DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Election/Restrictions
Claims 17-22 stand withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 14 January 2026.
Amendments
Applicant’s amendments to the claims and specification filed on 26 May 2026 have been entered and considered for this action. The prior objections are withdrawn.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 4, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1), as evidenced by Du et al. (“Transformation and reconstruction towards two-dimensional atomic laminates,” arXiv:2302.07718, 2023; DOI: 10.48550/arXiv.2302.07718).
Regarding claim 1, Shin teaches a method for fabricating a two-dimensional material (MXene nanosheet; abstract) by using gas phase method, the method comprising:
a gas phase etching step, wherein a gas having an etching effect reacts with a MAX phase material at a first predetermined temperature to etch an A component from the MAX phase material, and a two-dimensional material containing MX is obtained (the A atomic layer is first selectively removed from the MAX phase to obtain a nanosheet …Removing the A atomic layer may be performed under acidic conditions…The acid may be in a gas phase; [0053]-[0060]), wherein the gas having the etching effect comprises a halogen hydride, the halogen hydride being HCl (The acid may be, for example, a relatively strong acid containing a fluorine atom…these fluorine containing compounds may be mixed with a strong acid, e.g. hydrochloric acid; [0059]).
Though Shin does not teach a single embodiment with a gas phase etchant comprising HCl, Shin teaches both that the acid may comprise HCl and that the acid may be in the gas phase. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to perform the method using a gas phase etchant comprising HCl. One of ordinary skill in the art would have been motivated to do so because they would simply be combining two features of the etchant described by Shin.
Shin also teaches that the two-dimensional material containing MX produced by the etching step contains a functional group (T) where the functional group is introduced by the gas having the etching effect (According to example embodiments, the A atomic layer is first selectively removed from the MAX phase to obtain a nanosheet having a formula of Mn+1XnTs.The nanosheet having a formula of Mn+1XnTs means that the surface of the MXene layer is modified with the functional group Ts. Herein, Ts is a functional group binding to the surface of the MXene layer, and may include, for example, oxide (O), epoxide, hydroxide (OH), alkoxide having 1-5 carbon atoms, fluoride (F), chloride (Cl), bromide (Br), iodide (I), or a combination thereof; [0053]-[0054] where it is implicit that the halide functional groups would have originated from the halide-containing etchant).
Regarding the gas having an etching effect reacting with the A components in the MAX phase material to produce a gas phase product which is then removed from the reaction system, it is first noted that Shin teaches MAX-phase materials where A is aluminum (e.g., Ti2AlC, [0048] and [0089]) and reaction temperature above 180 °C (from about 20 °C to 800 °C, [0060]). While Shin is silent on the identity of the aluminum-containing product, the etchant HCl will inherently produce gas phase aluminum chloride (AlCl3 or the dimer Al2Cl6) from the MAX phase material Ti2AlC, as evidenced by Du et al. (HCl gas, whose molecules … directly and rapidly react with A species in MAX phases at high temperatures…with the main products of 2D atomic laminates and gaseous by-products of ACly (M-A-X + HCl (g) → M-X-Cl + ACly (g); p. 3-4 and Fig. 1a) under at least some of the temperatures suggested by Shin.
Because the desired MXene product does not contain AlCl3, it would have also been obvious to remove such a gas from the system once formed in order to form a more pure product that does not contain unwanted byproducts.
Regarding claim 4, Shin teaches the method of claim 1, where the first predetermined temperature is in the range of about 20 °C to about 800 °C ([0060]), which overlaps with the instantly claimed range of from 500 °C to 1200 °C.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore, the claimed temperature range merely represents an obvious variant and/or routine optimization of the values of the cited prior art.
Regarding claim 16, Shin teaches the method of claim 1 where the MAX phase material may be Ti2AlC, in which M is titanium, a transition element; A is aluminum, a main group element; and X is carbon ([0048]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use Ti2AlC as the MAX phase material. One of ordinary skill in the art would have been motivated to do so because Shin teaches that this is a suitable substrate on which to apply their method and because the MXene products derived from Ti2AlC have a broad range of applications ([0008]).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1) with evidence provided by Du et al. (“Transformation and reconstruction towards two-dimensional atomic laminates,” arXiv:2302.07718, 2023; DOI: 10.48550/arXiv.2302.07718), as applied to claim 1 above, and further in view Hassan et al. (US 2008/0102640 A1).
Regarding claim 5, Shin teaches the method of claim 1, but does not teach the gas comprising a carrier gas.
However, like Shin, Hassan teaches etching using gas phase halogenated hydrogen-containing gas, such as HF and HCl, ([0016]) and Hassan further teaches the etchant gas comprising a carrier gas which may be nitrogen ([0017]), and that such a carrier gas can be used to carry or transport the reactive etchant gases.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use in the method of Shin an etchant comprising nitrogen as a carrier gas, as taught by Hassan. One of ordinary skill in the art would have been motivated to do so because Hassan teaches that such constituents can be used to help transport the reactive gases.
Claims 6 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1) with evidence provided by Du et al. (“Transformation and reconstruction towards two-dimensional atomic laminates,” arXiv:2302.07718, 2023; DOI: 10.48550/arXiv.2302.07718), as applied to claim 1 above, and further in view of Ullmann’s Encyclopedia of Industrial Chemistry (Austin, S. and Glowacki, A. (2000). Hydrochloric Acid. In Ullmann's Encyclopedia of Industrial Chemistry, DOI: 10.1002/14356007.a13_283).
Regarding claims 6 and 7, Shin teaches the method of claim 1, but does not teach any method for producing the gas having the etching effect.
However, Ulmann teaches that that HCl can be produced by the reaction of sulfuric acid with sodium chloride, a halogen metal salt (p. 196, Section 3.1 and 3.2.2).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use in the method of Shin HCl gas that is produced by the reaction of sulfuric acid with sodium chloride, as taught by Ulmann, thereby meeting the limitations of claims 6 and 7. In doing so, one would be combining the known method of generating HCl taught by Ulmann with the known process of Shin that requires a source of HCl to yield predictable results. MPEP 2143(I)(A).
Claims 8-11 and 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1) with evidence provided by Du et al. (“Transformation and reconstruction towards two-dimensional atomic laminates,” arXiv:2302.07718, 2023; DOI: 10.48550/arXiv.2302.07718), as applied to claim 1 above, and further in view of Barsoum et al. (US 2014/0162130 A1) and Farag (Energy & Fuels 2002, 16, 944-950).
Regarding claims 8 and 9, Shin teaches the method of claim 1, but does not teach an adjustment step wherein the two-dimensional material containing MX reacts with a functional gas that is an elemental substance or a hydride of the fourth, fifth, or sixth main groups.
However, Barsoum also teaches the production of two-dimensional materials containing MX from MAX phase materials ([0006]-[0009] and [0025]), and Barsoum further teaches an adjustment step where the two-dimensional material is functionalized (the ability to functionalize the surfaces of the layers of the present invention to provide enrichment of a particular functional group provides a considerable synthetic and structural flexibility… an originally presented M-hydroxide surface may be converted to oxide or sub-oxide surface by application of heat or other dehydrating conditions. Nitrogen and sulfur surfaces may be analogously interconverted by methods known in the art for making such conversions; [0102] and [0106]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply an adjustment step to the method of Shin, as taught by Barsoum. In particular, one would have been motivated to create a sulfur-functionalized surface because Barsoum suggests doing so.
Barsoum does not teach a method to add the sulfur functionalization and only suggests doing so by methods known in the art. One of ordinary skill would therefore turn to the art to find such a method of interchanging an oxygen for a sulfur.
Farag teaches such a method for interchanging an oxide for a sulfur surface, as suggested by Barsoum. The method of Farag includes the use of hydrogen sulfide gas at a predetermined temperature and results in a material containing sulfur, an element of the sixth main group (p. 948, Eq. 4-6).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use in the method of Shin an adjustment step wherein the two-dimensional material containing MX reacts with hydrogen sulfide (H2S), a functional gas that is a hydride of the sixth main group, at a predetermined temperature to result in a two-dimensional material containing sulfur, an element of the sixth main group, as taught by Farag. One of ordinary skill in the art would have been motivated to do so because Barsoum suggests carrying out this transformation using a method known in the art, and Farag provides one such method.
Regarding claim 10, modified Shin teaches the method of claim 8, where Barsoum teaches replacing part or all of functional groups of the two dimensional material containing MX to obtain a two-dimensional material containing a functional group of sulfur, an element of the sixth main group (an originally presented M-hydroxide surface may be converted to oxide or sub-oxide surface by application of heat or other dehydrating conditions. Nitrogen and sulfur surfaces may be analogously interconverted by methods known in the art for making such conversions; [0106]).
Regarding claims 11 and 13, modified Shin teaches the method of claim 9, where Farag teaches the conversion of oxides to sulfides can be carried out at 600 °C (p. 948, Eq. 4), which falls in the instantly claimed ranges of both claims 11 and 13.
It is also noted that Farag further discusses the temperatures required, and relates the high temperatures required to the bulk crystalline, non-porous form of the materials being converted (MoO2 is so resistant to sulfiding by 5 wt%H2S/H2 gas mixture until reaching a very high temperature of ca. 800 °C. Probably the formed texture of MoO2 is not very porous, so diffusion limitations of 5 wt% H2S/H2 gas mixture are being concerned. This could be supported by the surface black color of such material that is very probably due to the sulfiding of minor amounts of surface species. Both MoO3 and MoO2 are formed in highly crystalline form; p. 198, col. 2, ¶ 1).
Because Shin teaches that there materials have highly exposed surfaces (e.g., Fig. 11B), one of ordinary skill in the art would recognize based on Farag’s analysis that the high temperatures used by Farag may not be required. It therefore would have been obvious to optimize by routine experimentation the predetermined temperature used in the adjustment step.
It is further noted that, generally, differences temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." See MPEP 2144.05 and In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claims 14 and 15, Shin teaches the method of claim 1, but does not teach providing a functional gas that is an elemental substance or a hydride of the fourth, fifth, or sixth main groups in the etching step to produce a material containing an element of the fourth, fifth, or sixth main groups.
However, Barsoum also teaches the production of two-dimensional materials containing MX from MAX phase materials ([0006]-[0009] and [0025]), and Barsoum further that these materials can be functionalized by methods known in the art for exchanging surface groups (the ability to functionalize the surfaces of the layers of the present invention to provide enrichment of a particular functional group provides a considerable synthetic and structural flexibility… The skilled artisan will be able to interchange the pendant groups by methods known in the art…an originally presented M-hydroxide surface may be converted to oxide or sub-oxide surface by application of heat or other dehydrating conditions. Nitrogen and sulfur surfaces may be analogously interconverted by methods known in the art for making such conversions; [0102] and [0106]).
Barsoum does not teach a specific method to add the sulfur functionalization but rather suggests doing so by methods known in the art (The skilled artisan will be able to interchange the pendant groups by methods known in the art; [0106]). One of ordinary skill would therefore turn to the art to find such a method of interchanging an oxygen for a sulfur, as suggested by Barsoum.
Farag teaches one such a method for interchanging an oxide for a sulfur surface. The method of Farag includes the use of hydrogen sulfide gas at a predetermined temperature and results in a material containing sulfur, an element of the sixth main group (p. 948, Eq. 4-6).
Regarding whether this functionalization is performed during or after the etching step, it is noted that the courts have held that any order of performing process steps is prima facie obvious in the absence of new or unexpected results (In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930); Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959)). See MPEP §2144.04 IV C.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide in the etching step taught by Shin the functional gas of hydrogen sulfide (H2S), a hydride of the sixth main group, so that the MAX phase material undergoes a gas phase etching reaction with the gas having the etching effect, as taught by Shin, and simultaneously the two-dimensional material containing MX and the functional gas undergo a functional-group adjustment reaction, as taught by Barsoum and Farag, wherein the gas phase etching step results in a two-dimensional material containing sulfur, an element of the sixth main group.
One of ordinary skill in the art would have been motivated to do so because Barsoum teaches that it is appropriate to introduce sulfur by functional group interchange on the etched material and Farag teaches that H2S is a reagent than can carry out this transformation. One of ordinary skill would have been further motivated to carry out the two reactions in one step because doing so would add additional efficiency to the process.
Claims 8-9 and 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Shin et al. (US 2017/0088429 A1) with evidence provided by Du et al. (“Transformation and reconstruction towards two-dimensional atomic laminates,” arXiv:2302.07718, 2023; DOI: 10.48550/arXiv.2302.07718), as applied to claim 1 above, and further in view of Urbankowski et al. (Nanoscale 2017, 9, 17722).
Regarding claims 8 and 9, Shin teaches the method of claim 1, but does not teach an adjustment step wherein the two-dimensional material containing MX reacts with a functional gas that is an elemental substance or a hydride of the fourth, fifth, or sixth main groups.
However, Urbankowski teaches an adjustment step of two-dimensional MX containing materials as a method to synthesize nitride MXenes, wherein the two-dimensional material containing MX reacts with ammonia (NH3), a functional gas that is a hydride of the fifth main group, at a predetermined temperature and resulting in a two-dimensional material containing an element of the fifth main group (the first transformation of Mo2CTx and V2CTx carbide MXenes into 2D metal nitrides via ammoniation at 600 °C; p. 2, col. 1, ¶ 2 and Scheme 1). Urbankowski further teaches that this methos affords nitride MXenes where other methods have been unsuccessful, and that nitride MXenes have potential applications in energy storage and plasmonics (p. 1, col. 2, ¶ 2 and p. 2, col. 1, ¶ 2).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply the adjustment step taught by Urbankowski to the products derived by the method of Shin. One of ordinary skill in the art would have been motivated to do so because this step can produce new materials with potential applications in energy storage and plasmonics, as taught by Urbankowski.
Regarding claims 11 and 13, modified Shin teaches the method of claim 9, where Urbankowski teaches performing the ammoniation at 600 °C, which meets the limitations of claims 11 and 13 (the first transformation of Mo2CTx and V2CTx carbide MXenes into 2D metal nitrides via ammoniation at 600 °C; p. 2, col. 1, ¶ 2).
Regarding claim 12, modified Shin teaches the method of claim 8, where Urbankowski teaches nitrogen, an element of the fifth main group, replacing all of the X component (carbon) in the two dimensional material containing MX and the adjustment step resulting in a two-dimensional material containing nitrogen (Scheme 1).
Response to Arguments
Applicant's arguments filed 26 May 2026 have been fully considered but they are not persuasive.
Applicant argues, page 10, that Shin discloses only MXene nanosheets with surfaces that are not substantially modified and points to [0010] and [0014] of Shin in support of this argument. However, these portions of Shin describe the final product following a reduction step which is conducted after the etching step (see intervening [0012]). The etching step alone is what is considered in the analysis above and Shin is clear that this step generates a functionalized product (“According to example embodiments, the A atomic layer is first selectively removed from the MAX phase to obtain a nanosheet having a formula of Mn+1XnTs. The nanosheet having a formula of Mn+1XnTs means that the surface of the MXene layer is modified with the functional group Ts”; [0053]-[0054]).
Furthermore, while Shin is silent on the identity of the products containing the A elements being etched away, the product of the reactions taught by Shin, in particular those between Al-containing MAX-phase materials and an HCl etchant, will necessarily contain aluminum chloride, which at the temperatures taught by Shin will be a gas-phase product.
Applicant’s remaining arguments, page 11, are also based upon the alleged deficiencies of Shin and are likewise unpersuasive.
Applicant’s request for rejoinder, page 12, is noted and rejoinder will be considered when all claims directed to the elected invention are in condition for allowance.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
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