Evaporation-Resistant Coating

Abstract

An improved evaporation barrier that incorporates multifunctional particles to reduce evaporation. The improved evaporation barrier is typically in liquid form. The improved evaporation barrier is formed of a mixture of one or more alkanes and a reflective and/or non-reflective material. The improved evaporation barrier can optionally include a nonvolatile oil in combination with the alkane. The reflective and/or non-reflective material can be optionally surface functionalized. The improved evaporation barrier can optionally include a hydrophobic compound.

Claims

1. An evaporation barrier formulated to be added to an aqueous phase so as to inhibit evaporation of the aqueous phase, said evaporation barrier comprising: a water-insoluble liquid having a density of less than 1 g/cc; and, an impermeable solid material, wherein said impermeable solid material is a flake, particle, microballoon, and/or microball, at least 20% of said impermeable solid material remains suspended in said water-insoluble liquid for at least 1 day after being mixed with said water-insoluble liquid.

2. The evaporation barrier as defined in claim 1, wherein said water-insoluble liquid has a viscosity of less than 400 cP at 25 C.

3. The evaporation barrier as defined in claim 1, wherein said impermeable solid material is at a concentration of 0.5-25 vol. % of said evaporation barrier.

4. The evaporation barrier as defined in claim 1, wherein at least 20% of said impermeable solid material is at least partially retained in said water-insoluble liquid when said evaporation barrier is added to said aqueous phase.

5. The evaporation barrier as defined in claim 1, wherein said impermeable solid material includes materials that have a reflectiveness of at least 50% in UV and/or IR ranges.

6. The evaporation barrier as defined in claim 1, wherein said impermeable solid material includes non-reflective materials that have a transmittance of at least 30% in the optical wavelengths.

7. The evaporation barrier as defined in 1, wherein said impermeable solid material includes one or more non-reflective materials selected from the group consisting of an optically transparent or translucent material such as glass or polymeric flakes, glass, ceramic, or polymeric microballoons and/or microballs, silica, and mica.

8. The evaporation barrier as defined in claim 1, wherein said impermeable solid material includes one or more materials selected from group of mica flakes, glass flakes, glass microspheres, ceramic microspheres, polymer flakes, polymer microspheres, calcite, gypsum/selenite, lucite, magnesium carbonate, zeolite, montmotillionite, kaolin, feldspar, polypropylene, polyacytal, and acrylic.

9. The evaporation barrier as defined in claim 1, wherein said impermeable solid material includes one or more reflective materials selected from the group consisting of aluminum, aluminum alloy, magnesium, magnesium alloy, metallized particle, material coated with a reflective pigment, microballoon, coated microballoon, microball, and coated microball.

10. The evaporation barrier as defined in claim 9, wherein said reflective material includes one or more materials selected from the group consisting of aluminum particles, aluminum flakes, aluminum alloy particles, aluminum alloy flakes, magnesium particles, magnesium flakes, magnesium alloy particles.

11. The evaporation barrier as defined in claim 9, wherein said reflective material has a reflectance of at least 75% in the visible wavelengths and at least 50% in the long IR wavelengths.

12. The evaporation barrier as defined in claim 9, wherein at least a portion of said reflective material degrades by at least 10% within 360 days upon exposure to water, saltwater or brine at a temperature of at least 90 F.

13. The evaporation barrier as defined in claim 1, wherein the impermeable solid material at least partially reacts in the aqueous phase to produce gas bubbles on an outer surface of said impermeable solid material which creates additional buoyancy of said impermeable solid material in the aqueous phase.

14. The evaporation barrier as defined in claim 1, wherein said impermeable solid material includes one or more materials having a density of greater than 1 g/cc.

15. The evaporation barrier as defined in claim 1, wherein said impermeable solid material includes one or more materials having a density of no greater than 3 g/cc.

16. The evaporation barrier as defined in claim 1, wherein said impermeable solid material includes one or more materials having a density of less than 1 g/cc.

17. The evaporation barrier as defined in claim 1, wherein said water-insoluble liquid has a vapor pressure of less than 0.1 torr at 80 C.

18. The evaporation barrier as defined in claim 1, wherein said water-insoluble liquid has a solubility in water that is less than 1000 ppm solubility.

19. The evaporation barrier as defined in claim 1, wherein said water-insoluble liquid has a solubility in water such that a water content in the water-insoluble liquid at a temperature of about 2580 C. is less than 5 vol. %.

20. The evaporation barrier as defined in claim 1, wherein said water-insoluble liquid includes one or more components selected from the group of hydrocarbons (e.g., alkanes, from C8-C30, including paraffin oils, mineral oils, JP8, fuel oil, heating oil, vegetable oil such as soybean oil, linseed oil, canola oil, or other vegetable oil, etc.), silicones, silicon oil, and mineral oil; said hydrocarbons including one or more compounds selected from the group consisting of alkane and hydrocarbon chains of C8-C30, said hydrocarbon chains of C8-C30 including one or more materials selected from the group consisting of paraffin oil, mineral oil, kerosene-based fuel, fuel oil, heating oil, and vegetable oil.

21. The evaporation barrier as defined in claim 1, wherein said water-insoluble liquid has a viscosity of less than about 10,000 cP at 25 C.

22. The evaporation barrier as defined in claim 1, wherein said impermeable solid material is treated with a coupling agent to form a hydrophobic or organophilic surface on an outer surface of said impermeable solid material.

23. The evaporation barrier as defined in claim 22, wherein said coupling agent includes one or more materials selected from the group consisting of silane, silicone, siloxane, and silizane.

24. The evaporation barrier as defined in claim 1, including a surfactant.

25. The evaporation barrier as defined in claim 24, wherein said surfactant includes one or more components selected from linear alkylbenzenesulfonates, lignin sulfonates, fatty alcohol ethoxylates, alkylphenol ethoxylates, ammonium lauryl sulfate, sodium lauryl sulfate, dioctyl sodium sulfosuccinate (DOSS), sorbitan monooleate (Span 80), and polyoxyethylenated sorbitan monooleate.

26. The evaporation barrier as defined in claim 1, including antimicrobial particles or antimicrobial medium soluble in said water-insoluble liquid.

27-33. (canceled)

34. An evaporation barrier formulated to be added to an aqueous phase so as to inhibit evaporation of the aqueous phase so as to block at least 60% of water evaporation from the aqueous phase at a temperature up to about 85 C. where said evaporation barrier forms a continuous film on a top surface of said aqueous phase, said aqueous phase is water, saltwater, brine, or fracking fluid that is located in a pond, tank, retention pond, reservoir, basin, lake, open retention container, or storage container for use in oil and gas operations, said evaporation barrier comprising: a water-insoluble liquid having a density of less than 1 g/cc, said water-insoluble liquid has a viscosity of less than 400 cP at 25 C., said water-insoluble liquid includes one or more components selected from the group of hydrocarbons (e.g., alkanes, from C8-C30, including paraffin oils, mineral oils, JP8, fuel oil, heating oil, vegetable oil such as soybean oil, linseed oil, canola oil, or other vegetable oil, etc.), silicones, silicon oil, and mineral oil; said hydrocarbons including one or more compounds selected from the group consisting of alkane and hydrocarbon chains of C8-C30, said hydrocarbon chains of C8-C30 including one or more materials selected from the group consisting of paraffin oil, mineral oil, kerosene-based fuel, fuel oil, heating oil, and vegetable oil; and, an impermeable solid material, said impermeable solid material is a flake, particle, microballoon, and/or microball, said impermeable solid material is at a concentration of 0.5-40 vol. % of said evaporation barrier, at least 20% of said impermeable solid material remains suspended in said water-insoluble liquid for at least one day after being mixed with said water-insoluble liquid.

35. The evaporation barrier as defined in claim 34, wherein said impermeable solid material includes a) materials that have a reflectiveness of at least 50% in UV and/or IR ranges, and/or b) non-reflective materials that have a transmittance of at least 30% in the optical wavelengths.

36. The evaporation barrier as defined in 34, wherein said impermeable solid material includes a) one or more non-reflective materials selected from the group consisting of an optically transparent or translucent material such as glass or polymeric flakes, glass, ceramic, or polymeric microballoons and/or microballs, silica, and mica, b) one or more materials selected from the group of mica flakes, glass flakes, glass microspheres, ceramic microspheres, polymer flakes, polymer microspheres, calcite, gypsum/selenite, lucite, magnesium carbonate, zeolite, montmotillionite, kaolin, feldspar, polypropylene, polyacytal, and acrylic, c) one or more reflective materials selected from the group consisting of aluminum, aluminum alloy, magnesium, magnesium alloy, metallized particle, material coated with a reflective pigment, microballoon, coated microballoon, microball, and coated microball, and/or d) one or more materials selected from the group consisting of aluminum particles, aluminum flakes, aluminum alloy particles, aluminum alloy flakes, magnesium particles, magnesium flakes, and magnesium alloy particles.

37. The evaporation barrier as defined in 35, wherein said impermeable solid material includes a) one or more non-reflective materials selected from the group consisting of an optically transparent or translucent material such as glass or polymeric flakes, glass, ceramic, or polymeric microballoons and/or microballs, silica, and mica, b) one or more materials selected from the group of mica flakes, glass flakes, glass microspheres, ceramic microspheres, polymer flakes, polymer microspheres, calcite, gypsum/selenite, lucite, magnesium carbonate, zeolite, montmotillionite, kaolin, feldspar, polypropylene, polyacytal, and acrylic, c) one or more reflective materials selected from the group consisting of aluminum, aluminum alloy, magnesium, magnesium alloy, metallized particle, material coated with a reflective pigment, microballoon, coated microballoon, microball, and coated microball, and/or d) one or more materials selected from the group consisting of aluminum particles, aluminum flakes, aluminum alloy particles, aluminum alloy flakes, magnesium particles, magnesium flakes, and magnesium alloy particles.

38. The evaporation barrier as defined in claim 34, wherein said reflective material has a reflectance of at least 75% in the visible wavelengths and at least 50% in the long IR wavelengths.

39. The evaporation barrier as defined in claim 34, wherein at least a portion of said reflective material degrades by at least 10% within 360 days upon exposure to water, saltwater or brine at a temperature of at least 90 F.

40. The evaporation barrier as defined in claim 34, wherein the impermeable solid material at least partially reacts in the aqueous phase to produce gas bubbles on an outer surface of said impermeable solid material which creates additional buoyancy of said impermeable solid material in the aqueous phase.

41. The evaporation barrier as defined in claim 34, wherein said impermeable solid material includes a) one or more materials having a density of greater than 1 g/cc, b) one or more materials having a density of no greater than 3 g/cc, and/or c) one or more materials having a density of less than 1 g/cc.

42. The evaporation barrier as defined in claim 34, wherein said water-insoluble liquid has a vapor pressure of less than 0.1 torr at 80 C.

43. The evaporation barrier as defined in claim 34, wherein said water-insoluble liquid has a solubility in water that is less than 1000 ppm solubility.

44. The evaporation barrier as defined in claim 34, wherein said water-insoluble liquid has a solubility in water such that a water content in the water-insoluble liquid at a temperature of about 25-80 C. is less than 5 vol. %.

45. The evaporation barrier as defined in claim 34, wherein said water-insoluble liquid has a viscosity of less than about 10,000 cP at 25 C.

46. The evaporation barrier as defined in claim 34, wherein said impermeable solid material is treated with a coupling agent to form a hydrophobic or organophilic surface on an outer surface of said impermeable solid material.

47. The evaporation barrier as defined in claim 46, wherein said coupling agent includes one or more materials selected from the group consisting of silane, silicone, siloxane, and silizane.

48. The evaporation barrier as defined in claim 34, including a surfactant.

49. The evaporation barrier as defined in claim 48, wherein said surfactant includes one or more components selected from linear alkylbenzenesulfonates, lignin sulfonates, fatty alcohol ethoxylates, alkylphenol ethoxylates, ammonium lauryl sulfate, sodium lauryl sulfate, dioctyl sodium sulfosuccinate (DOSS), sorbitan monooleate (Span 80), and polyoxyethylenated sorbitan monooleate.

50. The evaporation barrier as defined in claim 34, including antimicrobial particles or antimicrobial medium soluble in said water-insoluble liquid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0132] FIG. 1 illustrates a dispersion of glass flakes as the impermeable solid in a water-insoluble liquid, wherein glass flakes cover approximately 80% of the total surface area of the aqueous phase.

[0133] FIG. 2 illustrates a multilayered flake evaporation resistant coating with overlap of the flakes.

[0134] FIG. 3 illustrates an improved evaporation barrier incorporating glass microballoons as the impermeable solid, which cover approximately 50% of the surface area of the aqueous phase.

DESCRIPTION OF THE INVENTION

[0135] The improved evaporation barrier of the present invention incorporates multifunctional particles to reduce evaporation of liquid form a pond or reservoir. The improved evaporation barrier of the present invention is typically in liquid form. The improved evaporation barrier of the present invention includes:

[0136] 1. Water-Insoluble Liquid.

[0137] The water-insoluble liquid can include an alkane, non-volatile oil, and/or non-volatile silicone oil. The water-insoluble liquid generally has a density that is less than water (i.e., less than 1 g/cc), saltwater, brine, or fracking fluid so that the water-insoluble liquid floats on the top surface of the water, saltwater, brine or fracking fluid. Generally, the water-insoluble liquid includes a mixture of one or more alkanes and one or more non-volatile oils. The water-insoluble liquid typically has a vapor pressure of less than 0.1 torr at 80 C. Generally, the water-insoluble liquid is insoluble in water. Generally, the solubility of the water-insoluble liquid in water is less than 1000 ppm solubility in water, typically less than 100 ppm solubility in water, more typically no more than 10 ppm solubility in water, and even more typically no more than 1 ppm solubility in water. The water-insoluble liquid generally is formulated so as to not react with water. In one non-limiting embodiment, the water-insoluble liquid has a solubility such that the water content in the water-insoluble liquid at a temperature of about 25-80 C. is less than 5 vol. %, and typically less than 1 vol. %.

[0138] Non-limiting examples of water-insoluble liquid include hydrocarbons (e.g., alkanes, from C.sub.8-C.sub.30, including paraffin oils, mineral oils, JP8, fuel oil, heating oil, vegetable oils such as soybean oil, linseed oil, canola oil, or other vegetable oil, etc.), silicones and other insoluble, low vapor pressure oils, as well as mixtures of these oils. In one non-limiting embodiment, the water-insoluble liquid is or includes a low density vegetable oil that is mixed with a paraffin oil to reduce density of the mixture. A low viscosity PDMS (silicone oil) can also be added to the vegetable oil and paraffin oil mixture to form an easily spreadable, low viscosity water-insoluble liquid for mixing with the impermeable solid. The water-insoluble liquid has a viscosity of about 1-10,000 cP at 25 C. (and all values and ranges therebetween) (ASTM D7042-04), and generally from 5-500 cP at 25 C. The water-insoluble liquid should be viscous enough to easily retain the impermeable solid and to not be easily dispersed or atomized when added into a liquid such as water in a pond, reservoir, etc., but also not be so viscous as to prevent the impermeable solid from easily and quickly spreading on the surface of an aqueous phase (e.g., water, saltwater, brine, fracking fluid that is in a pond, reservoir, etc.).

[0139] The volume percent of the water-insoluble liquid in the evaporation barrier is generally 60-99.5 vol. % (and all values and ranges therebetween). When the water-insoluble liquid includes both alkane and non-volatile oil, the volume percent of the alkane content is generally at least 50 wt. % of the water-insoluble liquid, and typically greater than 50 wt. % of the water-insoluble liquid; however, this is not required. In one non-limiting embodiment, the volume ratio of the alkane to the non-volatile oil in the water-insoluble liquid is 1-100:1 (and all values and ranges therebetween), typically 1-25:1, more typically 1.01-10:1, and still more typically 1.1-5:1.

[0140] 2. Impermeable Solid.

[0141] The impermeable solid can be or include a reflective material and/or a non-reflective material (e.g., mica flakes, glass flakes, glass microspheres, ceramic microspheres, polymer flakes, polymer microspheres, calcite, gypsum/selenite, lucite, magnesium carbonate, zeolite, montmotillionite, kaolin, feldspar, polypropylene, polyacytal, acrylic, or other inorganic or organic particles).

[0142] Generally, the impermeable solid is an inorganic material; however, this is not required. In one non-limiting embodiment, 75-100% (and all values and ranges therebetween) of the impermeable solid is an inorganic material. The impermeable solid is generally in flake, platelet, or spherical form; however, other shapes can be used.

[0143] The impermeable solid generally has a density of less than about 3 g/cc (e.g., 2.99 g/cc to 0.1 g/cc and all values and ranges therebetween); however, this is not required. In one non-limiting embodiment, the impermeable solid generally has a density of less than about 2.5 g/cc. The impermeable solid may be hollow (e.g., glass microballoon and/or microball, ceramic microballoon and/or microball, polymer microballoon and/or microball, metal microballoons and/or microball, etc.) to reduce its effective density and provide buoyancy; however, this is not required. The impermeable solid may be include flake materials (e.g., glass flakes, mica flakes, polymer flakes, ceramic flakes, metal flakes, etc.).

The impermeable solid, and the resulting impermeable solid dispersion in the water-insoluble liquid, may optionally be transparent, translucent, or have a predetermined color, such as through the use of colored pigments or colored flakes. The degree of reflectivity of the improved evaporation barrier can be fine-tuned by the use of colored impermeable solid, and/or the use of different colored impermeable solid. For example, use of certain colored impermeable solid and/or the use of a certain amount of colored and/or non-colored impermeable solid can optionally be used to reflect certain light bandwidths to control the transmission/reflection of certain light bandwidths on the improved evaporation barrier. In addition or alternatively, the use of certain colored impermeable solid and/or the use of a certain amount of colored and/or non-colored impermeable solid can optionally be used to create a certain color on the top surface of the improved evaporation barrier which can be used as color coding for a certain pond, lake, reservoir, retention tank, etc. Such color coding can be used to identify certain ponds, lakes, reservoirs, retention tanks, etc., identify the contents of certain ponds, lakes, reservoirs, retention tanks, etc., and/or to distinguish different ponds, lakes, reservoirs, retention tanks, etc. from other ponds, lakes, reservoirs, retention tanks, etc.

[0144] The impermeable solid, when a reflective material, can be a material such as an aluminum, aluminum alloy, magnesium, and/or magnesium alloy in powder and/or flake form. Other or additional materials such as, but not limited to, microballoons and/or microballs (e.g., aluminum-coated 3M Scotchlight glass microballoons) can be used. The reflectivity or reflectance of the surface of the reflective material is its effectiveness in reflecting radiant energy. High reflection is defined as a reflectance of at least 75% in the visible (ASTM E903-96 and ASTM E903-88), and 50% in the long IR wavelengths (ASTM E408-71). Other separate phases with reflective properties can also be envisioned, such as phase-separating liquid phase with a high difference in refractive index to cause reflection. Other possible approaches are obtaining near perfect reflection at the water-hydrocarbon interface through control over refractive index. Reflection can be either specular or diffuse, with specular being a preferred solution, with diffuse being acceptable as long as greater than about 90% of the light is prevented from reaching more than a millimeter or two into the aqueous phase.

[0145] The impermeable solid, when a non-reflective material, can be a material such as an optically transparent or translucent material such as glass or polymeric flakes, glass, ceramic, or polymeric microballoons and/or microballs, silica, mica, or other translucent or transparent particle.

[0146] The impermeable solid can optionally be surface treated to make the surface of the particle or flake hydrophobic and/or oil-philic (e.g., lipophilic) so that the impermeable solid remains in the liquid phase (e.g., water-insoluble liquid) of the improved evaporation barrier of the present invention.

[0147] The aspect ratio of the impermeable solid can optionally be selected to improve the improved evaporation barrier. In one non-limiting embodiment, an impermeable solid having a higher aspect ratio (e.g., greater than 10) can be included in the improved evaporation barrier to 1) benefit the stability of the solid dispersion in the improved evaporation barrier, and/or 2) improve water conservation performance of the improved evaporation barrier by allowing less solids loading.

[0148] The volume percent of the impermeable solid in the evaporation barrier is about 0.5-40% (and all values and ranges therebetween). When the evaporation barrier includes both reflective material and non-reflective material, the reflective material generally constitutes 1-99 wt. % of the impermeable solid (and all values and ranges therebetween). In one non-limiting embodiment, the reflective material constitutes 5-99 wt. % of the impermeable solid with the balance of the impermeable solid constituting non-reflective material. In another non-limiting embodiment, the reflective material constitutes 25-99 wt. % of the impermeable solid with the balance of the impermeable solid constituting non-reflective material. In another non-limiting embodiment, the reflective material constitutes 40-99 wt. % of the impermeable solid with the balance of the impermeable solid constituting non-reflective material. In another non-limiting embodiment, the reflective material constitutes 50-99 wt. % of the impermeable solid with the balance of the impermeable solid constituting non-reflective material. In another non-limiting embodiment, the reflective material constitutes 50.1-99 wt. % of the impermeable solid with the balance of the impermeable solid constituting non-reflective material. In another non-limiting embodiment, the reflective material constitutes 55-99 wt. % of the impermeable solid with the balance of the impermeable solid constituting non-reflective material.

[0149] 3. Coupling Agent.

[0150] A coupling agent (when used) can be used to enable or facilitate the retention of the impermeable solid by surface tension in the water-insoluble liquid. The coupling agent is generally formulated to produce a hydrophobic or organophilic surface on the impermeable solid so as to retain the impermeable solid in the water-insoluble liquid. Generally the coupling agent is coated on the impermeable solid. Non-limiting examples of coupling agents are silane, silicone, siloxane, silizane. However, it can be appreciated that the coupling agent can be any surface treatment and/or impermeable solid surface chemistry capable of creating a highly wetted surface (e.g., contact angel of less than 90 degrees and typically less than 30) in the water-insoluble liquid. In one non-limiting embodiment, the coupling agent forms a hydrophobic surface on the impermeable solid where its contact angle with the aqueous phase (e.g., the water, saltwater, brine, fracking fluid) is greater than about 90 degrees, and typically greater than about 120. The surface functionalization of the impermeable solid (when used) typically results in a resultant surface with a surface energy of about 20-35 dynes/cm.sup.2 (and all values and ranges therebetween) (ASTM D2578). Non-limiting examples of coupling agents include ethyltrimethoxysilane, octadecyltrichlorosilane, methyltrimethoxysilane, nonafluorohexyltrimethoxysilane, vinyltriethoxysilane, propyltrimethoxysilane, trifluoropropyltrimethoxysilane, 3-(2-aminoethyl)-aminopropyltrimethoxysilane, p-tolyltrimethoxysilane, cyanoethyltrimethoxysilane, aminopropyltriethoxysilane, and acetoxypropyltrimethoxylsilane. The volume percent of the coupling agent in the evaporation barrier is about 0-4% (and all values and ranges therebetween). The coupling agent generally constitutes about 0.1-3 wt. % (and all values and ranges therebetween) of the coated particle (i.e., the impermeable solid that is coated with the coupling agent).

[0151] 4. Hydrophobic Compound.

[0152] The hydrophobic compound (when used) can be a hydrophobic constituent and/or surfactant that can be used to facilitate in the dispersion of the improved evaporation barrier of the present invention, the coating thickness of the present invention, and/or the stability improved evaporation barrier of the present invention when dispersed on the surface of the aqueous phase (e.g., water, saltwater, brine, fracking liquid, etc.). The hydrophobic compound is an optional component of the improved evaporation barrier of the present invention. One non-limiting hydrophobic compound that can be used includes surfactant; however, other or additional types of hydrophobic compound can be used (e.g., wetting agents, detergents, solubilizers, soaps, etc.). A surfactant, such as a non-ionic surfactant, (when used) can be added to the water-insoluble liquid to aid in the spreading of the improved evaporation barrier on the surface of the aqueous phase (e.g., water, saltwater, brine, fracking fluid), and/or to inhibit or prevent the breaking of the improved evaporation barrier on the surface of the aqueous phase. Non-limiting surfactants include linear alkylbenzenesulfonates, lignin sulfonates, fatty alcohol ethoxylates, alkylphenol ethoxylates, ammonium lauryl sulfate, sodium lauryl sulfate, dioctyl sodium sulfosuccinate (DOSS), sorbitan monooleate (Span 80), and polyoxyethylenated sorbitan monooleate, among others. The volume percent of the hydrophobic compound in the evaporation barrier is about 0-4% (and all values and ranges therebetween).

[0153] The improved evaporation barrier of the present invention has one or more of the following properties:

[0154] A. The improved evaporation barrier does not interfere with the chemistry of the aqueous phase (e.g., water, or saltwater, brine, fracking fluid);

[0155] B. The improved evaporation barrier has a boiling point above 150 C., and typically above 200 C.; and/or

[0156] C. The improved evaporation barrier has a low viscosity. Low viscosity is defined as less than 1000 mPa-s at room temperature (e.g., 77 F.). Typically, the viscosity of the evaporation barrier is between 20-400 mPa-s (and all values and ranges therebetween). The characterization method for the viscosity is performed by Stabinger Viscometer (ASTM D7042-04).

[0157] Alkane

[0158] As used herein, the term alkane refers to a class of aliphatic hydrocarbons characterized by a straight chain (having a generic formula C.sub.n H.sub.2n+2, an n-paraffinic hydrocarbon) or branched-chain or cyclic carbon chain each having from 1 to greater than 50 carbons that can be used as the water-insoluble liquid. Alkanes which are useful in the improved evaporation barrier of the present invention have at least about 6 carbons. One non-limiting type of alkane that can be used in the improved evaporation barrier of the present invention is straight-chain alkanes that include the C.sub.6 to C.sub.17 hydrocarbons (commonly referred to as mineral oils) and the C.sub.18 to C.sub.20 hydrocarbons (commonly referred to as waxes) which are solid at room temperature. Non-limiting examples of such alkanes are medium-chain alkanes having from 10 (decane) to 20 (icosane) carbons, and a wax octadecane (C.sub.18). Alkanes can have more than 20 carbons when the alkane is branched or cyclic. Mixtures of alkanes also can be used. Another non-limiting type of alkane that can be used is a mixture of C.sub.15 to C.sub.20 alkanes having approximately branched-chain alkanes and cycloalkanes and available commercially under the trade name ISOPAR V (CAS#64742-46-7Exxon Chemical Americas, Houston, Tex.).

[0159] The one or more alkanes that can be used in the improved evaporation barrier of the present invention have a density that is less than that of the aqueous phase (e.g., water, saltwater, brine, fracking liquid, etc.), thereby enabling the alkane to float on the aqueous phase. Generally, the density of the alkane or alkane mixture is from 0.73 to 0.86 (and all values and ranges therebetween) (ASTM D5002-94). The one or more alkanes generally have a low viscosity and a low vapor pressure; however, this is not required. As defined herein, low viscosity is less than 1000 mPa-s at room temperature, and typically from 20-400 mPa-s (ASTM D7042-04). Low vapor pressure is defined as less than 5 mmHg at room temperature (e.g., 77 F. or 25 C.). The following non-limiting non-volatile oils have low vapor pressure at room temperature: paraffin oil (<0.5 mmHg), vegetable oil (<1 mmHg), silicone oil (<5 mmHg). The vapor pressure is measured by ASTM D323 (Reid Method)), and is generally combustible rather than flammable liquids in atmospheric conditions (e.g., Earth's atmosphere at sea level); however, this is not required.

[0160] In addition to the characteristics of the alkanes described above, the one or more alkanes can have additional properties which enhance the features and properties of the improved evaporation barrier of the present invention. For example, the alkane can optionally have a melting point below room temperature, thereby making the alkane more easily dispersible in an aqueous phase (e.g., water, saltwater, brine, fracking fluid). The alkane can optionally have a low viscosity (e.g., less than 1000 mPa-s), thereby also making the alkane more easily dispersible in an aqueous phase (e.g., water, saltwater, brine, fracking fluid). When the alkane is or includes a wax, the wax is generally heated until the wax melts when mixing the wax with oil. The resulting mixture (up to 40 wt. % wax) remains liquid at room temperature (e.g., 77 F.) with suitable viscosity (e.g., 20-1000 mPa-s). The one or more alkanes are generally readily available, generally inexpensive, and available in high purity, thus making the use of such alkanes desirable in the improved evaporation barrier of the present invention.

[0161] It is noted that although an evaporation barrier can be formulated to only include alkanes (however, this is not required), when only the alkanes are used, the alkanes tend to smoke at temperatures of 90 C. or above. Such smoking indicates that the protective layer provided by the alkane evaporates at elevated temperatures, thereby resulting in the eventual loss of protection of the evaporation barrier.

[0162] Non-Volatile Oil

[0163] As used herein, the term non-volatile oil is used to refer to oils which can be heated to the boiling point of water without significant evaporation (e.g., less than 1% loss over a 30 minute period at 100 C.) and which can be the water-insoluble liquid. The non-volatile oil generally has a boiling point in excess of 200 C.; however, this is not required. The non-volatile oil generally is capable of forming a uniform mixture with the alkane. The non-volatile oils can include one or more of silicone oils, vegetable oils, mineral oils, and other oils having similar properties. In one non-limiting embodiment, the non-volatile oil is one or more vegetable oils. In another non-limiting embodiment, the non-volatile oil is one or more silicone oils. In another non-limiting embodiment, the non-volatile oil is a mixture of one or more silicone oils and one or more vegetable oils and/or one or more mineral oils.

[0164] As used herein, the term vegetable oil is used in its everyday sense and refers to the oil of any plant whether the oil is derived from a vegetable or a fruit. The vegetable oil is generally a refined, edible oil and can be derived from, for example, rapeseed (canola), soybean, safflower, sunflower, corn, cottonseed, palm, sesame, and olive, etc. However, any vegetable oil which can be heated to the boiling point of water without significant evaporation (e.g., less than 1% loss over a 30 minute period at 100 C.) is suitable. A further benefit of the use of one or more vegetable oils in the improved evaporation barrier of the present invention is that vegetable oil is generally safe and nontoxic, thus minimizing or eliminating safety and toxicity issues that might be factors with other compounds having similar physical properties. The vegetable oils are also readily available in large quantity and are relatively inexpensive. Generally, the vegetable oil is one that is suitable for deep frying applications. One non-limiting example is low erucic acid canola oil. Such low erucic acid canola oil has excellent resistance to oxidation and to thermal breakdown.

[0165] Silicone oils are commercially available from a number of sources including from Sigma Chemical Company, Saint Louis, Mo. (Product No.: M6884, CAS No.: 8020-83-5). When silicone oil is used, the silicone oil generally has a low viscosity, generally below 200 centipoise (cP) at 25 C. (ASTM D7042-04), and typically less than 30-50 cP, and more typically less than 10-15 cP. The non-volatile oil can be only silicone oil, or can be a mixture of one or more silicone oils with one or more mineral oils and/or one or more vegetable oils; however, this is not required.

[0166] The non-volatile oil can be or include one or more mineral oils (e.g., paraffin oil, etc.); however, this is not required.

[0167] Reflective Material

[0168] A reflective material can optionally be added to the improved evaporation barrier of the present invention to create an added physical barrier to evaporation and to reflect solar radiation to inhibit or prevent heating of the aqueous phase (e.g., water, saltwater, brine, fracking liquid, etc.). The improved evaporation barrier can include a reflective material and no non-reflective material, or include both a reflective and non-reflective material. In one non-limiting embodiment, the reflective material includes a) aluminum, aluminum alloy, magnesium and/or magnesium alloy powder having an average particle size of generally 0.01-200 microns (and all values and ranges therebetween), and/or b) aluminum, aluminum alloy, magnesium and/or magnesium alloy flakes having an average size of 1 micron or less in average thickness by about 60-200 microns in average diameter (and all values and ranges therebetween). The reflective material can also or alternatively include microballs or microballoons (e.g., aluminum-coated 3M Scotchlight glass microballoons, etc.); however, this is not required. The reflectance or reflectivity of the reflective material is generally greater than 70%, typically at least 80-90%, and more typically greater than 90% for solar radiation, particularly in the visible and near-IR wavelength ranges, and generally greater than 60%, and typically greater than 80-90% for the long wavelength (far) IR wavelengths. The transmittance of the reflective material is generally less than 20%, typically less than 10%, and more typically less than 5%.

[0169] Aluminum, magnesium, and their alloys are desirable reflector materials, but other reflective materials, including glass and engineered pigments such as TiO.sub.2, ZrO.sub.2, etc., can be used. White reflective pigments (such as ZnO, TiO.sub.2, etc.) have high diffuse reflectivity, while metals (such as aluminum or magnesium) have high specular reflection. Generally, the reflective liquid coating or pigment should have a reflectance of greater than 75%, and typically greater than 80-90%. One or more types of non-reflective material can be used in the improved evaporation barrier of the present invention.

[0170] Non-Reflective Material

[0171] A non-reflective material can optionally be added to the improved evaporation barrier of the present invention to create an added physical barrier to evaporation and to reflect solar radiation to inhibit or prevent heating of the aqueous phase (e.g., water, saltwater, brine, fracking liquid, etc.). The improved evaporation barrier can only include a non-reflective material or include both a reflective and non-reflective material. The non-reflective material can be a material such as an optically transparent or translucent material such as glass or polymeric flakes, glass, ceramic, or polymeric microballoons and/or microballs, silica, mica, or other translucent or transparent particle. The density of the non-reflective material can be greater than, equal to, or less than the density of water (i.e., 1 g/cc). The size of the non-reflective material is generally 0.01-200 microns (and all values and ranges therebetween). A non-reflective material is defined as a material that has at least 30% transmittance (e.g., at least 30% of the electromagnetic radiation passes through the through the material) (ASTM: D1003, ASTM C1649). The non-reflective material typically has a transmittance of up to 99% (e.g., 30-99% transmittance and all values and ranges therebetween), typically at least 40% transmittance, and more typically at least 65% transmittance. One or more types of non-reflective material can be used in the improved evaporation barrier of the present invention.

[0172] Coupling Agent

[0173] The reflective material or non-reflective material can optionally be functionalized with a lipophilic and/or hydrophobic coupling agent, generally through the use of a silane coupling agent, such that the reflective particle or element is wetted by and remains suspended in the hydrocarbon phase (e.g., water-insoluble liquid), even when the improved evaporation barrier of the present invention is dispersed in the aqueous phase (e.g., water, saltwater, brine, fracking fluid). The reflective material or non-reflective material can be coated with silane compound. The silane compound generally constitutes about 0.1-3 wt. % of the coated particle (and all values and ranges therebetween). The coating thickness can be about 10-500 nm (and all values and ranges therebetween). The coating process is generally by deposition of the silane compound from aqueous solution; however, other coating methods can be used. When the reflective material or non-reflective material may be heavier than aqueous phase (e.g., water, saltwater, brine, fracking liquid, etc.) and the oil, the reflective material or non-reflective material generally settles to the water-oil interface of the improved evaporation barrier of the present invention when dispersed in the aqueous phase, thus inhibiting or preventing the reflective material or non-reflective material from sinking to the bottom of the aqueous phase. Surface tension is thus relied upon to maintain the reflective material or non-reflective material at the surface of the aqueous phase. With the hydrophobic nature of the silicone coupling agent, combined with its lipophilic nature, the reflective material or non-reflective material remains suspended at the oil-water interface indefinitely or for extended periods of time (e.g., greater than 7 days).

[0174] Other methods of creating reflective interfaces are also familiar to those in the art, including through use of liquid interfaces with differing indexes of refraction. When certain ratios are obtained, normally using dielectric liquids (which can also be created using dielectric/optical nanoparticles), complete reflection can be achieved. When this is done with two immiscible liquid phases (one of which may be the aqueous phase), high reflectivity can be achieved. If the liquid phases are created in a stable dispersion, they can be quite effective in producing a reflective or otherwise opaque coating while not presenting any potential for pore blockage if introduced into a wellbore.

[0175] Hydrophobic Compound

[0176] A hydrophobic compound can optionally be included in the improved evaporation barrier of the present invention. One non-limiting hydrophobic compound that can be used includes surfactant; however, other or additional types of hydrophobic compound can be used (e.g., wetting agents, detergents, solubilizers, soaps, etc.). The desirable properties of the surfactant (when used) are in part influenced by the overall balance between the hydrophilic portion of the molecule and the lipophilic portion of the molecule (which can be described in terms of an overall numerical value called the HLB number [hydrophilic-lipophilic balance]) which serves as a guide to the behavior of the surfactant in aqueous or oil solutions. Surfactants with HLB values of greater than 10 are predominantly hydrophilic; surfactants with HBL values below 10 (but above zero) are predominantly lipophilic. When a surfactant is included in the improved evaporation barrier of the present invention, the HLB value is generally from 5 and 15 (and all values and ranges therebetween); however, any surfactant producing the desired effect of partitioning at the aqueous/oil interface is suitable for use in the improved evaporation barrier of the present invention.

[0177] The surfactant (when used) is generally compatible with oil and gas operations. Non-limiting examples of surfactant that can be used in the improved evaporation barrier of the present invention are polyoxyethylenesorbitans and/or polyoxyethylene ethers. Other non-limiting examples of surfactant that can be used in the improved evaporation barrier of the present invention are surfactants sold under the tradename BRIJ (e.g., polyoxyethylene 10 oleyl ether (sold under the tradename BRIJ 96, CAS#9004-98-2, Sigma Chemical Company, St. Louis, Mo.) which has an HLB value of approximately 12.4).

[0178] Improved Evaporation Barrier

[0179] The improved evaporation barrier of the present invention is generally formed of a liquid and is a mixture of an alkane, a non-volatile oil, and one or more reflective materials and/or non-reflective materials (which can optionally be surface functionalized with a coupling agent), and optionally a hydrophobic compound (e.g., surfactant). The improved evaporation barrier of the present invention can be prepared first by mixing the alkane and non-volatile oil (e.g., non-volatile oil, wax and non-volatile oil) and optional surfactant. Once this mixture is prepared, the reflective material and/or non-reflective material can be added to the mixture to form the improved evaporation barrier of the present invention. The reflective material and/or non-reflective material can be dispersed using any suitable method that breaks their surface tension and agglomerations such that they become fully wetted and dispersed in the alkane/non-volatile oil/optional surfactant mixture. The reflective material and/or non-reflective material is typically added in a quantity such that the overall density of the improved evaporation barrier of the present invention remains below the density of the aqueous phase (e.g., water, saltwater, brine, fracking fluid), such that upon dispersion into the aqueous phase, the improved evaporation barrier of the present invention separates and floats to the surface of the aqueous phase.

[0180] Preparation of the Improved Evaporation Barrier

[0181] The improved evaporation barrier of the present invention can be prepared by mixing appropriate proportions of the alkane and the non-volatile oil. If present in the mixture, the appropriate amount of surfactant is then added and mixing is continued until the surfactant is fully dissolved in the alkane/non-volatile oil mixture. Thereafter, the reflective material and/or non-reflective material can be added to the mixture. Following mixing, the improved evaporation barrier liquid can be stored at room temperature in a container (e.g., a clear or opaque glass bottle or container, plastic bottle or container, drum, etc.).

[0182] Use of the Improved Evaporation Barrier

[0183] The improved evaporation barrier of the present invention can be used by dispensing a sufficient amount of the liquid improved evaporation barrier to cover the aqueous phase. The improved evaporation barrier is generally added to the aqueous phase in a pond, lake, reservoir, retention tank, etc. to form a continuous film on the surface of the aqueous phase that has a thickness of at least about 0.05 microns (0.00005 mm). In one non-limiting embodiment, the thickness of the improved evaporation barrier of the present invention on the surface of the aqueous phase is generally about 0.05-5,000 microns (and all values and ranges therebetween). Generally, the thickness of the film is no more than 2 mm (2000 microns), and typically no more than 1 mm (1000 microns). In another non-limiting embodiment, the thickness of the improved evaporation barrier of the present invention on the surface of the aqueous phase is about 5-300 microns. In another non-limiting embodiment, the thickness of the improved evaporation barrier of the present invention on the surface of the aqueous phase is about 25-150 microns. In another non-limiting embodiment, the thickness of the improved evaporation barrier of the present invention on the surface of the aqueous phase is about 25-100 microns (0.001-0.004).

[0184] The impermeable solid is added to the water-insoluble liquid to form the improved evaporation barrier of the present invention and the improved evaporation barrier is dispersed into a film on the surface of the aqueous phase (e.g., water, saltwater, brine, fracking fluid in a pond, reservoir, retention tank, etc.) to inhibit or prevent evaporation of the aqueous phase. The impermeable solid is generally present in the improved evaporation barrier in sufficient concentration to cover at least 30% (e.g., 30-100% and all values and ranges therebetween) of the surface area an aqueous phase when the improved evaporation barrier is added to the aqueous phase. In one non-limiting embodiment, the impermeable solid is generally present in sufficient concentration in the improved evaporation barrier to cover 50-75% of the surface area of an aqueous phase when the improved evaporation barrier is added to the aqueous phase.

[0185] The impermeable solid can be arranged in a monolayer or multilayer fashion on or at the surface of the aqueous phase when the improved evaporation barrier is added to the aqueous phase. In one non-limiting embodiment, the impermeable solid is primarily arranged in a monolayer fashion when the improved evaporation barrier is added to the aqueous phase.

[0186] Area coverage from the impermeable solid, as well as surface tension forces and dispersion of the impermeable solid, are illustrated in FIGS. 1-3. In one non-limiting embodiment, about 30-100% of the impermeable solid is in the form of flakes. It has been found that flakes provide excellent coverage at the lowest concentration or amount in the improved evaporation barrier.

[0187] The film on the surface of the aqueous phase that is formed by the improved evaporation barrier is formulated to block at least 60% of water evaporation from the aqueous phase in a pond, lake, reservoir, retention tank, etc. at a temperature up to about 85 C. where the film remains intact on the surface of the aqueous phase. In one non-limiting embodiment, the film on the surface of the aqueous phase that is formed by the improved evaporation barrier is formulated to block at least 80% of water evaporation from the aqueous phase in a pond, lake, reservoir, retention tank, etc. at a temperature up to about 85 C. where the film remains intact on the surface of the aqueous phase, and typically the film on the surface of the aqueous phase that is formed by the improved evaporation barrier is formulated to blocks at least 95% of water evaporation from the aqueous phase in a pond, lake, reservoir, retention tank, etc. at a temperature up to about 85 C. where the film remains intact on the surface of the aqueous phase.

[0188] The film on the surface of the aqueous phase that is formed by the improved evaporation barrier is generally formulated to allow for the passage of trapped gasses and bubbles (which pass through the film as gas bubbles due to the density of the gas and film) to pass upwardly through the film. The film is also generally formulated to allow for the passage of water droplets or puddles (such as water from rain or water from a hose) to pass downwardly through the film and into the aqueous phase in a pond, lake, reservoir, retention tank, etc.

[0189] FIG. 1 illustrates an improved evaporation barrier EB formed of a dispersion of glass flakes 10 as the impermeable solid in a water-insoluble liquid 20, wherein flakes cover at least 80% of the total surface area of the top surface 32 aqueous phase 30. The flakes can be formed of glass, metal, and/or some other type of material. The flakes can have generally the same size, shape and dimensions; however, this is not required. The flakes are illustrated as being generally located half-way between the top and bottom surface of the water-insoluble liquid; however, this is not required. The flakes are added in a quantity to the water-insoluble liquid such that a single layer of flakes forms in the evaporation barrier after the evaporation barrier has been added to the aqueous phase 30.

[0190] FIG. 2 illustrates an improved evaporation barrier EB formed of multiple layers of flakes 100 dispersed in a water-insoluble liquid 120, wherein the flakes cover at least 80% of the total surface area of the top surface 32 aqueous phase 30. The flakes can be formed of glass, metal, and/or some other type of material. The flakes can have generally the same size, shape and dimensions; however, this is not required. The flakes are illustrated as being dispersed generally evenly between the top and bottom surface of the water-insoluble liquid; however, this is not required. The flakes are added in a quantity to the water-insoluble liquid such that multiple layers of flakes form in the evaporation barrier after the evaporation barrier has been added to the aqueous phase 30. The number of formed layers is non-limiting.

[0191] FIG. 3 illustrates an improved evaporation barrier EB formed of microballoons and/or microballs 210 as the impermeable solid dispersed in a water-insoluble liquid 220. The microballoons and/or microballs can be formed of glass, metal, and/or some other type of material. The microballoons and/or microballs can have generally the same size, shape and dimensions; however, this is not required. The microballoons and/or microballs are illustrated as being dispersed on the top surface of the water-insoluble liquid; however, this is not required. The microballoons and/or microballs are added in a quantity to the water-insoluble liquid such that a single layer of microballoons and/or microballs form on the top surface of evaporation barrier after the evaporation barrier has been added to the aqueous phase 30; however, it can be appreciated that the microballoons and/or microballs can be added in a quantity to the water-insoluble liquid such that multiple layers of microballoons and/or microballs form at, near, or on the top surface of the evaporation barrier after the evaporation barrier has been added to the aqueous phase 30. The number of formed layers is non-limiting. Generally, the microballoons and/or microballs are added in a quantity to the water-insoluble liquid such that the microballoons and/or microballs cover at least 50% of the top surface area of the top surface 32 aqueous phase 30.

[0192] The improved evaporation barrier of the present invention can be easily floated over the aqueous phase by simply dumping a bucket or barrel, or pumping the liquid improved evaporation barrier of the present invention onto or into a pond, basin or above-ground storage container that contains the aqueous phase. In addition, because of the dynamic nature of the improved evaporation barrier of the present invention, additional aqueous phase (e.g., water, saltwater, brine, fracking liquid, etc.) can be added in any manner (such as rain, pipe outflow, etc.) to the pond, basin or above-ground storage container that already contains the improved evaporation barrier of the present invention without damaging or impairing the effectiveness of the improved evaporation barrier of the present invention on the surface of the aqueous phase.

[0193] The general formulation of the improved evaporation barrier is as follows in volume percent:

TABLE-US-00001 Ingredient Ex. A Ex. B Ex. C Ex. D Water-Insoluble Liquid 60-99.5% 65-99.5% 70-99% 75-99% Impermeable Solid 0.5-40% 0.5-35% 1-30% 1-25% Hydrophobic Compound 0-4% 0-4% 0-4% 0-4% Coupling Agent 0-4% 0-2% 0-4% 4-4% Ingredient Ex. E Ex. F Ex. G Ex. H Water-Insoluble Liquid 75-98% 80-98% 80-97% 82-97% Impermeable Solid 1-20% 1-20% 1-20% 1-20% Hydrophobic Compound 0-3% 0-3% 0-2 0-2% Coupling Agent 0-2% 0-2% 0-2% 0-2%. Ingredient Ex. I Ex. J Ex. K Ex. L Water-Insoluble Liquid 85-99.5% 90-95% 90-95% 91-94% Impermeable Solid 0.1-13% 0.4-12% 0.5-11% 3-10% Hydrophobic Compound 0-4% 0-2% 0.05-2% 0.1-1% Coupling Agent 0-2% 0.05-1% 0.1-1% 0.1-0.5% Ingredient Ex. M Ex. N Ex. O Ex. P Non-volatile Oil 95.2% 99.1% 91.4% 93.7% Reflective/Non-reflective material 4.5% 0.6% 9.3% 5.8% Surfactant 0.15% 0.15% 0 0.15% Silane Compound 0.15% 0.15% 0.3% 0.35%.

[0194] The invention is further illustrated by the following specific but non-limiting examples.

Example 1Preparation of Improved Evaporation Barrier

[0195] In one non-limiting embodiment of the invention, an improved evaporation barrier was prepared as described below.

[0196] 0.5 liter of paraffin oil was blended with 0.25 liters of vegetable oil. 1 gram of surfactant (polyoxyethylene 10 oleyl ether) was added as a powder and the mixture was stirred until uniform. 30 grams of 1 micron by 60 micron aluminum flakes were prepared by coating with a silane coupling agent. The flakes were blended with the paraffin oil mixture using a high shear blender.

Example 2Preparation of Improved Evaporation Barrier

[0197] In another non-limiting embodiment of the invention, an improved evaporation barrier was prepared as described below.

[0198] A mixture of ISOPAR V oil and canola oil was prepared as described in Example 1. Following mixing, 1 gram of the surfactant polyoxyethylene 10 oleyl ether (CAS#9004-98-2, sold under the tradename BRIJ 96; Sigma Chemical Company, St. Louis, Mo.) was added to the alkane/non-volatile oil mixture and mixing was continued at room temperature (77 F.) until all of the surfactant was fully dissolved (about 10 minutes). 60 grams of H-2 aluminum powder (Valmet Inc.) was surface prepared with a silane coupling agent and added to the mixture using a high shear vortex mixer until completely dispersed.

Example 3Preparation of Improved Evaporation Barrier

[0199] In another non-limiting embodiment of the invention, an improved evaporation barrier was prepared as described below.

[0200] A mixture of silicon oil and mineral oil was prepared as described as follows: 0.5 liter of paraffin oil is blended with 0.25 liters of silicon oil. Following mixing, 40 grams of 60 aluminum flakes were surface prepared with a silane coupling agent and added to the mixture using a high shear vortex mixer and ultrasound sonication until completely dispersed.

Example 4Preparation of Improved Evaporation Barrier

[0201] In another non-limiting embodiment of the invention, an improved evaporation barrier was prepared as described below.

[0202] A mixture of ISOPAR V oil and canola oil is prepared as described in Example 1. Following mixing, 1 gram of the surfactant polyoxyethylene 10 oleyl ether (CAS#9004-98-2, sold under the tradename BRIJ 96; Sigma Chemical Company, St. Louis, Mo.) was added to the alkane/non-volatile oil mixture and mixing was continued at room temperature until all of the surfactant was fully dissolved (about 10 minutes). 4 grams of aluminum-coated 3M Scotchlight glass microballoons and/or microballs were surface prepared with a silane coupling agents and added to the mixture using a high shear vortex mixer until completely dispersed.

Example 5Preparation of Improved Evaporation Barrier

[0203] In another non-limiting embodiment of the invention, an improved evaporation barrier was prepared as described below.

[0204] A mixture of 0.5 liter of paraffin oil was blended with 0.25 liters of vegetable oil. 0-1 gram of surfactant (polyoxyethylene 10 oleyl ether) was added as a powder and the mixture was stirred until uniform. 30 grams of 1 micron non-reflective glass microballoons were added and blended with the paraffin oil mixture using a high shear blender.

Example 6Preparation of Improved Evaporation Barrier

[0205] In one non-limiting formulation of the improved evaporation barrier, there is provided an impermeable solid in the form of glass flakes having a particles size of approximately 150 microns in diameter by 3-10 microns thick. The surface of the glass flakes is surface treated with about 0.75 wt. % ethyltrimethoxysilane. The surface treated glass flakes are then added to a water-insoluble liquid that is formed of 50 wt. % paraffin oil, 40 wt. % soybean oil, and 10 wt. % or low viscosity silicone oil (PDMS). The glass flakes constitute about 8 wt. % of the improved evaporation barrier. About 0.3 wt. % sodium laurate is added as a surfactant to the improved evaporation barrier. The improved evaporation barrier was added to an aqueous phase such as 3 wt. % KCl brine in a retention tank to form a film of improved evaporation barrier on the surface of the aqueous phase having a thickness of 0.2 mm. The film formed by the evaporation resistant coating was transparent or nearly transparent. The film formed by the evaporation resistant coating blocked at least 95% of water evaporation from the 3 wt. % KCl brine in a retention tank at a temperature of 35 C.

[0206] It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the constructions set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. The invention has been described with reference to preferred and alternate embodiments. Modifications and alterations will become apparent to those skilled in the art upon reading and understanding the detailed discussion of the invention provided herein. This invention is intended to include all such modifications and alterations insofar as they come within the scope of the present invention. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which, as a matter of language, might be said to fall there between. The invention has been described with reference to the preferred embodiments. These and other modifications of the preferred embodiments as well as other embodiments of the invention will be obvious from the disclosure herein, whereby the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.