Graphene-based geosynthetics

Abstract

According to an embodiment, the geosynthetic structure includes a base resin polymer matrix containing a mixture. The geosynthetic structure further includes a graphene material impregnated in the base resin polymer matrix in a final amount of about 0.10 weight percent to about 5 weight percent. The geosynthetic structure also includes a stabilizer impregnated within the base resin polymer matrix.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 429,732, filed December 2, 2022, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to geosynthetics, and more particularly to graphene-based geosynthetics. [Background technology]

[0003] Geosynthetics, including geomembranes and geotextiles, are used worldwide in containment applications. These materials are used, for example, to contain pollutants produced by mining, waste management, and petrochemicals, as well as for water impoundment or structural barriers. Maintaining the integrity of geosynthetic structures is key to environmental protection for multiple applications, such as mining, waste management, and aquaculture. Summary of the Invention [Means for solving the problem]

[0004] According to an embodiment, the geosynthetic structure includes a base resin polymer matrix containing a mixture. The geosynthetic structure further includes a graphene material impregnated in the base resin polymer matrix in a final amount of about 0.10 weight percent to about 5 weight percent. The geosynthetic structure also includes a stabilizer impregnated within the base resin polymer matrix.

[0005] According to another embodiment, a geosynthetic structure includes a plurality of layers, at least one of which is a graphene layer, comprising a base resin polymer matrix having a mixture of a graphene material impregnated within the base resin polymer matrix in a final amount of about 0.10 weight percent to about 5 weight percent, and a stabilizer impregnated within the base resin polymer matrix.

[0006] Other features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail in this disclosure and are considered a part of the claimed invention. For a better understanding of the present invention, together with its advantages and features, reference is made to the description and drawings. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic partial cross-sectional view of a geosynthetic structure. [Figure 2] FIG. 2 is a schematic partial cross-sectional view of a geosynthetic structure having multiple layers. [Figure 3] FIG. 3 is a graph showing the extruder torque measured for samples with various amounts of carbon black or graphene. [Figure 4] FIG. 4 is a graph showing the measured extrusion weight for samples with various amounts of carbon black or graphene. [Figure 5] FIG. 5 is a graph showing the extrusion efficiency measured for samples with various amounts of carbon black or graphene. [Figure 6] FIG. 6 is an image of the surface of the geomembrane with graphene. [Figure 7] Figure 7 shows a schematic diagram of the surface of a geomembrane with graphene and shows the asperity height calculation. DETAILED DESCRIPTION OF THE INVENTION

[0008] For a more complete understanding of the present disclosure, reference is now made to the following brief description in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. Maintaining the integrity of geosynthetics in applications such as mining, waste management, and aquaculture is challenging, given the harsh environments in which these materials are used. When used as landfill liners, the long-term behavior of geosynthetics, such as geomembranes, is primarily controlled by the rate of antioxidant extraction from the geosynthetic material. This process involves dissolution or chemical reaction of antioxidants at the surface of the geosynthetic and their diffusion from the core structure to the surface due to concentration gradients. The loss of antioxidants makes the geosynthetic vulnerable to oxidative degradation. Other factors that contribute to the degradation of geosynthetic mechanical properties include, for example, high temperatures, which accelerate degradation, and oxidation from energy sources such as ultraviolet (UV) radiation.

[0009] Stabilization systems containing stabilizing additives are added to geosynthetics to mitigate oxidative damage. However, one problem is that the stabilizing additives are easily depleted from geosynthetics over time due to exposure to ultraviolet (UV) light, air, water, and / or other chemicals. Once the stabilizers are depleted, they are unable to mitigate oxidative damage to the geosynthetics.

[0010] Carbon black can be used as part of the stabilization system in geosynthetics. However, carbon black is generally undesirable for various environmental reasons. For example, carbon black is made from fossil fuels and therefore produces carbon dioxide, carbon monoxide, and other greenhouse gases as harmful and undesirable by-products. Carbon black also contains polycyclic aromatic hydrocarbons, which can be harmful to animals.

[0011] Therefore, there is a need to provide a stabilizer system for geosynthetics that not only provides protection from oxidation, but also protects against extraction of the protective stabilizer by physical means such as ultraviolet (UV) light, air, and / or water. Additionally, there is a need for an alternative stabilizer system to those that contain only carbon black, which is environmentally harmful and has the drawbacks discussed above.

[0012] Thus, this disclosure describes geosynthetics that include graphene impregnated throughout the structure or have graphene impregnated in one or more layers. In some embodiments, the geosynthetic structure includes a base resin polymer matrix containing a mixture; a graphene material impregnated in the base resin polymer matrix, the graphene material being impregnated in a final amount of about 0.10 weight percent to about 5 weight percent based on the total weight of the base resin polymer matrix if the graphene is impregnated throughout, or based on the total weight of the base resin polymer matrix if the graphene is only in individual layers; and a stabilizer impregnated within the base resin polymer matrix. The graphene material and stabilizer form a stabilization system that provides ultraviolet (UV) stability and improved mechanical properties.

[0013] In some embodiments, graphene materials are used in place of carbon black, thereby offering the advantage of being environmentally friendly. Graphene materials are made from natural graphite, not from quartz fuel, and do not produce carbon monoxide, carbon dioxide, or greenhouse gas by-products, and are free of carcinogenic polycyclic aromatic hydrocarbons. Furthermore, in some embodiments, adding graphene in place of carbon black, or synergistically with carbon black, can produce specifically targeted film properties, making films more conductive, thinner, and / or stronger.

[0014] 1 shows a geosynthetic structure 100 according to an embodiment of the present invention. The geosynthetic structure 100 may be a geomembrane, a geonet, or a geotextile. The geosynthetic structure 100 is formed from extruded materials, fibers, and / or yarns that comprise a base polymer matrix. Non-limiting examples of polymers for the base polymer matrix include high-density polyethylene, medium-density polyethylene, linear low-density polyethylene, low-density polyethylene, very low-density polyethylene, or any combination thereof. Other non-limiting examples of polymers for the base polymer matrix include polypropylene, polyethylene, polyvinyl chloride, acrylonitrile butadiene styrene, copolymers of any of the foregoing, or any combination thereof. In one or more embodiments, the polymer matrix comprises a polyolefin blend, a plastomer, a viscoelastic, carbon nanofibrils, or a combination thereof.

[0015] The geosynthetic structure 100 includes graphene material 102 impregnated in a base resin polymer matrix. In one or more embodiments, the graphene material 102 is substantially evenly distributed throughout the geosynthetic structure. In other embodiments, the graphene material 102 is impregnated in one or more layers, as described in more detail below.

[0016] Non-limiting examples of graphene material 102 include graphene particles, graphene nanoparticles, graphene nanofillers, graphene nanocomposites, graphene platelets, graphene powder, graphene concentrates, graphene platelets, graphene masterbatches, or combinations thereof. According to one or more embodiments, the graphene material is graphene platelets.

[0017] In some embodiments, the graphene material 102 is a two-dimensional carbon material having an average primary particle size of about 0.1 to about 30 micrometers. In other embodiments, the graphene material 102 has an average primary particle size of about 0.5 to about 2 micrometers. In one or more embodiments, the graphene material 102 has an average primary particle size ranging anywhere between about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30 micrometers.

[0018] In some embodiments, the graphene material 102 comprises between about 1 and about 50 atomic layers. In other embodiments, the graphene material 102 comprises between about 6 and about 10 atomic layers. In some embodiments, the graphene material comprises between about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 atomic layers, or any range.

[0019] In one or more embodiments, the graphene material 102 has a graphene purity of at least 90 percent at a thickness of about 1 to about 10 atomic layers. In other embodiments, the graphene material 102 has a graphene purity of at least 95 percent at a thickness of about 1 to about 10 atomic layers. In one or more embodiments, the graphene material 102 has a purity in any range of about 90, 91, 92, 93, 94, 95, 96, 97, 98, or 99 percent at a thickness of about 101, 2, 3, 3, 4, 5, 6, 7, 8, or 9 atomic layers.

[0020] In some embodiments, the graphene material 102 has a carbon content greater than 96 weight percent, and in other embodiments, the graphene material 102 has a carbon content anywhere between about 96, 97, 98, 99, and 99.9 weight percent.

[0021] In one or more embodiments, the graphene material 102 has an oxygen content of less than 1 weight percent, and in other embodiments, the graphene material 102 has an oxygen content in any range between about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 weight percent.

[0022] In some embodiments, the graphene material 102 is impregnated into the base resin polymer matrix of the geosynthetic structure, or into a layer of the geosynthetic structure, in a final amount between about 0.10 weight percent and about 5 weight percent. In other embodiments, the graphene material 102 is impregnated into the base resin polymer matrix of the geosynthetic structure, or into a layer of the geosynthetic structure, in a final amount between about 0.5 weight percent and about 3.0 weight percent. In one or more embodiments, the graphene material 102 is impregnated into the base resin polymer matrix of the geosynthetic structure, or into a layer of the geosynthetic structure, in a final amount ranging anywhere between about 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 weight percent.

[0023] When weight percentages of graphene, carbon black, stabilizers, or other additives are given herein, the weight percentages in a geosynthetic structure are by the total weight of the geosynthetic structure when distributed throughout the structure, or by the total weight of a single layer within the geosynthetic structure when in a single layer. References to geosynthetic structures are single layer or multi-layer structures.

[0024] The geosynthetic structure 100 further includes a stabilizer impregnated within the base resin polymer matrix. Non-limiting examples of stabilizers include antioxidants, radical scavengers, hindered amine light stabilizers, or combinations thereof. Non-limiting examples of antioxidants include phenols, phosphates, phosphites, phosphonites, or any combinations thereof. Non-limiting examples of radical scavengers include sterically hindered phenols, thioethers, hindered amine light stabilizers (e.g., Irganox® 1010 and similar additives), or any combinations thereof.

[0025] According to some embodiments, the geosynthetic structure 100 having the graphene material 102 in the base resin polymer matrix is ​​carbon black-free or substantially carbon black-free, making it environmentally friendly. As used herein, in some embodiments, when used in the context of carbon black content, "substantially free" means that the geosynthetic structure 100 having the graphene material 102 in the base resin polymer matrix contains less than 2%, less than 1.5%, less than 1%, less than 0.5%, less than 0.1%, or less than 0.01% carbon black. As used herein, in other embodiments, when used in the context of carbon black content, "substantially free" means that the geosynthetic structure 100 having the graphene material 102 in the base resin polymer matrix contains 0% carbon black.

[0026] In some embodiments, the geosynthetic structure 100 having graphene material 102 within a base resin polymer matrix further comprises carbon black. In some embodiments, the geosynthetic structure 100 comprises from about 0.01% to about 3.0% graphene material 102 and from about 0.1 to about 3.0% carbon black in the base resin polymer matrix. In other embodiments, the geosynthetic structure 100 comprises from about 0.1% to about 2.0% graphene material 102 and from about 0.1 to about 2.0% carbon black in the base resin polymer matrix. In still other embodiments, the geosynthetic structure 100 comprises graphene in an amount of between about 0.1%, 0.25%, 0.75%, 1.5%, 2.0%, 2.5%, and 3.0% or any range of ... and a base resin polymer matrix.

[0027] In some embodiments, the geosynthetic structure 100 is a single layer, as illustrated in Figure 1. In other embodiments, the geosynthetic structure 200 includes multiple layers, such as two, three, four, or more layers, in one or more embodiments, as illustrated in Figure 2.

[0028] The geosynthetic structure 200 of Figure 2 includes three layers: a first layer 202 (first skin structure), a second layer 204 (core structure), and a third layer 206 (second skin structure). In some embodiments, at least one of the layers is free of graphene or substantially free of graphene. For example, in one or more embodiments, the second layer 204 is substantially free of graphene, and the first layer 202 and the third layer 206 include graphene. In one or more embodiments, the first layer 202, the second layer 204, the third layer 206, or any combination thereof, includes graphene material. In other embodiments, the first layer 202, the second layer 204, the third layer 206, or any combination thereof, is substantially free of graphene material. In some embodiments, the term "substantially free" of graphene material means between about 3.0%, 2.5%, 2.0%, 1.5%, 1.0%, 0.5%, 0.1%, 0.01%, and 0% graphene material, or any range.

[0029] In embodiments, the geosynthetic structure includes a plurality of layers, at least one of which is a graphene layer. The graphene layer includes a base resin polymer matrix having a mixture of a graphene material impregnated in the base resin polymer matrix in a final amount of about 0.10 weight percent to about 5 weight percent, and a stabilizer impregnated in the base resin polymer matrix. In some embodiments, at least one of the plurality of layers is substantially free of graphene.

[0030] In one or more embodiments, the geosynthetic structure is a geomembrane, the plurality of layers includes a core structure, a first skin structure, and a second skin structure, and the core structure is a graphene layer.

[0031] The layers of the plurality of layers may have different properties or the same properties. In one or more embodiments, at least one of the plurality of layers (first layer 202, second layer 204, and / or third layer 206) has a tensile strength of at least 1.0×10 when measured according to ASTM D257 test method. 12In some embodiments, the first layer 202, the third layer 206, or both layers are insulating, having an insulation / insulation measurement of at least 1.0×10 ohms, as measured according to ASTM D257 test method. 12 In some embodiments, the first layer 202, the third layer 206, or both layers are insulating and have an insulating / insulating measurement of at least 1.0×10 ohms as measured according to ASTM D257 test method. 12 It has an isolation / insulation measurement in ohms.

[0032] In other embodiments, at least one of the layers (first layer 202, second layer 204, and / or third layer 206) has a hardness of 1.0×10 or less as measured according to ASTM D257 test method. 4 In some embodiments, at least one of the layers (first layer 202, second layer 204, and / or third layer 206) has a conductivity of 1.0×10 or less, as measured according to ASTM D257 test method. 3 In still other embodiments, at least one of the layers (first layer 202, second layer 204, and / or third layer 206) is electrically conductive, having a conductivity of less than 1.0×10 ohms, as measured according to ASTM D257 test method. 2 It has a sub-ohmic conductivity.

[0033] In some embodiments, second layer 204 (core structure) comprises a combination of graphene and carbon black in a base resin polymer matrix to provide a conductive material. In another example, second layer 204 (core structure) comprises a combination of about 2% to about 14% graphene and about 2% to about 14% carbon black in a base resin polymer matrix to provide a conductive material. In yet other embodiments, second layer 204 (core structure) comprises a combination of about 5% to about 10% graphene and about 5% to about 10% carbon black in a base resin polymer matrix to provide a conductive material. In one or more other embodiments, the second layer 204 (core structure) includes graphene in an amount of about 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, or 14%, carbon black in an amount of about 14%, and 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, or 13% of a base resin polymer matrix.

[0034] In embodiments where the second layer 204 (core structure) comprises a combination of graphene and carbon black in a base resin polymer matrix, it provides a conductive material. In some embodiments, the first layer 202 (first skin), the second layer 204 (core structure), and / or the third layer 206 (second skin) comprise a combination of graphene and carbon black.

[0035] In one or more embodiments, the first layer 202 (first skin structure) and / or the second layer 206 (second skin structure) are conductive, reflective, colored, antistatic, flame retardant, smooth, textured, or a combination thereof.

[0036] According to some embodiments, the first layer 202 (first skin), the third layer (second skin), or both are reflective. Yet, according to other embodiments, the first layer 202 (first skin), the third layer (second skin), or both are not reflective. In one or more embodiments, the term reflective refers to an average solar energy reflectance of at least 50% as measured at direct normal irradiance per ASTM E903-20 test method. In other embodiments, the term reflective refers to an average solar energy reflectance of at least 70% as measured at direct normal irradiance per ASTM E903-20 test method. Furthermore, in some embodiments, the term reflective refers to an average solar energy reflectance of at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99% as measured at direct normal irradiance per ASTM E903-20 test method.

[0037] In some embodiments, the first layer 202 (first skin), the third layer (second skin), or both, include one or more reflective additives, such as pigments, to provide reflectivity. Non-limiting examples of such additives include barium sulfate, titanium dioxide, zinc oxide, lead oxide, or combinations thereof. In some embodiments, the reflective additive is present in an amount of about 5% to about 20% by total weight of the layer. In other embodiments, the reflective additive is present in an amount of about 10% to about 15% by total weight of the layer. In still other embodiments, the reflective additive is present in an amount of about 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, and about 20% or any range therebetween of the total weight of the layer.

[0038] In embodiments, first layer 202 and second layer 204 have different polymer compositions, different textures, or both different polymer compositions and different textures. In other embodiments, two or all of first layer 202, second layer 204, and third layer 206 have different polymer compositions, different textures, or both different polymer compositions and different textures.

[0039] The geosynthetics described herein are static dissipative materials, which is desirable in a variety of applications because they prevent electrical charges from rapidly flowing through the material, which can be a safety hazard. In one or more embodiments, the geosynthetic structures described herein have a static dissipative capacity of about 1.0 x 10 when measured according to ASTM D257 test method. 6 ~Approx. 1.0×10 11 In other embodiments, the geosynthetic structures described herein have a static dissipative property of about 1.0 x 10 ohms as measured according to ASTM D257 test method. 7 ~Approx. 1.0×10 9 In some embodiments, the geosynthetic structures described herein have a static dissipative property of about 1.0 x 10 ohms, as measured according to ASTM D257 test method. 6 , 1.0×10 7 , 1.0×10 8 , 1.0×10 9 , 1.0×10 10 , and approximately 1.0 × 10 11 It has static dissipative properties in any range of ohms.

[0040] The geosynthetics described herein are preferably electrically conductive. In some embodiments, the first layer 202, the third layer 204, or both layers are electrically conductive. In one or more embodiments, the geosynthetic structures described herein have a conductivity of 1.0×10 Ω or less when measured according to ASTM D257 test method. 4 In other embodiments, the geosynthetic structures described herein have a conductivity of 1.0×10 ohms or less when measured according to ASTM D257 test method.3 In some embodiments, the geosynthetic structures described herein have a conductivity of 1.0×10 ohms or less when measured according to ASTM D257 test method. 2 It has a sub-ohmic conductivity.

[0041] In one or more embodiments, the geosynthetic structures described herein have a cross-sectional area of ​​at least 1.0×10 sieve strength as measured according to ASTM D257 test method. 12 In other embodiments, the geosynthetic structures described herein have an insulation measurement of at least 1.0 x 10 ohms when measured according to ASTM D257 test method. 13 In some embodiments, the geosynthetic structures described herein have an insulation measurement of at least 1.0 x 10 ohms when measured according to ASTM D257 test method. 14 Has an isolation measurement of ohms.

[0042] In some embodiments, the geosynthetic structure has a solar reflectance index that is at least 1.5 times higher when measured according to ASTM E903-20 compared to a geosynthetic structure that does not contain the graphene material. In other embodiments, the geosynthetic structure has a solar reflectance index that is about 1.5 to about 2.0 times higher when measured according to ASTM E903-20 compared to a geosynthetic structure that does not contain the graphene material.

[0043] In other embodiments, the geosynthetic structure has at least a 15% increase in High Pressure Oxidation Induction Time (HP-OIT) as measured by ASTM D3895 or ASTM D5885 test methods compared to a similar geosynthetic structure having the same base resin polymer matrix and 2.5% carbon black instead of graphene material. In some embodiments, the geosynthetic structure has about a 15% to about a 20% increase in High Pressure Oxidation Induction Time (HP-OIT) as measured by ASTM D3895 or ASTM D5885 test methods compared to a similar geosynthetic structure having the same base resin polymer matrix and 2.5% carbon black instead of graphene material.

[0044] ASTM tests D3895 and D5885 measure stabilizer compatibility via oxidative induction time (OIT). ASTM D3895 is the Standard Test Method for OIT of Polyolefins by Differential Scanning Calorimetry. ASTM D5885 is the Standard Test Method for OIT of Polyolefin Geosynthetics by High-Pressure Differential Scanning Calorimetry. The ASTM D5885 test is conducted at a higher pressure and lower temperature (150°C) than the ASTM D3895 test. The test involves placing a small sample of material in a heat and energy measuring device, which is then heated. Oxygen is introduced into the system, oxidizing the sample material, and the stabilizing system inhibits oxidation. Eventually, the stabilizer is completely consumed, causing the material sample to begin burning and providing additional energy. Therefore, HP-OIT is a measure of the material's stability.

[0045] Unexpectedly, as shown in Figure 6, the surface roughness of geosynthetics, particularly geomembranes, increased when graphene was used (in the skin, or outer layer) compared to carbon black. Surface roughness was measured according to ASTM D7466, which measures peak-to-valley height to assess the degree of surface roughness. As shown in Figure 7, peak-to-valley height is determined by measuring the distance between the peaks and valleys of up to three measurements. The outer surface of the graphene geomembrane was rougher than the surface with carbon black, which is unexpected because two-dimensional graphene has a higher surface area. One would assume that three-dimensional spherical carbon black particles, with their smaller surface area, would produce a greater surface roughness and therefore a larger measured peak-to-valley height, but this was not observed. High surface roughness is a desirable property for many geosynthetic applications.

[0046] According to one or more embodiments, a geosynthetic structure having graphene in one or both outer layers can be textured by one or more processes. The inclusion of graphene in the outer layers allows for more effective texturing. In one or more embodiments, a geosynthetic structure having 1% graphene in the outer layers has at least a 20% higher peak height as measured by ASTM D7466 compared to a geosynthetic structure having 2.5% carbon black. In other embodiments, a geosynthetic structure having 1% graphene in the outer layers has at least a 10% higher peak height as measured by ASTM D7466 compared to a geosynthetic structure having 2.5% carbon black. In some embodiments, a geosynthetic structure having 1% graphene in the outer layers has at least a 5%, at least a 10%, at least a 15%, or at least a 20% higher peak height as measured by ASTM D7466 compared to a geosynthetic structure having 2.5% carbon black. [Example]

[0047] Example 1: Extrusion Efficiency A sample of high-density polyethylene homopolymer (HDPE HOMOPOL) (control) was extruded and compared to extruded samples with graphene or carbon black (CB) masterbatches. The mixtures were prepared in a laboratory extruder without a die (screw diameter 0.5 inches), and the temperature settings were constant for all tests.

[0048] The following materials were extruded at three different extrusion speeds (75 rpm, 100 rpm, and 125 rpm): (1) polyethylene copolymer (reference control), (2) polyethylene copolymer with graphene at 1%, 2%, 3%, and 5% (weight percent), and (3) polyethylene copolymer with carbon black at 1%, 2%, 3%, and 5% (weight percent).

[0049] The extruded weight was measured three times over a 60-second period. The average extruded mass per minute was calculated. Torque was also measured by the extruder and used as an indication of energy intake. The results are shown in Figures 3-5, with torque shown in Figure 3, extruded weight shown in Figure 4, and extruded mass / torque shown in Figure 5.

[0050] As shown in Figure 4, increasing the graphene content increased the extrusion weight for all extrusion rates. However, increasing the carbon black content did not significantly affect the extrusion weight.

[0051] The torque decreased with increasing graphene content, as shown in Figure 3. In contrast, the torque increased slightly with increasing carbon black content. These data showed that graphene had an unexpected effect on both extruder torque (i.e., torque decreased with increasing graphene) as well as energy consumption (i.e., energy consumption decreased with increasing graphene).

[0052] FIG. 5 shows that graphene exceeded the performance of carbon black for all tested speed and weight percent combinations. Example 2: Reflectance The reflectance of the geomembrane with 1% graphene (Table 2) and the control without graphene (Table 1) was measured according to ASTM E903-20. A UV / VIS / NIR spectrophotometer with a spectral range of 350 to 2500 nanometers was used for the measurements.

[0053] As shown in Tables 1 and 2 below, the graphene geomembrane reflected 11.1% of the incoming solar energy, a significant increase compared to the 4.71% reflectance of the control geomembrane without graphene. This data indicated that graphene reduces heat buildup in the exposed areas of the membrane.

[0054] [Table 1]

[0055] [Table 2]

[0056] Example 3: Concave / convex height The asperity height of geomembranes with 2.5% carbon black and 1% graphene (in-skin) was measured according to ASTM D7466 testing. Asperity height measurements assess the degree of surface roughness. The results for the inner and outer surfaces of the geomembranes are shown in Table 3 below. The outer surface of the graphene geomembrane was rough, which was unexpected due to the large surface area of ​​two-dimensional graphene. Three-dimensional, spherical carbon black particles with a smaller surface area would presumably produce greater surface roughness and therefore a larger measured asperity height, but this was not observed. Other factors in geomembrane manufacturing, such as nitrogen and line speed, also affect asperity height; the volume and pressure of the gas used alters surface roughness. These conditions, including line speed, remained the same; only the graphene and carbon black were unique to each sample. This phenomenon is likely due, at least in part, to the rheological and viscometric differences between the plate-like structures in graphene and the spherical structures in carbon black. Graphene has a much larger surface area than carbon black, but in the molten state it orients lengthwise in the direction of flow, allowing the material to have less viscosity and therefore easier to press and form surface roughness.

[0057] [Table 3]

[0058] Example 4: HP-OIT measurement High-pressure oxidative induction time (HP-OIT) measurements were performed on blends of high-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) with either carbon black or graphene. Using ASTM 3895, the HP-OIT of blends with 2.5% carbon black, 0.5%, and 0.99% carbon black was measured. The results are shown in Table 4 below. The blend with 0.99% graphene had a 15% higher HP-OIT, measuring 2064, compared to the same blend with 2.5% carbon black. These data indicated that graphene significantly increased the stability of the material, even at lower weight percentages.

[0059] The samples were aged in an 85 degree Celsius oven for 90 days and exposed to UV light for 1600 hours. As also shown in Table 4 below, the initial HP-OIT increases significantly with the use of graphene (even without the addition of antioxidants or stabilizers other than the base resin package). The higher the HP-OIT value in the graphene samples, the increased level of stability, and this is true for both oven aging and UV.

[0060] [Table 4]

[0061] Example 5: Resistance of skin structure to weathering Ultraviolet-A (UVA) photoaging analysis of the skin structures was performed to determine their resistance to weathering according to the NF EN 12224-2000 test method. The absorbance, reflectance, and transmittance of the skin structures were measured by exposing the skins to UVA light according to the ASTM E903-20 test method under the conditions shown in Table 5. The skin structure was high-density polyethylene (HDPE) with stabilizers and pigments.

[0062] [Table 5]

[0063] The initial reflectance measurements are shown in Table 6 and are consistent with the increase in applied UV light intensity (215 millijoules per square meter (mJ / m)). 2 ), 345mJ / m 2 , 474 mJ / m 2 , 600mJ / m 2 , and 900 mJ / m 2 ), the subsequent test results are shown in Tables 7-11 below. As shown, the skins maintained their reflectivity over increasing light intensity and demonstrated the ability to resist weathering.

[0064] [Table 6]

[0065] [Table 7]

[0066] [Table 8]

[0067] [Table 9]

[0068] [Table 10]

[0069] [Table 11]

[0070] Various embodiments of the present invention are described herein with reference to the associated drawings. Alternative embodiments may be devised without departing from the scope of the present invention. While various connections and relationships (e.g., above, below, adjacent, etc.) are described between elements in the following description and drawings, those skilled in the art will recognize that many of the relationships described herein are orientation-independent, as the described functionality is maintained even when the orientation is changed. These connections and / or relationships may be direct or indirect, unless otherwise specified, and the present invention is not intended to be limited in this respect. Thus, a connection of entities may refer to either a direct or indirect connection, and a relationship between entities may be a direct or indirect relationship. As an example of an indirect relationship, a reference herein to layer "A" on layer "B" includes a situation in which one or more intermediate layers (e.g., layer "C") are present between layer "A" and layer "B," so long as the associated properties and functions of layer "A" and layer "B" are not substantially altered by the intermediate layers.

[0071] The following definitions and abbreviations should be used in interpreting the claims and the specification. As used in this disclosure, the terms "comprising," "comprising," "comprising," "comprising," "including," "has," "having," "contain," or "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or device that includes a list of elements is not necessarily limited to only those elements, but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or device.

[0072] Also, the term "exemplary" is used in this disclosure to mean "by way of example, instance, or illustration." Any embodiment or design described in this disclosure as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms "at least one" and "one or more" are understood to include any integer number greater than or equal to one, i.e., 1, 2, 3, 4, etc. The term "a plurality" is understood to include any integer number greater than or equal to two, i.e., 2, 3, 4, 5, etc. The term "connected / coupled" may include an indirect "connection" and a direct "connection."

[0073] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but that all embodiments may or may not include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, it is submitted that when a particular configuration, structure, or characteristic is described in connection with an embodiment, it is within the understanding of those skilled in the art to affect such configuration, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0074] For purposes of the following description, the terms "upper," "lower," "right," "left," "vertical," "horizontal," "top," "bottom," and their derivatives shall refer to the structures and methods described as oriented in the drawings. The terms "overlying," "atop," "positioned on," or "positioned atop" mean that a first element, such as a first structure, is on a second element, such as a second structure, where intervening elements, such as interfacial structures, may be present between the first and second elements. The term "direct contact" means that a first element, such as a first structure, and a second element, such as a second structure, are connected without any intermediate conductive, insulating, or semiconducting layers at the interface of the two elements.

[0075] The terms "about," "substantially," "approximately," and variations thereof are intended to include the degree of error associated with measurement of the particular quantity based on the equipment available at the time of filing. For example, "about" can include a range of ±8%, or 5%, or 2% of a given value.

[0076] The flowcharts and block diagrams in the figures illustrate possible implementations of manufacturing and / or operating methods according to various embodiments of the present invention. Various functions / acts of the method are represented in the flow diagrams by blocks. In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the functionality involved.

[0077] The corresponding structure, material, acts, and equivalents of all means or step-plus-function elements in the following claims are intended to include any structure, material, or acts for performing a function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the invention. The embodiments have been chosen and described to best explain the principles and practical application of the invention, and to enable those skilled in the art to understand the invention in various embodiments with various modifications suited to the particular uses intended.

[0078] While preferred embodiments of the present invention have been described, it will be appreciated that those skilled in the art, both now and in the future, may make various improvements and enhancements that fall within the scope of the following claims, which should be interpreted to maintain appropriate protection for the invention as originally described.

Claims

1. 1. A geosynthetic structure comprising: a base resin polymer matrix comprising the mixture; a graphene material impregnated within the base resin polymer matrix in a final amount of about 0.10 weight percent to about 5 weight percent; a stabilizer impregnated within the base resin polymeric matrix.

2. 10. The geosynthetic structure of claim 1, wherein the geosynthetic structure is a geomembrane, a geotexture, or a geonet.

3. 10. The geosynthetic structure of claim 1, wherein the mixture of the base resin polymeric mixture comprises high density polyethylene, medium density polyethylene, linear low density polyethylene, low density polyethylene, or combinations thereof.

4. 10. The geosynthetic structure of claim 1, wherein said mixture of said base resin polymeric mixture comprises a polyolefin mixture.

5. 10. The geosynthetic structure of claim 1, wherein the stabilizer is an antioxidant, a radical scavenger, a hindered amine light stabilizer, or a combination thereof.

6. 10. The geosynthetic structure of claim 1, wherein the geosynthetic structure has an increase in high pressure oxidation induction time of at least 15% as measured by ASTM D5885 test method compared to a similar geosynthetic structure having the same base resin polymer matrix and 2.5% carbon black in place of the graphene material.

7. 10. The geosynthetic structure of claim 1, wherein the base resin polymeric matrix comprises polypropylene, polyethylene, polyvinyl chloride, acrylonitrile butadiene styrene, gypsum, viscoelastic, copolymers of any of the foregoing, or combinations thereof.

8. 8. The geosynthetic structure of claim 7, wherein the polyethylene is high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, very low density polyethylene, or any combination thereof.

9. 10. The geosynthetic structure of claim 1, wherein the graphene material is in the form of graphene particles, graphene nanoparticles, graphene nanofillers, graphene nanocomposites, graphene platelets, graphene powder, graphene concentrates, graphene compounds, graphene masterbatches, or combinations thereof.

10. 10. The geosynthetic structure of claim 9, wherein the graphene material is in the form of graphene platelets.

11. 11. The geosynthetic structure of claim 10, wherein the graphene platelets have a thickness of about 1 to about 10 atomic layers and a graphene purity of at least 90 percent.

12. 10. The geosynthetic structure of claim 1, wherein the geosynthetic structure has a cross-sectional area of ​​1.0 x 10 when measured according to ASTM D257 test method. ６ ~1.0 x 10 １１ 10. The geosynthetic structure of claim 1 having ohmic static dissipative properties.

13. Approximately 1.0 x 10 when measured according to ASTM D257 test method ４ 10. The geosynthetic structure of claim 1 having sub-ohmic conductivity.

14. At least 1.0 x 10 when measured according to ASTM D257 test method １２ 10. The geosynthetic structure of claim 1 having an insulation measurement of ohms.

15. 10. The geosynthetic structure of claim 1, having a solar reflectance index that is at least 1.5 times higher compared to a geosynthetic structure without the graphene material, when measured according to ASTM E903-20.

16. 10. The geosynthetic structure of claim 1, having at least a 20% higher peak height as measured by ASTM D7466 testing compared to a geosynthetic structure having 2.5% carbon black.

17. 1. A geosynthetic structure comprising: A plurality of layers, a plurality of layers, at least one of the plurality of layers being a graphene layer; a base resin polymer matrix comprising the mixture; a graphene material impregnated within the base resin polymer matrix in a final amount of about 0.10 weight percent to about 5 weight percent; a stabilizer impregnated within said base resin polymer matrix.

18. 20. The geosynthetic structure of claim 17, wherein at least one layer of said plurality of layers is substantially free of graphene.

19. 18. The geosynthetic structure of claim 17, wherein the geosynthetic structure is a geomembrane, the plurality of layers comprising a core structure, a first skin structure, and a second skin structure, and the core structure is the graphene layer.

20. 20. The geosynthetic structure of claim 19, wherein the first skin structure and the second skin structure have different polymer compositions, different textures, or both different polymer compositions and different textures.

21. 20. The geosynthetic structure of claim 19, wherein the first skin, the second skin, or both are reflective, or the first skin, the second skin, or both are not reflective, where reflectivity means an average solar energy reflectance of at least 50% measured as direct normal irradiation according to ASTM E903-20 test method.

22. 23. The geosynthetic structure of claim 22, wherein when reflective, the first skin, the second skin, or both, comprise barium sulfate, titanium dioxide, zinc oxide, lead oxide, or a combination thereof.

23. 20. The geosynthetic structure of claim 19, wherein the core structure, first skin, or second skin further comprises carbon black.

24. 18. The geosynthetic structure of claim 17, wherein the plurality of layers comprises a core structure, a first skin structure, and a second skin structure, and one or more of the core structure, the first skin structure, or the second skin structure is substantially free of the graphene material.

25. the plurality of layers includes a core structure, a first skin structure, and a second skin structure, and one or more of the core structure, the first skin structure, or the second skin structure has a cross-sectional area of ​​at least 1.0 x 10 measured according to ASTM D257 test method. １２ 18. The geosynthetic structure of claim 17, which is insulating in an ohmic insulation measurement.

26. the plurality of layers includes a core structure, a first skin structure, and a second skin structure, and one or more of the core structure, the first skin structure, or the second skin structure has a tensile strength of 1.0 x 10 when measured according to ASTM D257 test method. ４ 18. The geosynthetic structure of claim 17, which is electrically conductive with a sub-ohmic conductivity.

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