Patent Application
20210095218
Understanding and controlling the root causes of friction have long been a tireless pursuit of mankind mainly because friction impacts our safety, mobility, and environment in so many ways. Accordingly, those scientists who study friction across many scales and engineers who design, manufacture, and operate moving mechanical assemblies (“MMAs”), like motored vehicles, have all aimed at drastically reducing or even totally vanishing friction or achieving superlubricity at engineering scales. The superlubric regime is attractive because it would provide the highest levels of savings in energy, environment, and money. Despite the development and use of many kinds of solid and liquid lubricants in recent years, superlubricity is seldom achieved at macro or engineering scales. Friction coefficients of above 0.01 to 0.1 are considered low friction and above that transitions to high friction. Generally, friction coefficients of less than 0.01 are considered superlow, and hence fall in the superlubric regime. Such levels of friction coefficients are typical of those surfaces that are either aero- or hydro-dynamically separated or magnetically levitated where little or no solid-to-solid contact takes place. Under sliding regimes where direct metal-to-metal contacts prevail and high contact pressures are present, achieving superlubric friction coefficients (i.e., less than 0.01) is difficult due to the concurrent and often very complex physical, chemical, and mechanical interactions taking place at sliding surfaces.
Superlubricity is very difficult to achieve at macro-scale tribological tests and mechanical systems. Sliding mechanical systems at high temperatures and high loads are the ubiquitous in industries such as automobile, heavy machinery, surface and underground drilling, space and extraterrestrial applications. These applications typically experience high loads applied at high temperatures that result in aggravated frictional losses resulting in significant deterioration of overall efficiency of the engine systems. This is because all sliding mechanical systems are prone to wear/tear and their efficiency directly depends on the friction that exists between sliding components. Currently, high temperature greases and limited compositions of synthetic oil-based lubricants are being used in such applications; these not only need replenishment at periodic intervals but also significantly fall short of the expected levels of friction elimination. Replacement of lubricant oils also calls for either partially or completely shutting down operations, which results in further lowering of efficiency and increased man hours for continuous functioning of the mechanical systems.
Multiple reports have thoroughly established and explained superlubricity at room temperature; however, no reports have demonstrated such an effect at high temperatures or high contact pressures and/or as an dynamically adaptive mechanism. Very low friction between linearly sliding surfaces in the order of 0.02-0.06 has been shown but only in inert and ultra-high vacuum (“UHV”) environments. The lubricants themselves are applied via an elaborate chemical or physical deposition technique.
MoS2 composites containing Ti, Au, or Sb2O3 have shown low friction comparable to the aforementioned values but are developed using elaborate procedures such as magnetron sputtering and/or pulsed laser deposition. MoS2 has been used in low wear solid lubricants widely in aerospace applications due to its ability to have its shear strength decrease with increasing temperature. However, the coefficient of friction (“COF”) is limited to about 0.02-0.06 in inert and UHV environments which is not in the range of superlubricity. MoS2 is sensitive to water and oxygen contamination and can rapidly deteriorate with increasing temperatures. The low friction regimes were limited to a high of 200° C., beyond which the lubricants were often observed to render ineffective. The best performance of MoS2 in ambient conditions has been shown to be between about 100° C. and about 250° C. Water vapor deteriorated the coating under 100° C., whereas oxidation deteriorated the coating above 250° C. due to interference and disruption of lamellar shear through physical bonding.
One embodiment relates to a method of forming a low friction wear surface. The method comprises preparing graphene by chemical exfoliation of highly oriented pyrolytic graphite, suspending the graphene in a solvent to form a solution of at least 1 mg/L, adding at least 1 g/L of MoS2 ultrafine nanocrystalline flakes to the solution, sonicating the MoS2 and the solution to form a homogeneous solution, and disposing the homogenous solution on a substrate. Disposing the homogenous solution includes spraying the homogenous solution on a substrate via a process of air-spray coating, forming a wet film on the substrate, and evaporating the solvent component to form a dry coating layer. The substrate has a temperature at about 275° C., and the graphene-oxide and the MoS2 are in a range of ratios in between (1±0.25):(1∓0.25) by weight.
One embodiment relates to a low friction wear surface. The low friction wear surface comprises a substrate, graphene-oxide in an oil-free solvent disposed over the substrate, and MoS2 ultrafine nanocrystalline flakes disposed over the substrate. The graphene-oxide and the MoS2 are in a range of ratios in between (1±0.25):(1∓0.25) by weight.
One embodiment relates to a method of forming sliding mechanical system on a low friction wear surface. The method comprises forming an oil-free homogenous solution comprising MoS2 and graphene-oxide in a range of ratios in between (1±0.25):(1∓0.25) by weight, disposing the homogenous solution over a substrate to form a first sliding component, and sliding the first sliding component against a second sliding component in open air. Scrolls of MoS2 are formed and encapsulated in the graphene-oxide in this sliding mechanical system.
It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. It should also be appreciated that terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.
The skilled artisan will understand that the drawings primarily are for illustrative purposes and are not intended to limit the scope of the inventive subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the inventive subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar and/or structurally similar elements).
Following below are more detailed descriptions of various concepts related to, and embodiments of, inventive low friction and wear resistant graphene containing surfaces. It should be appreciated that various concepts introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the disclosed concepts are not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.
Generally speaking, the various embodiments described herein include a low friction wear surface including two-dimensional (“2-D”) materials such as, but not limited to, MoS2, graphene-oxide (“GO”), WS2, MoTe2, and graphene. The wear surface may exhibit superlubricity in high temperatures (above 200° C., such as to a maximum of 400° C.) and under high loads (above 0.5 N, such as to a maximum of 9 N). Embodiments described herein may provide several advantages over conventional materials that demonstrate superlubricity, including, for example: (1) providing superlubricity (i.e., less than 0.01 COF) at high temperatures ranging from about 200° C. to about 400° C.; (2) significantly reducing wear, to the point of no measurable wear, at these high temperatures and at high loads with excellent longevity; (3) improving energy efficiency by reducing wear; (4) providing highly uniform surface finishes through a spray-coating application without limiting uniformity to flat surfaces; (5) reducing operational costs; (6) extending the service life of components; and (7) demonstrating the superlubricity and these improved properties without the restriction of a using a diamond like carbon counter face or a dry nitrogen environment as has been required by prior 2-D materials. Realization of superlubricity in sliding systems at high temperatures is extremely important not only from a scientific point of view but also from a technological point of view. It could make a significant positive impact on enhancing efficiency and durability of many rotating mechanical systems such as wind turbines and hence considerable savings on energy.
A low friction wear surface may be produced by any appropriate process. According to one embodiment, the process may include forming a homogenous solution from two 2-D materials. The 2-D materials may be MoS2 and GO. The MoS2 and GO form a homogenous suspension in a range of ratios in between (1±0.25):(1∓0.25), such as but not limited to 8:10 to 10:8, including 10:10. The homogenous suspension is disposed over a substrate heated to within the range of 250° C. to 300° C., such as 275° C. Water is a carrier medium to deposit the homogenous suspension of MoS2 and GO on to the substrate. It is believed that, as perfectly spherical water droplets containing the solid nano-materials impinge on to the superheated surface, they instantaneously evaporate with a miniature yet high energy explosion akin to cavitation. This transfers the entire solid materials on to the solid substrate as the liquid evaporates. This high activation energy contained in the small water-droplet system forces the solid particles together. Since the two phases (MoS2 and GO) are in equal or near-equal proportions in a homogenous suspension, they eventually form layered structure which is identified as the MoS2 layer-level encapsulation. Specifically, with regard to the lower end-point of the temperature range, the boiling point of the carrier liquid (100° C. in this case), amount of solid phases present (such as 2 g/L), and the droplet size are believed to impact the minimum temperature at which this occurs. Notably, the solid phases in the water drop act as impurities, as well as the impinging jet effectively eliminate Leidenfrost effect. The process may be carried out at atmospheric pressures and temperatures, that is exposed to oxygen (in the atmosphere) and at a temperature of about 20-22° C. contrary to the prior art requiring a dry, inert, or nitrogen environment. The disposing of the homogeneous solution on the substrate may be achieved by any suitable process, such as a spray casting or a solution processed method.
A GO solution may be then added to the container at 104. The GO solution has a concentration between 1-15 g/L for forming the lubricant. The GO solution may be obtained by exfoliating graphene and disposing the resulting graphene flakes in a liquid. The graphene may be exfoliated by any appropriate chemical or mechanical exfoliation process, such as chemical exfoliation of highly oriented pyrolytic graphite in the case of graphene. The GO solution may be an aqueous with an oil-free solvent. In some embodiments, the GO will be suspended in water. An oil-free solution is more environmentally friendly, devoid of oil related hazards, and easy to strip after usage. In some embodiments, the coating may be easily removed by immersing the coated substrate into de-ionized water and sonicating for 3 minutes or instantaneously by pressure jet washing. In some embodiments, the GO is suspended in a solvent to form a solution of at least 1 g/L, preferably 5 g/L.
Ultra-low friction is achieved when GO and MoS2 form heterostructures and lower the shear strength of layered 2-D materials with increasing temperature. The shear strength of MoS2 decreases with increasing temperature in itself, but does not achieve superlubricity without the addition of GO. MoS2 alone can produce a friction as low as 0.04 at 100° C. when tested in ambient atmospheric conditions. See Hare & Burris, “The Effects of Environmental Water and Oxygen on the Temperature-Dependent Friction of Sputtered Molybdenum Disulfide,” Tribology Letters 52(3), pp. 485-493 (2013). However, increase in temperature beyond 100° C. deteriorated lubricious properties due to rapid intercalation of MoS2 films from oxygen and water, as evidenced by formation of MoO3 compounds. It has been discovered that the addition of GO prevents such deleterious effects and prolongs the life of MoS2 for longer durations. It has been observed that MoS2 reorients the basal planes progressively, with increasing sliding distance and temperature. The signal from the A1g and Ag·B1g rises sharply indicating that this basal plane reorientation contributes to lowering of friction. These morphological changes are permitted by the protective graphene oxide layers that seal MoS2 from oxygen and vapor. In the absence of such a protection, MoS2 would generate rapidly before any reorientation and consequent friction reduction kicks into effect.
The method 100 for forming the low friction wear surface includes sonicating at 106 the mixture of MoS2 and GO in the container to form a homogeneous suspension 108. The solid MoS2 interacts with solid GO sheets in the suspension via van-der-Waals forces. The mixture includes solid graphene-oxide sheets suspended in water to form a solid in an liquid suspension. The reaction does not proceed by nucleation of MoS2/GO from a saturated/supersaturated solution, but rather evaporation of the carrier liquid and deposition of the solid materials onto the hot substrate. The deposition and instantaneous bond formation is aided by the cavitation type explosion as the water droplet impinges on to the surface as discussed previously. Sonication may be done in any device capable of applying sound energy to agitate particles in a sample, for example, but not limited to an ultrasonic bath or an ultrasonic probe. In one embodiment, the thin layers are mixed by sonication, “sonixing.” It is believed that physical agitation will not provide the necessary agitation for the materials to mix homogenously. However, the sonixing did not indicate any material modification of the parent phases. For example, the d-spacing of MoS2 and GO have remained same after sonication.
At 110, the 2-D materials may be introduced onto the surface via a process of air spray-coating by spraying a 2-D materials-containing solution (with a solvent such as water) over the substrate and then evaporating the solvent. In one embodiment, the coating can be applied using any technique that produces a mist. The mist droplets must contain the two phases in suspension. Alternatively, any physical deposition techniques wherein a carrier liquid is used to deliver the solid materials and the carrier liquid, but not require a chemical reaction, can evaporate without physically altering/changing/damaging MoS2 and GO can be used. Such deposition differs from those remaining in solution, such as graphene suspended in oil, or those applied chemically. For example, those materials in solution are, obviously, in solution and not bound to the substrate surface (e.g., flowable oil with suspended particles). In contrast, solid materials that have been deposited as by spraying will not be in solution, rather such materials will be controlled by Van der Waals forces to attach the materials to the substrate. Further, there is also a structural difference between such materials and those formed as a solid on the surface of the substrate by chemical vapor deposition, atomic layer deposition, or the like. In such instances, the material is reacted (covalently bonded) with or chemisorbed to the substrate rather than merely held by Van der Waals forces. The thickness is controlled by altering the samples' exposure time to the mist. The pressure/flowrate can also effectively be used to change the amount of soli-bearing liquid carrier impinged on to the surface. The thickness of the coating “required” to produce superlubric properties depends on the test load as would be appreciated in the art. Lower test loads transition into superlubric regime easily, whereas thicker coatings are required at higher loads and for longer sliding distances. Subsequent coats must be applied after the initial layers have completely dried and have adhered to the substrate firmly.
Further, for more than mono layer, the additional layers are also bound, whereas the solution processed materials experience weaker Van der Waals forces, enabling the sloughing of outer layers and the improved lubricity.
In some embodiments, the method 100 of forming the low friction wear surface includes evaporating the solvent component and encapsulating the MoS2 flakes in GO in one step (i.e., by simultaneous evaporation and consequent encapsulation). Encapsulating the MoS2 flakes greatly helps the longevity and lubricity of the low friction wear surface because the flakes are passivated from ambient oxygen and moisture, increasing the temperature range of the MoS2 flakes to above 250° C. The MoS2 flakes are uniformly, fully coated. This is ensured by virtue of the composition (wt %) of the two phases chosen. Also, this coating process is scalable to larger surfaces and is not restricted to flat surfaces. A large scale application of such may be to utilize a scanning spray nozzle to cover a large area with the graphene in solution and then vaporize the solvent. The surface is required to have some anchoring elements. In one embodiment, a rough surface of at least (Ra˜0.2-0.4) provides sufficient anchoring points. In case of extremely smooth substrates, the surfaces would be treated to make them amenable to the deposition techniques. Examples of such treatments include, but are not limited to, ozone treatment and doping with binders that make bonds between the steel and the initial layers and higher substrates (up to 400° C.) temperatures.
At 112, the substrate may be heated, for example to 275° C. In some embodiments, the substrate may be a steel surface, such as but not limited to self-mated hardened stainless steel, ferritic stainless steel, austenitic stainless steel, martensitic stainless steel, duplex stainless steel, and precipitation hardened stainless steel. In some embodiments, the substrate can comprise of at least a portion of a metal working die, a wind turbine, a polymer injection molding die, a piston, a piston ring, a piston sleeve, a ball and roller bearing element, an oil-free air compressor, a gas compressor, a gas seal, a sliding rail guide, or a heavy load bearing wheel guide.
In some embodiments, the low friction wear surface may undergo subjecting the wear surface on the substrate for high temperature wear testing at 114. The method 100 includes heating the temperature to about 200° C. to about 400° C. Normal loads may be applied to the low friction wear surface on the substrate at these high temperatures at 116.
Superlubricity may be defined as a regime of motion in which friction vanishes or nearly vanishes, such as a COF of less than about 0.01. The superlubric friction is measured by sliding the low friction wear surface using a ball-on-disc configuration of wear testing, under unidirectional sliding. The low friction wear surface may be applied on to heated steel samples and immediately tested at high temperatures (e.g., 200° C., 300° C., and 400° C.) or lower temperatures (e.g., 22° C. and 100° C.). The coated substrates were evaluated for wear-friction evaluation in a high temperature tribometer with loads from about 0.5 N to about 8 N and a rotating speed from about 50 rpm to about 300 rpm.
Solution-processed molybdenum disulfide was prepared by chemical exfoliation of bulk MoS2 crystal and was then suspended in ethanol with 18 mg/L graphene. The resulting solution contained 1 to 8 monolayers thick MoS2 flakes. The GO solution may be obtained by exfoliating graphene and disposing the resulting graphene flakes in a liquid. The graphene may be exfoliated by any appropriate chemical or mechanical exfoliation process, such as chemical exfoliation of highly oriented pyrolytic graphite in the case of graphene. The GO solution is suspended in an oil-free solvent to form a solution of at least 1 g/L.
The MoS2 flakes and the GO solution are prepared in different concentrations are then mixed together and then sonicated using an ultrasonic bath for 2-15 minutes at 20-125 kHz frequency. The now homogenous solution is then sprayed or drop casted (100-10,000 nm in diameter) on a self-mated stainless steel substrate heated to about 275° C. This process results in a uniformly distributed coating on the substrate surface. The expected area of 2-D MoS2 flakes per unit area of the substrate is in the range of 175-800 cm2 per mm2 of substrate.
In the ball-on-disc tests, the counterpart may be a stainless steel ball (440C grade) of 3-10 mm diameter.
Tribological tests were performed in ambient environmental conditions at temperatures ranging from about 22° C. to about 450° C. using a CSM ball-on-disk macroscale tribometer. The normal load during the tribotests was kept at with loads from about 0.5 N to about 8 N and a rotating speed from about 50 rpm to about 300 rpm (where the radius of the wear track varied from 1 mm up to 15 mm). Zero calibration of the machine was performed automatically at the beginning of each test. All the tests were repeated at least 5 times at each temperature to confirm reproducibility of the results.
The wear volume of the flat was very difficult to assess, as wear was manifested as deep scratches and could not be fit into a reliable wear equation. To estimate the wear volume for the balls after the tribotests, we used the following equation:
where
d is wear scar diameter, and r is the radius of the ball.
As shown in
As shown in
As shown in
In comparison to the aforementioned friction values from
The wear on a steel surface in comparison to a steel surface with the low friction wear surface coating is further demonstrated in
The wear scars were imaged with an Olympus UC30 microscope and characterized by an Invia Confocal Raman microscope using the red laser light (λ=514 nm). The wear debris formed during the tribotests was imaged with a JEOL JEM-2100F transmission electron microscope (“TEM”), for which samples were picked up from the wear track with a probe and transferred to a copper grid. SEM images were imaged with FEI Quanta Scanning Electron Microscope. To gain further insight into the evolution of the carbon-based tribolayer within the wear track and identify the chemical state of the MoS2, Raman spectroscopy studies were carried out.
The longevity of a low friction wear surface is further demonstrated in
TEM analysis from
It is believed that the reason for superlubricity is related to maintaining the inert layered structure of MoS2 by encapsulation of GO flakes. The layered structure may be scrolls, but must encapsulate the 2-D material, such as MoS2. It is believed that during sliding at high contact pressures at high sliding velocity and elevated substrate temperatures, structural re-orientation of MoS2 takes place resulting in layered structure as shown in
In summary, a low friction wear surface includes a substrate, GO in an oil-free solvent disposed over the substrate, and MoS2 ultrafine nanocrystalline flakes disposed over the substrate. The GO and the MoS2 are in a range of ratios of (1±0.25):(1∓0.25) by weight, respectively. In order to form this low friction wear surface, the substrate has a temperature of about 275° C. when the GO and the MoS2 are disposed on its surface. In some embodiments, the solvent mixed with GO is water.
As shown in the figures and descriptions above, the low friction wear surface displays a much lower COF than a surface without the low friction wear surface. In some embodiments, the low friction wear surface has a COF value less than 0.06 at a temperature in between about 200° C. and 400° C. for a duration of about 15 minutes to about 3.5 hours, inclusive. In some embodiments, the low friction wear surface has a maximum contact pressure in between about 0.1 GPa and about 1.0 GPa at a temperature in between about 200° C. and about 400° C. In some embodiments, the low friction wear surface has a COF less than 0.1 at a temperature in between about 22° C. and about 100° C. in ambient conditions.
In some embodiments, the substrate of the low friction wear surface is made of at least a portion of a metal working die, a wind turbine, a polymer injection molding die, a piston, a piston ring, a piston sleeve, a ball and roller-bearing element, an oil-free air compressor, a gas compressor, a gas seal, a sliding rail guide, or a heavy load bearing wheel guide. In some embodiments, the substrate of the low friction wear surface is a steel, for example but not limited to, a self-mated stainless steel, ferritic stainless steel, austenitic stainless steel, martensitic stainless steel, duplex stainless steel, or precipitation hardened stainless steel.
Furthermore, a method of a forming a low friction wear surface includes preparing graphene by chemical exfoliation of highly-oriented pyrolytic graphite, suspending GO in a solvent to form a solution of at least 1 g/L, adding at least 1 g/L of MoS2 ultrafine nanocrystalline flakes to the solution, sonicating the MoS2 and the solution to form a homogenous solution and disposing the homogenous solution on a substrate. The method of disposing the homogenous solution includes spraying the homogeneous solution on a substrate via a process of air-spray coating, wherein the substrate has a temperature of 275° C.; forming a wet film on the substrate; and evaporating the solvent component to form a dry coating layer. The GO and the MoS2 are in a range of ratios in between (1±0.25):(1∓0.25) by weight, respectively. The solvent in this method may be water, or the solvent may be oil-free. In some embodiments, the method further comprises evaporating the solvent component and encapsulating the MoS2 flakes in large blankets of GO in one step.
In some embodiments, the method of forming the low friction wear surface includes achieving a COF value in between about 0.001 and about 0.06 at a temperature in between about 200° C. and about 400° C. In some embodiments, this method includes demonstrating a COF value less than 0.05 for a duration of about 15 minutes to about 3.4 hours in between about 200° C. and 400° C. In some embodiments, the substrate is a steel material. In some embodiments, the method further includes a COF value less than 0.1 at a temperature in between about 22° C. and about 100° C. in ambient conditions.
A method of forming a sliding mechanical system with a low friction wear surface includes forming a homogeneous solution of MoS2 and GO in a range of ratios in between (1±0.25):(1∓0.25) by weight, disposing the homogeneous solution over a substrate to form a first sliding component, and sliding the first sliding component against a second sliding component in open air. Scrolls of MoS2 are formed and encapsulated in the GO. In some embodiments, the second sliding component may be a steel material. In some embodiments, the method may further include sliding the first sliding component and the second sliding component at a temperature in between about 200° C. and about 400° C. In some embodiments, the solution uses an oil-free solvent. In some embodiments, the homogeneous solution is disposed over the substrate via a method of air spray coating when the substrate is heated to a temperature of about 275° C.
While the present teachings have been described in conjunction with various embodiments and examples, it is not intended that the present teachings be limited to such embodiments or examples. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art.
While various inventive embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the inventive teachings is/are used. Those skilled in the art will recognize many equivalents to the specific inventive embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, inventive embodiments may be practiced otherwise than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the inventive scope of the present disclosure.
All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” Any ranges cited herein are inclusive.
The terms “substantially” and “about” used throughout this Specification are used to describe and account for small fluctuations. For example, they may refer to less than or equal to ±5%, such as less than or equal to±2%, such as less than or equal to±1%, such as less than or equal to±0.5%, such as less than or equal to±0.2%, such as less than or equal to±0.1%, such as less than or equal to±0.05%.
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” may refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of” “only one of” or “exactly one of” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.
As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) may refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.
The claims should not be read as limited to the described order or elements unless stated to that effect. It should be understood that various changes in form and detail may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. All embodiments that come within the spirit and scope of the following claims and equivalents thereto are claimed.
This invention was made with government support under Contract No. DE-ACO2-06CH11357 awarded by the United States Department of Energy to UChicago Argonne, LLC, operator of Argonne National Laboratory. The government has certain rights in the invention.
