polymer having sulfonate (S03-) group weight % of the dried film > 900 units equivalent so as to provide adequate ionic conductivity in the electrolyte coating. The sulfonic group incorporated in the fluoropolymer plays a crucial role in giving sufficient ionic conductivity and hydrophilicity while keeping chemical stability to the organic film, which shows otherwise no conductivity and hydrophilicity at all. This is the main reason sulfonic group has long been adopted as the chief functional group for the ion exchange resins applied widely nowadays. The desirable high amount of sulfonic group per polymer molecular i.e. more precisely greater than or equal to about 900 units equivalent, is indispensable to attain the adequate conductivity and hydrophilicity for the present invention.

[0058] In some embodiments, sulfonate group weight% of the dried film is, greater than or equal to about 900 units equivalent, greater than or equal to about 1000 units, greater than or equal to about 1 100 units equivalent, or greater than or equal to about 1200 units equivalent, greater than or equal to about 1500 units equivalent. In some embodiments, sulfonate group weight% is greater than or equal to about 1040 units equivalent. The weight% of sulfonate group is calculated based on the total weight of the dried film applied on the painted exterior metal surface.

[0059] In some embodiments, the electrolyte coating layer or dried film is applied on the conventional coated metal structure, wherein the thickness of the dried film is from about 0.005 microns to about 50 microns, from about 0.05 micron to about 40 microns, from about 0.1 microns to about 30 microns, from about 0.5 microns to about 25 microns, from about 1 microns to about 20 microns, from about 1.5 microns to about 15 microns, from about 5 microns to about 10 microns, from about 10 microns to about 50 microns. In some embodiments, the thickness of the electrolyte coating preferably is from about 0.3 microns to about 30 microns, more preferably from about 0.5 microns to about 20 microns In some embodiments the electrolyte coating is a thin film that has a transparent smooth finishing and can act as a protective coating to increase durability of conventional coating or paint. In some embodiments the thickness of the electrolyte coating film is measured after drying of the electrolyte coating. The electrolyte material used in the present invention is ionically conductive and has its resistivity less than the resistivity of the conventional paint.

[0060] In some embodiments the homogenous solution used in the present invention for electrolyte coating is made of the sulfonic group grafted polymer having formula (I) as under:

(I) [0061] In some embodiments of the present invention the anode material mounted on the electrolyte coating layer is at least one selected from the group consisting of but not limited to carbon, stainless steel, and noble metals. In one embodiment the noble metals used for the anode can be selected from the group consisting of, but not limited to Pt, Au, Pd, or Pu. In one embodiment the carbons selected as the anode can be a stable carbon in the form of carbon fiber.

[0062] The carbon fiber can be used as an electrical wiring which itself is non- susceptible to corrosion attacks whilst carbon glue is used to form an ohmic contact between the electrical carbon wiring and electrolyte. The carbon glue is used as adhesive to fix the anode on the electrolyte coating film. The carbon glue is used to establish an ohmic contact between the carbon fiber and the electrolyte. Without this contact the corrosion control system 100 as illustrated in Fig. 1 will fail to work. In a preferred embodiment the combination of carbon electrode and electrolyte coating can act as the anode in the cathodic protection system 100 described above. The cathode i.e. metal structure, and the anode i.e. carbon fiber mounted on the electrolyte coating layer are connected to a DC power source so that constant voltage ranging from about 6V to about 12V.

[0063] In accordance to one aspect of the present invention, there is provided a method to protect metal structures from atmospheric corrosion. In one embodiment the method comprises steps of pretreating metal surface 1 16 of the metal structure as illustrated in FIG. 1 , to remove impurities from the metal surface of the metal structure 102, coating the metal surface 1 16 with a material preferably an organic paint to form a conventional coating 104 on the metal surface 1 16, applying an electrolyte coating 106 composition uniformly onto the conventional coating 1 16, and drying the electrolyte coating 106 to form a dried layer having thickness from about 0.5 microns to about 20 microns, mounting an anode material 108 onto the dried layer 106, and coupling a power supply system 1 10 to the anode material 108, and to the metal of the metal structure 102, wherein, the dried layer acts as a good ionic conductor to help supply continuous or unlimited electron for current flow between the anode 108 and cathode 102 of the present system 100.

[0064] The process of applying the electrolyte coating composition 106 on the already painted metal surface 104 is illustrated by FIG. 2. In some embodiments the electrolyte composition 106 can be coated either directly or indirectly, after conventional coating 102, on to the metal surface 1 16, preferably iron or steel surface of the structure exposed to the atmospheric environment.

[0065] FIG. 2 illustrates a process 200 of applying the electrolyte composition 106 on the metal surface 1 16 to be prevented from the corrosion. In accordance to the present invention, the metal surface 202 is pre-treated for removing impurities e.g. dust, sand, rust, debris, etc. from the metal surface 1 16, preferably a steel structure. Thereafter a conventional coating 204 is applied on the purified metal surface 1 16 as protective coating which is generally applied on metal surfaces to prevent them from rusting, or corrosion happened due to the environmental factors. The protective coating can also be said "conventional coating" which generally comprises one or more layers of organic chemicals having hydrophobic properties. The conventional coating is further coated with a layer 106 of ionically conductive and anticaking electrolyte. The method is further comprising mounting an anode 108 on the dried film 106 with the help of some glue or adhesive, and supplying power to the anode 108 and cathode i.e. metal surface 102.

[0066] In accordance to FIG. 2, the pretreating 202 of the metal surface 1 16 is a generally adopted to get sufficient surface cleanliness and hence improved adhesion of organic paint onto it. The conventional coating 204 is a process of applying ordinary paint on the metal surface 1 16 to prevent the metal structure from corrosion, or rusting caused by the atmospheric environment. The metal surface 1 16 is composed of at least two layers more precisely, or primer to get firm adhesion and the top coat to get weathering durability. The electrolyte coating 106 plays a role in the present invention. The electrolyte coating 106 helps obtain sufficient ionic or electronic conductivity and hydrophilicity with this thin quasi-transparent coating layer. [0067] The anode materials composed of ionically conductive yet chemically stable substance is mounted 108 onto some part of the electrolyte coating layer to provide proton to this layer constantly. DC power supply 1 10 should be connected to the anode materials and the metal substrate itself as cathode to provide DC current for this corrosion control system.

[0068] In one aspect of the present invention, the electrolyte coating106 is originally developed for the self-cleaning purpose of the highly hydrophobic surface. Most of the environmental stain substances including rainfall soot are oily or oleophilic and can be attracted easily to hydrophobic surfaces.

[0069] The above environmental stain substances can be prevented by making metal surface highly hydrophilic. As a fringe result therefore, the electrolyte coating 106 of the present invention contributes not only to the corrosion control of the metal substrate preferably steel substrate coated with thick organic polymer but also to their self- cleaning as an original function.

[0070] The system and method disclosed in the present disclosure can be used to protect metal structures, preferably steel structure tanks, vessels and even off-shore platforms that are exposed to atmospheric corrosion.

[0071] The methods and system described herein may include other suitable components known in the art such as, but not limited to, anode material, metal used in the metal structures, mode of power supply, conventional coating including polymer used in the electrolyte coating formulation and glue or adhesive to fix the anode on to the electrolyte coating film having thickness from about 0.5 microns to 20 microns.

[0072] While certain embodiments have been illustrated and described, it should be understood that changes and modifications can be made therein in accordance with ordinary skill in the art without departing from the technology in its broader aspects as defined in the following claims.

[0073] The embodiments, illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms "comprising," "including," "containing," etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the claimed technology. Additionally, the phrase "consisting essentially of" will be understood to include those elements specifically recited and those additional elements that do not materially affect the basic and novel characteristics of the claimed technology. The phrase "consisting of" excludes any element not specified.

[0074] The present disclosure is not to be limited in terms of the particular embodiments described in this application. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and compositions within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds compositions or biological systems, which can of course vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0075] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member.

[0076] All publications, patent applications, issued patents, and other documents referred to in this specification are herein incorporated by reference as if each individual publication, patent application, issued patent, or other document was specifically and individually indicated to be incorporated by reference in its entirety. Definitions that are contained in text incorporated by reference are excluded to the extent that they contradict definitions in this disclosure.

[0077] Other embodiments are set forth in the following claims.