Retrofittable Flexible Fabric Liners with Surface-Functionalized Electroless Nickel Coatings for Midstream Transportation of Bitumen

This application claims the benefit of U.S. Provisional Application Ser. No. 63/657,152, filed Jun. 7, 2024, the disclosure of which is hereby incorporated by reference in its entirety, including all figures, tables, and drawings.

This invention was made with government support under IIP 2122604 awarded by the National Science Foundation. The government has certain rights in the invention.

Increasing energy demands has made the exploration of unconventional geological deposits containing heavy oil and bitumen economically viable, but the rheological properties make the handling and transportation of this oil much more challenging. Midstream transportation methods, including rail car, trucks, tankers, and pipelines, require extensive dilution, thermal jacketing, and are under heavy scrutiny regarding environmental and safety impact.

In view of the challenges discussed in the Background, designing surfaces that are repellent to oil would allow for much more efficient transportation as the need for diluents would be reduced and oil would no longer be lost due to excessive accumulation on the surface. Embodiments of the subject invention provide novel and advantageous compositions that are omniphobic (or superomniphobic), as well as methods of fabricating the same. An omniphobic (or superomniphobic) can be fabricate on (e.g., directly on) a fabric (e.g., cotton fabric) substrate. The multiscale textured surface can be achieved using a polytetrafluoroethylene (PTFE) electroless nickel coating, and the surface energy can be further reduced with the binding of a fluorinated monolayer. Once rendered repellant to both water and oil, the fabric substrates retain their repellency even after being contorted, fashioned into near-net-shape coatings or upon washing.

In an embodiment, a method of fabricating an omniphobic (e.g., superomniphobic) composition can comprise: performing a first surface functionalization on a substrate (e.g., a fabric substrate) using a first moiety; and after performing the first surface functionalization, performing electroless nickel deposition together with a texturization component (e.g., a polymer) on the substrate. The texturization component can provide texture to the substrate and/or the deposited nickel, and/or it can have texture itself. The omniphobic composition can be hydrophobic (e.g., superhydrophobic) and oleophobic (e.g., superoleophobic). The method can further comprise, after performing the first surface functionalization and before performing the electroless nickel deposition, performing a second surface functionalization on the substrate using a second moiety different from the first moiety. The second moiety can be, for example, PdClor 3-aminopropyltrimethoxysilane (APTMS). The first moiety can be, for example, APTMS or PdCl. The method can further comprise, after performing the electroless nickel deposition, performing a third surface functionalization using a third moiety different from the first moiety and the second moiety. The third moiety can be a fluorinated monolayer (e.g., 1H, 1H,2H,2H-perfluorooctanephosphonic acid (PFOPA)). The third surface functionalization can be performed for at least 10 hours (e.g., at least 24 hours, or for about 24 hours). The texturization component can be, for example, PTFE. The performing of the electroless nickel deposition can comprise using beads of a polymer (i.e., the texturization component can comprise beads of a polymer (e.g., PTFE)). The performing of the electroless nickel deposition can comprise using a nickel alloy (e.g., a nickel phosphorous alloy). The substrate can be, for example, a cotton fabric substrate. The electroless nickel deposition can be performed for at least 30 seconds (e.g., at least 1 minute, or for about 1 minute). The coating formed by the electroless nickel deposition can be disposed directly on (i.e, with no elements intervening) the substrate.

In another embodiment, an omniphobic (e.g., superomniphobic) composition can comprise: a substate (e.g., a fabric substrate); and an electroless nickel coating together with a texturization component disposed on the substrate. The omniphobic composition can be hydrophobic (e.g., superhydrophobic) and oleophobic (e.g., superoleophobic). The electroless nickel coating can be surface functionalized with a fluorinated monolayer (e.g., PFOPA). The texturization component can be, for example, PTFE. The electroless nickel coating can comprise a nickel alloy (e.g., a nickel phosphorous alloy). The substrate can be, for example, a cotton fabric substrate. The omniphobic composition can be flexible and can remain hydrophobic (e.g., superhydrophobic) and oleophobic (e.g., superoleophobic) after being contorted, formed to adapt to the shape of other receptacles, or being washed. The omniphobic composition can remain hydrophobic (e.g., superhydrophobic) and oleophobic (e.g., superoleophobic) up to a temperature of at least 220° C. (e.g., at least 230° C., at least 240° C., at least 250° C., or at least 260° C.). The electroless nickel coating can be disposed directly on (i.e., with no elements intervening) the substrate. The substrate can be surface functionalized with APTMS, PdCl, or both. The performing of the electroless nickel deposition can comprise using beads of a polymer (i.e., the texturization component can comprise beads of a polymer (e.g., PTFE)).

Embodiments of the subject invention provide novel and advantageous compositions that are omniphobic (or superomniphobic), as well as methods of fabricating the same. An omniphobic (or superomniphobic) coating can be fabricated on (e.g., directly on with no other elements therebetween) a fabric (e.g., cotton fabric) substrate. The multiscale textured surface can be achieved using a polytetrafluoroethylene (PTFE) electroless nickel coating, and the surface energy can be further reduced with the binding of a fluorinated monolayer. Once rendered repellant to both water and oil, the fabric substrates retain their repellency even after being contorted.

Increasing global energy needs, improved access, and favorable geopolitical considerations have spurred a surge in the worldwide reliance on unconventional deposits such as heavy crude oil and bitumen, which have emerged as major contributors to the fuel mix of modern economies. The handling and transportation of hydrocarbons from unconventional deposits is plagued by a distinctive set of challenges traceable to their complex rheological properties and high sulfur content. Transportation of viscous oils oftentimes entails dilution with light hydrocarbons and/or heating with an extensive thermal jacketing infrastructure to enable transportation through conduits such as pipelines, trucks, rail cars, and tankers. By geopolitical happenstance, the richest geological deposits for bitumen are located at a considerable distance (e.g., in the Athabasca region of Canada or Venezuela) from the refineries that are best equipped (in the Houston Gulf Coast area in the United States of America) to effectively convert these hydrocarbons into a diverse slate of products. Substantial viscosity modification is required to facilitate midstream transportation of heavy oil, which can have viscosities exceeding 300,000 centipoise (cP), American Petroleum Institute (API) gravity of less than 22.3°, and specific gravity of greater than 920 kilograms per cubic meter (kg/m) (see also, e.g.,). The addition of diluents, typically light condensates, reduces the transportation volume efficiency by approximately 30%, incurs considerable cost, and requires additional energy-intensive separation steps upon arrival at refineries to return the oil to its original composition. Other challenges attributable to the complex rheological properties of viscous oil include difficulties in maintenance and cleaning of various transportation vessels as well as the loss of substantial product volume (estimated to be as much as 10% in some cases) as a result of surface fouling.

In addition, much of the midstream infrastructure is constructed from base metals such as low alloy steels, which are prone to corrosion as a result of the high concentration of sulfur compounds, abrasive particles, and other highly corrosive species present in viscous crude oil. Corrosion-related failures can have a devastating impact on vulnerable ecosystems. As such, the inventors have recognized that there is a need for multifunctional coatings that mitigate surface fouling and facilitate ready transfer of viscous liquids. Given the complex form factors of transportation vessels spanning the range from bitutainers to containers in shipping barges, and the difficulties in on-field/on-board application of complex coatings, the design of flexible fabric liners represents an attractive solution for retrofitting current midstream infrastructure. Embodiments of the subject invention address the problems discussed above by providing oleophobic coatings on fabric surfaces that can be used in retrofitting applications across different forms of midstream conduits.

Fabricating surfaces that glide and are not wetted by oil streams represents a considerably greater challenge as compared to the design of surfaces repellant to water as a result of the much lower cohesive forces (primarily, van der Waals' interactions) and thus much lower surface tension of oil streams. Indeed, hydrophobic surfaces are reasonably abundant in nature, spanning the range from lotus leaves to shark skin and cuticles of insects, whereas oleophobic surfaces are not observed in nature. Three key aspects to controlling the behavior of liquid droplets and flow streams on a surface through modulation of interfacial interactions include: texturization across length scales, spanning the range from nanoscale and micron-sized topographies to define a landscape of trapped air bubbles; geometrical features that define reentrant curvature; and surface energy as governed by the chemical moieties that are available for interaction with an impinging liquid. Under an appropriate set of conditions, a liquid can be suspended in the metastable Cassie-Baxter regime, where it resides atop micro-and nano-textured surfaces and the air pockets embedded by the topographic features, which are known as plastrons. Superhydrophobic and superolcophobic behavior can be demonstrated utilizing ZnO tetrapods on metal meshes as textural elements, and by using the low-temperature sintering of TiOnanoparticles arrayed onto solid steel coupons by colloidal crystal templating (see also, e.g.; Douglas et al., Three-Dimensional Inverse Opal TiOCoatings to Enable the Gliding of Viscous Oils, Energy & Fuels 2020, 34 (11), 13606-13613; and O'Loughlin et al., Biomimetic plastronic surfaces for handling of viscous oil, Energy & Fuels 2017, 31 (9), 9337-9344; both of which are incorporated herein by reference in their entireties). However, the integration of these coatings with current transportation vessels is constrained by challenges in adhesion and durability of the coatings, and difficulties with field application, which have limited the viability of using such coatings in retrofitting existing infrastructure. Embodiments of the subject invention address this by providing superhydrophobic and superoleophobic electroless nickel composite coatings on a fabric surface (e.g., a cotton fabric surface) that allows for facile integration within existing transportation vessels and that can be readily fitted to adopt various form factors.

Electroless plating has found extensive industrial applications on planar metal surfaces (see also, e.g., Brenner and Riddell, Electroless plating on metals by chemical reduction, Proc Am Electropl Soc 1946, 33, 4-12; which is hereby incorporated herein by reference in its entirety). Electroless nickel coatings exhibit excellent corrosion as well as wear and abrasion resistance, homogeneous thickness across extended length scales, excellent adhesion to a variety of substrates, and applicability across a diverse range of form factors. Electroless nickel formulations typically contain a source of nickel ions, a reducing agent, complexing agents, and stabilizers. The autocatalytic reaction for electroless nickel deposition proceeds through the following half reactions:

The overall equation can be written as:

The versatility of electroless nickel coatings allows for the coating to be fine-tuned to suit particular environments and to incorporate various additives. Electroless nickel coatings are amenable to alloying, as well as the inclusion of bulk and surface precipitates. Nickel alloys can be deposited through the incorporation of phosphorous or boron from a reducing agent, and the volume of incorporated phosphorus influences the level of crystallinity of the electroless coatings. The incorporation of nanoparticles facilitates the formation of composite coatings with tailorable properties. For example, the inclusion of hard particles such as diamond or soft particles such as fluorinated salts can alter the lubricity of the coating. Guglielimi's theory describes the mechanism by which particles can be incorporated during electroless deposition. Adsorption occurs in two sequential steps, which establishes a relationship between the ultimate particle concentration embedded within the coating and particle concentration in the bath dispersion.

Embodiments of the subject invention include methods for electroless deposition to coat a fabric (e.g., a cotton fabric) substrate with nickel or a nickel alloy (e.g., nickel phosphorous alloy) incorporating polymer (e.g., PTFE) beads. The coating can be functionalized with a fluorinated monolayer (e.g., 1H,1H,2H,2H-perfluorooctanephosphonic acid (PFOPA)). The composite textured and low-surface-energy coating enables the rapid removal of heavy oil and water and retains superhydrophobic and superoleophobic properties even after mechanical deformation. The ability to fabricate large-area fabric substrates to exhibit robust omniphobicity provides an innovative retrofittable solution to challenges with viscous oil handling in the midstream sector.shows an illustration of fabric and oil. The fabric that can be used with embodiments of the subject invention can be, for example, cotton fabric of the same type that may be found in shirts and other common items of clothing. After activation, deposition, and/or functionalization, the fabric can repel the oil.

Each ofshows a schematic illustration of a method for fabricating omniphobic fabric substrates, according to an embodiment of the subject invention. Referring to, the method can include surface activation (e.g., using 3-aminopropyltrimethoxysilane (APTMS) and/or PdCl) of the fabric substrate, followed by electroless co-deposition of nickel (or a nickel alloy) and polymer (e.g., PTFE) beads. The method can also include further surface functionalization of the nickel coating (e.g., with PFOPA). Thoughlists some specific materials (e.g., APTMS, PdCl, PTFE, and PFOPA), these are for exemplary purposes and should not be construed as limiting.

Embodiments of the subject invention also include omniphobic (e.g., hydrophobic and oleophobic; such as superomniphobic (e.g., superhydrophobic and superoleophobic) compositions or coatings that can be applied to fabrics (e.g., cotton fabrics), as well as the coated fabrics. The composition or coating can comprise an electroless nickel (e.g., nickel alloy) coating with a polymer (e.g., PTFE). The composition or coating can further comprise a fluorinated monolayer (e.g., PFOPA) or surface-grafted fluorinated macromolecules bound to the nickel, the polymer, and/or the fabric. The fabric with the coating can be flexible and can retain its omniphobic (or superomniphobic) properties even after being contorted. The fabric with the coating can also retain its omniphobic (or superomniphobic) properties even at a temperature of, for example, at least 220° C. (e.g., at least 230° C., at least 240° C., at least 250° C., or at least 260° C.).

Embodiments of the subject invention also include methods of using an omniphobic composition as disclosed herein for midstream transport of bitumen or other oil products or byproducts. Embodiments also include a vehicle comprising an omniphobic composition as disclosed herein lining a transport section of the vehicle.

Embodiments of the subject invention represent a major advance in internal coatings of pipelines (gathering, transmission, and distribution), bitutainers, railcars, and Supermax tankers by providing an omniphobic flexible coating enabling rapid removal of heavy oil. Methods and compositions of embodiments of the subject invention allow for retrofittable application of omniphobic liners to enable rapid removal of rheologically challenging liquids such as heavy oil and bitumen. The liners can be incorporated directly as internal coatings of pipelines or vessels without the need for on-site coating application, which is exceedingly challenging under dry dock conditions given the large volumes and constraints on application of complex coatings. No related art coatings exist for the specific applications in handling of heavy oil.

Embodiments of the subject invention provide electroless deposition to coat a fabric (e.g., a cotton fabric) with an alloy (e.g., a nickel phosphorous alloy) incorporating beads (e.g., PTFE beads). The coating can be functionalized (e.g., with PFOPA). The composite textured and low-surface-energy coating enables the rapid removal of heavy oil and water and retains super-hydrophobic and superoleophobic properties after mechanical deformation. The ability to fabricate thermally robust and mechanically resilient large-area fabric substrates to exhibit robust omniphobicity provides an innovative retrofittable solution to challenges with viscous oil handling in the midstream sector.

When ranges are used herein, combinations and subcombinations of ranges (including any value or subrange contained therein) are intended to be explicitly included. When the term “about” is used herein, in conjunction with a numerical value, it is understood that the value can be in a range of 95% of the value to 105% of the value, i.e. the value can be +/−5% of the stated value. For example, “about 1 kg” means from 0.95 kg to 1.05 kg.

A greater understanding of the embodiments of the subject invention and of their many advantages may be had from the following examples, given by way of illustration. The following examples are illustrative of some of the methods, applications, embodiments, and variants of the present invention. They are, of course, not to be considered as limiting the invention. Numerous changes and modifications can be made with respect to embodiments of the invention.

The initial fabric activation step was performed by adapting a known procedure (see Guo et al., Electroless nickel deposition of a palladium-activated self-assembled monolayer on polyester fabric, Journal of applied polymer science 2013, 127 (5), 4186-4193; which is hereby incorporated herein by reference in its entirety). A 1-inch by 1-inch cotton fabric substrate (JOANN Fabrics and Crafts) was submerged in a 1 wt. % ethanol solution of APTMS (Sigma) at room temperature for 24 hours (h). Next, the substrate was removed from the solution, annealed at 70° C. for 30 minutes (min) in a muffle furnace, and rinsed with deionized water (p=18.2 megaohms per centimeter (MΩ/cm). Subsequently, the sample was immersed in a 0.05 wt. % aqueous solution of PdClcontaining 2 vol. % of an aqueous solution of 37 wt. % HCl at room temperature for 10 min, followed by rinsing with deionized water (about 2-5 milliliters (mL) per square inch). Next, a PTFE electroless nickel (EN-P) coating (Caswell, Inc. Lyons, NY, USA) was deposited onto the activated substrate. Briefly, the activated fabric was submerged in the EN-P precursor solution at approximately 100° C. for various lengths of time ranging from 1 min to 60 min. Upon removal from the EN-P bath the coated fabric was rinsed with water (about 2-5 mL per square inch). Next, the coating was immersed in a 27 millimolar (mM) solution of PFOPA (Sigma) in tetrahydrofuran (THF) (Fisher Chemical) for 24 h. The workflow for coating fabrication is schematically illustrated in.

Wettability of the coated substrates was evaluated by measuring contact angles with a goniometer (Attension Theta Lite). The values reported are an average of a minimum of three measurements taken in unique areas across the substrate. Water droplets of approximately 5 microliters (μL) were dispensed prior to recording a digital image. Heavy oil (Puma Energy) droplets with a viscosity of about 140 cP at 150° C., as measured using rotational rheometer with 40 millimeter (mm) parallel Peltier plate (Discovery Hybrid DHR-2 rheometer, TA instruments), were measured by manually placing oil droplets of about 10-15 μL onto the substrate and analyzing the droplet using the Attension Theta Lite software. Where specified, heavy oil contact angles were recorded at temperatures of 150° C.-200° C., by heating the heavy oil to the target temperature and placing the substrate on a hot plate set to the same temperature. All other measurements were acquired at room temperature unless otherwise denoted.

The surface morphology of the coated substrates was examined using field-emission scanning electron microscopy (FE-SEM) (JEOL JSM-7500F) with an emission current of 10 microamps (μA), probe current of 8 μA, accelerating voltage of 5 kilovolts (kV), and 15 mm working distance. Bare fabric substrates were coated with 3-4 nanometers (nm) of platinum (Pt) using a 208 HR High-Resolution Sputter Coater. Energy dispersive X-ray spectroscopy (EDX or EDS) measurements were recorded using the Oxford system with an accelerating voltage of either 5 kV, emission current of 20 μA, probe current of 12 μA, and working distance of 8 mm.

X-ray diffraction (XRD) patterns were collected on a copper (Cu)-source (Cu Kα, λ=1.5418 Angstroms (Å)) Bruker-ENDEAVOR powder instrument with a Lynxeye XTE Detector. Samples were cut into strips of approximately 1 centimeter (cm) by 2 cm, and secured to steel sample power XRD (PXRD) holders with carbon tape, with layers of carbon tape added to make each sample flush with the holder surface. Scans were taken from 5°-70°2Θ with a step size of 0.015 degrees per step (°/step) and a dwell time of 1 second(s).

A Bruker Vertex-70 with PIKE MIRacle single-reflection horizontal attenuated total reflectance (ATR) accessory was used to collect Fourier-transform infrared (FTIR) spectroscopy data.

Thermogravimetric Analysis (TGA) data was collected using a TA Instruments TGA 5500 at a ramp rate of 10° C. per minute (C/min)-20° C./min up to 900° C. In a typical experiment, a 3 milligram (mg)-7 mg sample was placed in a platinum pan under an inert atmosphere.

schematically depicts the coating fabrication process beginning with surface activation using APTMS and PdCl, electroless deposition of a nickel composite coating embedding PTFE beads, and surface functionalization with PFOPA. From analogous experiments on flat low-alloy steel substrates, it was determined that electroless nickel coatings provide smooth homogenous deposition. The addition of PTFE beads to the electroless deposition bath results in agglomerates of PTFE beads of about 200 nanometers (nm) in diameter being agglomerated across the surface (see also). Referring to, high-resolution scanning electron microscope (SEM) images show the intricate woven pattern of the cotton fabric and delineate the incorporation of a conformal electroless nickel thin coating and PTFE beads on each individual thread of the substrate. Contrasting the bare cotton fabric at varying magnifications fromwith the coated substrates, PTFE nanobeads are embedded along each strand and also observed in clusters at the intersections of the woven pattern.are EDX maps showing the distribution of Ni, P, and F, respectively, across the functionalized substrate without the PFOPA monolayer.show EDX maps showing the distribution of Ni, P, and F, respectively, across the functionalized substrate with the PFOPA monolayer.

shows XRD patterns acquired after electroless Ni/PTFE deposition contrasted to the bare cotton substrate. The curve depicting the functionalized cotton fabric (after 1 minute of PTFE electroless nickel deposition and immersion in a 27 mM PFOPA solution for 24 hours) shows broad reflections assigned to metallic nickel (JCPDS #88-2326) indicating the deposition of NiPthin films; another reflection assigned at 2Θ=18° can be indexed to crystalline PTFE (JCPDS #47-2217), in addition to unique cellulose reflections that are still apparent. FTIR spectroscopy was performed to evaluate the role of PFOPA functionalization.contrasts the distinctive vibrational bands of the pristine cotton substrate, cotton after EN-P deposition, and the EN-P substrate after functionalization with PFOPA.contrast the cotton fabric after initial surface activation with APTMS, PdCl, and neat PFOPA to further understanding the structural changes occurring after each activation step. The appearance of characteristic fluoroalkyl PFOPA bands in the functionalized fabric sample confirm PFOPA functionalization of the nickel (Ni) surface. Specifically, the bands at 1142 cm, 1184 cm, and 1207 cmare assigned to symmetric CF, asymmetric CF, and asymmetric CFstretches, respectively. The 1232 cmband is derived from overlapping symmetrical CFand P═O stretches. A slight blue shift is observed for the P═O and P—O bands from 952 cm, 935 cm, and 920 cmfor the free molecule to 995 cm, 977 cm, and 962 cmin the surface-bound species. Similar changes in PFOPA vibrational modes can be ascribed to formation of a fluorocarbon helix on the surface.

TGA was performed to evaluate the thermal robustness of the architected coatings. As shown in, the derivative curve indicates two separate thermal degradation processes. The first process is operational in the temperature range of° C.-° C. corresponding to decomposition of the surface bound PFOPA layer, whereas the second process corresponds beyond 420° C. to decomposition of the cotton substrate. The latter assignment was verified based on control TGA experiments performed on untreated cotton fabric and the fabric with EN-Ni/PTFE (but without PFOPA functionalization) as shown in. Because degradation occurs well beyond 220° C., the highest handling temperature of bitumen, the functionalized fabrics plainly have the thermal robustness needed for midstream applications.

Coating wettability and flexibility were evaluated as a function of electroless nickel/PTFE deposition time (which controls the thickness) and PFOPA concentration. Both of these variables are essential to controlling wettability as they allow for precise control of the multiscale texturization, reentrant curvature, and surface energy reduction. As depicted by the contact angle values shown in the table in, without functionalization with PFOPA, the fabric with EN-P/PTFE exhibits superhydrophilic behavior characterized by the flash spreading of water. The increased surface area resulting from the electrodeposited Ni and additional PTFE nanobeads amplify the intrinsic wettability of the cotton fabric (which has a water contact angle of) 0°, enabling the system to rapidly access the Wenzel wetting regime. Similarly, oil droplets completely wet the cotton fabrics with EN-P/PTFE without PFOPA functionalization with the flash spreading of the heavy oil when both are at a temperature of 150° C. There is a direct correlation between the time the fabric substrates were immersed in the PTFE electroless nickel bath and the coating deposition thickness. Upon varying the deposition rate from 1 min-60 min, the deposition thickness as deposited on the strands of thread varied from about 2 micrometers (μm) to 14 μm (see also the table in). Superhydrophobicity and superoleophobicity was achieved with just 1 min of the EN-P/PTFE deposition, corresponding to a thickness of 2.7 μm±3.8 μm upon surface functionalization of the Ni coating with PFOPA at a concentration of 27 mM in THF. In general, a decrease in oleophobicity was observed with increasing thickness of the PTFE electroless nickel deposition, as Ni deposits into crevices and reduces the asperities between the individual threads of the fabric substrate, which brings about an overall reduction in the different scales of texture. An optimal combination of hydrophobic and oleophobic behavior was observed for the 1 minute sample, which shows contact angles of 151°±1° for water, 156°±3° for heavy oil at 150° C., and 153°±4° for heavy oil at 200° C. The table indetails the water contact angles as a function of coating deposition time and PFOPA concentration in addition to wettability performance with heavy oil #2, which has a different viscosity as contrasted in.

In summary, upon deposition of the electroless nickel composite coating embedding PTFE beads and surface functionalization with a PFOPA monolayer, the cotton fabric was rendered both superhydropobic and superoleophobic. The functionalized fabric was flexible, could be fashioned into different forms as required to adapt to the geometries of different receptacles and pipelines, and glided both water and heavy oil. A coating thickness of about 2 um of electroless nickel/PTFE was found to be optimal for fully utilizing the hierarchical texturization of the cotton substrate while retaining its flexibility and enabling reduction in surface energy upon surface functionalization with PFOPA. The coatings were thermally robust and resisted degradation up to temperatures of 265° C., well beyond the 220° C. operational temperature limit considered to be the upper limits of operational temperatures for conventional midstream infrastructure. These results indicate a solution for the integration of treated fabric as liners in midstream transportation vessels, thereby mitigating the challenges of on-board coating, and bringing about substantial benefits in reducing product loss, minimizing the use of diluents and thermal jacketing, and greatly simplifying maintenance and cleaning operations.

depicts sequenced images demonstrating the superhydrophobic and superoleophobic behavior of the fabricated coatings (from Example 1). The cotton substrate was fashioned into an open-faced cubic receptacle, and filled with deionized water and heavy oil. The wettability was observed at room temperature for water and at 150° C. for the heavy oil. In both instances, the liquid was rapidly removed from the receptable and the coated fabric was readily recovered without residual contamination from oil. The omniphobicity of the coatings was maintained for over 6 months. The open-faced cube was further filled with water and was allowed to stand for 1 h. No outflows or leaks of water were observed, and the receptacle fully retained its ability to repel water. This indicates the robustness of the plastrons that are stabilized from the multiscale texture, reentrant curvature, and reduced surface energy.

Coatings were prepared similarly to those for Examples 1 and 2.

Parchment-colored 100% utility cotton (JOANN Fabrics & Crafts) was chosen as the substrate for coatings. A cotton fabric substrate was submerged in a 1 wt. % ethanol (96%, Fisher Chemical) solution of APTMS (97%, Sigma) at room temperature for 24 h. Next, the substrate was removed from the solution, annealed at 70° C. for 1 h in a muffle furnace (Thermo Scientific Thermolyne FD1540M), and rinsed with deionized (DI) water (Thermo Scientific Barnstead GenPure filtration system, p=18.2 MΩ·cm) using a spray bottle. Subsequently, the sample was immersed in a 0.05 wt. % PdClaqueous solution with 0.2 M HCl at room temperature for 10 min, followed by rinsing with deionized water (aboutmL to aboutmL per square inch). Next, the activated substrate was submerged in Caswell electroless nickel plating (EN) solutions at 85° C. to 90° C. (Caswell, Inc. Lyons, NY, USA) for various lengths of time ranging from 1 min to 60 min. The solution was replenished every 5 min to 10 min; PTFE beads were added as needed to obtain thicker coatings. Upon removal from the EN-PTFE bath the coated fabric was rinsed with DI water with a spray bottle until the runoff was clear. Next, the coating was immersed in a 27 mM solution of PFOPA (95%, Sigma) in ethanol for 24 h. The final coating is schematically illustrated in.

Wettability of the coated substrates was evaluated by measuring contact angles using a goniometer (Attension Theta Lite). The values reported are an average of a minimum of measurements taken across three distinct areas across the substrate. Approximately 20 μL of deionized water and light sweet crude oil (obtained from Permian Basin, specific gravity 0.8050 g/mL) 25 were dispensed onto substrate manually prior to recording a digital image. Heavy oil (Puma Energy) droplet contact angles, with a viscosity of ca. 140 cP at 150° C. as measured using rotational rheometer with 40 mm parallel Peltier plate (Discovery Hybrid DHR-2 rheometer, TA instruments), were measured by manually placing oil droplets of about 20 μL onto the substrate and analyzing the droplet using the Attension Theta Lite software. Heavy oil contact angles were recorded at temperatures of 175° C., by heating the heavy oil to the target temperature and placing the substrate on a hot plate (VWR VMSC4) set to the same temperature. All other measurements were acquired at room temperature unless otherwise denoted. Dynamic contact angles were measured with the same goniometer with a changing drop size of 0 μL to 20 μL at a rate-of-change 0.5 L/s (40 s advancing measurement and 40 s receding measurement).

Roll-off angles were obtained with 20 μL droplets based on two methods. In the first approach, the “tilting plate method”, droplets were dispensed onto a flat fabric surface and the surface angle changed at approximately 1°/s until translational motion of the droplet is initiated with reference to a marked location on the fabric to ensure objectivity. Multiple droplets were tested at different fabric surfaces. In the second approach, labeled as “centimeter drop”, droplets were also dispensed about 1 cm above a fabric substrate angled at 15° and the angle decreased at approximately 1° per droplet until the drop did not roll off on contact.

The surface morphology of the coated substrates was examined using field-emission scanning electron microscopy (FE-SEM) (JEOL JSM-7500F) with an emission current of 10 μA, probe current of 8 μA, accelerating voltage of 5 kV, and 15 mm working distance to the pole piece. Bare fabric substrates were mounted on Cu tape and coated with 5 nm of Pt using a 208HR high-resolution sputter coater. EDS measurements were recorded using the Oxford system with an accelerating voltage of 5 kV, emission current of 20 μA, probe current of 12 μA, and a working distance of 8 mm.

To determine the thickness of the coatings, cross-sectional samples were prepared for SEM. Fabric pieces were embedded in Epoxicure 2 resin and hardener (4:1 ratio) and left at room temperature to harden for 24 h. A cut through the embedded fabric was made with a Buchler IsoMet diamond precision saw and the cut surface was then ground with a Buchler EcoMet 30 grinding and polishing wheel using 1200 grit P600 silicon carbide sandpaper followed by 4000 grit P1200 silicon carbide sandpaper. Polishing was then done with an Electron Microscopy Sciences 1 μm diamond polishing paste and 200 mm Struers MD-Floc polishing pads. The polishing paste was diluted with Falcon Tool Company water-based polishing lubricant and diamond thinner. The samples were sputter coated with 5 nm of Pt and examined under FE-SEM and EDS. A minimum of three coating replicates were examined at three different locations to determine the thickness of the deposited nickel coating.

X-ray photoelectron spectroscopy (XPS) was recorded with an Omicron DAR 400 XPS/UPS system with a 128 micro-channel Argus detector. A 1253.6 eV Mg X-ray source at 15 kV and 20 mA emission current were utilized with a CN10 electron source to minimize charging. Spectra were calibrated to a carbon Is feature from adventitious carbon at 248.8 eV. Fabric samples were kept in an Across International model AT19 vacuum oven at 100° C. for 2 days prior to measurement.

A Bruker Vertex-70 with PIKE MIRacle single-reflection horizontal attenuated total reflectance (ATR) accessory was used to acquire Fourier-transform infrared (FTIR) spectroscopy data. Sample substrates were pinched underneath the sample head above a diamond ATR crystal. Thermogravimetric analysis (TGA) data were collected using a TA Instruments TGA 5500 at a ramp rate of 20° C./min up to 900° C. In a typical experiment, a 3 mg to 7 mg sample was placed in a platinum pan under an inert atmosphere.

Tensile testing was performed following ASTM D5035 to evaluate the mechanical properties of textile fabrics after coatings were applied for 1 min, 10 min, and 60 min, alongside uncoated control samples. Testing parameters were selected based on the results of textured fabric tensile studies reported in the literature. Specimens were precisely cut using a rotary cutter to prevent edge distortion and conditioned at room temperature (22° C.) before testing. A 1 kN Instron 5943 tensile tester with pneumatic side-action grips was used, applying a displacement rate of 100 mm/min. The gauge length between grips was set at 70 mm, and samples were stretched to rupture, recording breaking force (in N) and elongation at maximum force. At least fifteen replicates were tested per sample type to ensure statistical robustness. Data were analyzed for statistical significance, with results reported as mean values and standard deviations.

schematically illustrates the deposition of an alloyed Ni composite coating onto woven cotton fabric. Initial surface activation is achieved using APTMS and PdCl, followed by electroless deposition of a nickel composite coating embedding PTFE beads for various times (as denoted in sample labels), followed subsequently by surface functionalization with PFOPA. Based on analogous experiments performed on flat low-alloy steel substrates, electroless nickel coatings are observed to provide smooth conformal deposition; the addition of about 200 nm PTFE beads yields agglomerated beads dispersed across the surface ().

High-resolution scanning electron micrographs inshow the intricate woven pattern of the cotton fabric (bare cotton fibers are shown in) and attest to the incorporation of electroless nickel and PTFE on each individual thread of the substrate. Contrasting the bare cotton fabric at varying magnifications with the coated substrates, PTFE nanobeads are embedded along each strand. Some agglomeration of the PTFE beads in clusters is observed at the intersections of the woven pattern (). PTFE nanobeads are observed to agglomerate into complex texturizing elements at lower deposition times, as seen in. The corresponding EDS maps are shown in. After 10 minutes of electroless deposition, larger PTFE agglomerations are observed, as exhibited in. With coating thickness increases, it becomes more difficult to retain the PTFE bead texturization as it is over-coated by the electroless Ni alloy (). This “smoothening” effect is especially pronounced for reaction times more than 45 min. EDS maps of texturizing elements inare shown in, whereas the corresponding EDS spectra are plotted in.

The evolution of coating thickness as a function of electroless deposition reaction time is plotted in. After an initial rapid deposition of about 2 μm of the composite, the coating thickness increases at a steady rate of 0.2 μm/min. The rapid initial growth in thickness is consistent with the electroless reduction, nucleation, and deposition of nickel alloy particles mediated by sur-face activation of the cotton fibers by reaction with APTES and PdCl. Beyond the initial nucleation and deposition step, which proceeds until conformal coverage is achieved across the surface-functionalized cotton fibers, there is a direct correlation between the time the cotton fabric substrates are immersed in the PTFE electroless nickel bath and the coating thickness. During deposition times from 1 min to 60 min, the deposition thickness steadily increases from about 2 μm to about 14 μm ().

To evaluate the thermal stability of the engineered substrates, TGA was performed. As shown in, the derivative curve indicates three separate thermal degradation processes. Control TGA experiments were performed on untreated cotton fabric, cotton fabric with an electroless nickel coating without PTFE beads, cotton fabric with EN-PTFE (but without PFOPA functionalization), and finally cotton fabric with EN-PTFE coating and PFOPA functionalization. Based on these control experiments, the first process in the temperature range of 20° C. to 50° C. corresponds to a small mass loss arising from loss of volatile species from the cotton substrate. The second mass loss regime in the temperature range of 260° C. to 360° C. corresponds to the degradation of the cotton substrate. The third mass loss regime in the temperature range of 360° C. to 460° C. corresponds to the gradual decomposition of the PTFE beads. Because the bulk of the degradation occurs well beyond 220° C., the highest handling temperature of bitumen, the functionalized fabrics are observed to exhibit the desired thermal robustness needed for midstream applications.

The mechanical resilience of the coatings were evaluated using the tensile testing experiments shown in. The results indicate that the EN-PTFE coating increases the breaking force of fabric samples; a progressive increase in breaking force is observed with an increase in coating time. Statistical analyses confirm that all coated samples exhibited significantly higher breaking force as compared to plain cotton (p<0.05), demonstrating improved mechanical strength (see the table in). However, this increase in strength comes at the expense of reduced breaking strain, as coated samples exhibited progressively lower flexibility with longer coating durations. T-test results in the table inconfirmed that the reduction in elongation was also statistically significant (p<0.05), which indicates a trade-off between strength and flexibility. These findings suggest that while the coating reinforces the fabric, it also makes it less deformable, a factor that will need to be considered in designing liners for bitumen vessels with different form factors and geometries.

present spectroscopic characterization of the functionalized fabrics.contrasts the distinctive vibrational modes of the uncoated cotton substrate, cotton substrate after EN-PTFE deposition, and the EN-PTFE coated substrate after functionalization with PFOPA. An FTIR spectrum acquired for PFOPA is also shown for comparison. The appearance of characteristic fluoroalkyl modes observed in the functionalized fabric sample corroborates PFOPA functionalization of the Ni surface. Specifically, bands at 1142, 1184, and 1207 cmare assigned to symmetric —CF2—, asymmetric —CF3, and asymmetric —CF2— stretches, respectively. The 1232 cmband is derived from overlapping symmetrical —CF2 and —P═O stretches. A blue shift is observed for the P—O and P—O bands from 952 cm, 935 cm, and 920 cmfor the free molecule to 995 cm, 977 cm, and 962 cmin the surface-bound species, which corroborates the grafting of PFOPA to Ni surfaces through phosphonate head groups. Similar changes in PFOPA vibrational modes have been ascribed to formation of a fluorocarbon helix on the surface.plots the evolution of ATR-IR absorbance with varying EN-PTFE deposition times. Notably, the water IR bands at 1350 cmand 3700 cmare greatly diminished after 2 min of coating and the cotton bands (such as at 1000 cm, 2900 cm, and 3300 cm) are no longer discernible after 10 min of coating. The latter reflects the complete coverage of the cotton fibers by the composite Ni alloy coating.