Phase change barriers and methods of using same - Patents.com

Abstract

Modified surfaces and methods of use are provided for preventing or delaying the occurrence of phase changes such as condensation or frost formation. The present invention relates to surfaces that increase the energy barrier to, or the driving force required for, nucleation phase changes, such as, but not limited to, condensation and crystallization, and methods of use thereof, such as preventing condensation on heat exchangers in anti-fog glass applications and systems requiring only sensible cooling. [Selected Figure] Figure 2

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[01] This application claims the benefit of U.S. Provisional Application No. 62 / 669,507, filed May 10, 2018, which is incorporated by reference in its entirety.

[0002]

[02] The present invention relates to surfaces that increase the energy barrier or driving force required for nucleation phase changes, such as, but not limited to, condensation and crystallization, and methods of use thereof, such as in anti-fog glass applications and preventing condensation on heat exchangers in systems requiring only sensible cooling. [Background technology]

[0003]

[03] Typical condensation on low energy surfaces does not produce round droplets upon nucleation, but rather water and other condensates condense under stressed, lower contact angle conditions. The difference in contact area in nucleation through the wetting state compared to the dewetting state can shift the energy barrier for droplet formation (i.e., modify the energy barrier of the condensation process). Typical surfaces condense water from air at the dew point. Condensation is often undesirable on surfaces populated with electronic equipment such as computers or data centers that utilize below ambient cooling, or on glass surfaces where visibility is desired, such as windows, lenses, and mirrors.

[0004]

[04] Solutions to prevent condensation from heat transfer surfaces typically require keeping the coolant temperature significantly above the dew point, which can result in reduced heat transfer capacity and limited operating range. Often the coolant temperature is reduced to the minimum amount allowed by the system controls to prevent condensation while keeping capacity as high as possible. If a control or input error occurs to the system, there is a risk that water will condense on the surface and potentially destroy electronics. A solution is needed to allow the lowest possible coolant temperature to maximize heat transfer while allowing the maximum difference between the coolant temperature and the effective occurrence of condensation. Currently, this condensation occurrence is at the dew point.

[0005]

[05] Condensation and fogging on glass windows and mirrors, such as shower mirrors, car glass, and building windows, is also a problem. Typical solutions currently involve wiping the condensation off with a towel or squeegee, or using a hydrophilic coating to spread the condensation into a thin film so that one can still see through the window or reflected image in the mirror. These hydrophilic coatings are problematic in that they accelerate condensation and cause contaminants to build up on the surface, resulting in increased cleaning frequency.

[0006]

[06] According to classical nucleation theory, the free energy of homogeneous nucleation is the sum of a volume term and a surface term, ΔG homo =4 / 3(πr 3 )Δg+4πr 2 σ [where r is the radius of the sphere of the forming phase, Δg is the difference between the free energy per unit volume of the supersaturated phase and the free energy of the nucleation phase, and σ is the surface tension at the interface between the nucleus and its surroundings]. ΔG homo * The critical radius r of formation with a free energy barrier of * is d(ΔG homo ) / dr = 0. The radius at which this derivative becomes zero is r * =-2σ / Δg. The free energy of homogeneous nucleation then corresponds to ΔG homo * = ΔG homo (r * )=16πσ3 / (3(Δg) 2 Heterogeneous nucleation has a lower energy barrier for the phase change from vapor to liquid, which can be determined as a function of the contact angle (θ) on the surface. This relationship can be expressed as ΔG hetero * =f(θ)ΔG homo * [Wherein, f(θ)=(2−3cosθ+cos 3 θ) / 4.

[0007]

[07] As with the vapor-to-liquid transition, in many applications it is desirable to increase the barrier for the liquid-to-solid phase transition, such as on heat exchanger surfaces for refrigerators or freezers of various sizes, ranging from small dorm room units to industrial-scale distribution center units. Ice is problematic for these heat transfer systems because it requires the system to be shut down periodically for defrosting, which reduces throughput in industrial applications and consumes large amounts of energy. In addition, defroster units are expensive on a large scale.

[0008]

[08] Icing is also a problem on aircraft wings and airfoil surfaces such as wind turbines. Ice on aircraft wings is a hazard to flight and must be removed before takeoff, causing costly delays. Wind turbines can accumulate ice, which can cause a significant reduction in output power and pose a safety risk of blowing ice off the blade surfaces. Summary of the Invention

[0009]

[09] Provided herein are methods for reducing (e.g., preventing or delaying) condensation of a gas (e.g., vapor) phase below a gas-liquid transition temperature (e.g., dew point) or reducing (e.g., preventing or delaying) solidification (e.g., freezing) of a liquid phase, as well as systems, devices, and compositions for carrying out the methods or by which the methods are performed.

[0010]

[10] In one aspect, provided herein is a method for preventing or delaying the occurrence of a phase change on a surface. The method includes providing a modified surface that increases an energy barrier, or driving force required for a phase change from a first phase to a second phase, compared to an unmodified surface, and contacting a fluid stream with the modified surface under environmental conditions under which a phase change can occur on the unmodified surface, wherein the phase change is prevented or delayed compared to the unmodified surface. In one embodiment, a method for preventing or delaying the occurrence of a phase change includes providing a modified surface comprising a surface modification, where the modified surface increases an energy barrier, or driving force required for a phase change, for a substance in contact with the modified surface compared to an unmodified surface identical to the modified surface except that the modified surface does not include the surface modification; and contacting a fluid stream comprising at least one substance in a first phase (e.g., a gas (e.g., vapor) phase and / or a liquid phase) with the modified surface under environmental conditions under which a phase change to a second phase (e.g., gas to liquid; liquid to solid; gas to solid) can occur on the unmodified surface, whereby the phase change from the first phase to the second phase is prevented or delayed on the modified surface compared to the unmodified surface.

[0011]

[11] In some embodiments, at least one first phase comprises a gas (e.g., vapor) phase and the second phase comprises a liquid phase, and preventing or retarding the phase change comprises preventing or retarding condensation of the gas (e.g., vapor) to form a liquid on the surface. In one embodiment, the gas phase is water vapor and the fluid stream is air, and preventing or retarding the phase change comprises preventing or retarding condensation of the water vapor on the surface.

[0012]

[12] In some embodiments, at least one first phase comprises a gas (e.g., vapor) phase and a second phase comprises a solid phase, the gas (e.g., vapor) condenses on the surface to form a liquid (e.g., condensate), and preventing or delaying the phase change comprises preventing or delaying solidification of the liquid (e.g., condensate) to form a solid on the surface. In one embodiment, the gas phase is water vapor, the fluid stream is air, and the liquid phase is water condensate, and preventing or delaying the phase change comprises preventing or delaying solidification of the water condensate to form water frost or ice on the surface.

[0013]

[13] In some embodiments, at least one first phase includes a gas (e.g., vapor) phase and a liquid phase, and the second phase includes a liquid phase, and preventing or delaying the phase change includes preventing or delaying condensation of the gas (e.g., vapor) to form a liquid on the surface. In one embodiment, the gas phase is water vapor, the liquid phase is liquid water, and the fluid stream is air, and preventing or delaying the phase change includes preventing or delaying condensation of the water vapor on the surface.

[0014]

[14] In some embodiments, at least one first phase includes a gas (e.g., vapor) phase and a liquid phase, the second phase includes a solid phase, the surface includes condensation from the gas (e.g., vapor) and / or includes a liquid of the substance, and preventing or delaying the phase change includes preventing or delaying solidification of the condensate and / or liquid on the surface to form a solid. In one embodiment, the gas phase is water vapor, the liquid phase and liquid on the surface is water, the fluid stream is air, the surface includes condensation of water vapor and / or liquid water, and preventing or delaying the phase change includes preventing or delaying solidification of water condensate and / or liquid water on the surface to form water frost or ice on the surface.

[0015]

[15] In some embodiments, at least one first phase comprises a gas (e.g., vapor) phase and the second phase comprises a solid phase, and preventing or delaying the phase change comprises preventing or delaying solidification of the gas (e.g., vapor) on the surface to form a solid. In one embodiment, the gas phase is water vapor and the solid is water frost or ice, and preventing or delaying the phase change comprises preventing or delaying solidification of the water vapor on the surface to form water frost or ice. In one embodiment, the gas phase comprises or is CO2 gas and the solid is frozen CO2 (CO2 dry ice), and preventing or delaying the phase change comprises preventing or delaying solidification of the CO2 gas on the surface to form CO2 dry ice.

[0016]

[16] In some embodiments, the modified surface is subcooled below the equilibrium phase transition value (e.g., temperature) from a first phase to a second phase (e.g., gas (e.g., vapor) to liquid; gas (e.g., vapor) to solid; liquid to solid transition) and the material still exists as the first phase. In various embodiments, the modified surface is subcooled to a temperature that is more than about any of 0.25, 0.5, 1, 2, 3, 5, or 10° C. below the equilibrium phase transition value from the first phase to the second phase and the material still exists as the first phase.

[0017]

[17] In various embodiments, the energy barrier for a phase change from the first phase to the second phase is greater than about any of 50, 60, 70, 80, 90, 95, or 99% of the homogeneous nucleation energy.

[0018]

[18] In some embodiments, the phase change from a first phase to a second phase includes nucleation of a substance on the modified surface. The modified surface or surface coating where nucleation occurs may be, for example, a barrier coating, a conversion coating, or a combination thereof. In some embodiments, the modified surface or surface coating where nucleation occurs is nanostructured. In some embodiments, the modified surface or surface coating where nucleation occurs includes a metal oxide, for example, a metal oxide layer created by deposition or conversion, or a polymer, for example, a polymer containing alkyl or fluoroalkyl monomer units. In some embodiments, the modified surface or surface coating includes terminal alkyl or fluorinated compound(s).

[0019]

[19] In some embodiments, the first phase comprises primarily water vapor and the second phase comprises liquid water or water ice. In some embodiments, the first phase is air containing water vapor and the second phase is liquid water or water ice. In some embodiments, the first phase is liquid water and the second phase is water ice. In some embodiments, the first phase comprises carbon dioxide vapor and the second phase is dry ice or solid CO2.

[0020]

[20] In some embodiments, the first phase comprises a gas vapor and the second phase comprises a clathrate. For example, the substance may be raw natural gas, the first phase comprises a gas (e.g., vapor) phase and the second phase comprises a clathrate. In one embodiment, the first phase is a gas (e.g., vapor) or liquid and the second phase is a supercritical phase.

[0021]

[21] In some embodiments, the substance is a metal, the first phase comprises metal vapor, and the second phase comprises condensed metal vapor.

[22] In some embodiments, condensed droplets of a fluid above its critical radius of formation exist in a dewetting Cassie-Baxter state. In some embodiments, condensed droplets of a fluid above its critical radius of formation exist in a dewetting Cassie-Baxter state, instead of the previously wetted Wenzel state.

[0022]

[23] In some embodiments, the reforming surface is on a heat exchanger or heat transfer surface.

[24] In some embodiments, the modified surface is on the surface of glass, a window, a mirror, or a lens.

[0023]

[25] In some embodiments, the modified surface is patterned on the glass component such that condensation occurs in an aesthetically pleasing or functionally desirable manner.

[26] In some embodiments, the reforming surface is on a computer case or a cooling rack. In some embodiments, the reforming surface is on a gas vaporizer, such as a gas vaporizer heat exchanger. In some embodiments, the reforming surface is in a vaporizer device, and the reforming surface prevents or reduces fouling in the form of condensation on the vaporizer device.

[0024]

[27] In some embodiments, the modified surface is in an engine or combustion nozzle, for example, the modified surface prevents or reduces condensation of carbon dioxide in the engine or combustion nozzle.

[0025]

[28] In some embodiments, the modified surface is on a treatment device for industrial gases and / or liquids, e.g., the modified surface prevents or reduces the formation of water and gas hydrates, and / or clathrates during processing of industrial gases and liquids in the treatment device. In one embodiment, the substance is raw natural gas, and the phase change includes hydration or host-guest complexing (e.g., formation of a solid material). In some embodiments, the first phase is a gas (e.g., steam) or liquid, and the second phase is a supercritical phase.

[0026]

[29] In some embodiments, the modified surface is on a metal vapor illumination or advanced lithography apparatus, for example, the modified surface prevents or reduces condensation of metal vapor during operation of the metal vapor illumination or advanced lithography apparatus. In one embodiment, uniformity and prevention of deposition are important for the correct operation of the advanced lithography apparatus.

[0027]

[30] In another embodiment, there is provided a heat exchanger or heat transfer surface comprising a modified surface as described herein that increases the energy barrier to, or driving force required for, a phase change from a first phase to a second phase as compared to an unmodified surface, thereby preventing or delaying the occurrence of a phase change at the heat exchanger or heat transfer surface as compared to a heat exchanger or heat transfer surface that does not include the modified surface.

[0028]

[31] In another embodiment, there is provided a glass, window, mirror, or lens comprising a modified surface as described herein that increases the energy barrier to, or driving force required for, a phase change from a first phase to a second phase compared to an unmodified surface, thereby preventing or delaying the occurrence of a phase change on the glass, window, mirror, or lens compared to a glass, window, mirror, or lens that does not include the modified surface.

[0029]

[32] In another embodiment, a glass component is provided that includes a patterned modified surface as described herein that increases the energy barrier, or driving force required for a phase change from a first phase to a second phase, compared to an unmodified surface, thereby preventing or delaying the occurrence of a phase change on the modified surface compared to the unmodified surface. For example, the patterning can provide a decoratively and / or functionally desirable pattern on the glass such that condensation occurs in an aesthetically pleasing and / or functional manner.

[0030]

[33] In another embodiment, a computer case or cooling rack is provided that includes a modified surface as described herein that increases the energy barrier or driving force required for a phase change from a first phase to a second phase compared to an unmodified surface, and prevents or delays the occurrence of a phase change on the computer case or cooling rack compared to a computer case or cooling rack that does not include the modified surface. For example, the modified surface may prevent or reduce condensation-related damage to electronic equipment or computer devices housed therein.

[0031]

[34] In another embodiment, a gas vaporizer is provided that includes a modified surface as described herein that increases the energy barrier, or driving force required for a phase change from a first phase to a second phase, compared to an unmodified surface, and prevents or delays the occurrence of a phase change on the gas vaporizer compared to a gas vaporizer that does not include the modified surface. For example, the modified surface may prevent or reduce condensation and / or frost on an internal vaporizer heat exchanger. [Brief description of the drawings]

[0032] [Figure 1]

[35] Figure 1A shows the phase changes of water on surface-modified and unmodified aluminum plates as described in Example 1. Figure 1B shows the phase changes of water on surface-modified and unmodified aluminum plates as described in Example 1. [Diagram 2]

[36] Figure 12 is a graph showing the results of ice formation on surface modified and unmodified heat exchangers in the experiment described in Example 2. [Diagram 3]

[37] FIG. 1 is a schematic diagram showing a closed loop air conditioning system as described in Example 3. [Figure 4]

[38] Figure 12 is a graph showing the results of adding a condensation nucleation barrier to a heat exchanger, as described in Example 3. [Diagram 5]

[39] Figure 5A shows the time progression of the liquid to solid phase change of water on an unmodified surface and a modified surface as described in Example 4. Figure 5B shows the time progression of the liquid to solid phase change of water on an unmodified surface and a modified surface as described in Example 4. Figure 5C shows the time progression of the liquid to solid phase change of water on an unmodified surface and a modified surface as described in Example 4. Figure 5D shows the time progression of the liquid to solid phase change of water on an unmodified surface and a modified surface as described in Example 4. Figure 5E shows the time progression of the liquid to solid phase change of water on an unmodified surface and a modified surface as described in Example 4. [Figure 6]

[40] FIG. 13 is a graph showing a plot of ice thickness versus time for unmodified and modified surfaces in an environmental chamber with controlled air velocity and surface temperature, as described in Example 5. [Figure 7]

[41] FIG. 12 is a graph showing the air-side pressure drop for the reformed and unreformed heat exchangers described in Example 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033]

[42] The ability to condense droplets at high contact angle rounding reduces the effective onset temperature of condensation below the bulk dew point by increasing the energy barrier for droplet formation. Provided herein are modified surfaces and methods that prevent or delay the onset of condensation or frost formation under certain environmental conditions, e.g., temperature and / or relative humidity, by increasing the energy barrier for nucleation phase change. The materials and methods of use described herein are applicable to systems where condensation and / or ice formation is undesirable. Additionally, methods are provided for increasing safety in certain applications or expanding the range of environmental conditions for safe or effective operation of such systems. Methods are also provided for improving performance by delaying or eliminating the need to defrost or dry such systems.

[0034]

[43] Other phase change phenomena addressed by the materials and methods described herein include the formation of solid carbon dioxide from CO2 systems, such as the formation of clathrate hydrates in deep-sea exploration systems, and the condensation of vapor phase compounds in vaporization systems. Systems operating at both subcritical and supercritical operating conditions are also covered.

[0035]

[44] In some embodiments, a system such as a heat exchanger can operate at lower temperatures or handle larger temperature fluctuations without condensation compared to an identical system that does not include the surface modifications described herein. In some embodiments, nucleation can be suppressed at supercooling (difference between dew point and surface temperature) of less than 5°C.

[45] In some embodiments, the surface modification comprises a nanostructured composition.

[0036] definition

[46] The numerical ranges presented herein are inclusive of the numbers defining the range.

[0037]

[47] “A”, “an” and “the” include plural references unless the context clearly dictates otherwise.

[48] ​​An "equilibrium phase transition value" is the temperature / pressure condition at which a phase change can thermodynamically occur without an energy barrier. This phase change can be a transition at either the dew point (e.g., condensation), frost point (e.g., frost formation), or freezing point (e.g., crystallization), and occurs when the transition phase reaches a saturated state. "Frost point" refers to the formation of a less dense solid water phase, while "freezing point" refers to the formation of ice that is close to full density. Typically, for water, frost appears white and powdery like snow, while freeze / ice is the denser, optically clear ice.

[0038]

[49] The “homogeneous nucleation energy” is the energy barrier to nucleation, ΔG, as defined in classical nucleation theory. homo * Refers to...

[50] The "dew point" is the temperature for a given set of environmental pressure and humidity conditions at which the liquid water phase is energetically favored over the vapor phase. It is the point at which condensation would occur in the absence of an energy barrier.

[0039]

[51] "Contact angle" is the angle measured through a liquid between a surface and the liquid-vapor interface at the contact point.

[52] "Free surface energy" refers to the energy of an interface (liquid-vapor, solid-liquid, or vapor-solid). High-energy surfaces are more easily wetted than low-energy surfaces.

[0040]

[53] A "barrier coating" forms a physical barrier and thus minimizes contact with undesirable elements (e.g., water (as a "moisture barrier"); electrolytes (as a "corrosion barrier").

[0041]

[54] “Conversion coating” refers to a surface layer in which a reactant chemically reacts with the surface to be treated.

[55] A "nanostructured" coating refers to a coating composition having features that are less than 100 nanometers in at least one dimension.

[0042]

[56] "Condensing conditions" refers to conditions where a surface is cooled below the dew point of the vapor.

[57] “Sensible heat” refers to the amount of heat resulting from a change in temperature of a gas or object without a change of phase.

[0043]

[58] “Sensible cooling capacity” refers to the amount of heat that can be transferred to a material in the absence of a phase change.

[59] "Latent heat" refers to the amount of energy (e.g., heat) required to change phase (e.g., between a solid phase and a liquid or gas phase; or between a liquid and a gas phase) without a change in temperature.

[0044]

[60] “Latent cooling capacity” refers to the amount of energy (e.g., heat) that can be transferred to or from a material by a phase change.

[61] "Sensible heat ratio" refers to the ratio of sensible cooling capacity to total cooling capacity, which is often the sum of sensible and latent cooling capacity.

[0045]

[62] The “Cassie–Baxter state” refers to the formation of a state in which a droplet rests on a textured surface where a hybrid interface exists, typically in the form of a gas phase trapped beneath the surface of the droplet.

[0046]

[63] The term “Wenzel state” refers to the formation of a state in which a volume of liquid is in contact with a textured surface and the liquid wets the underlying surface.

[64] “Raw natural gas” refers to unprocessed natural gas, which may contain natural gas liquids (e.g., condensate, natural gasoline, liquefied petroleum gas), water, and other impurities (e.g., nitrogen, carbon dioxide, hydrogen sulfide, helium).

[0047]

[65] "Hydration" and "host-guest complexation" in relation to phase change herein refer to the formation of a different phase or the formation of an inclusion compound or clathrate-like structure by uptake of water.

[0048]

[66] A "clathrate" is a compound in which molecules of one substance are physically trapped within the crystal structure of another substance.

[67] "Supercritical conditions" refers to the temperature and pressure conditions at which a material exists in its supercritical phase. "Supercritical phase" refers to a fluid at a temperature and pressure above its critical temperature and pressure. A substance's critical temperature is the temperature above which the vapor of the substance cannot be liquefied, no matter how much pressure is applied. A substance's critical pressure is the pressure required to liquefy the gas at its critical temperature.

[68] "Supercool" or "subcool" (subcooling) refers to cooling a substance in a first phase to a temperature below the equilibrium phase change temperature to a second phase (e.g., the dew point or freezing point) for a given pressure, where the substance does not transition to the second phase (e.g., a substance cools below the dew point without becoming a liquid, or a substance cools below the freezing point without becoming a solid).

[0049] Surface Modification

[69] Provided herein are surface modifications that maintain spherical or substantially spherical droplets with a size less than the uniform nucleation critical radius, thereby resulting in a surface temperature at the time of nucleation occurring that is less than the dew point. In some embodiments, water does not condense on the modified surfaces described herein (e.g., enough material aggregates to form a liquid phase that is easily observed or large enough to measure the contact angle), even when the surface temperature is below the equilibrium dew point.

[0050]

[70] In some embodiments, the surface modification is in the form of a barrier coating, a conversion coating, or a combination thereof. In one embodiment, the surface modification is a nanostructured surface modification. The surface modification results in a reduction in the free surface energy, which causes the droplets to become more spherical at sizes below the critical nucleation radius.

[0051]

[71] In certain embodiments, the surface modification includes a metal oxide or a polymer. In one embodiment, the surface modification includes a polymer containing alkyl or fluoroalkyl monomer units. In one embodiment, the surface modification includes a metal oxide layer created by deposition or conversion. In one embodiment, the surface modification is completed with an alkyl or fluorinated compound(s).

[0052]

[72] In some non-limiting embodiments, the surface is modified with nanostructured mixed metal oxides, for example, by immersing the cleaned substrate in a mixture of 0.25M to 1M group II or transition metal salts, such as zinc nitrate, magnesium nitrate, and / or manganese sulfate, and 0.1M to 2M amines, such as hexamine or urea, for a period of about 5 minutes to about 2 hours at a solution temperature of about 40°C to about 90°C. The sample can then be removed from the solution, rinsed, and baked at a temperature of about 100°C to about 600°C. The sample can then be immersed in a dilute solution of a hydrophobic chemical, for example, a solution of stearic acid in hexane, a solution of hexadecylphosphonic acid in isopropanol, or a solution containing perfluorodecyltriethoxysilane in ethanol, for about 5 minutes to about 120 minutes. The substrate can then be removed and dried in an oven at about 105°C for about 1 hour.

[73] Non-limiting embodiments of surface modifications that may be used herein are described, for example, in WO2018 / 053452 and WO2018 / 053453, which are incorporated herein by reference in their entireties.

[0053] Purpose of use

[74] In applications of the modified surfaces described herein, the surface increases the energy barrier to a phase change from a first phase to a second phase.

[0054]

[75] In some embodiments, the first phase may be subcooled below the equilibrium phase transition value to the second phase and still exist as the first phase. For example, the first phase may be subcooled to a temperature about 0.25°C to about 10°C, about 0.25°C to about 1°C, about 0.5°C to about 2°C, about 1°C to about 5°C, about 3°C ​​to about 5°C, or about 5°C to about 10°C below the equilibrium phase transition value to the second phase and still exist as the first phase. In some embodiments, the first phase may be subcooled to a temperature about 0.25°C, 0.5°C, 1°C, 2°C, 3°C, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, or 10°C below the equilibrium phase transition value to the second phase and still exist as the first phase.

[0055]

[76] In some embodiments, the energy barrier for the phase change from the first phase to the second phase is about 50% to about 99%, about 50% to about 70%, about 60% to about 80%, about 70% to about 90%, about 80% to about 90%, about 85% to about 95%, or about 95% to about 99% of the homogeneous nucleation energy. In some embodiments, the energy barrier may be greater than any of about 50%, 60%, 70%, 80%, 90%, 95%, or 99% of the homogeneous nucleation barrier.

[0056]

[77] In some embodiments, nucleation is inhibited by supercooling greater than about 5°C.

[78] In one embodiment, the first phase consists or consists essentially of water vapor and the second phase is liquid water or ice. In another embodiment, the first phase is air containing water vapor and the second phase is liquid water or ice. In another embodiment, the first phase is liquid water and the second phase is water ice. In another embodiment, the first phase consists or consists essentially of air and water vapor and the second phase is water ice. In another embodiment, the first phase is carbon dioxide vapor and the second phase is carbon dioxide ice (dry ice). In another embodiment, the first phase is a liquid and the second phase is a condensation of a solid phase. In another embodiment, the first phase is a metal vapor and the second phase is a condensed metal vapor.

[0057]

[79] In some embodiments of the uses described herein, condensed droplets at a critical radius of formation exist on the modified surface in a dewetting state (i.e., a Cassie-Baxter state).

[80] Heat exchanger / heat transfer uses include using the materials herein to enhance heat exchange and reduce the temperature at which condensation is observed. Additionally, using these materials on heat exchangers to reduce the temperature at which frosting occurs provides benefits over conventional materials by increasing operational run times, minimizing the impact of ice formation on heat transfer performance, and increasing the operating range of the system. Also provided are heat exchangers that include the materials described herein, for example, as a coating or layer on one or more surfaces of the heat exchanger, where the surface material provides the functional property of enhancing heat exchange and reducing the temperature at which condensation is observed and / or the temperature at which frosting occurs.

[0058]

[81] Use applications for glass windows, mirrors, or lenses include using the surface modifications described herein to prevent undesirable condensation for visual applications. Additionally, methods of use may include materials that can be patterned and used to provide decorative patterns on glass, for example, forming patterns on the outside of a water, wine, or beer glass so that condensation occurs in an aesthetically pleasing manner. Glass, mirrors, and lenses are also provided that include the materials described herein on the surface of the glass, mirror, or lens, for example as a coating or layer, where the surface material provides the functional property of preventing undesirable condensation, and in some embodiments includes a surface coating or layer of a decorative pattern.

[0059]

[82] Computer case / rack cooling applications include using the surface modifications described herein to prevent unwanted condensation-related damage to electronics. Additionally, methods of use may include applying the surface modifications described herein to provide an additional operational barrier to the formation of condensation on the coldest components of the computer case or rack. Increasing the driving force required for condensation provides an additional operational margin of safety. Computer cases and / or racks are also provided that include the surface modifications described herein on the surface of the computer case or rack, e.g., as a coating or layer, where the surface material provides the functional property of preventing unwanted condensation that may damage electronics.

[0060]

[83] Use applications for gas vaporizers include using the surface modifications described herein to prevent undesired condensation and frost on vaporizer heat exchangers, such as, but not limited to, liquid nitrogen exchangers. Condensation and ice formation on vaporizer heat exchangers limits the effectiveness of the heat exchanger, reducing the available flow of expanding gas or requiring a larger heat exchanger. A secondary benefit of using the surface modifications described herein is an improved ability to slough off ice formed on the exchanger. Also provided are gas vaporizers that include the surface modifications described herein, e.g., as a coating or layer, on the surface of the vaporizer, e.g., on the surface of a vaporizer heat exchanger, such as a liquid nitrogen exchanger, where the surface material provides the functional property of preventing undesired condensation and / or frost.

[0061]

[84] Anti-fouling condensation uses include using the surface modifications described herein to prevent undesirable condensation on vaporizer devices. In such embodiments, the prevention of condensation is intended to prevent adhesion and deposition of heavier components and natural oils. An example is a glycol-based e-cigarette or other similar device. Additional anti-fouling applications include nozzle-based thermal printers and devices. Vaporizers are also provided that include the surface modifications described herein, for example as a coating or layer, on the surface of the vaporizer, such as an e-cigarette or similar device, or the nozzle of a thermal printer or device, where the surface material provides the functional property of preventing condensation and preventing adhesion and / or deposition of heavy components and oils.

[0062]

[85] Engine / nozzle icing uses include preventing carbon dioxide condensation in engine and combustion nozzle applications. Also provided are combustion engines and nozzles that include a surface modification described herein, e.g., as a coating or layer, on a surface of the engine or nozzle, where the surface material provides the functional property of preventing carbon dioxide condensation.

[0063]

[86] Hydrate and clathrate prevention uses include preventing the formation of water and gas hydrates during industrial gas and liquid processing in processing equipment, such as compressed natural gas production, or methane clathrate deposition in high pressure drilling applications. Industrial gas and liquid processing equipment is also provided that includes a surface modification described herein, e.g., as a coating or layer, on a surface of the processing equipment, where the surface material provides the functional property of preventing water and gas hydrate formation.

[0064]

[87] Use applications for metal vapor condensation prevention include preventing metal condensation during operation of metal vapor illumination, or advanced lithography applications where uniformity and deposition prevention are important for proper operation. Metal vapor illumination and lithography devices are also provided that include a surface modification described herein, e.g., as a coating or layer, on a surface of the device, where the surface material provides the functional property of preventing metal condensation during operation of the device.

[0065]

[88] The following examples are intended to illustrate, but not limit, the invention. EXAMPLES

[0066] Example 1

[89] modified aluminum sheets with nanostructured mixed metal oxides by immersing cleaned aluminum sheets in mixtures of 0.25 M to 1 M group II or transition metal salts, such as zinc nitrate, magnesium nitrate, and / or manganese sulfate, and 0.1 M to 2 M amines, such as hexamine or urea, for periods of 5 min to 2 h at solution temperatures of 40 °C to 90 °C. The samples were then removed from the solution, rinsed, and baked at temperatures of 100 °C to 600 °C. The samples were then immersed for 30 to 90 min in a dilute solution of stearic acid in hexane, a dilute solution of hexadecylphosphonic acid in isopropanol, or a solution containing perfluorodecyltriethoxysilane in ethanol. The samples were then removed and dried in an oven at 105 °C for 1 h.

[0067]

[90] A surface-modified aluminum plate was placed on the surface and photographed through a microscope while cooled to -10 °C. Condensation was observed to begin much sooner on the uncoated sample, and much slower on the coated sample, where condensation began upon lowering the surface temperature below the dew point (Figure 1A). Continuing the experiment, the uncoated sample nucleated the water into ice, while the coated sample remained liquid water (Figure 1B). This example illustrates the nucleation barrier for both the vapor-to-liquid and liquid-to-solid transitions.

[0068] Example 2

[91] The surface of a heat exchanger was modified with a nucleation barrier coating as described in Example 1. An ice test was performed in which the heat exchanger and air were simultaneously cooled to temperatures below 0°C in a closed-loop wind tunnel to determine the onset of frost. Figure 2 shows the results of the test, where the unmodified heat exchanger began to form ice and the surface-modified heat exchanger did not form ice (middle band, labeled nucleation barrier). The surface modification reduced the temperature of nucleation by approximately 2°C compared to the control unmodified surface.

[0069] Example 3

[92] As shown in Figure 3, a closed-loop air conditioning system circulates room air at 30°C and 50% relative humidity (RH) through the server racks, where the air is heated to approximately 40°C and 27% RH. The air is immediately passed through a liquid-to-air heat exchanger, where the coolant enters at 20°C.

[0070]

[93] As shown in Figure 4, the air entering and leaving the server rack both has an equilibrium dew point of 18 °C. Using an unmodified heat exchanger would leave a 2 °C error in the control system, preventing condensation that could drip onto the server rack. Adding a condensation nucleation barrier to the heat exchanger adds an energy barrier such that condensation is not observed until 16 °C, effectively doubling the safety margin and adding an extra layer of protection to the equipment.

[0071] Example 4

[94] Two 3003 aluminum plates, one modified and one unmodified control, were thermally bonded side-by-side on a cold plate cooled to -10 °C. Air temperature was about 22 °C and humidity was 40%. The air was passed over the surfaces of the plates through an 8 ft long wind tunnel with a front speed of about 2 m / s. The surfaces were modified using a procedure similar to that of Example 1. The cold plate was allowed to frost for 1 hour and defrost for 10 minutes by turning the cold plate on and off before starting this experiment. The progression of images in Figures 5A-5E shows the phase change over time from about 30 seconds in Figure 5A to about 1 hour in Figure 5E. The modified surface delays the phase change from liquid water to water ice and slows its formation thereafter. After 1 hour, liquid water is still present on the modified sample, but on the unmodified sample, the liquid water is completely frozen.

[0072] Example 5

[95] An unmodified aluminum plate and an aluminum plate modified according to the method described in Example 1 were placed on a thermoelectric cooling plate with a surface temperature of about -5°C. Air was passed across the plate in a wind tunnel with a frontal wind speed of 1.5 m / s, air temperature and relative humidity of 25°C and 40%, respectively. Ice thickness was measured using a microscope and cross-sections were taken as a function of time. A plot of ice thickness as a function of time is illustrated in Figure 6. On the modified aluminum plate, frost formation began at 11 minutes as measured by microscope, and it took 6 minutes longer to form frost than the unmodified plate. This barrier delay in phase change continued for the entire duration, resulting in a 3 mm thin layer of ice after 2 hours. The ice thickness on the unmodified plate was 7 mm, while the ice thickness on the modified plate was 4 mm.

[0073] Example 6

[96] An aluminum-finned stainless steel tube heat exchanger with four parallel fins per inch was modified with a phase change barrier coating as described in Example 1 and tested in a wind tunnel against an unmodified heat exchanger. The glycol refrigerant temperature was set at -4°C and passed through the tube side of the coil at a flow rate of approximately 800 grams per second. Air was passed through the fin side of the coil at a face velocity of 3 m / s, with inlet temperature and humidity of 2°C and 83%, respectively. The heat transfer capacity and air side pressure drop of the coil were monitored for 5 hours. On the unmodified coil, water condensed from the air and instantly froze on the surface, which was at a temperature below the freezing point of water. This resulted in an increased pressure drop. On the heat exchanger whose fins were modified with a phase change barrier coating, it took much longer for the liquid water on the surface to freeze, resulting in water condensing from the air flowing out of the coil for a longer period of time. After 5 hours, the air-side pressure drop over the unmodified coil was about 195 Pa, and the air-side pressure drop over the modified coil was about 140 Pa. This delay in the liquid-to-solid phase change resulted in about a 30% improvement in the air-side pressure drop. A plot of the air-side pressure drop as a function of time is shown in FIG. 7.

[0074]

[97] Although the foregoing invention has been described in some detail by way of illustration and example for clarity of understanding, it will be apparent to those skilled in the art that certain changes and modifications can be made without departing from the spirit and scope of the invention as set forth in the appended claims. Accordingly, the description should not be construed as limiting the scope of the invention.

[0075]

[98] All publications, patents, and patent applications cited in this specification are hereby incorporated by reference in their entirety for all purposes to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. Specific embodiments of the present invention are as follows. [Aspect 1] 1. A method for preventing or delaying the occurrence of a phase change on a surface, comprising: providing a modified surface comprising a surface modification, said modified surface increasing the energy barrier to, or the driving force required for, a phase change from a first phase to a second phase for a material in contact with said modified surface compared to an unmodified surface identical to said modified surface except that said surface does not include said surface modification; and contacting a fluid stream containing at least one first phase substance, including vapor and / or liquid phase substances, with the modified surface under environmental conditions that permit a phase change to a second phase to occur on the unmodified surface; Including, The method, wherein the phase change is prevented or delayed on the modified surface compared to the unmodified surface. [Aspect 2] 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase and the second phase comprises a liquid phase, and wherein the preventing or retarding the phase change comprises preventing or retarding condensation of the vapor to form a liquid on the surface. [Aspect 3] 3. The method of claim 2, wherein the vapor is water vapor, the fluid stream is air, and the preventing or retarding a phase change comprises preventing or retarding condensation of the water vapor on the surface. [Aspect 4] 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase and the second phase comprises a solid phase, the vapor condenses on the surface to form a condensate, and the preventing or retarding the phase change comprises preventing or retarding solidification of the condensate on the surface to form a solid. [Aspect 5] 5. The method of claim 4, wherein the vapor is water vapor, the fluid stream is air, the condensate is water condensate, and the preventing or retarding the phase change comprises preventing or retarding solidification of the water condensate to form frost or ice on the surface. [Aspect 6] 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase and a liquid phase, the second phase comprises a liquid phase, and the preventing or retarding the phase change comprises preventing or retarding condensation of the vapor to form a liquid on the surface. [Aspect 7] 7. The method of embodiment 6, wherein the vapor is water vapor, the liquid is water, the fluid stream is air, and the preventing or retarding a phase change comprises preventing or retarding condensation of the water vapor on the surface. [Aspect 8] 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase and a liquid phase, the second phase comprises a solid phase, the surface comprises condensate from the vapor and / or liquid, and the preventing or retarding the phase change comprises preventing or retarding solidification of the condensate and / or the liquid to form a solid on the surface. [Aspect 9] 9. The method of claim 8, wherein the vapor is water vapor, the liquid is water, the fluid stream is air, the surface contains condensation of the water vapor and / or liquid water, and the preventing or delaying of the phase change comprises preventing or delaying solidification of the water condensate and / or liquid water on the surface forming frost or ice on the surface. [Aspect 10] 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase and the second phase comprises a solid phase, and wherein the preventing or retarding the phase change comprises preventing or retarding solidification of the vapor on the surface to form a solid. [Aspect 11] 11. The method of claim 10, wherein the vapor is water vapor and the solid is water frost or ice, and wherein preventing or retarding the phase change comprises preventing or retarding solidification of the water vapor to form water frost or ice on the surface. [Aspect 12] The vapor is CO 2 CO is a gas and the solid is frozen 2 and the prevention or retardation of the phase change is achieved by the deposition of frozen CO 2 on the surface. 2 forming CO 2 11. The method of embodiment 10, comprising preventing or retarding solidification of the gas. [Aspect 13] 2. The method of claim 1, wherein the modified surface is supercooled below an equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 14] 14. The method of claim 13, wherein the modified surface is supercooled to a temperature greater than about 0.25° C. below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 15] 15. The method of claim 14, wherein the modified surface is supercooled to a temperature greater than about 0.5° C. below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 16] 16. The method of embodiment 15, wherein the modified surface is supercooled to a temperature more than about 1° C. below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 17] 17. The method of embodiment 16, wherein the modified surface is supercooled to a temperature more than about 2° C. below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 18] 18. The method of embodiment 17, wherein the modified surface is supercooled to a temperature more than about 3° C. below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 19] 20. The method of claim 18, wherein the modified surface is supercooled to a temperature more than about 5° C. below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 20] 20. The method of claim 19, wherein the modified surface is supercooled to a temperature more than about 10° C. below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase. [Aspect 21] 2. The method of embodiment 1, wherein an energy barrier for a phase change from the first phase to the second phase is greater than about 50% of a homogeneous nucleation energy. [Aspect 22] 22. The method of embodiment 21, wherein an energy barrier for a phase change from the first phase to the second phase on the modified surface is greater than about 60% of a homogeneous nucleation energy. [Aspect 23] 23. The method of embodiment 22, wherein an energy barrier for a phase change from the first phase to the second phase on the modified surface is greater than about 70% of a homogeneous nucleation energy. [Aspect 24] 24. The method of embodiment 23, wherein an energy barrier for a phase change from the first phase to the second phase on the modified surface is greater than about 80% of a homogeneous nucleation energy. [Aspect 25] 25. The method of embodiment 24, wherein an energy barrier for a phase change from the first phase to the second phase on the modified surface is greater than about 90% of a homogeneous nucleation energy. [Aspect 26] 26. The method of embodiment 25, wherein an energy barrier for a phase change from the first phase to the second phase on the modified surface is greater than about 95% of a homogeneous nucleation energy. [Aspect 27] 27. The method of embodiment 26, wherein an energy barrier for a phase change from the first phase to the second phase on the modified surface is greater than about 99% of a homogeneous nucleation energy. [Aspect 28] 28. The method of any one of the preceding aspects, wherein the phase change from the first phase to the second phase comprises nucleation of the material on the surface modification, and the surface modification comprises a barrier coating, a conversion coating, or a combination thereof. [Aspect 29] 29. The method of embodiment 28, wherein the surface modification on which nucleation occurs is nanostructured. [Aspect 30] 30. The method of embodiment 28 or 29, wherein the surface modification on which nucleation occurs comprises a metal oxide or a polymer. [Aspect 31] 31. The method of embodiment 30, wherein the surface modification on which nucleation occurs comprises a polymer comprising alkyl or fluoroalkyl monomer units. [Aspect 32] 31. The method of embodiment 30, wherein the surface modification on which nucleation occurs comprises a metal oxide layer created by deposition or conversion. [Aspect 33] 33. The method of any one of aspects 30 to 32, wherein the surface modification at which nucleation occurs comprises one or more terminal alkyl or fluorinated compounds. [Aspect 34] 2. The method of embodiment 1, wherein the substance is water, the first phase comprises primarily water vapor, and the second phase comprises liquid water or water ice. [Aspect 35] 2. The method of embodiment 1, wherein the substance is water, the first phase comprises water vapor in air, and the second phase is liquid water or water ice. [Aspect 36] 2. The method of embodiment 1, wherein the substance is water, the first phase is liquid water, and the second phase is water ice. [Aspect 37] 2. The method of embodiment 1, wherein the substance is carbon dioxide, the first phase comprises carbon dioxide vapor, and the second phase is dry ice. [Aspect 38] 2. The method of claim 1, wherein the substance is raw natural gas, the first phase comprises a gaseous vapor, and the second phase comprises a clathrate. [Aspect 39] The method of any one of the preceding claims, wherein the first phase is a vapor or liquid and the second phase is a supercritical phase. [Aspect 40] 2. The method of embodiment 1, wherein the substance is a metal, the first phase comprises metal vapor, and the second phase comprises condensed metal vapor. [Aspect 41] 1. A heat exchanger or heat transfer surface comprising a modified surface comprising a surface modification that increases the energy barrier to, or driving force required for, a phase change from a first phase to a second phase for a material in contact with the modified surface compared to an unmodified surface identical to the modified surface except that the modified surface does not include the surface modification, such that the occurrence of the phase change is prevented or delayed at the heat exchanger or heat transfer surface compared to a heat exchanger or heat transfer surface not comprising the modified surface. [Aspect 42] 2. The method of embodiment 1, wherein the modified surface is on a heat exchanger or heat transfer surface. [Aspect 43] A glass, window, mirror, or lens comprising a modified surface comprising a surface modification that increases the energy barrier to, or the driving force required for, a phase change from a first phase to a second phase for a material in contact with the modified surface compared to an unmodified surface identical to the modified surface except that the modified surface does not include the surface modification, such that the occurrence of the phase change is prevented or delayed on the glass, window, mirror, or lens compared to a glass, window, mirror, or lens that does not include the modified surface. [Aspect 44] 2. The method of embodiment 1, wherein the modified surface is on a surface of glass, a window, a mirror, or a lens. [Aspect 45] 1. A glass component comprising a patterned modified surface comprising a surface modification that increases an energy barrier or driving force required for a phase change from a first phase to a second phase for a material in contact with the modified surface compared to an unmodified surface identical to the modified surface except that the modified surface does not include the surface modification, and the phase change is prevented or delayed from occurring on the modified surface compared to the unmodified surface, and the modified surface is configured in a decorative pattern on the glass such that the phase change occurs in an aesthetically pleasing manner. [Aspect 46] 2. The method of embodiment 1, wherein the modified surface is patterned on a glass component such that the phase change occurs in an aesthetically pleasing manner. [Aspect 47] A computer case or cooling rack comprising a modified surface comprising a surface modification, wherein the modified surface increases an energy barrier to, or a driving force required for, a phase change from a first phase to a second phase for a material in contact with the modified surface compared to an unmodified surface identical to the modified surface except that the modified surface does not include the surface modification, and wherein the phase change is prevented or delayed from occurring on the computer case or cooling rack compared to a computer case or cooling rack not comprising the modified surface, wherein the phase change comprises condensation of water, and wherein the modified surface prevents or reduces condensation-related damage to electronic equipment contained therein compared to the unmodified surface. [Aspect 48] 2. The method of embodiment 1, wherein the modified surface is on a computer case or a cooling rack. [Aspect 49] A gas vaporizer or gas vaporizer heat exchanger comprising a modified surface comprising a surface modification, wherein the modified surface increases an energy barrier to, or a driving force required for, a phase change of a substance from a first phase to a second phase compared to an unmodified surface identical to the modified surface except that the modified surface does not include the surface modification, and wherein the phase change is prevented or delayed from occurring on the gas vaporizer, wherein the substance is water and the phase change includes condensation of water and / or formation of frost, and wherein the modified surface prevents or reduces condensation and / or frost formation on the gas vaporizer or gas vaporizer heat exchanger compared to an unmodified surface. [Aspect 50] 2. The method of embodiment 1, wherein the modified surface is on a gas vaporizer. [Aspect 51] 51. The method of embodiment 50, wherein the reforming surface is on a gas vaporizer heat exchanger. [Aspect 52] 2. The method of embodiment 1, wherein the modified surface is in a vaporizer device, the substance is water, the phase change includes condensation of water, and the modified surface prevents or reduces fouling in the form of condensation on the vaporizer device compared to an unmodified surface. [Aspect 53] 2. The method of claim 1, wherein the modified surface is in an engine or combustion nozzle, the substance is carbon dioxide, the phase change includes condensation of carbon dioxide, and the modified surface prevents or reduces condensation of carbon dioxide in the engine or combustion nozzle compared to an unmodified surface. [Aspect 54] 2. The method of claim 1, wherein the modified surface is on a treatment device for industrial gases and / or liquids, the substance is raw natural gas, the phase change comprises hydration or host-guest complexation, and the modified surface prevents or reduces the formation of water and gas hydrates, and / or clathrates during processing of the industrial gases and liquids in the treatment device compared to an unmodified surface. [Aspect 55] 55. The method of embodiment 54, wherein the first phase is a vapor or liquid and the second phase is a supercritical phase. [Aspect 56] The method of embodiment 1, wherein the modified surface is on a metal vapor illumination or advanced lithography apparatus, the material is a metal, the phase change includes condensation of metal vapor, and the modified surface prevents or reduces condensation of metal vapor during operation of the metal vapor illumination or advanced lithography apparatus. [Aspect 57] 57. The method of embodiment 56, wherein uniformity and prevention of deposition are important for proper operation of the advanced lithographic apparatus.

Claims

1. 1. A method for preventing or delaying the occurrence of a phase change on a surface, comprising: providing a modified surface comprising a nanostructured surface modification, the nanostructured surface increasing an energy barrier to, or a driving force required for, a phase change from a first phase to a second phase for a material in contact with the modified surface compared to an unmodified surface identical to the modified surface except that the unmodified surface does not include the nanostructured surface modification; and contacting a fluid stream containing at least one first phase substance, including vapor and / or liquid phase substances, with said modified surface under environmental conditions that permit a phase change to a second phase to occur on said unmodified surface; Including, the phase change from the first phase to the second phase comprises nucleation of the material on the nanostructured surface modification; condensed droplets of the material are present on the nanostructured surface at or above a critical radius of formation in a Cassie-Baxter state of dewetting; the phase change is prevented or delayed on the modified surface compared to the unmodified surface; The method, wherein the nanostructured surface modification is produced by a process comprising: contacting a substrate with a solution comprising a metal salt and an amine, thereby depositing a nanostructured metal oxide coating on the substrate; and fixing the nanostructured coating on the substrate by heating at a temperature of about 100 to about 600°C.

2. 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase comprising water vapor and the second phase comprises a liquid phase comprising water, and the preventing or retarding the phase change comprises preventing or retarding condensation of the vapor to form a liquid on the surface.

3. 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase comprising water vapor, the second phase comprises a solid phase comprising water, the vapor condenses on the surface to form a condensate comprising the liquid droplets in the Cassie-Baxter state, and the preventing or delaying the phase change comprises preventing or delaying solidification of the condensate on the surface to form a solid.

4. 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase including water vapor and a liquid phase, the second phase comprises a liquid phase including water, and the preventing or retarding the phase change comprises preventing or retarding condensation of the vapor to form a liquid on the surface.

5. 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase including water vapor and a liquid phase, the second phase comprises a solid phase including water, the surface comprises condensate from the vapor and / or liquid including the droplets in the Cassie-Baxter state, and the preventing or delaying the phase change comprises preventing or delaying solidification of the condensate and / or the liquid to form a solid on the surface.

6. 2. The method of claim 1, wherein the at least one first phase comprises a vapor phase and the second phase comprises a solid phase, and the preventing or retarding the phase change comprises preventing or retarding solidification of the vapor to form a solid on the surface.

7. 7. The method of claim 6, wherein the vapor is water vapor and the solid is water frost or ice, and the preventing or retarding the phase change comprises preventing or retarding solidification of the water vapor to form water frost or ice on the surface.

8. 8. The method of claim 7, wherein the nanostructured surface modification reduces the temperature at which frost formation occurs.

9. The vapor is CO ２ gas and the solid is frozen CO ２ and the prevention or retardation of the phase change is achieved by the deposition of frozen CO ２ The CO ２ 7. The method of claim 6, comprising preventing or retarding solidification of the gas.

10. 10. The method of claim 1, wherein the modified surface is supercooled below an equilibrium phase transition value from the first phase to the second phase, and the material still exists in the first phase.

11. 11. The method of claim 10, wherein the modified surface is supercooled to a temperature greater than about 0.25°C below the equilibrium phase transition value from the first phase to the second phase, and the material remains in the first phase.

12. 2. The method of claim 1, wherein an energy barrier for a phase change from the first phase to the second phase is greater than about 50% of a homogeneous nucleation energy.

13. 13. The method of any of claims 1 to 12, wherein the nanostructured surface modification comprises a barrier coating, a conversion coating, or a combination thereof.

14. 14. The method of any of claims 1 to 13, wherein the nanostructured surface modification on which nucleation occurs comprises a metal oxide or a polymer.

15. 15. The method of claim 14, wherein the nanostructured surface modification on which nucleation occurs comprises one or more terminal alkyl or fluorinated compounds.

16. 10. The method of claim 1, wherein the modified surface is on a metal vapor illumination or advanced lithography apparatus, the material is a metal, the phase change includes condensation of metal vapor, and the modified surface prevents or reduces condensation of metal vapor during operation of the metal vapor illumination or advanced lithography apparatus.

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