DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 112
2. The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
3. Claims 1, 2, 3, 4, 5, 6, 7, and 8 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding 1, it is unclear if the parenthetical phrasing “at elevated temperature until a graphene layer is obtained” is a required limitation of the claim since drying of a suspension to form a film would not necessarily require elevated temperatures as this operation, i.e. drying, can also be achieved using reduced pressure (i.e.: in vacuo) or using a gaseous sparge/purge of nitrogen. Since Claims 2, 3, 4, 5, 6, 7, and 8 depend from Claim 1, they are also rejected under 112(b).
Regarding Claim 2, the parenthetical phrase sulfates and/or sulfates renders the claim indefinite because it is unclear if these should be interpreted as part of the scope of the claim limitation since sulfur salts compounds could also be many other compounds including sulfonates or sulfoniums.
The phrasing of the composition in Claim 4 where it is written: “0.1 M ammonium sulfate and 0.1 M ammonium persulfate, or a mixture thereof in a 99:1 to 1:99 weight ratio” is unclear, since “ammonium sulfate and ammonium persulfate” is already a mixture. Based on ¶17 in the specification cited as US Pub. No. 2024/0018666 A1, the claim limitation is being interpreted to be: 0.1 M ammonium sulfate, 0.1 M ammonium persulfate, or a mixture thereof in a 99:1 to 1:99 weight ratio.
Claim Rejections - 35 USC § 103
4. 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.
5. Claims 1, 2, 4, 6, and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Markovic et al.
Markovic et al. (“Semi-transparent, conductive thin films of electrochemical exfoliated graphene,” RSC Adv. 2016, 6, 39275-39283) is directed toward using electrochemically exfoliated graphene (pg. 39275: abstract).
Regarding Claim 1, Markovic et al. discloses a method for producing graphene flakes by electrochemical exfoliation (pg. 39275: abstract), where electrodes together with electrolyte constitute an electrochemical circuit with current flowing through it as indicated on pg. 39276 in the experimental section with a graphite rod anode (“SPG”), a Pt-wire counter electrode, and an aqueous 0.1 M ammonium persulfate electrolyte. Markovic et al. further teaches the electrodes are at least partially immersed in the electrolyte and electrolysis is carried out, during which graphite flakes detach from the electrodes to be released into the electrolyte solution (“electrode fragmentation”) on pg. 39276 in the experimental section. Markovic et al. also teaches the exfoliated graphene flakes are recovered from the electrolyte solution by filtration, then the precipitate is washed with distilled water and dried wherein the precipitate is taken up in DMF and the obtained suspension is subjected to ultrasound, then the precipitate is centrifuged resulting in filtrate comprising graphene (pg. 39276: 2. Experimental Section). Markovic et al. finally teaches the formation of graphene films via vacuum filtration which is analogous to the limitation of Claim 1 where “then graphene is recovered from the supernatant thus obtained by evaporating the suspension to dryness by drying at elevated temperature until a graphene layer is obtained (pg. 39276: 2. Experimental Section). Markovic et al. does not specify the same time or power of the ultrasonic treatment as Claim 1; however, these experimental parameters would be optimized by one of ordinary skill in the art to effectively disperse the exfoliated graphene in the DMF to form a stable dispersion. See 2144.05(II) - Optimization Within Prior Art Conditions or Through Routine Experimentation.
Regarding Claim 2, Markovic et al. discloses the method according to Claim 1, wherein the anode is mineral graphite (SPG or HOPG), the cathode is a platinum wire, and the electrolyte is a solution containing sulfur salts (i.e.: ammonium persulfate) on pg. 39275: 2. Experimental Section).
Regarding Claim 4, Markovic et al. discloses the method of Claim 1, characterized in that the solution is 0.1 M ammonium persulfate (on pg. 39275: 2. Experimental Section).
Regarding Claim 6, Markovic et al. discloses the method of Claim 1, characterized in that the anode (“SPG” or “HOPG”) is a rod containing over 30% by weight mineral graphite (on pg. 39275: 2. Experimental Section).
Regarding Claim 7, Markovic et al. discloses the method according to Claim 1, characterized in that the cathode is a metal that is insoluble in cold sulfuric acid, e.g.: platinum (on pg. 39275: 2. Experimental Section). The platinum cathode of Markovic et al. is a wire, which is analogous to the rod-shape of the cathode in Claim 7.
6. Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Markovic et al. as applied to Claim 1 above, and further in view of Hsieh et al.
Markovic et al. (“Semi-transparent, conductive thin films of electrochemical exfoliated graphene,” RSC Adv. 2016, 6, 39275-39283) is directed toward using electrochemically exfoliated graphene (pg. 39275: abstract). Hsieh et al. (“Electrochemical exfoliation of graphene sheets from a natural graphite flask in the presence of sulfate ions at different temperatures,” RSC Adv. 2016, 6, 64826-64831) is directed toward a formation of graphene sheets in the presence of sulfate at different temperatures (pg. 64826: abstract).
Regarding Claim 3, Markovic et al. discloses the method of Claim 1, but the DC voltage application is only at 12 V for a time ranging from 120 minutes to 24 hours (pg. 39275: 2. Experimental Section).
Hsieh et al. is directed toward the electrochemical exfoliation of graphite which makes it analogous art to Markovic. The electrochemical exfoliation method of Hsieh uses a dilute sulfuric acid electrolyte, a graphite rod electrode, and a platinum electrode with a two-step DC voltage application process (i.e.: 1st step of 1 V for 5 minute and 2nd step of 5 V for 10 min). The electrochemical exfoliation of Hsieh et al. occurs in multiple stages as explained on pg. 64827. The first stage is ionic adsorption and surface wetting on the NG surface during initial insertion of the graphite anode into the electrolyte (pg. 64827). At low applied voltages (i.e.: 1-2 V), ionic intercalation (e.g.: sulfate ions) occurs in which sulfate migrates in between the graphitic sheets via electrophoresis and oxidation begins (pg. 64827). As the voltage is increased (i.e.: greater than 5 V), sulfate ions are electrochemically broken down into gases (SO2 or SO3) that drive the exfoliation of the graphite sheets into graphene nanosheets (pg. 64827).
It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the exfoliation method of Markovic et al. with a low voltage step (i.e.: 1-2 V) as taught by Hsieh et al. before the higher voltage application (i.e.: 12 V) to ensure more efficient graphene production. The more efficient graphene production would result from the effective intercalation of sulfate ions into the graphite sheets prior to the formation of graphene nanosheets at higher voltages.
7. Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Markovic et al. as applied to Claim 1 above, and further in view of Kang et al. with evidentiary support from APS-SDS.
Markovic et al. (“Semi-transparent, conductive thin films of electrochemical exfoliated graphene,” RSC Adv. 2016, 6, 39275-39283) is directed toward using electrochemically exfoliated graphene (pg. 39275: abstract). Kang et al. (KR20160072535A) is directed toward a method of manufacturing graphene nanosheets (title). APS SDS ("Ammonium Persulfate Safety Data Sheet," published 2010 by Santa Cruz Biotechnology, Inc.) is an SDS for ammonium persulfate which discloses the pH range over different concentrations.
Markovic et al. only discloses the method of electrochemical exfoliation of Claim 1, but only provides a narrow set of operational variables (e.g.: electrolyte concentration/pH and electrolyte bath temperature). Kang et al. discloses an analogous method of the electrochemical exfoliation of graphite as Markovic et al. One of ordinary skill in the art would reasonably expect to be able to apply the operational variables of Kang et al. to the method of Markovic as they would be obvious to try given the similarity of the methods.
Pertaining to Claim 5, Kang et al. discloses the steps of electrochemical exfoliation of graphene in ¶15 to ¶19 while providing a larger range for operation parameters. Kang et al. includes ammonium persulfate (“APS”), potassium persulfate, and sodium persulfate as acceptable persulfate sources, which are used in concentrations ranging from 0.01 mol/L to 10 mol/L based on the total concentration of the electrolyte (¶17 in Kang et al.). Different concentrations of ammonium persulfate will yield different pH electrolytes. Kang et al. does not provide the range of pH covered by the APS concentration in the electrolyte, but APS-SDS provides evidence of inherency of the pH of APS solutions at different concentrations as ranging from 2.3-4.0 (in a 1% or 0.05 mol/L solution for example). It has been held that a prima facie case of obviousness exists when the prior art discloses a range (for pH) that overlaps with the claimed range. See MPEP 2144.05(I) – Overlapping, Approaching, and Similar Ranges, Amounts, and Proportions.
8. Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Markovic et al. as applied to Claim 1 above, and further in view of Kang et al.
Markovic et al. (“Semi-transparent, conductive thin films of electrochemical exfoliated graphene,” RSC Adv. 2016, 6, 39275-39283) is directed toward using electrochemically exfoliated graphene (pg. 39275: abstract). Kang et al. (KR20160072535A) is directed toward a method of manufacturing graphene nanosheets (title).
Markovic et al. only discloses the method of electrochemical exfoliation of Claim 1, but only provides a narrow set of operational variables (e.g.: electrolyte concentration/pH and electrolyte bath temperature). Kang et al. discloses an analogous method of the electrochemical exfoliation of graphite as Markovic et al. One of ordinary skill in the art would reasonably expect to be able to apply the operational variables of Kang et al. to the method of Markovic as they would be obvious to try given the similarity of the methods.
Pertaining to Claim 8, Kang et al. discloses the steps of electrochemical exfoliation of graphene in ¶15 to ¶19 while providing a larger range for operation parameters. In ¶19, Kang et al. teaches the (ammonium) persulfate electrolyte solution temperature ranges 2 °C to 80°C during the electrolysis of graphite It has been held that a prima facie case of obviousness exists when the prior art discloses a range (for pH) that overlaps with the claimed range. See MPEP 2144.05(I) – Overlapping, Approaching, and Similar Ranges, Amounts, and Proportions.
Conclusion
9. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Zhamu et al. (US Pub. No. 2017/0158513 A1) is directed toward a chemical-free production of graphene materials (title). Loh et al. (US Pub. No. 2013/0102084 A1) is directed toward methods of forming graphene by graphite exfoliation (title). Dryfe et al. (US Pub. No. 2015/0027900 A1) is directed at graphene production (title).
10. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KEVIN SYLVESTER whose telephone number is (703)756-5536. The examiner can normally be reached Mon - Fri 8:15 AM to 4:30 PM EST.
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/KEVIN SYLVESTER/Examiner, Art Unit 1794
/JAMES LIN/Supervisory Patent Examiner, Art Unit 1794