Semiconductive polymeric system, devices incorporating the same, and its use in controlling corrosion

Semiconducting polymer system, devices incorporated into the system and its use for corrosion control

<p>10. . . solution resistance</p><p>11. . . galvanic electrode potential at the anode</p><p>12. . . galvanic electrode potential at the cathode</p><p>13. . . noise source in the cirCuit</p><p>14. . . faradaic impedance of the faradaic impedance of the anode</p><p>15. . . faradaic impedance of the faradaic impedance of the cathode</p><p>16. . . Diode diode</p><p>17. . . noise fiIter</p>

By referring to the following detailed description in conjunction with the accompanying drawings, it will be easier to obtain a more complete understanding of the present invention and its many accompanying advantages, among which:

Fig. 1 is a diagram of a Zn/ZnO junction in a preferred embodiment of the present invention.

Figure 2 shows an equivalent circuit diagram depicting the system of the present invention.

Background of the invention

The present invention relates to a semiconductor system combining organic coating, electronic components and semiconductor technology, and its use to replace conventional semiconductor compositions and to prevent corrosion.

Discourse on background art

In the past few centuries, various methods of controlling corrosion have been developed, with particular emphasis on extending the life of metal structures in corrosive environments. These methods typically include protective coatings mainly used to upgrade the corrosion resistance of ferrous metals, such as steel, and some non-ferrous metals, such as aluminum, and avoid the need for more expensive alloys. Therefore, it can improve performance and reduce costs. However, such protective coatings typically have some drawbacks, including poor coatability to non-metallic structures that can corrode or foul.

Protective coatings can be classified into two categories. The most important of these categories are local coatings such as paint, which act as a physical barrier against the environment. The second category consists of sacrificial coatings, such as zinc or cadmium, which are designed to preferentially attack to prevent the base metal from being corroded.

Both cathodic protection and coating are engineering methods whose main purpose is to reduce and prevent corrosion. The methods are different: cathodic protection is to introduce current from an external source to offset the normal electrochemical corrosion reaction and prevent corrosion, while the coating forms a barrier to prevent the naturally occurring anode and cathode or in the galvanic couple The corrosion current or the flow of electrons. Each of these methods provides only limited results. Coating is by far the most common method for general corrosion prevention (see Leon et al. U.S. Patent No. 3,562,124 and Hayashi et al. U.S. Patent No. 4,219,358). However, cathodic protection is used to protect hundreds of thousands of miles of pipes and acres of steel surfaces that are buried or submerged.

The technology of cathodic protection is used to reduce the corrosion of metal surfaces by making it have sufficient cathodic current so that its anode dissolution rate becomes negligible (for example, see Pryor, US Patent No. 3,574,801; Wasson, US Patent No. No. 3,864,234; Maes, U.S. Patent No. 4,381,981; Wilson et al., U.S. Patent No. 4,836,768; Webster, U.S. Patent No. 4,863,578; and Stewart et al., U.S. Patent No. 4,957,612). The concept of cathodic protection works by applying sufficient current to polarize the cathode to the position of the anode so that the potential energy difference between the local anode and the surface of the cathode disappears. In other words, the effect of applying the cathode current is to reduce the area that continues to be an anode, rather than reducing the corrosion rate of these remaining anodes. When all anodes are destroyed, complete protection is achieved. From an electrochemical point of view, this indicates that sufficient electrons have been supplied to the protected metal so that any tendency of the metal to ionize or dissolve is neutralized.

Recent corrosion research work has found that the electrochemical corrosion process seems to be related to the electrical properties of the electrochemical system, such as random fluctuations in battery current and electrode potential. In the art, these random fluctuations are called "noise". Researchers have begun to apply noise analysis techniques to study the corrosion process in electrochemical systems.

Riffe, US5,352,342 and Riffe, US5,009,757 disclose a silicate coating based on zinc/zinc oxide used in combination with electronic components in a corrosion prevention system. It reveals that the zinc/zinc oxide particles in the coating have semiconductor properties, mainly at the pn junction of the Zn-ZnO phase boundary. This shows that when reverse biased, the pn junction behaves like a diode and inhibits the transmission of electrons through the boundary. This restriction restricts the transfer of electrons from the site of oxidation of Zn to the site of oxygen reduction on the surface of Zn0. The resistance between the anode and the cathode of the local corrosion battery is effectively increased, and the corrosion is effectively reduced.

Generally speaking, the junction with Zn-ZnO as the main component will be due to the oxidation of Zn on the surface of Zn and the 0 ₂ The potential energy related to the reduction effect is reversely biased. However, significant random voltage fluctuations can occur. These voltage fluctuations cause the junction insertion to become forward biased. When the forward bias voltage, the electron transport across the junction increases, and there is oxidation of Zn and O ₂ The acceleration of the reduction effect. There is an effective short circuit between the anode and the cathode of the local corrosion battery, and the corrosion is effectively promoted.

Riffe's patent discloses the installation of fixed-value capacitors in the electrochemical circuit of the corrosion prevention system. However, it is not possible to control the value of the capacitance and any recommended method for determining the capacitance value required to effectively prevent corrosion in any specified structure. Therefore, it is necessary to use overcapacitors in the system to make it effective.

The recent development of conductive organic polymers has reached a level that is commercially viable. Its uses include charge storage batteries, antistatic films, conductive hoses, gaskets, cable shielding, conductive textiles, chemical sensors, electromagnetic shielding, gas separation films, electro-optical devices, and electrolithographic applications In the discharge layer, and as a corrosion preventive paint. One such corrosion prevention application is a commercial product called CATIZE that can be purchased from GeoTech Chemical Company, LLC through a distributor-Seegott, Inc. of Ohio. This is a conductive polyaniline polymer doped with zinc metal or ions, which is used as a sacrificial cathodic protection layer on metal structures.

A disadvantage of the previous corrosion prevention methods, such as the Riffe method disclosed above, is that the color selection that can be obtained from the silicate-based coating disclosed therein is quite inelastic, and the only color that can be easily obtained is gray. Although this is acceptable in most marine and structural applications, there is still a need for a non-sacrifice, and it can be provided in many colors to be used as a substitute for paint, especially for corrosion prevention coatings in the automotive and transportation industries. .

Summary of the invention

Therefore, one object of the present invention is to provide an organic conductive polymer coating that can provide semiconductor properties, especially when connected to a power source by an electrode.

Another object of the present invention is to provide an organic conductive polymer coating that can provide corrosion resistance to any conductive structure.

Another object of the present invention is to provide a method for protecting the conductive metal structure from corrosion by fine-tuning the unique characteristics of the metal structure.

Another object of the present invention is to provide a method for preventing corrosion of conductive structures by using organic polymer-based semiconductor technology without using external anodes, electrolytes, and current flow.

Another object of the present invention is to provide a system for protecting conductive structures from corrosion, wherein the system provides long-term protection while requiring minimal system maintenance.

Another object of the present invention is to provide an organic polymer coating that has anti-corrosion properties and can be provided in any desired color to use an organic polymer coating as a substitute for lacquer.

Another object of the present invention is to provide a semiconductor system that uses organic coatings and electronic components and can be easily applied to various applications.

These and other objectives were met by the discovery of a semiconducting organic polymer coating and a related electronic system, where this system can be operated by filtering only the voltage fluctuations in the conductive structure on which the semiconducting organic coating is placed, where The method of using this system includes: coating a conductive structure with a semiconductor organic polymer coating, connecting a fixed electronic filter to the coated structure, and monitoring the noise generated by the coating connected to the fixed electronic filter, Use an adjustable filter connected to the coating to determine the response of the anti-corrosion filter required to minimize the noise generated by the coating; and use a filter response with at least the response of the anti-corrosion filter The passive or active filter replaces the adjustable filter.

The present invention further relates to a semiconductor system, which includes a semiconductor organic polymer coating on a conductive or non-conductive structure, a capacitor (or filter) electrically connected to the semiconductor organic polymer coating (directly or indirectly), fixed or Adjustable); and its use in various semiconductor applications.

Schematic description

By referring to the following detailed description in conjunction with the accompanying drawings, it will be easier to obtain a more complete understanding of the present invention and its many accompanying advantages, among which:

Fig. 1 is a diagram of a Zn/ZnO junction in a preferred embodiment of the present invention.

Figure 2 shows an equivalent circuit diagram depicting the system of the present invention.

Detailed description of preferred embodiments

The broadest form of the present invention provides a semiconductor system that includes a semiconductor organic polymer coating on a substrate and a capacitor (or filter) electrically connected to the semiconductor organic polymer coating. This capacitor (or filter) can be any desired capacitance value. Regarding filters, the fixed and adjustable filters described below regarding corrosion prevention can also be used in semiconductor systems.

The semiconductor organic polymer coating and system of the present invention can be used with various conductive substrates and provide some important properties. The semiconductor organic polymer coating of the present invention can be any conductive or semiconductor organic polymer coating, including, but not limited to, polyacetylene, polyphenylene, polyfuran, poly Thiophene, polypyrrole, poly(arylene vinylene), and polyaniline. In addition, the organic polymer coating of the present invention can be any of these polymer types and any suitable thermoplastic or thermosetting polymers, and optionally with one or more conventional fillers, such as fiber glass, mineral fillers, carbon fibers, etc. Blends, composites or colloids. Kirk-Othmer Encyclopedia of Chemical Technology Technology), 4th edition, Volume 9, pages 61-85 (1994) disclose various conductive organic polymers, the entire contents of which are incorporated herein by reference. It can be used in one or more dyes or pigments commonly used in the coating or paint industry to further formulate the coating into a colored coating, as long as the dye or pigment does not damage the conductivity of the organic polymer coating. Preferred coatings include CATIZE (a combination of polyaniline and zinc metal, as mentioned above), BAYTRONP (naturally conductive, transparent, and substantially colorless (light blue) PEDT/PSS [poly(3,4- Ethylenedioxythiophene) poly(styrene sulfonate)]) and LIGNO-PANI (polyaniline), which are all purchased from Geotech Chemical Co., LLC through a distributor-Seetech, Inc. in Ohio.

The semiconductor system of the present invention can be applied to any conventional conductive or semiconductor applications, including, but not limited to, semiconductors and electronic components, such as semiconductor chips, charge storage batteries, antistatic films, conductive hoses, gaskets, cables Wire shields, conductive textiles, chemical sensors, electromagnetic shields, gas separation membranes, electro-optical devices, electrical discharge layers in electrolithographic applications, and as corrosion preventive paints. Kirk-Osma Encyclopedia of Chemical Technology, 4th Edition, Volume 21, pp. 720-816 (1994) discloses various other semiconductor uses and their preparation, the entire contents of which are incorporated herein by reference middle. This system can be used to manufacture semiconductor layers in semiconductor wafers, where semiconductor organic polymers replace conventional semiconductor materials. The semiconducting organic polymer can be coated by any conventional method for forming a coating, including, but not limited to, self-melting or liquid coating, coating the polymer on the wafer substrate, and then drying/curing on the surface /polymerization. One method of coating a polymer with a liquid is to spray the substrate with a polymer solution, and then dry the polymer layer so formed to remove the solvent. The choice of solvent depends on the particular semiconducting organic polymer used, and it is within the abilities of those skilled in the art. Ideally, the solvent is a solvent that does not produce volatile organic substances. For water-soluble polymers, water is the best. Other solvents include, but are not limited to, alcohols, hydrocarbons, ethers, dimethylsulfene, dimethylformamide, and ketones such as methyl vinyl ketone or acetone. The conventional negative or positive mask and etching techniques, including chemical etching and radiation-based etching methods, can be used to form the semiconductor polymer of the present invention into any desired wafer pattern. Therefore, the semiconductor system of the present invention can be used to replace semiconductor materials in any conventional semiconductor-based devices, including, but not limited to, chips, diodes, rectifiers, amplifiers, transistors, and varistors.

The semiconducting organic polymer of the present invention can be of any desired molecular weight (unless otherwise specified, all molecular weights are weight average molecular weights), as long as the polymer can form a film or coating under the designed use conditions (ie, as generally Under low temperature conditions, the molecular weight can be lower while still forming a suitable coating or film). The preferred molecular weight is from 10 ³ To 10 ⁷ ,10 ³ To 10 ⁶ Better. Since the conductivity of organic polymers changes with the increase in molecular weight, the molecular weight of the polymer can also be used to adjust the semiconductor properties of the final device. The use of two or more different polymers (with different chemical composition or molecular weight or both) can provide different semiconducting regions that react to different inputs within the same device.

The substrate on which the semiconductor organic polymer is arranged can be conductive or non-conductive. The conductive substrate can be metal or non-metal. The non-conductive substrate can be any material that serves as an insulator, such as silicon wafers or other non-metallic substrates. The manufacturing of such non-conductive or conductive substrates in the semiconductor wafer manufacturing technology is well known to those skilled in the art.

In a preferred embodiment, the present invention provides a method for preventing corrosion of any conductive structure that is susceptible to corrosion, which includes coating the conductive structure with a semiconductor organic polymer coating, and connecting the resulting coated structure To the fixed electronic filter, monitor the corrosion noise generated by the system, and determine the filter response required to minimize the corrosion noise (in the case of the present invention, the term "corrosion noise" is used to describe the current Voltage fluctuations that occur during the corrosion process). In a specific embodiment, the present invention includes the use of an adjustable filter to adjust the filter response to determine the filter response required to minimize the noise generated by the coated structure, and then to at least have the measured resistance The passive electronic filter that corrodes the filter response replaces the adjustable filter. In another embodiment, the present invention replaces the adjustable filter with an active electronic filter and a monitoring system that continuously monitors noise and automatically adjusts the filter response to minimize fluctuations in the system.

The present invention minimizes this corrosion noise by connecting the semiconductor organic polymer coating to the electronic filter. The electronic filter has a filter response defined as the degree of noise reduction at a certain frequency in the context of the present invention. As mentioned earlier, the filter can be a passive, low-pass RC filter or an active filter. In each case, the filter minimizes voltage fluctuations. The junction existing in the semiconductor coating maintains reverse bias. In the semiconducting organic polymer coating, the time-average electron flow from the anode to the cathode domain then decreases, and the coating is effectively passivated.

Passive, low-pass RC filters are basically a capacitor and a resistor. In the case of this system, the organic polymer coating of the semiconductor is used to some extent as a resistor, which completes the RC filter with the capacitor. Suitable active filters include, but are not limited to, Butterworth filters, Bessel filters, and Sallen-Key filters. These active filters are commercially available and/or can be easily prepared by those skilled in the art. These active filters are basically operational amplifier circuits with capacitors. The main component of the filter of the present invention is a capacitor, and the filter response is better related to the capacitance required to provide noise reduction at a certain frequency.

Use the noise measurement aspect of the present invention to fine-tune the design of the system for specific applications. Based on the measurement noise, the necessary filter properties and the installation position of the filter in the system can be determined and improved, so that even if it is tied to a relatively large structure, such as an aircraft carrier or a sea-crossing bridge, it can still be on the entire surface of the structure To achieve continuous corrosion prevention. In the present invention, the voltage fluctuation between the coated surface and the low-noise, high-impedance reference electrode is monitored. A suitable high-impedance reference electrode can be prepared, for example, from a saturated calomel electrode or a saturated sulfate electrode. Commercially available high-impedance reference electrodes suitable for this purpose can be purchased from various catalog equipment companies, such as Beckman Instruments or Corning. Noise can be monitored using these electrodes with an oscilloscope to show voltage fluctuations. Alternatively, the data obtained from the electrodes can be stored and analyzed using a PC computer using analog-digital converters, and using timing analysis programs, such as Fast Fourier Transform (FFT) analysis or maximum entropy method (MEM method) analysis data. These methods can provide immediate and delayed results as needed. Using these methods can determine the filter response value and the filter setting position required to produce a nearly flat line (even if the noise is minimized) on the oscilloscope. This can be done at a single location on the structure, or for finer control, can be done at multiple locations near the surface of the structure. The nature of the electronic filter and the installation position of the filter can be adjusted to minimize the measured voltage fluctuation, thereby maximizing the passivation effect of the coating. The end result is that the life of the corrosion prevention system for any desired structure type is greatly increased. This is due to the reduction of corrosion noise, so that the sacrificial corrosion of the semiconductor organic polymer coating is greatly reduced.

The semiconductor organic polymer coating of the present invention can be used in various applications. The main purpose is to prevent corrosion of conductive structures. The system for preventing the corrosion of conductive substrates includes: (a) a semiconductor organic polymer coating in conductive contact with at least part of the surface of the conductive structure; and (b) a device for filtering corrosion noise, wherein the device includes electronics Electronsink, such as a battery or other power source, and a filter connected to a coated conductive substrate, such as a capacitor; and finding a corrosion prevention method that includes: (1) cleaning the outer surface of the conductive structure; 2) Coating the outer surface with the semiconductor organic polymer coating of the present invention; and (3) Using electronic filters to minimize corrosion noise in the system.

One of the key points of the anti-corrosion method and system of the present invention is to measure the corrosion noise generated by the entire system (including, but not limited to, the substrate, coating and filter components), and to make the noise generated by the application of an electronic filter. The information is minimized.

In the specific embodiment of corrosion and fouling prevention, the system includes two interdependent components: (1) a semiconductor organic polymer coating, and (2) a device that imparts a net negative bias to the coated conductive structure . Generally speaking, the semiconductor organic polymer coating is applied to the conductive surface after being cleaned, in order to spray the metal surface to commercial spray polishing or to use an equivalent method for the non-metal conductive structure. good. When the conductive surface is cleaned by spraying or equivalent methods, the surface will have many grooves or dents from 0.1 mil to several mils in depth. The semiconductor organic polymer coating of the present invention should be coated at a depth of at least 2 mils greater than the depth of the cavity formed by the cleaning method, preferably from 2 to 10 mils, and 7 to 9 mils. optimal. On smooth surfaces without significant pits, the coating can be applied as low as about 0.5 mils without adversely affecting system performance.

The structure that can be protected by this method and system can be any conductive material that is easily corroded. This structure is preferably a metal structure of ferrous metal or non-ferrous conductive metal. Typical metals include, but are not limited to, iron, steel, and aluminum. In a preferred embodiment, the substrate is a metal car body of an automobile or other vehicle, and the semiconductor organic polymer coating includes an organic conductive polymer (contains conductive dopants, such as Zn, if necessary) and a visual It is necessary to provide one or more dyes or pigments of the coating color. In this specific embodiment, the car body can have the desired color in a single coating, but the anti-corrosion properties are more often required (typically more than three of the total of primer, color and top coat Combination) The conventional automobile operation of coating coating has been significantly improved. In a more preferred embodiment, a single dip coating is used to coat all exposed surfaces of the entire metal body of the automobile with the semiconductor organic polymer coating of the present invention, and after the final assembly of the automobile, the electronic monitoring and control of the system are added. filter.

The semiconductor organic polymer coating of the present invention includes (a) conductive organic polymers with or without dopants, and (b) optional one or more metals or metal alloys, with or without metal oxidationGood things. The thing is better. In a preferred embodiment, the metal or metal alloy contained in the coating is a Zn/ZnO system. The metal or metal alloy (when present) in the conductive organic polymer or coating must have a higher oxidation potential than the protected conductive material. Due to the oxidation potential of most protected materials, the semiconductor organic polymer coating of the present invention contains one or more metals or metal alloys, with or without metal oxides being the best. Familiar with the standard electrode potential of most metals, and present them below for various metals.

<tables><img file="TW548784B_D0001.tif" /></tables>

(Source: CRC Handbook of Chemistry and Physics, 60th edition, edited by Robert C. Weast, CRC Press, Inc., Boca Raton, FL, 1979) Because the coating of this system and method is relatively The protected conductive material is sacrificed (although there is a minimum sacrifice when the corrosion noise is minimized), but when deciding the metal to be included in the coating, choose a material with a larger negative value than the protected conductive material Metal with standard rate electrode potential. For example, in order to protect Fe (such as present in steel), the coating can use Zn, Ti, or any other metal with a larger negative value of the standard rate electrode potential than -0.44. When protecting metals with relatively large negative electrode potentials, such as aluminum (-1.68), it is acceptable to use metals with small negative electrode potentials (such as Zn) and large negative electrode potentials Alloys combined with metals (such as Mg). This alloy will make the coating have the necessary sacrificial properties, and at the same time, it can avoid the extreme oxidation that would occur in the coating that only contains metals with extremely negative electrode potentials, such as Mg. It is also possible to add a metal with extremely high negative electrode potential to one of the above-mentioned adhesives, so as to avoid the coating that sacrifices too quickly. Instead of an alloy of two metals, a metal with a larger negative electrode potential can be added as the counter ion of the silicate binder.

The coating of the present invention may also include additional n-type semiconductors, such as Sn/SnO, added to the coating. In addition, the coating can be doped with metals such as Al or Ga to improve the conductivity of the coating, or doped with 1-5% Li to reduce the conductivity of the coating. The metal/metal oxide interface (Zn/ZnO) in the preferred coating of the present invention is used as a diode in an electrochemical system. Therefore, the coating contains many micro-domains as diodes. Due to the corrosion noise generated by the coating, the diodes are periodically switched on and off due to the fluctuation of the conductive potential in the micro-domains in the coating. The fluctuation of the conductive potential and the switching of the diode cause the coating to be sacrificially corroded. By doping, such as Li, reducing the conductivity of the coating, the switching position of the diode can be reduced below the lowest point in the noise fluctuation curve. This will minimize the sacrificial corrosion of the coating while still protecting the conductive material of the protected structure.

The traditional passive and novel active barriers can be obtained by appropriately selecting the semiconductor organic polymer coating material for the conductive surface.

In a preferred embodiment, the zinc powder of the coating of the present invention forms a metal-semiconductor junction, where zinc metal and zinc oxide form an interface, and zinc oxide is an n-type semiconductor.

Figure 1 schematically shows a preferred embodiment of the finished coating. Figure 1 shows the porous properties of the preferred zinc/zinc oxide/polymer coating (4) of the present invention. The zinc particles (1) are covered by a zinc oxide layer (2), and the particles of each coated oxide are surrounded by a conductive organic polymer binder (3).

The conductive structure of the present invention can be any conductive structure that needs corrosion protection, including metal structures and non-metal structures. Examples of such metal structures include metal vehicles, such as ships, airplanes, automobiles, military tanks or vehicles, metal vehicle parts, bridges, railway connection mechanisms, containers, pipe fittings, and metal towers, as well as smaller structures such as biomedical Device. Examples of metal vehicle parts include metal parts of vehicles such as automobiles, airplanes, trains, military land vehicles such as tanks, and ships and other maritime vehicles. Examples of containers are refining containers, storage bins, and storage boxes. Examples of non-metallic conductive structures include conductive concrete and conductive polymer structures. The corrosion process will also affect these non-metallic conductive structures, and can also be minimized by the present invention. It has been proposed that conductive concrete is a possible material for the preparation of floating airport runways. The system of the present invention will help prevent the corrosion of concrete, thereby prolonging the life and structural integrity of the concrete structure.

A significant advantage obtained in the present invention is that by minimizing the sacrificial corrosion of the semiconductor organic polymer coating, the life of the coating can be extended to many times longer than that of the conventional coating protection system. Although this can be achieved in water by applying a cathode current, this will require substantial current and will be quite difficult to control. The method of the present invention acts inside the coating, so it can prevent atmospheric corrosion in which the corrosive medium is only moisture condensed from the air. This is useful for protecting the surface of car bodies such as automobiles and other vehicles, as well as the inner surface of new-style ships (which provide increased strength design with increased susceptible areas), as well as protecting automobile parts, bridges, airplanes, and trains. Is extremely important.

Another preferred embodiment is to use the method and system on the inner surface of modern ships, where condensation is the most corrosive due to its high salt water content, and at the same time the cathodic protection system does not have enough moisture to operate. Without the noise filter of the present invention, the zinc in the coating will be quickly filtered out and will be corroded by the flow of condensate to the bottom of the ship. However, when the noise filter according to the present invention is applied to a metal substrate, this leaching can be effectively stopped.

In addition, the use of noise filters on the substrate steel of automobiles does not substantially interfere with the electronic components on the board. This is an important consideration in the highly computerized and electronic automobiles currently sold. In addition, using it on the base steel of the ship will not cause greater interference than turning on the lights inside the ship, and because although the noise filter uses batteries or other electronic sources, it does not produce any noticeable The ground radiation exceeds the field of the coating, so it will not cause the opposite detection device to generate a detectable signal. The absorption characteristics of zinc are well known, and it is usually used for EM shielding and electronic component sealing. Therefore, there will be no measurable EM radiation from the coastal-based structure to which this system is applied.

The fixed electronic filter of the present invention is used as a capacitor connected with an electronic tank, so that the capacitor maintains a reverse bias voltage. The fixed electronic filter is a conventional power source, such as a direct current (DC) power supply device such as a battery, preferably a 12 volt battery, and a combination of a solar battery and an alternating current (AC) power supply device is preferred. It should be noted that although this component is referred to as a "power supply" in this description, there is neither current nor voltage in this system. Therefore, the name of the power source is for convenience only, and it does not mean the flow of electrons. If a complete circuit is available, the power supply device used is preferably sufficient to provide a voltage from 0.5 to 30 volts, and 10 to 20 volts is the best. Fixed electronic filters (ie, power supplies and capacitors) can be directly connected to the substrate or to the coating, while connected to the coated conductive substrate. In a preferred embodiment, the power supply device of the present invention has a negative terminal directly connected to the protected conductive structure. The positive terminal of the power supply device is connected to the conductive structure through a filter/capacitor, which is far more difficult to connect to the negative terminal. By using a conductive organic polymer as the coating of the present invention, these electrical connections can be made directly to the organic polymer coating instead of the conductive structure, or the positive terminal can be connected to the organic polymer coating or conductive One of the structures, and the negative terminal is connected to the other. Since the present invention does not rely on the generation of current flow (which will decrease as the distance between the terminals increases), the distance between the terminals is not important, as long as the positive and negative terminals do not touch each other. It is better to connect the positive terminal to a structural position 0.01 to 30 meters away from the connection position of the negative terminal, and 5 to 10 meters away from the connection position of the negative terminal.

The method of the present invention contributes to the longevity of the system. It does not require regular monitoring and control of current or potential like conventional cathodic protection systems. In addition, this system is unlikely to lose control and severely damage the supporting structure like the cathodic protection system in the impression. Therefore, the only effective reduction in coating life will come from abrasion in the wind and water. Since the wear resistance of the coating is slightly better than that of galvanized, the life expectancy of the coating can be extended to the range of several decades.

In addition, by using active filters and monitoring systems that continuously monitor noise fluctuations and adjust filter properties (such as filter response and cut-off frequency), it is possible to prevent the increase in the sacrificial loss rate due to the increase in corrosion over time, And extend the life of the coating.

Figure 2 shows an equivalent circuit diagram depicting the system of the present invention. In the circuit, 1o is the solution resistance (Rs), and 11 and 12 are the electrode potentials at the anode (Ea) and cathode (Ec), respectively. 13 indicates the source of noise in the circuit (En). 14 and 15 respectively show the Faraday impedance of the anode (Ra) and cathode (Rc). The diode (D) 16 is shown at the metal-semiconductor junction at the Zn/ZnO boundary. 17 denotes the noise filter (F) of the active or passive filter.

Obviously, the present invention can be modified and changed in many ways based on the above-mentioned teaching. Therefore, it should be understood that the present invention can be implemented in other ways within the scope of the attached patent application, except as explicitly stated in the text.

Symbol description of main components

10. . . solution resistance

11. . . galvanic electrode potential at the anode

12. . . galvanic electrode potential at the cathode

13. . . noise source in the cirCuit

14. . . faradaic impedance of the faradaic impedance of the anode

15. . . faradaic impedance of the faradaic impedance of the cathode

16. . . Diode diode

17. . . noise fiIter