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 .
Election/Restrictions
Applicant’s election without traverse of Claims 1-13 in the reply filed on 05/05/2026 is acknowledged.
Claims 14-2 withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected system for redox polymer electrodialysis, there being no allowable generic or linking claim.
Claim Rejections - 35 USC § 112
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.
Claim 9 is 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.
Claim 9 uses the term “molecular weight” but it is unclear whether the term is referring to number average molecular weight or weight average molecular weight. For the sake of further examination, “molecular weight” is interpreted to refer to “weight average molecular weight.”
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.
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 1-11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over US 20220223885 A1 (henceforth referred to as "Beh") in view of P. S. Borchers, M. Strumpf, C. Friebe, I. Nischang, M. D. Hager, J. Elbert, U. S. Schubert, Aqueous Redox Flow Battery Suitable for High Temperature Applications Based on a Tailor-Made Ferrocene Copolymer. Adv. Energy Mater.2020, 10, 2001825. https://doi.org/10.1002/aenm.202001825 (henceforth referred to as "Borchers").
Below is an annotated and de-numbered version of Beh’s figure 1A
PNG
media_image1.png
415
557
media_image1.png
Greyscale
Below is an annotated and de-numbered version of the present application’s figure 1.
PNG
media_image2.png
625
630
media_image2.png
Greyscale
In regard to claims 1 and 5, Beh teaches in their figure 1A a system (electrochemical cell) comprising:
a first electrode (anode)
a second electrode (cathode) positioned in opposition to the first electrode
a pair of anion exchange membranes (AEM), taught in [0043] that in some cell designs are microporous membranes which by definition would function as size-exclusion membranes, positioned between the first and second electrodes
an ion exchange membrane (cation exchange membrane, CEM) positioned between the pair of anion exchange membranes, wherein the ion exchange membrane defines a feed channel (desalinate chamber) and an accumulating channel (salinate chamber) between the AEMs.
a redox channel containing the first and second electrodes, separated from the feed and accumulating channel by the AEM’s
a redox solution that is flowed through the redox channel comprising a redox copolymer as taught in [0076]
the feed channel is fed with water that contains salt
voltage is applied across the electrodes, putting a positive charge on the anode and a negative charge on the cathode which results in oxidation of the redox copolymer at the anode and reduction of the redox shuttle (small molecule not a polymer) at the cathode as described in [0123].
The ionic species are drawn through the CEM and AEM adjacent to the feed (desalinate) stream and the water remains in the feed stream.
Beh fails to teach a redox copolymer in the redox solution.
Borchers teaches an aqueous redox flow battery which by definition involves electrochemically adjusting the concentrations of ions in solution and in scheme 3 the free radical copolymerization of ferrocenylpropyl methacrylamide (FPMAm), a redox active monomer, and [2-(methacryloyloxy)-ethyl]-trimethylammonium chloride (METAC), a water soluble monomer. Borchers teaches in page 2, column 1 paragraph 2 that polymers can be retained by size exclusion membranes instead of ion-selective membranes to lower the cost of the system.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the present invention to use the copolymer of Borchers in the system of Beh to allow for a more affordable membrane to be used as the AEM.
In regard to claim 2, by meeting claim 1 with the teaching of salt, claim 2, which further limits the charged organic matter of claim 1, is also considered to be met.
In regard to claim 3, Beh teaches the system and method as described as above, but fails to teach a redox temperature maintained between 25 and 100 degrees C.
Borchers teaches in table 1 that their system was tested at 80 degrees C successfully and in page 7 column 2 under the “Conclusion” section, Borchers explains that their copolymer was stable for use at 60 degrees C and the elevated temperature aids the electrochemical processes and removes a need for cooling solutions.
It would have been obvious to a person having ordinary skill in the art to use the copolymer of Borchers and to operate the cell at 60 degrees to avoid the need for a cooling solution.
In regard to claim 4, Beh teaches in [0123] that the cell has a voltage of 0.5 V applied across it during operation which is within the claimed range.
In regard to claim 6, Borchers teaches in table 1 different monomer ratios intended for their copolymer formation including P3 (1:1) and P4 (2:5) which falls within the claimed range.
In regard to claim 7, Borchers teaches in the supplemental section 1.3.5 “Synthesis of FPMAM-co-METAC (Pn)” that their example copolymer synthesis comprises a redox active monomer concentration of 0.86 mmol in 3 mL of methanol which is 0.29 M, which is within the claimed range for monomer concentration.
In regard to claim 8, Borchers teaches in scheme 3 the synthesis of a redox copolymer comprising ferrocenyl-propyl-methacrylamide and [2-(methacryloxy) ethyl] trimethyl-ammonium chloride.
In regard to claim 9, Borchers teaches in supplemental figure S28 that the weight average molar mass of their copolymer is 52000 g/mol which falls in the claimed range.
In regard to claim 10, as shown in the rejection for claim 1, Beh’s system circulates the redox shuttle and it would have been obvious to use the redox copolymer of Borchers so the redox copolymer would be circulated through the redox channel while the voltage is applied. Oxidation will occur at the anode (first electrode) and reduction will occur at the cathode (second electrode).
In regard to claim 11, as shown in the rejection to claim 1, Beh teaches in figure 1 an electrochemical cell with a circulation of redox shuttle with AEMs that can function as size-exclusion membranes where the redox shuttle does not pass through the AEMs and the ionic species, depicted as Na+ and Cl-, do pass through.
In regard to claim 13, Beh teaches in figure 1 an electrochemical cell in which a cationic species (Na+) is drawn through the cation exchange membrane (CEM) and an anionic species (Cl-) is drawn through the size-exclusion membrane (AEM) which is adjacent to the feed channel (arrow titled “redox shuttle movement”) where the anionic species moves through the redox channel before entering the accumulating channel (salinate chamber).
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Beh in view of Borchers as applied to claim 1 above, and further in view of Christopher Bellona, Jörg E. Drewes, The role of membrane surface charge and solute physico-chemical properties in the rejection of organic acids by NF membranes, Journal of Membrane Science, Volume 249, Issues 1–2, 2005, Pages 227-234, ISSN 0376-7388, https://doi.org/10.1016/j.memsci.2004.09.041. (henceforth referred to as “Bellona”).
In regard to claim 2, Beh in view of Borchers teaches the electrochemical cell as described in the rejection of claim 1 above. While the combination teaches the purification of water containing ionic species such as NaCl as shown in figure 1A, the combination fails to explicitly teach the purification of water containing a carboxylate, an organic acid, a fatty acid, a perfluoroalkyl substance, a polyfluoroalkyl substance, and/or a surfactant.
Bellona teaches a study on nanofiltration (size-exclusion) membranes being used for separating organic acids. Specifically, Bellona teaches on page 233 under the "conclusions" section that nanofiltration membranes have larger rejection of negatively charged organic acids. It would have been obvious to use the electrodialysis system of Beh to purify water containing organic acids as the system of Beh comprises polyamide membranes (as taught in Beh’s claim 13) and Bellona teaches that polyamide membranes function well to separate organic acids.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Beh in view of Borchers as applied to claim 1 above, and further in view of Jaydevsinh M. Gohil, Paramita Ray, A review on semi-aromatic polyamide TFC membranes prepared by interfacial polymerization: Potential for water treatment and desalination, Separation and Purification Technology, Volume 181, 2017, Pages 159-182, ISSN 1383-5866, https://doi.org/10.1016/j.seppur.2017.03.020. (henceforth referred to as “Gohil”)
In regard to claim 12, Beh in view of Borchers teaches the electrochemical cell as described in the rejection of claim 1 above. While Beh teaches in [0043] that in some cell designs the anion exchange membranes used are microporous membranes and in claim 13 they teach that the size-exclusion membrane material comprises polyamide, they fail to teach a nominal pore size of 0.1 to 10 nm.
Gohil teaches in table 6 a number of commercially available polyamide membranes used for nanofiltration, essentially a list of membranes usable for the size-exclusion. Several of the listed size-exclusion membranes feature molecular weight cut offs (MWCO’s) between 200 and 600, which falls within the claimed 0.1 nm and 10 nm pore size. Gohil further teaches on page 165 under section 4.1 “Polyamide” that polyamide membranes can have different performance depending on the surface morphology and charge based on the amines and acyl chlorides used to form the membranes. It would have been obvious to use one of the many commercially available polyamide size-exclusion membranes as the size-exclusion membrane in the electrochemical cell of Beh due to Beh’s claimed use of polyamide membranes.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. The web article visited on 06/24/2026 at https://www.lenntech.com/services/mwco.htm conveniently translates the MWCO values into pore size.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ASHLEY SABATOSE whose telephone number is (571)272-9893. The examiner can normally be reached 8:00-6:00 M-Th.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Nikki Dees can be reached at 571-270-3435. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/A.C.S./Examiner, Art Unit 1791
/Nikki H. Dees/Supervisory Patent Examiner, Art Unit 1791
Prosecution Insights