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.
Information Disclosure Statements
The Information Disclosure Statement filed on 23 February 2026 has been received and considered by the Examiner.
Amendments
Applicant’s amendments to the claims filed on 10 May 2023 have been received and considered for this action. The prior claim objection and rejections under 35 USC § 112 are withdrawn.
Claim Objections
Claim 29 is objected to because certain the formula for H3PO4 lacks proper subscripts and because some formulas appear to use zeroes in place of the letter O (H3PO4 and H2O2). Appropriate correction is required.
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 15-26 and 28-37 are rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (Carbon 2019, 146, 618-626) in view of Gebreegziabher et al. (Mater. Today Chem. 2019, 12, 233-239), Vu et al. (WO 2018/178845 A1; document A02 on the IDS filed 13 June 2023), and Liu et al. (Carbon 2017, 119, 544-547; hereinafter Liu ‘17).
Regarding claim 15, Liu teaches a method of for the manufacture of graphene oxide from graphite comprising:
providing the graphite (use of graphite in subsequent steps means it was provided);
intercalating the graphite with a persulfate salt and an acid at 35 °C to obtain intercalated graphite ((NH4)2S2O8 can successfully intercalate into the interlayer of graphite along with the concentrated sulfuric acid; p. 619, col. 1, ¶ 2 and Section 2.4);
expanding the intercalated graphite at 35 °C to obtain expanded graphite (Section 2.3 and Fig. 1); and,
mixing the expanded graphite with an acid and an oxidizing agent (another 120 ml concentrated sulfuric acid was poured into the mixture. … 16 g KMnO4 was equally divided into six parts and each part was slowly added into the mixture every 10 min; Section 2.4), so that the expanded graphite is simultaneously oxidized and exfoliated (Fig. 1).
Liu further teaches that the floating graphite particles after expansion indicate that that many holes containing plenty of gases existed between the interlayer of graphite flakes (after the gas expansion step, almost all graphite flakes transferred from the bottom to the surface, indicating that many holes containing plenty of gases emerged between the interlayer of graphite flakes; p. 621, col. 1, ¶ 1). Only after oxidation did the graphite cease to float (interesting phenomenon should be noticed is that after the oxidizing step, the graphite after gas expansion step which was floated on the surface of the mixture uniformly dispersed in the mixture; p. 621, col. 1, ¶ 1). These observation teach that the gases generated during the expansion step were still at least partially present during the subsequent treatment with acid and oxidizing agent.
Liu does not teach the graphite being Kish graphite, the intercalation and expansion steps occurring at room temperature, or the method producing reduced graphene oxide.
However, Vu teaches that Kish graphite, a byproduct or the steelmaking process, is a good candidate to produce graphene based materials including graphene oxide and reduced graphene oxide (p. 1, ¶ 3).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the graphite flakes used by Liu with Kish graphite, as taught by Vu. One of ordinary skill in the art would have been motivated to use Kish graphite because they would be valorizing an industrial byproduct that is a good candidate for such a process, as taught by Vu.
Additionally, Liu ’17 teaches that the intercalation of ammonium persulfate and sulfuric acid into graphite and the subsequent expansion can occur at room temperature (p. 544, col. 2, ¶ 2). Liu ’17 further teaches that their approach is lower cost and energy-saving in comparison to approaches that require heating (p. 547, ¶ 4).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to conduct the intercalation and expansion processes at room temperature, as taught by Liu ‘17. One of ordinary skill would have also been motivated to carry out the intercalation and expansion at room temperature in order to save energy, as taught by Liu ’17.
Furthermore, Gebreegziabher teaches that reduced graphene oxide can be prepared directly from graphite by mixing with an acid and an oxidizing agent, simultaneously oxidizing, exfoliating, and reducing the graphite into reduced graphene oxide (the preparation of reduced graphene oxide (rGO) directly from graphite in a solution of potassium permanganate and concentrated sulfuric acid; abstract).
Therefore, it would have further been obvious to use the acid/oxidizing treatment of Gebreegziabher to simultaneously oxidize, exfoliate, and reduce the graphite directly to reduced graphene oxide, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because such a treatment affords reduced graphene oxide directly without the need of separate reducing step and its accompanying extra time and intensive purification processes (Gebreegziabher, p. 234, col. 1, ¶ 1).
Regarding claim 16, modified Liu teaches the method of claim 15 and Liu further teaches that the gases generated during the expansion step include O2 (the mixture of gases contains 51.2% oxygen; p. 620, col. 2, ¶ 2).
Regarding claim 17, modified Liu teaches the method of claim 15, where Liu teaches the expanded graphite is used in situ (Section 2.4) and is therefore not cleaned before mixing with the acid and oxidizing agent.
Regarding claim 18, modified Liu teaches the method of claim 15 but does not explicitly teach performing the expansion in a closed vessel. However, Liu does teach that the generated gases were carefully inlet into an air trap and that a gas component analysis was performed by gas chromatography (GC; p. 620, col. 2, ¶ 2). The use of an air trap and connection to GC suggests that the reaction vessel can be considered a closed vessel, analogous to the closed vessel formed by connection of the vessel to a gas syringe or to a mass spectrometer, as described in the instant specification (p. 11, lines 7-8).
Alternatively, 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 reaction in closed vessel. One of ordinary skill in the art would have been motivated to use a closed vessel so that the gasses could not escape without being trapped and monitored and analyzed by GC, as taught by Liu.
Regarding claim 19, modified Liu teaches the method of claim 15 where Liu teaches the expansion is performed in an open vessel (the gas expansion process must be done in an open beaker or in other open reactors; Section 2.4).
Regarding claims 20, modified Liu teaches the method of claim 15 where Liu teaches the expanded Kish graphite is mixed with the at least an acid and an oxidizing agent 2 h after the start of the expansion step (Section 2.4).
Regarding claims 21, modified Liu teaches the method of claim 15 where Liu teaches the expanded Kish graphite is mixed with the at least an acid and an oxidizing agent 2 h after the start of the expansion step (Section 2.4). This time falls outside the claimed range of less than 1 hour.
However, it is well known to persons of ordinary skill in the art that the time of process steps in chemical processes affect the completion of the chemical reaction and the yield of products. Absent new and unexpected results, “where 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II. Therefore, the claimed range of time merely represents an obvious variant and/or routine optimization of the values of the cited prior art.
Regarding claim 22 and 23, modified Liu teaches the method of claim 15, and further teaches that gas remains in the expanded graphite, as analyzed above. Liu is silent on the volume fraction of gas remaining present in the expanded Kish graphite when mixed with the at least an acid and an oxidizing agent.
However, the method taught by modified Liu is substantially similar to the method instantly disclosed. Therefore, it would be expected that the volume of gas remaining would also be substantially similar, thereby meeting the limitations of claim 22 and 23.
Regarding claim 24, modified Liu teaches the method of claim 15 where Liu and Gebreegziabher each teach the graphite first mixed with the acid and then the oxidizing agent being gradually added (Liu, Section 2.4; Gebreegziabher, Section 2.2).
Regarding claim 25, modified Liu teaches the method of claim 24 where Liu teaches the addition of the oxidizing agent over 1 hour (six parts, each part added every 10 min; Section 2.4) , while Gebreegziabher teaches merely the “gradual addition of KMnO4 (Section 2.2).
However, it is well known to persons of ordinary skill in the art that the time of process steps in chemical processes affect the completion of the chemical reaction and the yield of products. Absent new and unexpected results, “where 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II. Therefore, the claimed range of addition time merely represents an obvious variant and/or routine optimization of the gradual additions in the cited prior art.
Regarding claim 26, modified Liu teaches the methos of claim 15, where Liu further teaches mixing the product with H2O2 to eliminate the rest of the oxidizing agent (plenty of H2O2 was added into the mixture to remove the unreacted KMnO4; Section 2.4). Gebreegziabher likewise mixes the product with H2O2 (13 mL of 30% H2O2 was added to complete the oxidation process; Section 2.2).
Regarding claim 28, modified Liu teaches the method of claim 15 where Gebreegziabher teaches washing the reduced graphene oxide with water (obtained samples were purified by washing with deionized water; Section 2.2).
Regarding claim 29, modified Liu teaches the method of claim 16 where Liu teaches the expanded Kish graphite is mixed with the at least an acid and an oxidizing agent 2 h after the start of the expansion step, the acid being H2SO4 and the oxidizing agent being KMnO4 (Section 2.4).
Regarding claims 30 and 31, modified Liu teaches the method of claim 29, where Vu teaches that expanding and exfoliating Kish graphite affords nanoplatelets of reduced graphene oxide that have micrometric (20 μm to 30 μm) lateral sizes and thicknesses of 1-6 nm, which are on the order of two graphene layers (p. 11, Table for Trial 1). Liu also teaches that their method affords monolayer graphene oxide sheets (Section 4) while Gebreegziabher teaches that simultaneous exfoliation/oxidation/reduction afford reduced graphene oxide of a few layers (~5; Section 3.6) graphene sheet thickness, each of which is interpreted as being “on the order of” 2 sheets thickness, as required by the instant claim.
Therefore, it is concluded that when applying the method of modified to Kish graphite, as taught by Vu, one would obtain nanoplatelets of reduced graphene oxide with a thickness of 1-5 layers of graphene, which is on the order of 2 layers, and a width and a length that are micrometric.
It is noted that once a reference teaching a product appearing to be substantially identical is made the basis of a rejection, and the examiner presents evidence or reasoning to show inherency, the burden of production shifts to the applicant. "[T]he PTO can require an applicant to prove that the prior art products do not necessarily or inherently possess the characteristics of [their] claimed product. Whether the rejection is based on inherency’ under 35 U.S.C. 102, on prima facie obviousness’ under 35 U.S.C. 103, jointly or alternatively, the burden of proof is the same, and its fairness is evidenced by the PTO’s inability to manufacture products or to obtain and compare prior art products." In re Best, 562 F.2d 1252, 1255, 195 USPQ 4380, 483-34 (CCPA 1977)), see MPEP 2112. Applicant has not clearly shown an unobvious difference between the instant invention and the prior art’s product.
Regarding claim 32, modified Liu teaches the method of claim 15, where Liu ’17 teaches that the reaction conditions for intercalating and expanding can be simple stirring and standing at room temperature (p. 544, col. 2, ¶ 1 and 3), which does not involve any regulation of the temperature through cooling or heating.
While Liu and Gebreegziabher each teach heating for the step of mixing with at least an acid and an oxidizing agent, it is noted that Liu also teaches heating for the steps of intercalating and expanding, while Liu ’17 teaches that heating is not always necessary and that processes that avoid heating steps are simpler, lower cost, and less polluting (p. 547, ¶ 4).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to also conduct the mixing in the method of modified Liu without regulation of the temperature through cooling or heating. One of ordinary skill in the art would have been motivated to do so in order to make the process more simple, lower cost, and less polluting, as taught by Liu ’17, and because Liu ’17 teaches that temperatures which are lower than those used by Liu may be effective for carrying out the same transformation when the form of the graphite is modified.
Furthermore, generally, differences in temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such a 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 claim 33, Liu teaches a method of for the manufacture of graphene oxide from graphite comprising:
providing the graphite (use of graphite in subsequent steps means it was provided);
intercalating the graphite with a persulfate salt and an acid at 35 °C to obtain intercalated graphite ((NH4)2S2O8 can successfully intercalate into the interlayer of graphite along with the concentrated sulfuric acid; p. 619, col. 1, ¶ 2 and Section 2.4);
expanding the intercalated graphite at 35 °C to obtain expanded graphite (Section 2.3 and Fig. 1); and,
approximately two hours after the start of the expansion step (the suspension was held at 35 °C for two hours; Section 2.4), mixing the expanded graphite with an acid and an oxidizing agent (another 120 ml concentrated sulfuric acid was poured into the mixture. … 16 g KMnO4 was equally divided into six parts and each part was slowly added into the mixture every 10 min; Section 2.4), so that the expanded graphite is simultaneously oxidized and exfoliated (Fig. 1).
Liu further teaches that the floating graphite particles after expansion indicate that that many holes containing plenty of gases existed between the interlayer of graphite flakes (after the gas expansion step, almost all graphite flakes transferred from the bottom to the surface, indicating that many holes containing plenty of gases emerged between the interlayer of graphite flakes; p. 621, col. 1, ¶ 1), and that the gases generated during the expansion step comprise O2 (the mixture of gases contains 51.2% oxygen; p. 620, col. 2, ¶ 2). Only after oxidation did the graphite cease to float (interesting phenomenon should be noticed is that after the oxidizing step, the graphite after gas expansion step which was floated on the surface of the mixture uniformly dispersed in the mixture; p. 621, col. 1, ¶ 1). These observation teach that gases comprising O2 generated during the expansion step were still at least partially present during the subsequent treatment with acid and oxidizing agent.
Liu does not teach the graphite being Kish graphite, the intercalation and expansion steps occurring at room temperature, or the method producing reduced graphene oxide.
However, Vu teaches that Kish graphite, a byproduct of the steelmaking process, is a good candidate to produce graphene based materials including graphene oxide and reduced graphene oxide (p. 1, ¶ 3).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the graphite flakes used by Liu with Kish graphite, as taught by Vu. One of ordinary skill in the art would have been motivated to use Kish graphite because they would be valorizing an industrial byproduct that is a good candidate for such a process, as taught by Vu.
Additionally, Liu ’17 teaches the intercalation of ammonium persulfate and sulfuric acid into graphite at room temperature, and that the subsequent expansion can occur by leaving the mixture of intercalated graphite, the persulfate salt, and the acid at room temperature (p. 544, col. 2, ¶1-3). Liu ’17 further teaches that their approach is lower cost and energy-saving in comparison to approaches that require heating (p. 547, ¶ 4).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Liu to conduct the intercalation at room temperature, and to conduct the expansion step by leaving the mixture of the intercalated Kish graphite, the persulfate salt and the acid at the room temperature to obtain expanded Kish graphite, as taught by Liu ’17. One of ordinary skill would have also been motivated to carry out the intercalation and expansion at room temperature in order to lower costs and save energy, as taught by Liu ’17.
Furthermore, Gebreegziabher teaches that reduced graphene oxide can be prepared directly from graphite by mixing with an acid and an oxidizing agent, simultaneously oxidizing, exfoliating, and reducing the graphite into reduced graphene oxide (the preparation of reduced graphene oxide (rGO) directly from graphite in a solution of potassium permanganate and concentrated sulfuric acid; abstract).
Therefore, it would have further been obvious to use the acid/oxidizing to simultaneously oxidize, exfoliate, and reduce the graphite directly to reduced graphene oxide, as shown possible by Gebreegziabher, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because such a treatment affords reduced graphene oxide directly without the need of separate reducing step and its accompanying extra time and intensive purification processes (Gebreegziabher, p. 234, col. 1, ¶ 1).
It is additionally noted that the method taught by Liu, Vu, and Liu ’17 is substantially similar to that of the instant invention, and that if the method of the instant invention produces reduced graphene oxide, one of ordinary skill in the art would expect the method taught by the prior to do the same.
Regarding claim 34, modified Liu teaches the method of claim 33 where the acid is H2SO4 and the oxidizing agent is KMnO4 (Section 2.4).
Regarding claims 35 and 36, modified Liu teaches the method of claim 33, where Vu teaches that expanding and exfoliating Kish graphite affords nanoplatelets of reduced graphene oxide that have micrometric (20 μm to 30 μm) lateral sizes and thicknesses of 1-6 nm, which are on the order of two graphene layers (p. 11, Table for Trial 1). Liu also teaches that their method affords monolayer graphene oxide sheets (Section 4) while Gebreegziabher teaches that simultaneous exfoliation/oxidation/reduction afford reduced graphene oxide of a few layers (~5; Section 3.6) graphene sheet thickness, each of which is interpreted as being “on the order of” 2 sheets thickness, as required by the instant claim.
Therefore, it is concluded that when applying the method of modified Liu to Kish graphite, as taught by Vu, one would obtain nanoplatelets of reduced graphene oxide with a thickness of 1-5 layers of graphene, which is on the order of 2 layers, and a width and a length that are micrometric.
Regarding claim 37, modified Liu teaches the method of claim 33, where Liu ’17 teaches that the reaction conditions for intercalating and expanding can be simple stirring and standing at room temperature (p. 544, col. 2, ¶ 1 and 3), which does not involve any regulation of the temperature through cooling or heating.
While Liu and Gebreegziabher each teach heating for the step of mixing with at least an acid and an oxidizing agent, it is noted that Liu also teaches heating for the steps of intercalating and expanding, while Liu ’17 teaches that heating is not always required and that processes that avoid heating steps are simpler, lower cost, and less polluting (p. 547, ¶ 4).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to also conduct the mixing in the method of modified Liu without regulation of the temperature through cooling or heating. One of ordinary skill in the art would have been motivated to do so in order to make the process more simple, lower cost, and less polluting, as taught by Liu ’17, and because Liu ’17 teaches that temperatures which are lower than those used by Liu may be effective for carrying out the same transformation, for example when the form of the graphite is different.
Furthermore, generally, differences in temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such a 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).
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Liu et al. (Carbon 2019, 146, 618-626) in view of Gebreegziabher et al. (Mater. Today Chem. 2019, 12, 233-239), Vu et al. (WO 2018/178845 A1; document A02 on the IDS filed 13 June 2023), and Liu et al. (Carbon 2017, 119, 544-547; hereinafter Liu ‘17), as applied to claim 15, and further in view of Awad et al. (US 9,815,701 B1).
Regarding claim 27, modified Liu teaches the method of claim 15 but does not teach mixing the reduced graphene oxide with any of the acids recited in claim 27 to remove byproducts formed during the oxidation.
However, Awad teaches a preparation of reduced graphene oxide by mixing a graphitic carbon source (soot) with the same acid (H2SO4) and oxidant (KMnO4; col. 2, lines 40-46) as modified Liu and further teaches that the reduced graphene oxide so prepared can be washed with 5% HCl.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the reduced graphene oxide nanoparticles of modified Liu with HCl and to perform a washing, as taught by Awad, which will remove by-products formed during the oxidation of the expanded Kish graphite. One of ordinary skill in the art would have been motivated to do so because Awad teaches that such treatment is a washing, which would be expected to improve the purity of the reduced graphene oxide.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 15-17, 19-26, and 28-37 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-25 of U.S. Patent No. 12,404,179 B2 in view of Gebreegziabher et al. (Mater. Today Chem. 2019, 12, 233-239).
Regarding instant claim 15, 20, and 21, claim 1 of the ‘179 patent recite providing Kish graphite (step A); intercalating Kish graphite with a persulfate salt and an acid at room temperature to obtain intercalated Kish graphite (step C); expanding the intercalated Kish graphite at room temperature to obtain expanded Kish graphite (step D). Claim 1, step E further recites an oxidation of the expanded Kish graphite, which would be understood by one of ordinary skill in the art as requiring the addition of an oxidizing agent. Claim 1 further specifies that this oxidation is to take place after 2-5 minutes (the expansion of the intercalated kish graphite at room temperature lasts 2-5 minutes), a period of time meeting the limitations of instant claims 20 and 21 and during which the gasses generated during the expansion will be at least partially still present.
Claim 7 further recites that the oxidation of step E includes mixing the expanded Kish graphite with at least an acid and an oxidizing agent.
The claims of the ‘179 patent do not teach the expanded Kish graphite being simultaneously oxidized, exfoliated and reduced into reduced graphene oxide.
However, Gebreegziabher teaches that reduced graphene oxide can be prepared directly from graphite by mixing with an acid and an oxidizing agent, simultaneously oxidizing, exfoliating, and reducing the graphite into reduced graphene oxide (the preparation of reduced graphene oxide (rGO) directly from graphite in a solution of potassium permanganate and concentrated sulfuric acid; abstract).
Therefore, it would have further been obvious to use the acid/oxidizing treatment of Gebreegziabher to simultaneously oxidize, exfoliate, and reduce the expanded graphite formed by the method of the ‘179 patent directly to reduced graphene oxide, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because such a treatment affords reduced graphene oxide directly without the need of separate reducing step and its accompanying extra time and intensive purification processes (Gebreegziabher, p. 234, col. 1, ¶ 1).
Regarding instant claim 16, claim 4 of the ‘179 patent teaches using ammonium persulfate to intercalate into the kish graphite, which during the expansion will necessarily generate O2.
Regarding instant claim 17, because the method of the ‘179 patent do not recite a washing step between steps D and E, it would have been obvious to not add a washing step.
Regarding instant claim 19, claim 6 of the ‘179 patent recites performing the reaction in an open vessel.
Regarding instant claim 22 and 23, the modified method of the ‘179 patent is substantially similar to the method instantly disclosed, including the timing taught by the claims in the ‘179 patent, therefore, it would be expected that the volume of gas remaining would also be substantially similar, thereby meeting the limitations of claim 22 and 23.
Regarding instant claims 24 and 25, Gebreegziabher teaches the graphite is first mixed with the acid and then the oxidizing agent being gradually added (Section 2.2). Further regarding claim 25, while Gebreegziabher teaches merely the “gradual addition of KMnO4” (Section 2.2), it is well known to persons of ordinary skill in the art that the time of process steps in chemical processes affect the completion of the chemical reaction and the yield of products. Absent new and unexpected results, “where 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II. Therefore, the claimed range of addition time merely represents an obvious variant and/or routine optimization of the gradual additions in the cited prior art.
Regarding instant claim 26, claim 10 of the ‘179 patent shows that H0O2 can be used to stop the oxidation reaction. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the reduced graphene oxide with H2O2 to eliminate the rest of the oxidizing agent.
Regarding instant claim 28, Gebreegziabher further teaches washing the reduced graphene oxide with water (obtained samples were purified by washing with deionized water; Section 2.2).
Regarding instant claim 29, claims 8 and 9 of the ‘179 patents teach the further limitations of the instant claim.
Regarding instant claims 30-31, claims 2 and 15 of the ‘179 patent teach particles formed with dimensions meeting the limitations of the instant claims.
Regarding instant claim 32, the claims of the ‘179 patent recite conducting the steps at room temperature, and so it would have been obvious to one of ordinary skill in the art to do so without control of heating or cooling.
Regarding claims 33-37, each of the further limitations of these claims are also found in the claims of the ‘179 patent, as analyzed for those claims which contain the same limitations but depend upon claim 1.
Claim 27 is rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-25 of U.S. Patent No. 12,404,179 B2 in view of Gebreegziabher et al. (Mater. Today Chem. 2019, 12, 233-239), as applied to claim 15 above, and further in view of Awad et al. (US 9,815,701 B1).
Regarding instant claim 27, the method of claim 15 is obvious over the claims of the ‘179 patent, but these claims do not recite mixing the reduced graphene oxide with any of the acids recited in instant claim 27 to remove byproducts formed during the oxidation.
However, Awad teaches a preparation of reduced graphene oxide by mixing a graphitic carbon source (soot) with the same acid (H2SO4) and oxidant (KMnO4; col. 2, lines 40-46) as modified Liu and further teaches that the reduced graphene oxide so prepared can be washed with 5% HCl.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the reduced graphene oxide nanoparticles produced by the modified method of the ‘179 patent with HCl and to perform a washing, as taught by Awad, which will remove by-products formed during the oxidation of the expanded Kish graphite. One of ordinary skill in the art would have been motivated to do so because Awad teaches that such treatment is a washing, which would be expected to improve the purity of the reduced graphene oxide.
Claims 15-17, 19-26, 28-29, 32-34, and 37 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 17-39 of copending Application No. 17/611,249 (claim set filed 13 October 2025) in view of Gebreegziabher et al. (Mater. Today Chem. 2019, 12, 233-239) and Liu et al. (Carbon 2019, 146, 618-626).
Regarding instant claim 15, claims 17, 36, and 38 of the ‘249 application each recite providing Kish graphite (step A); intercalating Kish graphite with a persulfate salt and an acid at room temperature to obtain intercalated Kish graphite (step C); expanding the intercalated Kish graphite at room temperature to obtain expanded Kish graphite (step D). Claim 1, step E further recites an oxidation of the expanded Kish graphite, which would be understood by one of ordinary skill in the art as requiring the addition of an oxidizing agent, and claims 36 and 38 each recite oxidation with an acid and an oxidizing agent.
The claims of the ‘249 application do not teach mixing the expanded Kish graphite with the acid and the oxidizing agent while the gases generated during the expansion step are still at least partially present or the expanded Kish graphite being simultaneously oxidized, exfoliated and reduced into reduced graphene oxide.
However, Liu also teaches intercalating graphite with a persulfate salt and an acid to obtain intercalated graphite ((NH4)2S2O8 can successfully intercalate into the interlayer of graphite along with the concentrated sulfuric acid; p. 619, col. 1, ¶ 2 and Section 2.4) and expanding the intercalated graphite to obtain expanded graphite (Section 2.3 and Fig. 1) before mixing the expanded graphite with an acid and an oxidizing agent (another 120 ml concentrated sulfuric acid was poured into the mixture. … 16 g KMnO4 was equally divided into six parts and each part was slowly added into the mixture every 10 min; Section 2.4), so that the expanded graphite is simultaneously oxidized and exfoliated (Fig. 1).
Liu further teaches that the gases generated during the expansion step were still at least partially present during the subsequent treatment with acid and oxidizing agent, as analyzed above (Claim Rejections – 35 USC § 103).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to carry out the reaction described in the ‘249 application according to the timing taught by Liu, when the gasses will still be at least present. One of ordinary skill in the art would have been motivated to do so Liu teaches specific reaction conditions that exfoliate the graphite.
Furthermore, Gebreegziabher teaches that reduced graphene oxide can be prepared directly from graphite by mixing with an acid and an oxidizing agent, simultaneously oxidizing, exfoliating, and reducing the graphite into reduced graphene oxide (the preparation of reduced graphene oxide (rGO) directly from graphite in a solution of potassium permanganate and concentrated sulfuric acid; abstract).
Therefore, it would have further been obvious to use the acid/oxidizing treatment of Gebreegziabher to simultaneously oxidize, exfoliate, and reduce the expanded graphite formed by the method of the ‘249 application directly to reduced graphene oxide, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because such a treatment affords reduced graphene oxide directly without the need of separate reducing step and its accompanying extra time and intensive purification processes (Gebreegziabher, p. 234, col. 1, ¶ 1).
Regarding instant claim 16, claim 21 of the ‘249 application teaches using ammonium persulfate to intercalate into the kish graphite, which during the expansion will necessarily generate O2.
Regarding instant claim 17, because the method of the ‘249 application do not recite a washing step between steps D and E, it would have been obvious to not add a washing step.
Regarding instant claim 19, claim 23 of the ‘249 application recites performing the reaction in an open vessel.
Regarding instant claims 20 and 21, Liu further teaches the expanded graphite is mixed with the at least an acid and an oxidizing agent 2 h after the start of the expansion step (Section 2.4), meeting the limitations of claim 20. While this time falls outside the claimed range of less than 1 hour, it is well known to persons of ordinary skill in the art that the time of process steps in chemical processes affect the completion of the chemical reaction and the yield of products. Absent new and unexpected results, “where 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II. Therefore, the claimed range of time merely represents an obvious variant and/or routine optimization of the values of the cited prior art.
Regarding instant claim 22 and 23, the modified method of the ‘249 application is substantially similar to the method instantly disclosed, therefore, it would be expected that the volume of gas remaining would also be substantially similar, thereby meeting the limitations of claim 22 and 23.
Regarding instant claims 24 and 25, Gebreegziabher teaches the graphite is first mixed with the acid and then the oxidizing agent being gradually added (Section 2.2). Further regarding claim 25, while Gebreegziabher teaches merely the “gradual addition of KMnO4” (Section 2.2), it is well known to persons of ordinary skill in the art that the time of process steps in chemical processes affect the completion of the chemical reaction and the yield of products. Absent new and unexpected results, “where 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II. Therefore, the claimed range of addition time merely represents an obvious variant and/or routine optimization of the gradual additions in the cited prior art.
Regarding instant claim 26, claim 28 of the ‘249 application shows that H2O2 can be used to stop the oxidation reaction. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the reduced graphene oxide with H2O2 to eliminate the rest of the oxidizing agent.
Regarding instant claim 28, Gebreegziabher further teaches washing the reduced graphene oxide with water (obtained samples were purified by washing with deionized water; Section 2.2).
Regarding instant claim 29, Liu further teaches the expanded graphite is mixed with the at least an acid and an oxidizing agent 2 h after the start of the expansion step (Section 2.4), and claims 26 and 27 of the ‘249 application recite the acid and oxidant of the instant claim.
Regarding instant claim 32, the claim 17 of the ‘249 application recites conducting the steps at room temperature, and so it would have been obvious to one of ordinary skill in the art to do so without control of heating or cooling.
Regarding claims 33-34 and 37, each of the further limitations of these claims are also found in the claims of the ‘249 application, as analyzed for those claims which contain the same limitations but depend upon claim 1, or are taught by Liu and there inclusion in the method of the ‘249 application would have been obvious for the same reason as recited above.
Claim 27 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 17-39 of copending Application No. 17/611,249 (claim set filed 13 October 2025) in view of Gebreegziabher et al. (Mater. Today Chem. 2019, 12, 233-239) and Liu et al. (Carbon 2019, 146, 618-626), as applied to claim 15 above, and further in view of Awad et al. (US 9,815,701 B1).
Regarding instant claim 27, the method of claim 15 is obvious over the claims of the ‘249 application, but these claims do not recite mixing the reduced graphene oxide with any of the acids recited in instant claim 27 to remove byproducts formed during the oxidation.
However, Awad teaches a preparation of reduced graphene oxide by mixing a graphitic carbon source (soot) with the same acid (H2SO4) and oxidant (KMnO4; col. 2, lines 40-46) as modified Liu and further teaches that the reduced graphene oxide so prepared can be washed with 5% HCl.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to mix the reduced graphene oxide nanoparticles produced by the modified method of the ‘249 application with HCl and to perform a washing, as taught by Awad, which will remove by-products formed during the oxidation of the expanded Kish graphite. One of ordinary skill in the art would have been motivated to do so because Awad teaches that such treatment is a washing, which would be expected to improve the purity of the reduced graphene oxide.
Response to Arguments
Applicant's arguments with respect to the claim rejections under 35 USC § 103, pages 8-15 of the reply filed 23 February 2026 have been fully considered but they are not persuasive.
Applicant argues on pages 8-10 that the cited references would not have suggested using Kish graphite. However, the fact that Liu does not use sodium nitrate while Vu does use sodium nitrate does not make the two methods irreconcilable, as claimed. The test for obviousness is not whether all the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
In the instant case, Vu teaches that Kish graphite can be converted to graphene oxide by oxidation, thereby valorizing an industrial byproduct. There is nothing in Vu or in Liu that would prevent one of ordinary skill from swapping out only the graphite source for one that would allow for the valorization of an industrial byproduct while using the general method of Liu; this is a rational underpinning that provides a prima facie case of obviousness.
Applicant further argues, pages 10-12, that the cited references would not have led one of ordinary skill in the art to intercalate and expand Kish graphite at room temperature. Applicant turns to the fact that Liu and Liu ’17 use different sources of graphite that require different oxidation conditions. However, the fact that Liu uses elevated temperatures to oxidize materials that they acknowledged are “very difficult” to oxidize, as noted in p. 11 ¶ 1-2 of the reply, only further supports that when Liu swaps out the graphite source for a Kish graphite, as taught by Vu, that they would be motivated to experiment with different temperature conditions, such as those taught by Liu ’17.
The further discrepancies between Liu ’17 and Liu, such as the additional washing steps, would not render the teachings incompatible or non-obvious.
The arguments with respect to the lack of a teaching for Kish graphite in either Liu or Liu ’17, page 12, are also not persuasive because it was previously acknowledged that neither Liu nor Liu ’17 teach this feature, and nothing about Liu or Liu ’17 is incompatible with introducing this feature that is taught by Vu.
The Examiner respectfully thanks Applicant for pointing out that reduced graphene oxide (rGO) and graphene oxides (GO) are two different products with different properties, but notes that this this distinction was not unappreciated in the prior Action.
In response to applicant's argument that any reasonable modification of Liu would not have led to the conditions used by Gebreegziabher for the production of rGO, it is noted the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
In the instant case, the rejection of claim 15 provided above does not require and does not suppose that one of ordinary skill in the art would modify the method of Liu to use the temperatures suggested by Gebreegziabher, as argued on p. 13. The only teaching required from Gebreegziabher is that reduced graphene oxide can be produced from a process step that causes simultaneous oxidation, exfoliation, and reduction. The process steps taught by the combination of Liu ,Vu, and Liu ‘17 are:
providing Kish graphite, intercalating the Kish graphite with ammonium persulfate ((NH4)2S2O8) and concentrated sulfuric acid at room temperature to obtain expanded Kish graphite, expanding the intercalated Kish graphite at room temperature to obtain expanded graphite, and, after 2 h mixing the expanded Kish graphite with sulfuric acid and an oxidizing agent (KMnO4), so that the expanded graphite is at least simultaneously oxidized and exfoliated.
These steps alone are expected to produce reduced graphene oxide, as evidenced by the instant disclosure, p. 14, and one of ordinary skill in the art would have recognized such a product as being formed, even in the absence of a reductant, in view of the teaching of Gebreegziabher that such a reaction is possible. As noted above, different starting materials often require different temperature conditions, as supported by the different temperatures used in Liu and Liu ’17, and so one ordinary skill in the art would not have been compelled to use the high temperature conditions of Gebreegziabher when modifying Liu in view of Vu and Liu ’17, even if optimizing to produce reduced graphene oxide.
Applicant’s argument that providing reduced graphene oxide directly would have frustrated the purpose of Liu et al. is also not persuasive, as Liu et al. themselves ultimately convert their graphene oxide product to reduced graphene oxide (p. 624, col. 2, and Fig. 6). Additionally, it would have been known to one of ordinary skill in the art that graphene oxide is an intermediate in the synthesis of reduced graphene oxide (graphene), which itself has many applications, as supported by Gebreegziabher (abstract).
Applicant’s arguments regarding claim 27, p. 14-15, and new claims 29-37, p. 17, are based upon there being a deficiency in the teachings of Liu, Vu, Liu ’17 and Gebreegziabher with respect to the rejection of claim 15. The arguments with respect to claim 15 were not found not persuasive, and so the rejection of claim 27 over the additional teaching of Awad is maintained, and the rejections of new claims 29-37 are presented above.
Applicant’s further arguments with respect to new claims 32 and 37, p. 17-18, have been fully considered by they are not persuasive.
Applicant argues that because Liu teaches cooling and heating for intercalating and expanding it would not have been obvious to perform the steps recited in claims 32 and 37 without regulation of the temperature through cooling or heating. However, Liu ’17 teaches that the temperature regulation used by Liu is not always required, and additionally teaches advantages of not doing so, including increased simplicity and decreased cost. Therefore, in view of Liu ’17 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 taught by the cited art with regulation of temperature by heating or cooling.
Applicant’s arguments with respect to the non-statutory double patenting rejections over US Pat No. 12,404,179 B2, p. 15, have been fully considered but are not persuasive.
As previously set forth, one of ordinary skill in the art would have been motivated to modify the method of the ‘179 claims to provided reduced graphene oxide more directly without the need of separate reducing step and its accompanying extra time and purification processes, as taught by Gebreegziabher (p. 234, col. 1, ¶ 1). The fact that the conditions used by Gebreegziabher differ from those of the claims in the ‘179 patent would not render the modification non-obvious. Optimization of temperature and reaction time are routine in the art, as it is well known to persons of ordinary skill in the art that the time of process steps in chemical processes affect the completion of the chemical reaction and the yield of products.
Applicant’s arguments with respect to the provisional non-statutory double patenting rejections over US Patent Application 17/611,249, p. 16, have been fully considered but are not persuasive.
Applicant argues that in the absence of the present claims one of ordinary skill would not have had reason to modify the claims of the ‘249 application. However, as noted previously, the advantages of producing reduced graphene oxide directly present advantages that would have been obvious to one of ordinary skill in the art in view of Gebreegziabher, namely the elimination of the need for a separate reducing step and its accompanying extra time and intensive purification process (Gebreegziabher, p. 234, col. 1, ¶ 1).
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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