Selectively applied gradient coating composition

Abstract

Surface modifiers and coating materials are provided which can be applied to a substrate to reduce or eliminate impairments that would create environmental impacts or operating stresses when incorporated into a device such as a heat exchanger. Structured ceramic surface modification materials can be incorporated into the surface modifiers and can optionally include gradients of one or more physical or chemical properties.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of priority to PCT Application No. PCT / US2019 / 065978, filed Dec. 12, 2019, and to U.S. Provisional Application No. 62 / 989,092, filed Mar. 13, 2020, U.S. Provisional Application No. 62 / 989,150, filed Mar. 13, 2020, U.S. Provisional Application No. 63 / 038,642, filed Jun. 12, 2020, U.S. Provisional Application No. 63 / 038,693, filed Jun. 12, 2020, and U.S. Provisional Application No. 63 / 039,965, filed Jun. 16, 2020, the entire disclosures of all of which are incorporated herein by reference. Technical field

[0003] The present invention relates to coating materials, and in particular to coating materials that provide a gradient of one or more physical or chemical properties, which mitigate environmental or operational damage to a substrate on which the coating material is applied, such as corrosion. Background art

[0004] When heat exchangers and other target systems are exposed to local environments, they can experience conditions that can affect their performance and ultimately their utility. Observable effects are local corrosion, increased corrosion due to water and frost accumulation, debris accumulation, or abrasion from airborne debris, which can reduce the effectiveness of corrosion protection or lead to microbial growth and subsequent corrosion. As a further example, significantly more debris accumulation occurs on the leading edge surface of a heat exchanger than on the trailing edge surface. Water accumulation during the condensation process can collect on the trailing edge of the heat exchanger surface, increasing corrosion damage. Road wear occurs in the areas where the tires contact, and oil accumulation occurs in the center of the lane, both of which change the road wear and corrosion patterns. To improve the performance of these devices and systems, it is desirable to directly address these conditions in a targeted manner in the target areas. Summary of the invention

[0005] Provided herein are coating compositions and methods of using the same.

[0006] In one aspect, a composition in the form of a coating or modifier on a surface of a substrate is provided, wherein the coating or modifier includes a gradient of at least one physical or chemical property on at least a portion of the substrate surface. For example, the at least one physical or chemical property of the gradient can include, but is not limited to, one or more of thickness, density, pore size, pore size distribution, pore filling rate, chemical or physical composition, oxidation state, metal concentration, crosslink density, isoelectric point, conductivity, thermal conductivity, and capacitance. In some embodiments, the gradient, such as a gradient of any of the above properties, can vary by about 1% to about 99%, about 5% to about 95%, about 10% to about 90%, about 20% to about 80%, or any one of about 1%, about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, or about 99% relative to the maximum value of a given property of the coating or modifier or the maximum value of a given property on the substrate, or any one of at least about 1%, about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95%, or about 99%.

[0007] In some embodiments, the coating or modifier including a gradient of at least one physical or chemical property is in a single layer on the substrate surface. For example, the coating or modifier can comprise a ceramic, a polymeric material, or a self-assembled monolayer.

[0008] In some embodiments, the coating or modifier includes multiple layers, wherein at least one of the layers includes a gradient of at least one physical or chemical property. For example, at least one layer including the gradient can comprise a ceramic, a polymeric material, or a self-assembled monolayer. In one embodiment, the multiple layers include a first layer in contact with the substrate that includes a gradient of at least one physical or chemical property and a second functional material layer on the first layer that does not include a gradient.

[0009] In another embodiment, the multiple layers include a first layer in contact with the substrate that does not include a gradient and a second functional material layer on the first layer that includes a gradient.

[0010] In some embodiments, the coating or modifier is applied in spatially discrete regions on the surface of the substrate, and one or more regions of the substrate surface do not include the coating or modifier. For example, the coating or modifier can be applied to a plurality of spatially discrete regions on the surface of the substrate. In some embodiments, about 1% to about 99%, about 5% to about 95%, about 10% to about 90%, about 20% to about 80%, or any one of about 1%, about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95% or about 99%, or at least about 1%, about 5%, about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, about 95% or about 99% of the substrate surface is coated with the coating, layer or modifier.

[0011] In some embodiments, the coating or modifier is spatially continuous over the entire or substantially entire region of the substrate surface.

[0012] In some embodiments, the substrate is modified with a conversion coating or primer over the entire or substantially entire substrate surface, and a layer including a gradient in at least one physical or chemical property is coated on top of the conversion coating or primer. In one embodiment, the layer including a gradient in at least one physical or chemical property is applied in spatially discrete regions of the conversion coating or primer, and one or more regions of the conversion coating or primer do not contain the layer including the gradient. In one embodiment, the layer including a gradient in at least one physical or chemical property is applied to a plurality of spatially discrete regions of the conversion coating or primer. In one embodiment, the layer including a gradient in at least one physical or chemical property is spatially continuous over the entire or substantially entire region of the conversion coating or primer. In some embodiments, the conversion coating or primer contains one or more of chromate, fluozirconate, fluorotitanate, sol-gel, phosphate, zirconium, rare earth metals, and blue or black oxides. In some embodiments, the layer including a gradient in at least one physical or chemical property contains a ceramic, a polymeric material, or a self-assembled monolayer.

[0013] In some embodiments, the layer including a gradient in at least one physical or chemical property is coated on at least a portion of the substrate surface, and a uniform or substantially uniform functional material layer is coated on top of the layer including the gradient and over the entire or substantially entire region of the substrate surface. In some embodiments, the layer including a gradient in at least one physical or chemical property contains a ceramic, a polymeric material, or a self-assembled monolayer.

[0014] In some embodiments, a coating or modifier or layer comprising a gradient of at least one physical or chemical property comprises or consists of a ceramic material. For example, the ceramic material can be a binderless ceramic material having a crystallinity greater than about 20%. The ceramic material can include metal oxides, hydrates of metal oxides, metal hydroxides, and / or hydrates of metal hydroxides. In some embodiments, the ceramic material includes metal hydroxides, at least a portion of which are in the form of layered double hydroxides. In some embodiments, the ceramic material includes one or more properties selected from the following: about 10 m 2 to 1500 m 2 of surface area per square meter of projected substrate area; about 15 m 2 to 1500 m 2 of surface area per gram of ceramic material; an average pore diameter of about 2 nm to about 20 nm; a thickness of about 0.2 microns to about 25 microns; a porosity greater than about 10%; and a void volume of about 100 mm 3 / g to about 7500 mm 3 / g as determined by mercury intrusion porosimetry.

[0015] In some embodiments, a coating or modifier or layer comprising a gradient of at least one physical or chemical property comprises or consists of latex, paraffin (alkane), olefin, alcohol, acrylic acid, alkyd resin, enamel, epoxy resin, silicone, fluoropolymer, or urethane.

[0016] In some embodiments, a coating or modifier or layer comprising a gradient of at least one physical or chemical property comprises molecules having a head group and a tail group. For example, the head group includes silyl, sulfonate, sulfonic acid, borate, boric acid, phosphonate, phosphonic acid, carboxylate, carboxylic acid, vinyl, hydroxide, alcohol, thiolate, thiol, and / or quaternary ammonium, and the tail group includes hydrocarbon, fluorocarbon group, vinyl, phenyl, epoxy group, acrylic group, acrylate, hydroxide, carboxylic acid, thiol, and / or quaternary ammonium.

[0017] In some embodiments, the substrate surface is the surface of a heat exchanger, vehicle, aircraft, ship, or bridge, or any other surface that is susceptible to environmental wear or degradation under the environmental conditions in which it is located or operates. For example, the substrate surface can be the surface of a brazed aluminum heat exchanger, a copper tube-aluminum fin heat exchanger, or a steel tube-aluminum fin heat exchanger.

[0018] In another aspect, there is provided a heat exchanger or a component thereof, wherein the composition described herein (i.e., a coating or modifier including at least one gradient of physical or chemical properties on at least a portion of the surface of a substrate as described herein) is applied to the surface of the heat exchanger or the surface of a component of the heat exchanger. For example, the heat exchanger can be a brazed aluminum heat exchanger, a copper tube-aluminum fin heat exchanger, or a steel tube-aluminum fin heat exchanger. The heat exchanger surface or component can exhibit enhanced resistance to environmental damage compared to the same heat exchanger or component that does not include the composition described herein.

[0019] In another aspect, there is provided a method of protecting a substrate from environmental damage. The method includes applying the composition described herein (i.e., a coating or modifier including at least one gradient of physical or chemical properties on at least a portion of the surface of a substrate) to the substrate, wherein the substrate exhibits enhanced resistance to environmental damage compared to the same substrate that does not include the composition. For example, environmental damage can include, but is not limited to, one or more of corrosion, debris accumulation, water or ice accumulation, biofouling, and abrasion. In one embodiment, corrosion due to water or ice accumulation is reduced or prevented compared to the same substrate that does not include the composition described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Shows the drying rate of the ceramic-coated plate as described in Example 43. DETAILED DESCRIPTION

[0021] The selective application of coating compositions can be used to provide protection against environmental damage. In addition, over time, the conditions that need to be prevented or treated change. This can be addressed by a layered coating structure that provides different protection as the layers change, for example, over the entire lifetime of the device.

[0022] Coating compositions and substrate modifications are provided herein to minimize environmental wear or degradation, such as corrosion, in areas where environmental exposure and damage are particularly challenging, such as at edges, material or composite interfaces, low velocity regions, high electrochemical corrosion potential regions, or regions exposed to or susceptible to excessive moisture, salt, debris accumulation, biofouling, or abrasion.

[0023] Coating materials or surface modifiers can be used to apply more corrosion-resistant materials in areas of high environmental exposure or stress or stress caused by operating factors during device use, or to promote or enhance the movement of liquids such as water away from the substrate, partially coating components without the need for a coating of the entire surface or device, to protect the material differently over time, for example, by differences in the thickness of the coating material or surface modification over the entire substrate surface or by surface normal gradients (e.g., gradients of one or more chemical or physical properties from the top of the coating material or surface modifier to the bottom in contact with the substrate surface) and / or as a branding or cost-cutting measure.

[0024] The selective application of coating materials or surface modifiers can also be used to achieve complementary benefits such as corrosion resistance while minimizing potential negative impacts such as heat transfer losses due to the heat resistance of the coating.

[0025] One application involves heat exchangers. Some outdoor heat exchangers corrode and fail at very specific locations due to water pooling after rain, sprinkler devices, proximity to or use in a marine environment, or animal (e.g., cat) urination. Other environmental stresses that can be mitigated or eliminated by applying the compositions and surface modifiers described herein include exhaust pollution, urban pollution, dust / debris, fertilizers, road salts, sand, marine aerosols, industrial emissions (e.g., refineries, water treatment, manufacturing), or microbial (e.g., bacteria, fungi) or viral exposure and / or degradation, including biofilm formation (i.e., antimicrobial, antibacterial, antifungal, or antiviral coatings or surface modifiers). Spatial gradients of properties can be used to produce gradient effects. For example, a spatial gradient of porosity that directionally wicks a fluid such as water and "pumps" it from one direction to another can be used for corrosion protection and other purposes such as enhancing drying or fluid transfer.

[0026] In some embodiments, the coating or surface modifier can make the heat exchanger or its components resistant to impact contaminants (e.g., slaughterhouse particles, corrosive aerosols, etc.) and increase the thermal resistance to reduce the frosting rate by reducing the thermal conductivity and thereby increasing the surface temperature. Downstream of the fin array, the coating can be different to reduce the corrosion resistance rate and improve the heat transfer / defrosting performance.

[0027] The coating or surface modifier can be applied to the entire substrate surface or selectively (applied to one or more parts of the substrate surface, such as one or more areas exposed to adverse environmental conditions or subjected to environmental or operating stresses). In certain embodiments described herein, the coating or surface modifier is configured as a one-dimensional or multi-dimensional gradient (i.e., spatial variability) on the substrate surface or on a device or part or component of a device. Exemplary material parameters can include gradients of material density, pore size distribution, pore filling (i.e., the filling rate or spatial gradient of the material filling the pores of a porous material), or material thickness.

[0028] Methods are provided for reducing or preventing environmental or operational damage to a substrate or to a device or assembly incorporating the substrate. The methods include spatially continuously or discontinuously applying any of the coatings or surface modification materials described herein, including one or more materials including at least one gradient of chemical or physical properties, wherein the substrate is resistant to environmental or operational damage, such as but not limited to corrosion, debris accumulation, water or ice accumulation, biofouling or wear, as compared to a substrate that does not include the coating or substrate modifier.

[0029] Definitions

[0030] The numerical ranges provided herein include the values defining the range.

[0031] "A", "an", and "the" include plural referents unless the context clearly dictates otherwise.

[0032] The phrase "and / or" as used herein in the specification and claims should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Except for the elements specifically identified by the "and / or" clause, additional elements may optionally be present, whether related or unrelated to those specifically identified, unless clearly indicated to the contrary. Thus, as a non-limiting example, when used in conjunction with open-ended language such as "comprising", a reference to "A and / or B" can refer in one embodiment to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); and so forth.

[0033] "Binder" or binding agent is any material or substance that holds or draws other materials together by adhesion or cohesion, mechanically or chemically, to form a bonded mass.

[0034] "Binder-free" means the absence of a binder that can be externally added to the primary material to improve structural integrity, particularly with respect to organic binders or resins (e.g., polymers, gums, adhesives, asphalt) or inorganic binders (e.g., lime, cement glass, gypsum, etc.).

[0035] "Capillary rise" means the surface tension-driven upward flow of a liquid along a sample upon contact with the free surface of the liquid due to a porous substrate (capillary rise is parallel and opposite to the direction of the force (vector) due to gravity).

[0036] "Ceramics" or "ceramic materials" refer to solid materials that include inorganic compounds of metals or metalloids and non-metals with ionic or covalent bonds. "Non-metal" can include oxygen (oxide ceramics), or carbon (carbides) or nitrogen (nitrides) (non-oxide ceramics). "Metal" can include non-hydrogen elements of Group 1 of the periodic table, elements of Groups 2-12 of the periodic table, or elements from the p-block (Groups 12-17 of the periodic table), such as Al, Ga, In, Tl, Sn, Pb, Bi, or combinations thereof. "Metalloid" can include B, Si, Ge, As, Sb, Se, Te, or Po, or combinations thereof.

[0037] "Contact angle" refers to the angle measured through a liquid between a surface and the liquid-vapor interface at the surface of contact.

[0038] "Continuous" or "adjacent" refers to walls and features that are in direct contact with each other, or pores and structures that share a common wall over a region or dimension that is large relative to a single pore or structure.

[0039] "Conversion coating" refers to a surface layer in which reactants chemically react with the surface to be treated, which converts the substrate into a different compound. The process is generally not an addition or deposition, but may result in a minor mass change.

[0040] "First quartile pore diameter" refers to the pore diameter value at which the cumulative pore surface area measured in the direction of increasing pore diameter is equal to 25% of the total cumulative pore surface area determined by BJH gas adsorption / desorption measurements.

[0041] "Functional material layer" refers to a material layer that can be used as the uppermost surface layer for interaction with the surrounding environment or as an interface layer (an intermediate layer between two other material layers) for subsequent materials. The functional material layer imparts one or more desired functional properties to the underlying substrate and / or the materials deposited thereon.

[0042] "Gradient" as used herein refers to a quantitative increase or decrease in one or more physical or chemical properties of a material, which is observed by transfer from one point in space to another along the surface of a substrate on which the material is located or fixed, and is observed to vary in the x, y, or z direction in Cartesian coordinates on or through the material. Non-limiting examples of gradient properties include thickness, density, hardness, ductility, pore diameter, pore size distribution, pore filling rate, or chemical or physical composition, including but not limited to oxidation state, metal concentration, or crosslink density, such as resulting in changes in isoelectric point, conductivity, thermal conductivity, capacitance, etc.

[0043] "Hydrophilic" refers to a surface that has a high affinity for water. The contact angle can be very low (e.g., less than 30 degrees when measured through liquid water in the presence of air) and / or immeasurable.

[0044] "Layered double hydroxide" refers to a class of ionic solids characterized by a layered structure of the general sequence [AcB ZAcB] n where c represents a metal cation layer, A and B are hydroxide anion layers, and Z is a layer of other anions and / or neutral molecules (such as water). Layered double hydroxides are also described in PCT application No. PCT / US2017 / 052120, the entire content of which is incorporated herein by reference.

[0045] "Macropore" refers to a geometric space within a solid, the characteristic dimension of which is substantially greater than the characteristic dimension (e.g., thickness) of an individual pore or feature, e.g., at least about 5x to about 10x or about 10x to about 100x greater than the characteristic dimension.

[0046] "Average value" refers to the arithmetic mean or average.

[0047] "Average pore diameter" is calculated using the total surface area and total volume measurements from the Barrett-Joyner-Halenda (BJH) adsorption / desorption method, i.e., 4 times the total pore volume divided by the total surface area (4V / A), assuming cylindrical pores.

[0048] "Multimodal" refers to a distribution that contains more than one distinct mode, manifested as more than one distinct peak.

[0049] "Permeability" in fluid mechanics is a measure of the ability of a porous material to allow a fluid to pass through it. The permeability of a medium is related to the porosity but also to the shape of the pores in the medium and their degree of connectivity.

[0050] "Pore size distribution" refers to the relative abundance of each pore size or pore size range determined by mercury intrusion porosimetry (MIP) and the Washburn equation.

[0051] "Porosity" is a measure of the void (i.e., "empty") space in a material and is the fraction of the volume of voids (i.e., macropores). It is between 0 and 1 on the total volume, or as a percentage between 0% and 100%. The porosity disclosed herein is measured by mercury intrusion porosimetry.

[0052] "Porous" refers to the spaces, pores, or voids within a solid material.

[0053] "Superhydrophobic" refers to a surface that is very difficult to wet. The contact angle of a water droplet on a superhydrophobic material herein refers to the sessile droplet contact angle > 150°. A highly hydrophobic contact angle > 120°. The contact angle mentioned here is formed between the surfaces of the liquid.

[0054] "Surface area per unit projected substrate area" means the surface area measured in practice (usually in square meters) divided by the surface area of the substrate (if the substrate were atomically smooth (no surface roughness)), also usually in square meters.

[0055] "Synergy" or "synergistic" means the interaction or cooperation between two or more substances, materials or reagents to produce a combined effect that is greater (positive synergy) or less (negative synergy) than the sum of their individual effects when acting alone.

[0056] "Thickness" means the length between the surface of the substrate and the top of the surface-modifying (e.g., ceramic) material.

[0057] "Third quartile pore diameter" means the pore diameter value at which the cumulative pore surface area measured in the direction of increasing pore diameter is equal to 75% of the total cumulative pore surface area determined by BJH gas adsorption / desorption measurements.

[0058] "Tortuosity" means the fraction Δl of the shortest path through a porous structure and the Euclidean distance Δx between the start and end points of that path.

[0059] "Tunable" means the ability of a material's function, property or quality to be changed or modified.

[0060] Selective coating and surface-modifying materials

[0061] Selective coating of a substrate (e.g., the surface of a heat exchanger) can be carried out in a variety of ways, such as: partial (selective) coating on a part of the substrate surface based on local corrosion resistance requirements or other needs, such as but not limited to restricting microbial growth in high-moisture areas (e.g., Legionella) or the movement of a liquid (such as water) away from the substrate, where some locations are uncoated and some are coated; completely coating the substrate with a first material A and partially coating a second material B on the first material (i.e., selectively coating the second material B on a part (one or more regions) of the surface of the first material A), where the second material can be the same as or different from the first material; and gradients within the coating on the substrate based on the need for protection against environmental or operating stress conditions.

[0062] The gradients herein are spatially variable with respect to at least one chemical or physical property. For example, the coating or surface-modifying material A can be a uniform material on the substrate surface or can include spatial gradients (variability) of one or more properties, such as but not limited to material density, pore size distribution, pore filling rate or thickness.

[0063] Additionally, an optional second material B can also be applied on material A, which can be a uniform material or can have spatial variability in one or more properties such as, but not limited to, the material density, pore size distribution, thickness, and / or pore filling rate of material A. In some embodiments, an optional third material C can also be selectively applied and can be a uniform material on or across the substrate directly below the material, or can have spatial variability in one or more properties such as, but not limited to, the material density, pore size distribution, thickness, and / or pore filling rate of material B. In some embodiments, material C is applied on a material stack such as, but not limited to, A-B-A, and can have spatial variability in one or more properties such as, but not limited to, the material density, pore size distribution, thickness, and / or pore filling rate of the material (such as material A) directly below material C. Other optional uniform or gradient material layers can also be included. The coating or surface modification material can be applied continuously over the entire substrate surface or in one or more discrete (selective) regions, such as the regions of the substrate that are subjected to environmental or operating stresses in applications of devices or assemblies in which the substrate is incorporated.

[0064] The gradient layers disclosed herein can include gradients in one or more properties of the structural layers. For example, the gradient can include higher porosity near the seam, variations in the thickness of the structural composite material on the panel, e.g., thicker near the bottom or edge due to drainage and drying during the impregnation process at a specific temperature, selective spraying of materials in selected regions, addition of an additional material coating in selected regions, configurations of the spraying application that result in more material being added at the leading edge, or compositional variations that affect the electrochemical potential.

[0065] The gradient can be formed during the processing of the structural layer, e.g., by changing the concentration levels (decreasing) of the reactants or components of the composition during processing, which results in a change in the composition through the coating thickness, and / or by changing the temperature during processing, such as the temperature of the processing bath, to change the structure or the component temperature during processing, or having variable temperature zones during processing, such as the hot and cold zones of the component, to produce thicker, thinner, or different materials, e.g., structured ceramic materials. Alterations in local chemical reactivity by mechanical agitation of the component, fluid advection, addition of local heat or light, pressure differences, and / or gravitational sedimentation differences can also be used to produce gradient properties. The drying and curing processes can also be used to produce property gradients by using selected temperature zones, drying orientations, and / or selective light addition.

[0066] In some embodiments, one or more coating or surface modification materials (e.g., Materials A - C) are structured ceramics, such as binderless ceramic surface modification materials, e.g., having pores that can be filled, unfilled, or partially filled, optionally in a way that creates a gradient with respect to the partial filling of pores with a second material. In one embodiment, the ceramic material includes a continuous pore network filled with a second material such as a polymeric material.

[0067] In some embodiments, the surface modification material can be a conversion coating or primer (e.g., but not limited to trivalent chromium phosphate, other chromates, fluozirconates, fluorotitanates, sol - gels, phosphates, bluing or black oxide coatings, or anodization).

[0068] In some embodiments, one or more surface modification materials are applied to a paint primer. For example, the deposited material can be a paint, such as latex, acrylic, alkane, alkene, alcohol, enamel, epoxy, silicone, polysilazane, fluoropolymer, or urethane. For example, the deposited material can be a natural or processed fatty acid, alcohol, hydrocarbon, or oil, such as linoleic acid, palmitic acid, oleic acid, glycerol, paraffin wax, turpentine, tall oil, linseed oil, palm oil, tung oil, or boiled linseed oil, hydrogenated fatty acids, refined glycerol, distilled paraffin wax, mineral oil, or refined palm oil.

[0069] In some embodiments, one or more surface modification materials are monolayer chemicals that can provide any of a range of properties, such as but not limited to wettability, sealant, optical, etc.

[0070] Many substrates have multi - metal components, such as copper - aluminum heat exchangers, steel - aluminum heat exchangers, brazed aluminum heat exchangers, screws and rivets in bridges and vehicles, and other components that contain composite interfaces. Selective protection in these composite scenarios can provide additional protection (e.g., selective anodic protection) for a variety of environments and galvanic corrosion - sensitive metal pairs in anodic / cathodic regions. Other substrates, whether compositionally uniform or non - uniform, include local regions that are vulnerable to corrosion due to local environments such as local wear, stagnant liquids, or air flow gradients.

[0071] In some embodiments, the substrate is a heat exchanger or a component thereof, such as a microchannel heat exchanger. Other embodiments include bridges, airplanes, vehicles, and boats or components thereof.

[0072] Non - limiting examples of the properties and composition of the coating or surface modifier include, for the layer as described herein, (“n”):

[0073] n 1 Conversion coating or primer - continuous coverage without gradient

[0074] n 2 Conversion coating or primer - continuous coverage with gradient

[0075] n 3 Conversion coating or primer - non - gradient selective (discrete) coverage

[0076] n 4 Conversion coating or primer - gradient selective coverage

[0077] n 5 Structured ceramic - non - gradient continuous coverage

[0078] n 6 Structured ceramic - gradient continuous coverage

[0079] n 7 Structured ceramic - non - gradient selective coverage

[0080] n 8 Structured ceramic - gradient selective coverage

[0081] n 9 Deposited single layer / paint / oil / resin - non - gradient continuous coverage

[0082] n 10 Deposited single layer / paint / oil / resin - gradient continuous coverage

[0083] n 11 Deposited single layer / paint / oil / resin - non - gradient selective coverage

[0084] n 12 Deposited single layer / paint / oil / resin - gradient selective coverage

[0085] Non - restrictive arrangements of coatings or surface modifiers (n = "A", "B", "C", …, where A, B, C, etc. are listed in the order of application or proximity to the substrate, e.g., where A is the bottom - most material in a material or multi - layer material in contact with or closest to the substrate) include:

[0086] A 1 -B 11 (Continuous coverage of conversion coating + selective coverage of paint)

[0087] A 1 -B 10 (Continuous coverage of conversion coating + continuous coverage of gradient paint)

[0088] A 1 -B 12 (Continuous coverage of conversion coating + selective coverage of gradient paint)

[0089] A 1 -B 6 (Continuous coverage of primer + continuous coverage of gradient structured ceramic)

[0090] A 1 -B 7 (Continuous coverage primer + Selective coverage structured ceramic)

[0091] A 1 -B 8 (Continuous coverage primer + Selective coverage gradient structured ceramic)

[0092] A 1 -B 5 -C 9 -D 11 (Continuous coverage conversion coating + Continuous coverage structured ceramic + Continuous coverage functional material layer + Selective coverage paint)

[0093] A 1 -B 5 -C 10 (Continuous coverage conversion coating + Continuous coverage structured ceramic + Continuous coverage gradient functional material layer)

[0094] A 1 -B 5 -C 11 (Continuous coverage conversion coating + Continuous coverage structured ceramic + Structural functional material layer)

[0095] A 1 -B 5 -C 12 (Continuous coverage conversion coating + Continuous coverage structured ceramic + Selective coverage gradient functional material layer)

[0096] A 3 (Selective coverage conversion layer)

[0097] A 5 -B 9 -C 11 (Continuous coverage structured ceramic + Continuous coverage functional material layer + Coverage selective paint)

[0098] A 5 -B 10 (Continuous coverage structured ceramic + Continuous coverage gradient functional material layer)

[0099] A 5 -B 11 (Continuous coverage structured ceramic + Selective coverage functional material layer)

[0100] A 5 -B 12 (Continuous coverage structured ceramic + Selective coverage gradient functional material layer)

[0101] A 6(Continuous Coverage Gradient Structured Ceramics)

[0102] A 6 -B 9 (Continuous Coverage Gradient Structured Ceramics + Continuously Covered Functional Material Layer)

[0103] A 6 -B 10 (Continuous Coverage Gradient Structured Ceramics + Continuously Covered Gradient Functional Material Layer)

[0104] A 6 -B 11 (Continuous Coverage Gradient Structured Ceramics + Selectively Covered Functional Material Layer)

[0105] A 6 -B 12 (Continuous Coverage Gradient Structured Ceramics + Selectively Covered Gradient Functional Material Layer)

[0106] A 7 (Selectively Covered Structured Ceramics)

[0107] A 7 -B 9 (Selectively Covered Structured Ceramics + Continuously Covered Functional Material Layer)

[0108] A 7 -B 11 (Selectively Covered Structured Ceramics + Selectively Covered Functional Material Layer)

[0109] A 8 (Selectively Covered Gradient Structured Ceramics)

[0110] A 9 -B 11 (Continuously Covered Single - Layer Coating + Selectively Covered Paint)

[0111] A 10 (Continuously Covered Gradient Paint)

[0112] A 11 (Selectively Covered Paint)

[0113] A 12 (Selectively Covered Gradient Paint)

[0114] Structured Ceramic Material

[0115] The continuous or discrete coating or surface modification material described herein can be a structured ceramic, such as a binderless (e.g., surface-fixed) ceramic, such as a binderless ceramic having a crystallinity greater than about 20%. In some embodiments, the structured ceramic is porous. Non-limiting examples of ceramic materials are provided in PCT / US19 / 65978, the entire content of which is incorporated herein by reference.

[0116] The ceramic material can include metal oxide and / or hydroxide ceramics, such as single-metal or mixed-metal oxide and / or hydroxide ceramics. In some embodiments, the ceramic material includes metal hydroxide and / or hydroxide ceramics, such as single-metal or mixed-metal oxide and / or hydroxide ceramics. In some embodiments, the ceramic material includes metal oxide and metal hydroxide ceramics, wherein the metal oxide and metal hydroxide include the same or different single metals or mixed metals. In some embodiments, the ceramic material includes metal oxide and / or metal hydroxide ceramics, wherein the substrate is hydrated with water or other compounds, resulting in a change in surface energy and potentially altering the ratio of the metal oxide to metal hydroxide composition of the ceramic. In some embodiments, the ceramic material includes metal hydroxide, wherein at least a portion of the metal hydroxide is in the form of a layered double hydroxide, such as at least about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the metal hydroxide is in the form of a layered double hydroxide.

[0117] In some embodiments, the "metal oxide" or "metal hydroxide" can be in the form of a hydrate of the metal oxide or metal hydroxide, respectively, or a portion of the metal oxide or metal hydroxide can be in the form of a hydrate of the metal oxide or metal hydroxide, respectively.

[0118] The mixed-metal oxide or mixed-metal hydroxide can respectively include, for example, oxides or hydroxides of more than one metal, such as but not limited to iron, cobalt, nickel, copper, manganese, chromium, titanium, vanadium, zirconium, molybdenum, tantalum, zinc, lead, tin, tungsten, cerium, praseodymium, samarium, gadolinium, lanthanum, magnesium, aluminum, or calcium.

[0119] In some embodiments, the ceramic material is a binderless ceramic material, i.e., deposited onto a substrate without a binder. In some embodiments, the ceramic material is fixed to the substrate.

[0120] In some embodiments, the ceramic material has an open porous structure. For example, it is characterized by one or more of the following: capable of achieving capillary rise of a liquid with a low surface tension greater than about 5 mm (e.g., less than about 25 mN / m, such as isopropyl alcohol) against gravity along the surface upward in a closed container within 1 hour; a surface area of about 0.1 m 2 / g to about 10,000 m 2 / g; an average pore diameter of about 10 nm to about 1000 nm or about 1 nm to about 1000 nm; a pore volume measured by mercury (Hg) intrusion porosimetry of about 0 to about 1 cc / g; and a tortuosity of about 1 to about 1000, where the tortuosity is defined as the "arc ratio" of the length of the fluid path to the shortest distance; and / or a permeability of about 1 to about 10,000 millidarcies.

[0121] In some embodiments, the ceramic material is porous with a porosity of about 5% to about 95%. In some embodiments, the porosity can be at least about or greater than about any one of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%. In some embodiments, the porosity is about 10% to about 90%, about 30% to about 90%, about 40% to about 80%, or about 50% to about 70%.

[0122] In some embodiments, the porous ceramic material has a permeability of about 1 to 10,000 millidarcies. In some embodiments, the permeability can be at least about any one of 1, 10, 100, 500, 1000, 5000, or 10,000 millidarcies. In some embodiments, the permeability is about 1 to about 100, about 50 to about 250, about 100 to about 500, about 250 to about 750, about 500 to about 1000, about 750 to about 2000, about 1000 to about 2500, about 2000 to about 5000, about 3000 to about 7500, about 5000 to about 10,000, about 1 to about 1000, about 1000 to about 5000, or about 5000 to about 10,000 millidarcies.

[0123] In some embodiments, the porous ceramic material includes a void volume of about 100 mm 3 / g to about 7500 mm 3 / g as determined by mercury intrusion porosimetry. In some embodiments, the void volume is at least about any one of 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, or 7500 mm3 Any of those in / g. In some embodiments, the void volume is about 100 to about 500, about 200 to about 1000, about 400 to about 800, about 500 to about 1000, about 800 to about 1500, about 1000 to about 2000, about 1500 to about 3000, about 2000 to about 5000, about 3000 to about 7500, about 250 to about 5000, about 350 to about 4000, about 400 to about 3000, about 250 to about 1000, about 250 to about 2500, about 2500 to about 5000 or about 500 to about 4000 mm 3 Any of those in / g.

[0124] The characteristics of the porous ceramic materials disclosed herein can lie in their interaction with liquid materials. As previously mentioned, the ceramic materials can be characterized by the ability to achieve capillary rise of a liquid with a low surface tension of greater than about 5 mm against gravity along the surface within 1 hour in a closed container (e.g., less than about 25 mN / m, such as isopropyl alcohol). Other solvents with a surface tension less than about 25 mN / m at 20 °C can be used, including but not limited to perfluorohexane, perfluoroheptane, perfluorooctane, n - hexane (HEX), polydimethylsiloxane (Baysilone M5), tert - butyl chloride, n - heptane, n - octane (OCT), isobutyl chloride, ethanol, methanol, isopropyl alcohol, 1 - chlorobutane, isoamyl chloride, propanol, n - decane (DEC), ethyl bromide, methyl ethyl ketone (MEK), n - undecane, cyclohexane. Other solvents with a surface tension >25 mN / m at 20 °C can be used, including: acetone (2 - acetone), n - dodecane (DDEC), isovaleronitrile, tetrahydrofuran (THF), dichloromethane, n - tetradecane (TDEC), carbon tetrachloride, n - hexadecane (HDEC), chloroform, 1 - octanol, butyronitrile, p - cymene, cumene, toluene, dipropylene glycol monomethyl ether, 1 - decanol, ethylene glycol monoethyl ether (ethyl cellosolve), 1,3,5 - trimethylbenzene (mesitylene), benzene, m - xylene, n - propylbenzene, ethylbenzene, n - butylbenzene, 1 - nitropropane, o - xylene, dodecylbenzene, diethyl fumarate, decalin, nitroethane, carbon disulfide, cyclopentanol, 1,4 - dioxane, 1,2 - dichloroethane, chlorobenzene, dipropylene glycol, cyclohexanol, hexachlorobutadiene, bromobenzene, pyrrole (PY), N,N - dimethylacetamide (DMA), nitromethane, diethyl phthalate, N,N - dimethylformamide (DMF), pyridine, methylnaphthalene, benzyl alcohol, ethyl anthranilate, iodobenzene, N - methyl - 2 - pyrrolidone, tricresyl phosphate (TCP), m - nitrotoluene, bromoform, o - nitrotoluene, phenyl isothiocyanate, α - chloronaphthalene, furfural (2 - furfural), quinoline, 1,5 - pentanediol, aniline (AN), polyethylene glycol 200 (PEG), methyl anthranilate, nitrobenzene, α - bromonaphthalene (BN), diethylene glycol (DEG), 1,2,3 - tribromopropane, benzyl benzoate (BNBZ), 1,3 - diiodopropane, 3 - pyridinemethanol (PYC), ethylene glycol (EG), 2 - aminoethanol, carbon tetrabromide, diiodomethane (DI), thiodiglycol (2,2'-thiodiethanol) (TDG), formamide (FA), glycerol (GLY), water (WA) and mercury.

[0125] The porous ceramic surface - modified materials can have the ability to achieve water capillary rise at various temperatures. These materials can have the ability to separate miscible materials and binary azeotropes (e.g., ethanol - water, ethyl acetate - ethanol or butanol - water) to break ternary azeotropes or remove pentanol from a mixture including ethanol and water.

[0126] The pores of the surface-modified porous ceramic material can include open pores filled with one or more gases, can include partially filled pores (e.g., partially filled with one or more solid materials), or can include fully or substantially filled pores (e.g., fully or substantially filled with one or more liquids and / or solid materials). In some embodiments, the pores are partially, substantially, or fully filled with a gas, liquid, or solid substance, or a combination thereof.

[0127] In some embodiments, the pores are partially filled with a first material and then partially or fully filled with a second material. In some embodiments, the second material is added as a material layer over the partially filled pores. In some embodiments, the first material is a gas, solid, or liquid, or a combination of gas, liquid, and / or solid substances. In some embodiments, the second material is a gas, solid, and / or liquid substance, or the environment (e.g., air). Examples include and the functions conferred thereby include changes in porosity, wicking, repellency, and / or wetting behavior; changes in the composite material (including the porous material and the second material) to alter electrical / dielectric properties, change mechanical properties such as abrasion resistance, hardness, toughness, tactile feel, elastic modulus, yield strength, yield stress, Young's modulus, surface (compressive or tensile) stress, and / or elasticity; changes in thermal properties such as thermal diffusivity, electrical conductivity, coefficient of thermal expansion, thermal interface stress, and / or thermal anisotropy; changes in optical properties such as emissivity, color, reflectivity, and / or absorption coefficient; changes in chemical properties such as corrosion, catalysis, reactivity, inertness, compatibility, fouling resistance, ion pump blockage, microbiological resistance, and / or microbiological compatibility; and / or as a substrate for biocatalysis.

[0128] In some embodiments, the first material interacts with the second material in a positive or negative synergistic manner to change one or more functional properties of the ceramic material, such as but not limited to wettability, hardness, elasticity, mechanical, electrical, piezoelectric, optical, adhesion, or thermal properties, microbial affinity or tolerance, alteration of biofilm growth, catalytic activity, permeability, aesthetic appearance, liquid repellency, and / or corrosion resistance.

[0129] Non-limiting materials that can be used to partially or completely fill the pores include molecules that can be incorporated into the surface, such as molecules having a head group and a tail group, where the head group is a silane, phosphonate or phosphonic acid, carboxylic acid, vinyl, hydroxide, thiol or ammonium compound. The tail group can include any functional group, such as a hydrocarbon, fluorocarbon, vinyl, phenyl and / or quaternary ammonium group. Other ceramic materials can also be partially or completely deposited into the pores. Polymers can also be partially or completely deposited into the pores. Ceramic materials can include, for example, one or more oxides of zinc, aluminum, manganese, magnesium, cerium, gadolinium and cobalt. In addition, ceramic materials can include any solid material that can be added to the surface modification material, including inorganic compounds of metal, non-metal or metalloid atoms held mainly by ionic and covalent bonds, such as clay, silica and glass. Polymers can include, for example, natural polymer materials, such as hemp, shellac, amber, wool, silk, natural rubber, cellulose and other natural fibers, sugars, hemicellulose and holocellulose, polysaccharides and bio-derived materials such as extracellular proteins, DNA, chitin. Synthetic polymers include, for example, polymers and copolymers containing polyethylene, polypropylene, polystyrene, polyvinyl chloride, synthetic rubber, phenolic resin (or phenoplast), neoprene, nylon, polyacrylonitrile, PVB, silicone, polyisobutylene, PEEK, PMMA and PTFE.

[0130] In some embodiments, the pores are partially filled with a thin composite polymer layer to produce a surface modification material having porosity and functionality provided by the polymer. In other embodiments, the pores are completely filled with a thick polymer layer to produce a surface modification material having a thick polymer layer with the composite properties of the porous matrix material and the polymer layer. The polymers described in the compositions herein include copolymers.

[0131] In some embodiments, the pores are partially or completely filled with a layer of material deposited on the surface of the surface modification material. In some embodiments, a layer of material that adds one or more functional groups to the surface modification material is deposited, such functional groups including but not limited to ammonium groups (e.g., quaternary ammonium groups), alkyl groups, perfluoroalkyl groups, fluoroalkyl groups. In some embodiments, a polymer or ceramic layer is deposited. In one embodiment, a ceramic top surface layer is deposited, which is the same or different ceramic as the ceramic of the binderless porous ceramic material on the substrate. Examples of the functional groups and functions thus imparted include quaternary ammonium groups for antimicrobial function, alkyl chains for hydrophobicity and hydrocarbon affinity, perfluoroalkyl groups for water and oil repellent functions, polymers for mechanical property functions, and other ceramics for aesthetic, optoelectronic or anticorrosion functions.

[0132] In some embodiments, the pores are partially or completely filled with a gas, liquid, or solid material or a combination thereof, and the composition further comprises a top surface material layer on the ceramic material, and the top surface material imparts one or more functions such as, but not limited to, wettability with a liquid and / or selective separation of compounds in a liquid. In certain embodiments, the top surface material is a material separate from the material with which the pores are partially, substantially, or completely filled, and does not itself fill or squeeze into the pores. In some embodiments, the top surface material interacts with the material in the pores. For example, the top surface material can interact with the material in the pores to provide one or more functions such as, but not limited to, thermal management, regulation of electrochemical reactivity, and / or regulation of mechanical properties. In certain embodiments, the top surface material is the surrounding environment in contact with the binderless porous ceramic material.

[0133] In some embodiments, the pores are substantially or completely filled with a polymer or ceramic material.

[0134] In some embodiments, the material in the pores interacts with the ceramic material. Examples of such materials and the functions conferred thereby include oxidation of surface-modifying materials by ambient liquids or vapors, condensation of trace components (e.g., environmental pollutants), capture or oxidation of harmful environmental materials such as CO or H 2 S and / or collection and retention of materials in the environment.

[0135] In some embodiments, moisture in the environment or added to the pores interacts with the material in the pores to modify the material in the pores or the surface-modifying material. Examples of such materials and the functions conferred thereby include changes in wetting behavior, changes in optical properties, changes in oxidation state or reactivity, changes in evaporation rate, frosting, icing, or condensation.

[0136] In some embodiments, the material in the pores can be designed to interact with the ceramic material to “tune” the properties of the overall surface. Examples of tunable properties include, but are not limited to, wettability, hardness, microbial resistance, catalytic activity, corrosion resistance, color, and / or photochemical activity.

[0137] In some embodiments, the ceramic surface-modifying material and the material in the pores interact in a synergistic manner, e.g., enhancing or reducing at least one function of the surface-modifying material and / or the material in the pores as compared to the functions of the surface-modifying material and / or the material in the pores alone. In some embodiments, two or more materials in the pores interact in a synergistic manner, e.g., enhancing or reducing at least one function of at least one of the materials in the pores as compared to the functions of the materials alone.

[0138] In some embodiments, the ceramic surface modification material is asymmetric, e.g., not spherical, cylindrical, cubic, or otherwise ordered pore morphology having a well-defined, relatively constant normal distribution of surface area to volume, characterized by the ratio of the pore diameter at the first quartile to the pore diameter at the third quartile as a function of the thickness of the binderless ceramic surface modification. In particular, the pore morphology is asymmetric about its center when compared to spherical, cylindrical, or cubic structures. Non-limiting examples of asymmetric pores are described in PCT application No. PCT / US19 / 39743, which is incorporated herein by reference in its entirety.

[0139] The porous ceramic surface modification material can be characterized by a broad pore size distribution that varies with distance from the substrate. In particular, the pore structure at a given distance from the substrate can be locally characterized, e.g., as described herein, and have different characterizations at different distances. The resulting asymmetry is determined in situ by a combination of the substrate, ion mobility, and processing conditions such as temperature, pressure, and concentration. The degree of asymmetry can be further modified by bulk methods such as mixing, stirring, electric field modulation, and slot filtration, or by surface-directed processing methods such as shear rate, impinging streams, or surface charge modification and modulation. The asymmetry can be determined ex situ by various methods such as etching, track etching, ion beam milling, oxidation, photocatalysis, or by additional methods. These methods refer to materials with a narrower or symmetric pore structure having thickness and / or pore depth, such as zeolites, track-etched membranes, or expanded PTFE membranes.

[0140] In some embodiments, the porous ceramic surface modification material includes mesopores having an average pore diameter in the range of about 2 nm to about 50 nm. In other embodiments, the average pore diameter ranges from about 50 nm to about 1000 nm. In some embodiments, the binderless porous ceramic material includes an average pore diameter of about 2 nm to about 20 nm. In some embodiments, the average pore diameter is at least about any one of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nm. In some embodiments, the average pore diameter is about any one of 2 to about 5, about 4 to about 9, about 5 to about 10, about 7 to about 12, about 9 to about 15, about 12 to about 18, about 15 to about 20, about 4 to about 11, about 5 to about 9, about 4 to about 8, or about 7 to about 11 nm.

[0141] The ceramic surface modification material may include one or more metal oxides and / or metal hydroxides (and / or their hydrates). Non-limiting examples of metals that may be included in the ceramic compositions disclosed herein include: zinc, aluminum, manganese, magnesium, cerium, copper, gadolinium, tungsten, tin, lead, and cobalt. In some embodiments, the ceramic material includes transition metals, Group II elements, rare earth elements (e.g., lanthanum, cerium, gadolinium, praseodymium, scandium, yttrium, samarium, or neodymium), aluminum, tin, or lead. In some embodiments, the ceramic material includes two or more metal oxides (e.g., mixed metal oxides), including but not limited to zinc, aluminum, manganese, magnesium, cerium, praseodymium, and cobalt.

[0142] In some embodiments, the ceramic surface modification material includes: a mixture of oxides and / or hydroxides of zinc and aluminum; a mixture of ZnO and Al 2 O 3 ; and zinc aluminate; a mixture of materials containing any and / or all phases containing Zn, Al, and oxygen; a mixture of oxides and / or hydroxides of manganese and magnesium; manganese oxide; aluminum oxide; mixed metal manganese oxides and / or hydroxides; a mixture of oxides and / or hydroxides of magnesium and aluminum; a mixture of oxides and / or hydroxides of magnesium, cerium, and aluminum; a mixture of oxides and / or hydroxides of zinc, gadolinium, and aluminum; a mixture of oxides and / or hydroxides of cobalt and aluminum; a mixture of oxides and / or hydroxides of manganese and aluminum; a mixture of oxides and / or hydroxides of cerium and aluminum; a mixture of oxides and / or hydroxides of iron and aluminum; a mixture of oxides and / or hydroxides of tungsten and aluminum; a mixture of tin and aluminum oxides; tungsten oxide and / or tungsten hydroxide; magnesium oxide and / or magnesium hydroxide; manganese oxide and / or manganese hydroxide; tin oxide and / or tin hydroxide; or zinc oxide and / or zinc hydroxide.

[0143] In some embodiments, at least one metal in the ceramic material is in a 2 + oxidation state.

[0144] In some embodiments, the ceramic surface modification material includes one or more oxides and / or hydroxides of zinc, aluminum, manganese, magnesium, cerium, gadolinium, and cobalt, and the substrate is aluminum or an aluminum alloy.

[0145] In some embodiments, the ceramic surface modification material is superhydrophobic. In some embodiments, the surface modification material is highly hydrophobic. In some embodiments, compared to a substrate that does not include the ceramic material, the surface modification material includes one or more functional properties selected from: wettability, hardness, elasticity, mechanical, electrical, piezoelectric, electromagnetic, optical, adhesion, or thermal properties, microbial affinity or tolerance, alteration of biofilm growth, catalytic activity, permeability, aesthetic appearance, and corrosion resistance.

[0146] In some embodiments, a functional material layer (e.g., a top layer material) is deposited on a ceramic material. Examples of such materials include, but are not limited to, quaternary ammonium groups for antimicrobial functionality, alkyl chains for hydrophobic and hydrocarbon affinity, perfluoroalkyl groups for water and oil repellency functionality, polymers for mechanical property functionality, and other ceramics for aesthetic, optoelectronic, or anticorrosion functionality. Examples of functions imparted by such materials include, but are not limited to, changes in porosity, wicking, repellency, and / or wetting behavior; changes in composite materials (including porous materials and a second material) to alter electrical / dielectric properties, to change mechanical properties such as abrasion resistance, hardness, toughness, tactile feel, modulus of elasticity, yield strength, yield stress, Young's modulus, surface (compressive or tensile) stress, tensile strength, compressive strength, and / or elasticity; changes in thermal properties such as thermal diffusivity, electrical conductivity, coefficient of thermal expansion, thermal interface stress, thermal anisotropy, to change optical properties such as emissivity, color, reflectivity, and / or absorption coefficient, to change chemical properties such as corrosion, catalysis, reactivity, inertness, compatibility, stain resistance, ion pump blockage, antimicrobial resistance, and / or microbial compatibility, to promote adhesion of subsequent material layers, and / or to serve as a substrate for biocatalysis.

[0147] In some embodiments, the ceramic surface modification material has resistance to ultraviolet radiation degradation as compared to a substrate material such as a polymer or any of the substrate materials disclosed herein.

[0148] In some embodiments, the ceramic surface modification material includes a thickness of from about 0.5 microns to about 20 microns. In some embodiments, the ceramic material includes a thickness of from about 0.2 microns to about 25 microns. In some embodiments, the thickness is at least about any one of 0.2, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 microns. In some embodiments, the thickness is from about 0.2 to about 0.5, from about 0.5 to about 1, from about 1 to about 5, from about 3 to about 7, from about 5 to about 10, from about 7 to about 15, from about 10 to about 15, from about 12 to about 18, from about 15 to about 20, from about 18 to about 25, from about 0.5 to about 15, from about 2 to about 10, from about 1 to about 10, from about 3 to about 13, from about 0.5 to about 15, from about 0.5 to about 5, from about 0.5 to about 10, or from about 5 to about 15 microns.

[0149] In some embodiments, the ceramic surface modification material is characterized by a water contact angle of from about 0° to about 180°. In other embodiments, the water contact angle is less than about 30 degrees. In other embodiments, the water contact angle is greater than about 150 degrees.

[0150] In some embodiments, the ceramic surface modification material includes about 1.1 m per square meter of projected substrate area 2Up to about 100 m 2 of surface area. In some embodiments, the ceramic material comprises from about 10 m 2 to about 1500 m 2 of surface area per square meter of projected substrate area. In some embodiments, the surface area is at least about 10, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450 or 1500 m 2 per square meter of projected substrate area. In some embodiments, the surface area is from about 10 to about 100, about 50 to about 250, about 150 to about 500, about 250 to about 750, about 500 to about 1000, about 750 to about 1200, about 1000 to about 1500, about 70 to about 1000, about 150 to about 800, about 500 to about 900, or about 500 to about 1000 m 2 per square meter of projected substrate area.

[0151] In some embodiments, the ceramic material comprises from about 15 m 2 to about 1500 m 2 of surface area per gram of ceramic material. In some embodiments, the surface area is at least about 15, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150, 1200, 1250, 1300, 1350, 1400, 1450 or 1500 m 2 per gram of ceramic material. In some embodiments, the surface area is from about 15 to about 100, about 50 to about 250, about 150 to about 500, about 250 to about 750, about 500 to about 1000, about 750 to about 1200, about 1000 to about 1500, about 50 to about 700, about 75 to about 600, about 150 to about 650, or about 250 to about 700 m 2 per gram of ceramic material.

[0152] Substrate

[0153] The substrate on which one or more coatings or surface modification materials as described herein are applied or deposited can be composed of any material suitable for structural or functional properties or functional applications, for example, in a device such as a heat exchanger. In some embodiments, the substrate is aluminum or contains aluminum (e.g., aluminum alloy), ferrous alloy, zinc, zinc alloy, copper, copper alloy, nickel alloy, nickel, titanium alloy, titanium, cobalt-chromium-containing alloy, glass, polymer, copolymer, natural material (e.g., cellulose-containing natural material), or plastic.

[0154] In some embodiments, the substrate comprises a metal and the native metal in the ceramic surface modification material as described herein is different from the native metal in the substrate. The native metal is the metal that constitutes at least about 50%, 60%, 70%, 80%, 90%, or 95% of the total metal in the substrate or ceramic material, e.g., as determined by x-ray diffraction based on atomic metal. Examples of substrate native metals include, but are not limited to, aluminum, iron, copper, zinc, nickel, titanium, and magnesium. Examples of ceramic native metals include, but are not limited to, zinc, aluminum, manganese, magnesium, cerium, copper, gadolinium, tungsten, tin, lead, and cobalt.

[0155] In some embodiments, the substrate comprises a metal that is capable of reacting (e.g., dissolving) under reaction conditions that permit local dissolution of the substrate metal, and the substrate metal is incorporated into the substrate modification material, such as a ceramic material, e.g., a binderless porous ceramic material. For example, an aluminum substrate can provide aluminum (e.g., Al 2+ ), which is incorporated into the ceramic material when the ceramic material is deposited on the substrate.

[0156] The following examples are intended to illustrate and not limit the invention.

[0157] Examples

[0158] The substrate or component to which the coating is applied generally undergoes a process starting with: (a) surface preparation or cleaning, followed by (b) a conversion or primer step, (c) deposition of a structured ceramic, and (d) deposition of another ceramic layer, conversion of the deposited structured ceramic layer, or deposition of a single layer, paint, oil, or resin. In certain cases, some steps can be bypassed to obtain different results.

[0159] (a) Surface preparation and cleaning steps: In the following examples, the surface is prepared as follows. The metal substrate or component is cleaned or wiped with isopropyl alcohol (IPA) and a towel in a tank to remove any residual oil. Then, the part is immersed in a caustic etching bath with a pH > 10 at a nominal room temperature of 20 °C until the surface appears dull, or for about 15 minutes. Then the substrate or component is rinsed in water to remove any residual caustic or loosely adhered material. Next, the part is immersed in a nitric acid solution with a pH below 3 and a temperature of 20 °C to remove stains, etching reaction products, intermetallic compounds, and surface oxides, or to pickle the substrate, thereby exposing a clean surface. Other surface preparation techniques for producing a clean surface are also applicable. The polymer and cellulose substrates are cleaned or wiped with isopropyl alcohol on a towel to remove any residues.

[0160] (b) Conversion coating or primer: Unless otherwise specified, the conversion coatings and / or primers in the following examples are considered continuous. By partial chemical exposure and / or by selective coverage using a masking agent. The conversion coating or primer consists of a film produced by chemical or electrochemical conversion of the substrate, which produces a thin film with low porosity when compared to the following structural ceramic deposition layer. The conversion coating is typically an oxide, phosphate, or chromate, and is carried out at a low pH. The application methods include dip coating, which may include applying an electrical bias in some cases, or spraying a chemical solution onto the substrate to be coated. Inorganic materials such as aqueous acidic chromium(III) phosphate are combined with other metal and anion reactants to change the solution pH. The solution consisting of insoluble solid materials is heated from 40 °C to 100 °C, and the solution / substrate contact is maintained for 1 to 90 minutes. Surfactants can be added to increase the film composition or substrate conversion reaction rate. The exposed substrate surface reacts to form a dense layer, where the conversion of the substrate surface provides a diffusion barrier to limit further reaction. A heat stabilization step can be used to accelerate the formation of the conversion layer.

[0161] Unless otherwise specified, the conversion layer or primer is dried before introducing the structural ceramic deposition method or depositing a single layer / paint / oil / resin layer. Unless otherwise specified, the processing time between applying the conversion layer and subsequent treatment is less than 24 hours.

[0162] (c) Structured or porous ceramic deposition: Unless otherwise specified, the structured ceramic deposition in the following examples is considered continuous. By partial chemical exposure and / or by using a masking agent for selective coverage. Then the substrate or component is placed in a structured ceramic deposition bath containing 20 - 500 mM metal nitrate and a similar amount of amine (such as ethylenediamine, hexamethylenetetramine or urea), and allowed to react at a reaction temperature of 30 °C - 90 °C before the substrate is inserted. The component is kept in the bath until the turbidity drops below 100 NTU, or for about 5 minutes to about 90 minutes. The substrate or component is removed, drained, rinsed and placed in an oven to be dried and / or calcined at about 100 °C - 800 °C for several hours. Then the part is cooled to room temperature. Unless otherwise specified, the structural ceramic is dried before depositing a single layer / paint / oil / resin layer.

[0163] (d) Deposited single layer / paint / oil / resin - continuous / selective coverage with / without gradient: Unless otherwise specified, the deposited single layer / paint / oil / resin in the following examples is considered continuous. By partial contact and / or by using a masking agent for selective coverage. Unless otherwise specified, before the post - processing step, the structural ceramic produced in (c), such as the converted deposited ceramic or the second ceramic that partially or completely fills the porous interconnected ceramic network for deposition, is dried. Unless otherwise specified, the substrate temperature is generally maintained at room temperature, and the deposition solution is generally maintained at ambient room temperature. The deposited single layer / paint / oil / resin consists of materials applied to the upper surface layer by painting, spraying, dipping, wicking, vapor condensation, and may include heat treatment or catalytic treatment to accelerate the drying of the material and / or increase the chemical or mechanical adhesion to the upper surface layer. These processing steps are described in more detail in each example as needed.

[0164] Example 1.A 1 -B 11 -Conversion coating + Selective covering paint

[0165] The heat exchanger (HX) is completely coated in a conversion coating, such as a trivalent chromium process (TCP), by impregnation or spraying processes. The manifold and the brazed joints of the manifold and pipes are then painted by local dipping or spraying at specific locations on the component. In this particular case, the entire coil is completely immersed to apply the conversion coating. In a subsequent step, the manifold of the heat exchanger is sequentially immersed in a paint bath. The converted area of the coil will have corrosion protection while maintaining its heat transfer coefficient, while the painted manifold and manifold - pipe joints will have an additional anti - corrosion protection layer.

[0166] Example 2.A 1 -B 10 -Conversion coating + gradient paint

[0167] The HX is completely coated in a conversion coating, such as TCP, applied to the entire HX through an impregnation step. This processing step is followed by a complete coating of paint that is thicker at the bottom of the HX than at the top, which is applied by dip coating and prompts the paint to drain in a preferred orientation, thereby creating a thicker layer in that orientation. A complete spray application with an additional channel of a sprayer at the desired thicker locations would be similar. The areas with the thicker paint coating will have enhanced corrosion resistance. Since the exposure time of the accumulated liquid is shorter, the top of the HX requires less paint, thus reducing the production cost of having a uniform thickness across the entire HX while providing the same amount of corrosion protection, which also reduces heat HX losses by minimizing the application of paint to the areas mainly requiring protection and / or restricting the material applied to the critical heat exchange surfaces.

[0168] Example 3.A 1 -B 10 -Conversion coating + gradient paint

[0169] The HX is completely coated in a conversion coating, such as TCP, and subsequently completely coated with a paint that is thicker at the bottom than at the top, which is applied in sequential dip coating steps with sequentially shallower dip depths. When water accumulates at the bottom of the coil during use, the thicker paint coating at the bottom has enhanced corrosion resistance. Since the exposure time of the accumulated liquid is shorter, the top of the HX requires less paint, thus reducing the production cost of having a uniform thickness across the entire HX while providing the same amount of corrosion protection.

[0170] Example 4.A 1 -B 12 -Conversion coating + Selective coverage gradient paint

[0171] An aluminum-containing marine alloy that can form a hull is completely coated with a conversion coating, such as TCP. The alloy is then coated with a corrosion-resistant paint by contact or spraying. In areas where additional corrosion protection is required, such as near the waterline and at the bottom of the hull, the paint is applied in multiple layers to provide scratch protection. The thicker paint layers increase the higher corrosion resistance of the areas most exposed to the corrosive environment.

[0172] Example 5.A 1 -B 6 -Primer + Gradient Structured Ceramic

[0173] The finned tube HX coil is completely coated with a corrosion-resistant primer, such as TCP or a similar phosphate coating. The HX is then completely modified with a ceramic surface modifier in an impregnation deposition system. The speed of the deposition fluid is varied in different areas of the coil, thereby changing the composition of the structured ceramic in the areas with varying speeds. This method can be used to create a pore size gradient on the coil. Different pore sizes create variable wicking patterns, which can carry water away from the areas prone to corrosion.

[0174] Example 6.A 1 -B 7 -Primer + Selectively Covered Structured Ceramics

[0175] The brazed aluminum HX is fully coated with a ceramic surface modifier primer having corrosion resistance properties, such as TCP or a similar phosphate coating. Then the manifold and the manifold-pipe brazed joints are coated with a multi-layer structured ceramic that prevents corrosive solutions from reaching the HX surface at the most vulnerable areas. The structured ceramic material also changes the way rain, condensate, and other applied liquids remain on the surface. As an example, the structured ceramic layer can have a low contact angle, resulting in a thinner liquid layer at the application location, which will lead to faster drying of the surface.

[0176] Example 7.A 1 -B 8 -Primer + Selective coverage gradient-structured ceramic

[0177] The HX is fully coated with a primer or conversion coating having corrosion resistance properties, such as TCP or cerium dioxide. Then the upper half of the HX is modified with a structured ceramic surface modifier, during which the shear rate is changed to produce a pore size gradient towards the top of the HX. The gradient of the pore size causes water to wick towards the top of the HX, away from the most vulnerable areas of the HX.

[0178] Example 8.A 1 -B 5 -C 9 -D 11 -Primer + Structured Ceramic + Functional Material Layer + Selective Overlay Paint)

[0179] The brazed aluminum HX is fully coated with a primer coating, followed by a structured ceramic surface modifier and an optional layer of functional material such as stearic acid to provide surface energy modification. Then the manifold and the manifold-pipe joints are painted by spraying or dipping to provide additional corrosion protection or aesthetic appearance. The main part of the coil with the functional material layer has a higher contact angle and prevents water from staying on the surface and increases the heat capacity, while the less functional areas prone to corrosion are protected by corrosion-resistant paint.

[0180] Example 9.A 1 -B 5 -C 10 -Conversion coating + Structured ceramic + Functionally graded material layer

[0181] The marine alloy that can form the hull is fully coated in a conversion coating, such as TCP, and then fully coated with a structured ceramic surface modifier. Then the hull is modified with a functional material layer to produce a superhydrophobic surface. Applying the functional material layer makes the bow of the hull more hydrophobic than the stern. The superhydrophobic surface allows the ship to more effectively reduce drag and / or be more durable at the point of the highest water shear rate during operation, while the TCP and the ceramic surface modifier protect the rest of the hull from seawater corrosion.

[0182] Example 10.A 1 -B 5 -C 11 -Conversion coating + structured ceramic + selectively covered functional material layer

[0183] The HX is fully coated with a conversion coating and then coated with a structured ceramic surface modifier. The lower half of the coil is layered with a functional material to produce a superhydrophobic surface. The lower half of the coil prevents water condensation and prevents water from accumulating at the fabricated joints and design features (such as manifold-pipe joints, fin-pipe joints, or louvers). As the water accumulation in the most vulnerable areas of the coil decreases, the most corrosion-prone areas of the coil are protected.Example 11.A 1 -B 5 -C 12 -Conversion coating + Structured ceramic + Selective Covered gradient functional material layer

[0184] The HX is fully coated with a conversion coating and then coated with a structured ceramic surface modifier. Then the coiled tube is coated in a corrosion-resistant functional material layer that is thicker on the outer side of the HX than on the inner side. This protects the outer side of the HX (e.g., the environment or the air flow) from a corrosive environment (acid rain, cat urine, etc. or pollutants in the air flow). While the inner side (e.g., the side not exposed to environmental conditions or air flow) exhibits a limited reduction in heat transfer performance. Overall, the pressure drop is reduced relative to a uniform thickness coverage.

[0185] Example 12.A 3 - Selective overcoating conversion coating

[0186] The brazed aluminum HX is partially coated with a conversion coating on the manifold, and the brazed joints of the manifold and the pipes are applied by selectively dipping into a processing bath. The coated area prevents corrosion in the most corrosion-prone areas.

[0187] Example 13.A 5 -B 9 -C 11 -Structured ceramic + functional material layer + selective coating paint

[0188] The HX is fully coated in a structured ceramic surface modifier without a binder, followed by a functional material layer that enhances hydrophobicity to form a superhydrophobic surface. The manifold and the brazed joints of the manifold and the pipes are painted to produce a more corrosion-resistant coiled tube area. The superhydrophobic area of the coiled tube prevents water accumulation during use, while the painted manifold and manifold-pipe joints protect the more vulnerable areas from corrosion.

[0189] Example 14.A 5 -B 10 -Structured ceramics + functionally graded material layer

[0190] The HX is fully coated with a binder-free structured ceramic surface modifier. Then the coiled tube is coated in a corrosion-resistant functional material layer that is thicker on the outer side of the HX than on the inner side. This protects the outer side of the HX from a corrosive environment (acid rain, cat urine, etc.), while the inner side exhibits a limited reduction in heat transfer performance. Overall, the pressure drop is reduced relative to a uniform thickness coverage.

[0191] Example 15.A 5 -B 11 -Structured ceramics + Selective covering functional material layer

[0192] The brazed aluminum heat exchanger is completely coated with a binder-free structured magnesium oxide ceramic surface modifier, which is deposited in an aqueous solution of magnesium nitrate at 25 to 100 mM and a similar amount of hexamethylenetetramine at a temperature of about 50 °C to 80 °C for a period of about 15 to 90 minutes. Then the coil is calcined at a temperature of about 400 °C for about 1 hour. The coil is cooled and then, at a temperature of about 50 °C to 80 °C, immersed a second time in an aqueous solution of magnesium nitrate at 25 to 100 mM and a similar amount of hexamethylenetetramine for a period of about 15 to 90 minutes. Then the coil is calcined a second time at a temperature of about 400 °C for about 1 hour. Then the coil is cooled and partially immersed in a solution containing room temperature vulcanizing (RTV) silicone at a concentration of 0.5 wt% to 10 wt% in tert-butyl acetate, preferably about 2 wt%. The heat exchanger is immersed such that approximately half of the heat exchanger is in the solution and approximately half of the heat exchanger is in the vapor space above the solution. The heat exchanger is immersed for about 10 to 300 minutes, preferably about 30 minutes. Then the heat exchanger is placed in air for 24 to 72 hours, where the RTV silicone forms a superhydrophobic functional layer on the surface of the heat exchanger with a contact angle >120°. Then the unfunctionalized portion of the heat exchanger is placed in an aqueous solution containing 0.1 wt% to 10 wt%, preferably about 5 wt% of aminoethylaminopropyl sesquisiloxane. The heat exchanger is immersed for 10 minutes to 240 minutes, preferably about 30 minutes. The heat exchanger is thoroughly rinsed with deionized water to remove any residual solution from the surface and annealed in an oven at a temperature of 90 °C and 140 °C, preferably about 110 °C, for 30 minutes to 300 minutes, preferably about 60 minutes. The sesquisiloxane-functionalized structured ceramic is hydrophilic and has a water contact angle <60°.

[0193] On the finished heat exchanger, there is an interface between the RTV-functionalized ceramic surface and the sesquisiloxane-functionalized ceramic surface. On the RTV side of this interface, water droplets bead up and roll off the surface. On the sesquisiloxane-functionalized ceramic surface, water droplets wet the surface and spread along the surface.

[0194] Example 16.A 5 -B 11 -Structured ceramic + Selectively coated functional material layer

[0195] The HX is completely coated with a binder-free structured ceramic surface modifier containing oxides / hydroxides of magnesium and aluminum as described above. At a temperature of about 60 °C to 80 °C, the HX is immersed in an aqueous solution of magnesium nitrate at 25 to 75 mM containing a similar amount of hexamethylenetetramine for a period of about 30 to 120 minutes. Then the coil is calcined at a temperature of about 400 °C to 600 °C for about 1 hour. Subsequent treatment is carried out by immersing half of the coil in a bath containing the chemical substances of the functional material layer. The functional material hexadecylphosphonic acid layer is applied to the lower half of the coil. The functional material layer produces a superhydrophobic surface on the lower half of the coil.

[0196] The heat exchanger is then assembled into the controlled air stream and cooled below the dew point of the air stream using chilled ethylene glycol. The upper half of the heat exchanger that only contains the structural ceramic layer produced condensate during the test, which remained in the heat exchanger body. The lower part of the heat exchanger treated with a functional material layer that creates a superhydrophobic surface (contact angle > 150 degrees) produced condensate that demonstrated heat exchange, but the condensate did not remain in the heat exchanger body during the wind tunnel test in which condensation occurred therein.

[0197] Example 17.A 5 -B 12 -Structured ceramics + functionally graded material layer

[0198] The brazed aluminum heat exchanger is completely coated with a binder-free structured magnesium oxide ceramic surface modifier that is deposited for a period of about 30 to 90 minutes in an aqueous solution of magnesium nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine at a temperature of about 60 °C to 80 °C. The coil is then calcined at a temperature of about 400 °C to 600 °C for about 1 hour. The coil is cooled and, at a temperature of about 50 °C to 80 °C, is immersed a second time in an aqueous solution of magnesium nitrate at 25 to 100 mM and a similar amount of hexamethylenetetramine for a period of about 15 to 90 minutes. The coil is then calcined a second time at a temperature of about 400 °C for about 1 hour. Two different solutions are produced, one being a solution containing room temperature vulcanizing (RTV) silicone at a concentration of 0.5 wt% to 10 wt%, preferably 2 wt% in tert-butyl acetate. The other solution is an aqueous solution containing aminoethylaminopropyl sesquisiloxane at a concentration of 0.1 wt% to 10 wt%, preferably about 5 wt%. The heat exchanger is placed in a spray chamber and the solutions are each sprayed in such a way that one side of the heat exchanger is sprayed with the RTV solution and the other side is sprayed with the aminoethylaminopropyl sesquisiloxane solution for 1 minute to 30 minutes, preferably about 5 minutes. The heat exchanger is annealed in an oven at a temperature of 90 °C to 140 °C, preferably about 110 °C for 30 minutes to 300 minutes, preferably about 60 minutes. The sesquisiloxane-functionalized structured ceramic is hydrophilic and has a water contact angle of < 60°, while the RTV-functionalized structured ceramic is hydrophobic and has a contact angle of > 120°.

[0199] On the finished heat exchanger, due to the spray pattern, there is a gradient interface between the RTV-functionalized ceramic surface and the sesquisiloxane-functionalized ceramic surface. When water is sprayed onto the heat exchanger, the water droplets bounce off the hydrophobic-functionalized surface and are wicked into the fin arrays on the hydrophilic-functionalized surface. When water condenses or is introduced onto the surface, it can flow from the hydrophobic region to the hydrophilic region and improve the heat transfer of the surface.

[0200] Example 18.A 5 -B 12 -Structured ceramic + selectively coated gradient functional material layer

[0201] The aluminum plate is modified with a structured ceramic material of manganese oxide and aluminum oxide, and the material is deposited in an aqueous solution of manganese nitrate at 50 to 150 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 120 minutes at a temperature of about 70 °C to 80 °C. Then the plate is baked at a temperature of about 400 °C for about 1 hour. Then the plate is selectively coated with a sealant material, such as a drying oil, such as tung oil or linseed oil, or a wax, such as paraffin wax or beeswax, such that about 10% of the top of the plate is not covered with oil or wax. This allows for electrical contact with the sample and can be used as an electrode for a battery or capacitor.

[0202] Example 19.A 6 - Gradient-structured ceramics

[0203] The HX coil is fully coated with a magnesium-based structured ceramic surface modifier containing oxides / hydroxides of magnesium and aluminum. At a temperature of about 60 °C to 80 °C, the surface is deposited in an aqueous solution of magnesium nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. Then the coil is calcined at a temperature of about 400 °C to 600 °C for about 1 hour. The shear rate of the reaction chemical mixture varies in different regions adjacent to and along the coil, which produces a thickness gradient of the surface modifier. The heat exchanger is treated to apply the structured ceramic as described above. The recirculation system moves the treatment liquid from the bottom of the immersion tank to the pump and filter to remove suspended solids from the liquid flow. The liquid returns to the immersion tank containing the heat exchanger through a liquid injector, which focuses and amplifies the liquid movement adjacent to the injector. The recirculated fluid is directed to the midpoint of a manifold and along the length of the heat exchanger. Regions with higher shear rates have an increased amount of ceramic modifiers with different pore sizes. The deposition level increase is evidenced by visually observing the color of the material along the manifold and the heat exchanger surface. The color of the regions where deposition increase is observed is whiter than the rest of the heat exchanger, which has a gray appearance. X-ray fluorescence (XRF) measurements confirm that the whiter-looking regions have a higher amount of magnesium oxide and aluminum oxide surface modifiers compared to adjacent regions that look darker in color. These regions with thicker structural layers can provide additional protection against corrosive elements from the surrounding environment.

[0204] Example 20.A 6 - Gradient-structured ceramics

[0205] The HX coil is fully coated with a structured ceramic surface modifier. At a temperature of about 60 °C to 80 °C, the coil is placed in an aqueous solution of magnesium nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. The coil is then calcined at a temperature of about 400 °C to 600 °C for about 1 hour. During the process, the temperature, concentration, and shear rate are varied to produce a denser structure with smaller pore sizes closer to the fins and a less dense structure with increased pore sizes in the ceramic deposits further away from the fins. The gradient of the ceramic structure with the surface modifier thickness enhances the water absorption characteristics in the outer region of the ceramic deposit to reduce the drying time, while the increased density and smaller porosity towards the fin surface of the HX minimize the amount of water in contact with the substrate. This increases the drying time and the frosting time while inhibiting corrosion of the surface.

[0206] Example 21.A 6 -B 9 -Gradient-structured ceramic + functional material layer

[0207] The HX is fully coated with a magnesium oxide-based structured ceramic surface modifier. At a temperature of about 60 °C to 80 °C, the coil is placed in an aqueous solution of magnesium nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. The coil is then calcined at a temperature of about 400 °C to 600 °C for about 1 hour. The shear rate varies in different regions along the coil, producing a pore size gradient and changing the morphology of the ceramic surface. The HX is then uniformly treated with a functional material layer to produce a superhydrophobic surface, such as perfluoroalkylsilane, fatty acid, or alkylphosphonic acid. The gradient produced by the ceramic modifier creates regions that provide droplet repulsion characteristics to control the wettability of certain areas of the coil. These droplet repulsion regions can be concentrated in areas known to be more susceptible to corrosion-related failures.

[0208] Example 22.A 6 -B 10 -Gradient-structured ceramics + gradient functional material layer

[0209] The brazed aluminum heat exchanger is immersed in a dipping tank and agitated during operation by oscillating in a direction orthogonal to the main air flow direction. When considering the main operating air flow direction, the movement of the component causes the structured ceramic layer to deposit more at the leading and trailing edges than in the central part of the heat exchanger body. This greater deposition rate increases the material thickness at the leading and trailing edges that provides protection. The component is then subsequently treated by applying a functional material layer on the leading edge (when considering the air flow direction) to provide additional wear and abrasion protection on the leading edge.

[0210] Example 23.A 6 -B 11 -Gradient-structured ceramics + Selectively coated functional material layer

[0211] The aluminum alloy that can form the airframe is coated with a structured ceramic surface modifier. The shear rate is changed such that the forward portions of the wings, propeller blades, horizontal stabilizer, and rudder have increased topographical variability. Then, the forward portions of the wings, propeller blades, horizontal stabilizer, and rudder are selectively treated with a functional material layer. The increased topographical variability of the ceramic surface modifier causes the functional material layer to have droplet-repellent properties, which are used to prevent icing on the most vulnerable areas of the aircraft. The total weight of the aircraft is reduced by selective protection.

[0212] Example 24.A 6 -B 12 -Gradient-structured ceramic + selectively coated gradient functional material layer

[0213] The HX is fully coated with a structured ceramic surface modifier. The shear rate is changed such that the top of the HX has a thicker ceramic layer than the bottom. Then, the lower half of the coil is painted by dip coating or spraying, with emphasis on the manifold-pipe brazed joints. The thicker areas of the paint protect the more vulnerable areas of the coil, while the thicker ceramic layer wicks water away from the underlying core of the paint, so that water or other corrosive solutions cannot undercut the paint.

[0214] Example 25.A 7 - Selective covering of structured ceramics

[0215] The steel-aluminum heat exchanger is coated with a structured ceramic surface modifier that has corrosion resistance and also preferentially deposits on the aluminum fins rather than the steel pipes. At a temperature of about 60 °C to 80 °C, the coil is placed in an aqueous solution of 25 to 75 mM magnesium nitrate and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. Then, the coil is calcined at a temperature of about 400 °C to 600 °C for about 1 hour. The structured ceramic includes oxides / hydroxides of zinc and aluminum. The ceramic surface is hydrophilic and wicks water from the steel pipes to the aluminum fins to allow for better water management and improve the performance of the heat exchanger, while protecting the steel pipes from corrosion.

[0216] Example 26.A 7 - Selective coating of structured ceramics

[0217] The aluminum plate is selectively protected (masked) in a pattern. The plate is masked with a silicone tape in the desired pattern and the masked plate is deposited with a structured ceramic. At a temperature of about 60 °C to 80 °C, the masked surface is placed in an aqueous solution of 25 to 75 mM magnesium nitrate and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. The masking is removed from the plate and then the plate is calcined at a temperature of about 400 °C to 600 °C for about 1 hour. When the masking is removed, a patterned structural ceramic is left, allowing for a selective moisture collection (wicking) pattern or moisture removal (drainage) pattern. The component also contains a bare metal area adjacent to the structural layer, which can be used for electrical contact with a substrate.

[0218] Example 27.A 7 - Selective coating of structured ceramics

[0219] Selectively protect (mask) an aluminum plate in a pattern. Mask the plate in the desired pattern with a permanent marker containing a dye pigment, a resin, and an organic solvent. Subsequently, the masked plate is coated in a binder-free structured ceramic surface modifier comprising oxides / hydroxides of zinc and aluminum. At a temperature of about 60 °C to 80 °C, the masked plate is placed in an aqueous solution of zinc nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. Then the plate is calcined at a temperature of about 400 °C to 600 °C for about 1 hour. During the heat treatment, the dye pigment, resin, and organic solvent in the mask are evaporated and oxidized, leaving the bare aluminum substrate. The structured ceramic remains, thus allowing for a selective water collection (wicking) pattern or water removal (drainage) pattern. The component also includes a bare metal area adjacent to the structured layer, which can be used for electrical contact with the substrate.

[0220] Example 28.A 7 - Selective covering of structured ceramics

[0221] Selectively protect (mask) an aluminum plate in a pattern. Mask the plate in the desired pattern with a permanent marker containing a dye pigment, a resin, and an organic solvent. Subsequently, the masked plate is coated in a binder-free structured ceramic surface modifier comprising oxides / hydroxides of zinc and aluminum. At a temperature of about 60 °C to 80 °C, the masked plate is placed in an aqueous solution of zinc nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. Then the plate is calcined at a temperature of about 400 °C to 600 °C for about 1 hour. During the heat treatment, the dye pigment, resin, and organic solvent in the mask are evaporated and oxidized, leaving the bare aluminum substrate. Then the structured ceramic is modified with a cetylphosphonic acid functional layer selective for the ceramic material. This results in a superhydrophobic structured ceramic surface adjacent to a more hydrophilic bare aluminum surface. The water contact angle of the functionalized structured ceramic surface is higher than that of the bare aluminum plate.

[0222] Example 29.A 7 B 9 - Selective coating of structured ceramics + continuous functional materials

[0223] Selectively protect (mask) an aluminum plate in a pattern. Mask the plate in the desired pattern with a polyimide tape. Subsequently, the masked plate is coated in a structured binder-free ceramic surface modifier comprising oxides / hydroxides of magnesium and aluminum. At a temperature of about 60 °C to 80 °C, the plate is deposited in an aqueous solution of magnesium nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. Then the plate is calcined at a temperature of about 400 °C to 600 °C for about 1 hour. The adhesive in the polyimide tape is evaporated and redeposited on the metal surface, forming a superhydrophobic structured ceramic. After removing the mask, due to the presence of the structured ceramic layer, there is a difference in the contact angle between the structured ceramic surface coated with the functional layer and the aluminum surface coated with the same functional layer.

[0224] Example 30.A 7 - Selective covering of structured ceramics

[0225] Selectively protect (mask) an aluminum plate in a pattern. Subsequently spray or shower the masked plate to deposit a ceramic surface modifier on the unmasked surface. When the masking is removed, a patterned structural ceramic containing oxides / hydroxides of magnesium and aluminum is left, allowing for a selective moisture collection (wicking) pattern or moisture removal (drainage) pattern. The spray or shower application of the ceramic material is configured to provide additional deposition coverage to preferential drainage locations.

[0226] Example 31.A 7 -B 11 -Selective covering of structured ceramics + selective covering of paint

[0227] Use Kapton (polyimide) tape to selectively protect (mask) an aluminum plate in a pattern. As described in Example 29, subsequently coat the masked plate with a binderless structured ceramic surface modifier containing oxides / hydroxides of magnesium and aluminum. Silicone tape has also been successfully used on aluminum plates and HX materials. When the masking is removed, a patterned structural ceramic is left. The patterned plate is then immersed in an anodic dye, where the patterned structural ceramic preferentially absorbs the pigment of the dye, only changing the color of the structured deposit portion.

[0228] Example 32.A 7 -B 9 -Selective covering of a structured ceramic + functional material layer

[0229] A stainless steel-aluminum heat exchanger is coated with a structured ceramic surface modifier that preferentially dissipates heat from the aluminum fins but not from the stainless steel or copper tubes. The heat exchanger is coated with the structured ceramic surface by immersing it in an aqueous solution of magnesium nitrate at about 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes at a temperature of about 60 °C to 80 °C. The coiled tubes are then calcined at a temperature of about 400 °C to 600 °C for about 1 hour. The heat exchanger is then functionalized with a monolayer material by immersing it in a dilute solution (0.1 wt% - 1 mass%) of cetylphosphonic acid, perfluoroalkylsilane, fatty acid, or alkylsilane to create a superhydrophobic surface on the aluminum fins. The superhydrophobic functional material layer on the fins results in droplet repulsion properties, preventing water from accumulating on the fins and improving the performance of the heat exchanger compared to a similar uncoated heat exchanger. The surface properties also provide a protective layer against corrosion. Since the ceramic surface modifier selectively modifies the aluminum fins, less raw material is used compared to the case where the surface modifier is applied to the fins and tubes simultaneously, resulting in a cheaper process.

[0230] Example 33.A 7 -B 9 -Selective covering of a structured ceramic + functional material layer

[0231] Selectively protect (mask) the aluminum plate in a pattern. Mask the plate with polyimide tape in the desired pattern, and deposit the masked plate with a structured ceramic material, and do not remove the polyimide material before exposure to high temperature. At a temperature of about 60 °C to 80 °C, place the plate in an aqueous solution of magnesium nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. Then calcine the plate at a temperature of about 400 °C to 600 °C for about 1 hour. The resulting plate has a patterned structured ceramic containing oxides / hydroxides of magnesium and aluminum, and the area containing the structured ceramic layer is significantly more hydrophobic than the patterned (covered) area not containing the structured ceramic. The masked area does show a contact angle difference relative to the untreated plate.

[0232] Example 34.A 7 -B 11 Selective coverage of structured ceramics + Selective coverage of functional material layer

[0233] A stainless-steel-aluminum heat exchanger is coated with a structured ceramic surface modifier that preferentially dissipates heat from the aluminum fins but not from the stainless-steel tubes. Then, due to the chemical bonding selectivity of the functional material for the ceramic relative to the steel, the functional material is selectively laminated onto the ceramic material. This creates a superhydrophobic surface on the fins, preventing water from accumulating on the fins, which reduces the airflow through the fin array of the heat exchanger while maintaining the natural corrosion resistance of the unmodified stainless steel.

[0234] Example 35.A 8 - Selective coverage gradient-structured ceramics

[0235] A stainless-steel-aluminum heat exchanger is coated with a structured ceramic surface modifier that preferentially dissipates heat from the aluminum fins but not from the stainless-steel tubes. The processing time on one side of the fins is longer than the other side. This creates a porosity gradient on the aluminum fins.

[0236] Example 36.A 8 - Selective coverage of gradient-structured ceramics

[0237] A stainless-steel-aluminum heat exchanger is coated with a structured ceramic surface modifier that preferentially dissipates heat from the aluminum fins but not from the stainless-steel tubes. Due to the manufacturing process and grain boundaries, the fins have surface roughness, where the structured ceramic material is deposited thicker due to selectively targeting these areas to mitigate corrosion.

[0238] Example 37.A 8 - Selective covering gradient structured ceramics

[0239] As shown in Table 1, a series of 3003 aluminum Q-plate test substrates are coated with a binderless structured ceramic surface modifier containing oxides / hydroxides of magnesium and aluminum and are subjected to different flow conditions during deposition. At a temperature of about 60 °C to 80 °C, place the plate in an aqueous solution of magnesium nitrate at 25 to 75 mM and a similar amount of hexamethylenetetramine for a period of about 30 to 90 minutes. Calcine the plate at a temperature of about 400 °C to 600 °C for about 1 hour.

[0240] As shown in Table 1, the speed, deposit quality, and resulting concentration are relative to the base case shown in the second row, with the speed setpoint and resulting quality and concentration as references. The varying flow conditions result in changes in the deposited mass and deposit composition. All other process parameters, temperature, composition, and materials remain unchanged. This example demonstrates that processing parameters can be used to create gradients in the structural properties of a binderless ceramic surface layer to provide useful benefits.

[0241] Table 1

[0242] Velocity condition Mass of the obtained sediment Concentration of the obtained sediment 0.04V 0.35M 0.33C 1.0V 1.0M 1.0C 4.25V 1.53M 1.67C 9.75V 1.15M 1.67C

[0243] Example 38.A 8 - Selective coverage gradient structured ceramics

[0244] The aluminous heat exchanger is coated with a structured ceramic surface modifier and is subjected to varying process conditions during processing. Compared to a heat exchanger processed at a uniform temperature, the temperature of the processing bath decreases during processing, resulting in a change in the composition of the structural layer with the deposit thickness.

[0245] Alternatively, compared to a heat exchanger processed with a uniform chemical composition, the chemical composition of the processing bath increases during processing, resulting in a change in the composition of the structural layer with the deposit thickness.

[0246] Alternatively, during processing, a working fluid with a temperature different from that of the processing bath passes through the heat exchanger, resulting in a temperature change on the heat exchanger surface. Then, the structured ceramic material will have structural properties consistent with the local temperature during processing. In final use, due to the temperature difference in the heat exchanger, the heat exchanger can also have a working temperature gradient, and thus the desired properties of the ceramic surface layer are consistent with the working requirements of the heat exchanger.

[0247] Example 39.A 9 -B 11 -Coating + Selective covering paint

[0248] All steel surfaces for the bridge are coated with an anti-corrosion coating to prevent corrosion of the steel. Then, the surface closest to the bridge pavement is coated with a protective paint. This part of the paint layer protects the anti-corrosion coating from the harsh chloride ions used in de-icing agents. Instead of spraying all structural steel elements of the bridge, only the areas exposed to de-icing agents require the protective paint layer, thus reducing the overall spraying cost.

[0249] Example 40.A 10 -Gradient paint

[0250] The HX is coated with anti-corrosion paint by dip coating or spraying. The paint is applied such that the paint thickness is thinnest in the middle of the coil and thickest on the outer side of the manifold. The painting cost is reduced while still maintaining corrosion protection in the areas most vulnerable to corrosion.

[0251] Example 41.A 11 - Selective covering paint

[0252] The brazed aluminum HX coil is painted by dip coating or spraying on the manifold and the manifold - pipe brazed joint. This creates a corrosion - resistant coating around the most vulnerable areas of the coil.

[0253] Example 42.A 12 - Selective covering gradient paint

[0254] The HX coil is coated with corrosion - resistant paint only at the manifold and the manifold - pipe brazed joint by dipping or spraying. A gradient is created by applying multiple layers or varying the spraying time in selected areas of the substrate. The application of the paint is concentrated on the manifold - pipe brazed joint, which is most vulnerable to corrosion - related failures. This method greatly reduces the cost of painting while maintaining corrosion protection in the areas where it is most needed. The absence of paint in the functional areas of the coil (fin stack) also prevents loss of HX performance.

[0255] Example 43

[0256] As described herein, the improved drying characteristics of 3003 aluminum plates are tested. All plates are tested by measuring the mass of the plates subjected to controlled environmental conditions of 68°F - 70°F and 30% - 50% relative humidity (RH) and monitoring the mass when adding a certain amount of two 100 - microliter droplets during subsequent drying. The bare plate has a drying rate of approximately 3 mg water / cm2 - hr (measured by mass loss after adding droplets). Similarly, an electrocoated plate with polyurethane UV protection is determined to have a similar drying rate of 3 mg / cm2 - hr. As described in PCT / US19 / 65978, plates coated with various structured ceramic layers are determined to have drying rates of 20 to 50 mg / cm2 - hr. Three different structured ceramic layer formulations are applied. One plate includes oxides / hydroxides of magnesium and aluminum (“structured ceramic 1”) applied as described in PCT / US19 / 65978. Another plate includes oxides / hydroxides of magnesium and aluminum (“structured ceramic 2”) deposited for a shorter period under similar process conditions. The third plate includes oxides / hydroxides of manganese and aluminum (“structured ceramic 3”). The results are as Figure 1 shown.

[0257] Plates similar to those including structured ceramic layers are further treated with a functional material layer containing cetylphosphonic acid to increase the contact angle. The application of a 100 - microliter droplet causes the droplet to roll off the surface of the plate. When the droplet rolls off the surface before the first time point, no mass measurement is provided.

[0258] Example 44

[0259] Similar to that described in Example 33, a series of 3003 aluminum q-plates were coated with a binderless structured ceramic surface modifier comprising oxides / hydroxides of magnesium and aluminum and subjected to an impregnation temperature of 70 °C or 80 °C for an impregnation period ranging from 1 minute to 64 minutes. Samples previously prepared under these same conditions showed that the porosity and pore size distribution of the structured ceramic surface varied with the impregnation time. The capillary rise of deionized water in the samples was measured, and the data demonstrated the ability of the process parameters to affect how water interacts with the surface. Longer impregnation times resulted in improved capillary rise, and impregnation at higher temperatures also resulted in improved capillary rise. This indicates that changing the process parameters on the surface of the material can be used to optimize how the surface interacts with water for specific applications. Imaging of the structured ceramic layer with a scanning electron microscope (SEM) confirmed differences in nano-scale and micro-scale features. When capillary rise measurements were made with bare aluminum q-plates, there was no change in the air-water interface.

[0260] Although the foregoing invention has been described in considerable detail by way of illustration and example for purposes of clarity of understanding, it will be apparent to those skilled in the art that certain changes and modifications may be practiced without departing from the spirit and scope of the invention. Accordingly, the description should not be construed as limiting the scope of the invention.

[0261] All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes, and to the extent incorporated as if each individual publication, patent, or patent application was specifically and individually incorporated by reference herein.

Claims

1. A composition comprising a surface-modifying material on the surface of a substrate, wherein the surface-modifying material includes a gradient of at least one physical or chemical property on at least a portion of the substrate surface, wherein the substrate includes a metal capable of reacting under reaction conditions that permit local dissolution of the substrate metal, and the substrate metal is incorporated into the surface-modifying material, wherein at least one physical or chemical property of the gradient comprises pore size, wherein the gradient is in the z-direction in Cartesian coordinates on or through the surface-modifying material, wherein the surface-modifying material includes a plurality of layers, wherein at least one of the layers includes the gradient of at least one physical or chemical property, wherein the plurality of layers includes a first layer in contact with the substrate that includes the gradient of at least one physical or chemical property and a second functional material layer on the first layer that does not include the gradient, and wherein the first layer is a ceramic.

2. The composition according to claim 1, wherein the surface-modifying material is applied in spatially discrete regions on the substrate surface, and wherein one or more regions of the substrate surface do not contain the surface-modifying material.

3. The composition according to claim 2, wherein the surface-modifying material is applied in a plurality of spatially discrete regions on the surface of the substrate.

4. The composition according to claim 1, wherein the surface-modifying material is spatially continuous over the entire region of the substrate surface.

5. The composition according to claim 1, wherein the first layer is coated on at least a portion of the substrate surface, and the second functional material layer is coated on top of the first layer and over the entire region of the substrate surface.

6. The composition according to any one of claims 1 to 5, wherein the ceramic is a binderless ceramic material having a crystallinity greater than 20%.

7. The composition according to any one of claims 1 to 5, wherein the ceramic includes metal oxides, hydrates of metal oxides, metal hydroxides, and / or hydrates of metal hydroxides.

8. The composition according to claim 7, wherein the ceramic includes metal hydroxides, and wherein at least a portion of the metal hydroxides includes layered double hydroxides.

9. The composition according to any one of claims 1 to 5, wherein the ceramic comprises one or more of the following: The surface area per square meter of the projected substrate area is 10 m 2 to 1500 m 2 ; 15 m to 1500 m of surface area per gram of ceramic material 2 2 of the surface area;​ an average pore size of 2 nm to 20 nm; a thickness of 0.2 microns to 25 microns; a porosity greater than 10%; and Pore volume of 100 mm 3 / g to 7500 mm 3 / g determined by mercury intrusion porosimetry.

10. The composition according to any one of claims 1 to 5, wherein the surface-modifying material comprises latex, alkanes, alkenes, alcohols, acrylic acids, alkyd resins, enamels, epoxy resins, siloxanes, fluoropolymers, or urethanes.

11. The composition according to any one of claims 1 to 5, wherein the surface-modifying material comprises molecules having a head group and a tail group, wherein the head group includes a silyl group, a sulfonate group, a sulfonic acid group, a borate group, a boric acid group, a phosphonate group, a phosphonic acid group, a carboxylate group, a carboxylic acid group, a vinyl group, a hydroxyl group, an alcohol group, a thiolate group, a thiol group, and / or a quaternary ammonium group, and wherein the tail group includes a hydrocarbon group, a fluorocarbon group, a phenyl group, an epoxy group, an acrylic group, an acrylate group, a hydroxyl group, a carboxylic acid group, a thiol group, and / or a quaternary ammonium group.

12. The composition according to any one of claims 1 to 5, wherein the surface-modifying material comprises a molecule having a head group and a tail group, wherein the head group includes a silyl group, a sulfonate group, a sulfonic acid group, a borate group, a boric acid group, a phosphonate group, a phosphonic acid group, a carboxylate group, a carboxylic acid group, a vinyl group, a hydroxyl group, an alcohol group, a thiolate group, a thiol group, and / or a quaternary ammonium group, and wherein the tail group includes a vinyl group.

13. The composition according to any one of claims 1 to 5, wherein at least one physical or chemical property of the gradient comprises pore size and is selected from thickness, density, pore size, pore size distribution, pore filling rate, chemical or physical composition, oxidation state, metal concentration, crosslink density, isoelectric point, conductivity, thermal conductivity, capacitance, or a combination thereof.

14. The composition according to claim 13, wherein the substrate surface is the surface of a heat exchanger, a vehicle, an aircraft, a ship, or a bridge.

15. The composition according to claim 14, wherein the substrate surface is the surface of a heat exchanger or a component thereof.

16. The composition according to claim 15, wherein the heat exchanger is a brazed aluminum heat exchanger, a copper tube-aluminum fin heat exchanger, or a steel tube-aluminum fin heat exchanger.

17. The composition according to claim 15, wherein the heat exchanger or a component thereof has enhanced resistance to environmental damage compared to the same heat exchanger or component that does not contain the composition.

18. A heat exchanger or a component thereof, comprising a surface-modifying material on the surface of the heat exchanger or the component, wherein the surface-modifying material includes a gradient of at least one physical or chemical property of at least a portion of the surface of the heat exchanger or the component, and wherein the surface of the heat exchanger or the component includes a metal capable of reacting under reaction conditions that allow local dissolution of the metal on the surface of the heat exchanger or the component, and the metal on the surface of the heat exchanger or the component is incorporated into the surface-modifying material of the heat exchanger or the component, wherein at least one physical or chemical property of the gradient comprises pore size, wherein the gradient is in the z direction in the Cartesian coordinates on or through the material, wherein the surface-modifying material includes a plurality of layers, wherein at least one of the layers includes the gradient of at least one physical or chemical property, wherein the plurality of layers includes a first layer in contact with the surface of the exchanger or its component that includes the gradient of at least one physical or chemical property and a second functional material layer on the first layer that does not include the gradient, and wherein the first layer is a ceramic.

19. The heat exchanger or a component thereof according to claim 18, wherein the heat exchanger is a brazed aluminum heat exchanger, a copper tube-aluminum fin heat exchanger, or a steel tube-aluminum fin heat exchanger.

20. The heat exchanger or a component thereof according to claim 18, wherein the heat exchanger or a component thereof has stronger resistance to environmental damage compared to the same heat exchanger or component not containing the surface modification material.

21. A method for protecting a substrate from environmental damage, comprising applying the composition according to any one of claims 1 to 13 to the substrate, wherein the substrate has stronger resistance to environmental damage compared to the same substrate not containing the composition. wherein the substrate comprises a metal capable of reacting under reaction conditions that allow local dissolution of the substrate metal, and the substrate metal is incorporated into the surface modification material. wherein at least one physical or chemical property of the gradient comprises pore size. wherein the gradient is in the z - direction in the Cartesian coordinates on or through the material.

22. The method according to claim 21, wherein the environmental damage comprises one or more of corrosion, debris accumulation, water or ice accumulation, biofouling, and wear.

23. The method according to claim 22, wherein corrosion due to water or ice accumulation is reduced or prevented.

24. The method according to any one of claims 21 to 23, wherein the substrate is the surface of a heat exchanger or a component thereof.

Images