Prosecution Insights
Last updated: April 19, 2026
Application No. 18/194,121

HIGH-PERFORMANCE HYDROXIDE EXCHANGE MEMBRANE

Non-Final OA §102
Filed
Mar 31, 2023
Examiner
TESKIN, FRED M
Art Unit
1762
Tech Center
1700 — Chemical & Materials Engineering
Assignee
UNIVERSITY OF MARYLAND, BALTIMORE
OA Round
1 (Non-Final)
90%
Grant Probability
Favorable
1-2
OA Rounds
2y 3m
To Grant
97%
With Interview

Examiner Intelligence

Grants 90% — above average
90%
Career Allow Rate
1176 granted / 1313 resolved
+24.6% vs TC avg
Moderate +8% lift
Without
With
+7.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 3m
Avg Prosecution
34 currently pending
Career history
1347
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
38.7%
-1.3% vs TC avg
§102
17.0%
-23.0% vs TC avg
§112
27.6%
-12.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1313 resolved cases

Office Action

§102
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/Restriction Applicant’s election of the invention of Group I, claims 1-2, 4-5, 7-8, 10, 12, 14-20, and 22, in the reply filed on 02/11/2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)). Claims 24, 46-47, and 54 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to nonelected inventions, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 02/11/2026. Information Disclosure Statement(s) The information disclosure statement(s) (IDS) filed on 04/08/2024 is in compliance with the provisions of 37 CFR 1.97, 1.98 and MPEP § 609, and therefore the information referred to therein has been considered as to the merits. Initialed copies of the IDS are included with the mailing/transmittal of this Office action. Priority Claim The later-filed application must be an application for a patent for an invention which is also disclosed in the prior application (the parent or original nonprovisional application or provisional application). The disclosure of the invention in the parent application and in the later-filed application must be sufficient to comply with the requirements of 35 U.S.C. 112(a) or the first paragraph of pre-AIA 35 U.S.C. 112, except for the best mode requirement. See Transco Products, Inc. v. Performance Contracting, Inc., 38 F.3d 551, 32 USPQ2d 1077 (Fed. Cir. 1994). The disclosure of the prior-filed application, provisional Application No. 63/362,358, fails to provide adequate support or enablement in the manner provided by 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph for one or more claims of this application. In particular, the provisional application only describes chitosan-Cu hydroxide exchange membranes comprising Cu2+ crosslinked chitosan chains (see, e.g., page 4 and page 18, final para.). By contrast, pending claims 1-2, 4-5, 7-8, 12, 14-20 and 22 are all generic to an ion exchange membrane comprising a plurality of chitosan molecular chains crosslinked with a crosslinking agent selected from “multivalent cations and mixtures thereof” (cf., claim 1, lines 1-4). The description in the prior-filed application of a single species of divalent cation (Cu2+) as crosslinking agent for the chitosan chains of a hydroxide exchange membrane is deemed non-representative of the full scope of, and variation of members within, the genus of crosslinking agents embraced the above-listed claims, and therefore fails to provide adequate support for those claims in the manner provided by 35 U.S.C. 112(a). See MPEP §§ 2163(3)(a)(ii) and 2163.03(III). In consequence, claims 1-2, 4-5, 7-8, 12, 14-20 and 22 are accorded an effective filing date of 03/31/2023, the filing date of the present application; whereas pending claim 10, which is specific to “ions of copper” as the crosslinking agent, is accorded the provisional application’s filing date of 04/01/2022. Objection – Claims Claim 20 is objected to because of the following informalities: in line 2, it is presumed “in” was intended to read –is-- (i.e., the membrane [[in]] is an anion exchange membrane); however, clarification and appropriate correction are required. Claim Rejections – 35 U.S.C. 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claims 1-2, 4-5, 7-8, 12, 14-20, and 22 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wu et al (Nature Nanotechnology 17, 629-636, published 04/18/2022, with Supplementary Information) (hereinafter, ‘Wu”). Regarding Claim 1, reference to Wu specifically discloses an ion-exchange membrane (p. 2, lines 29-30) comprising: a plurality of chitosan molecular chains crosslinked with a crosslinking agent selected from the group consisting of multivalent cations and mixtures thereof (p. 2, lines 34-35; Cu+2 -crosslinked chitosan); wherein the ion exchange membrane has a structure including a crystalline crosslinking zone (p. 12, lines 208-209; p. 13, Fig. 3). Regarding Claim 2, Wu further discloses wherein: the membrane has a hydroxide conductivity of greater than 10 mS cm-1 at room temperature (p. 15, lines 246-247; 67 mS cm-1 at 100% relative humidity and room temperature). Regarding Claims 4-5, Wu further discloses wherein: the membrane includes polygonal nanochannels (specifically, hexagonal nanochannels of ~1.0 nm in diameter [for claim 5]; p. 11, lines 192-194). Regarding Claim 7, Wu further discloses wherein: the chitosan molecular chains have a threefold helical conformation (p. 11, lines 194-195; crosslinking of six chitosan helixes by three Cu2+ ions). Regarding Claim 8, Wu further discloses wherein: the multivalent cations are coordinated with amino groups and hydroxyl groups of the chitosan molecular chains (p. 4, lines 89-91). Regarding Claim 12, Wu further discloses wherein: the membrane has a trigonal crystal structure (p. 13, Table 1: Chitosan-Cu, Trigonal Crystal system). Regarding Claim 14, Wu further discloses wherein: the membrane has a σIEC of greater than 30 mS g cm-1 mmol-1 (p. 15, lines 256-257; 41.9 mS g cm-1 mmol-1). Regarding Claim 15, Wu further discloses wherein: the membrane has a thickness in a range of 1 to 100 micrometers (p. 7, lines 130-132; chitosan-Cu membrane uniformly thin (5 µm)). Regarding Claim 16, Wu further discloses wherein: the membrane includes 1 wt.% to 10 wt.% of the crosslinking agent based total weight percent of the membrane (Supplementary Table 1: Chitosan-Cu membrane Cu concentration (wt.%): 5.6). Regarding Claim 17, Wu further discloses wherein: the membrane has a water self-diffusion coefficient (Dwater) greater than 10 x 10-10 m2 s-1 at 90% relative humidity (Supplementary Table 3: Dwater of chitosan-Cu membrane: 19 (10-10 m2 s-1) at 90 RH%). Regarding Claim 18, Wu further discloses wherein: the membrane has a methanol permeability of less than 1.5 x 10-6 cm2 s-1 (p. 19, lines 327-328; chitosan-Cu membrane methanol crossover is only 1.02 x 10-6 cm2 s-1). Regarding Claim 19, Wu further discloses wherein: the membrane maintains a tensile strength of at least 100 MPa when soaked with water (p. 19, lines 344-345; chitosan-Cu membrane soaked with water maintains a tensile strength of 112 (MPa)). Regarding Claim 20, Wu further discloses wherein: the membrane in an anion exchange membrane (p. 4, lines 93-94; chelated Cu2+ ions in chitosan-Cu promote the transport of anions). Regarding Claim 22, Wu further discloses wherein: the membrane has a water uptake of less than 60% (Supplementary Fig. 14; chitosan-Cu membrane shows moderate water uptake of 56%). Allowable Subject Matter Claim 10 is objected to as being dependent on a rejected base claim, but would be allowable if rewritten in independent form including all the limitations of the base claim and any intervening claim. The following is a statement of reasons for the indication of allowable subject matter: Closest prior art to Wan et al (see attached PTO-892, cites W and X) disclose membranes composed of crosslinked chitosan or crosslinked quaternized-chitosan derivatives, with ethylene glycol diglycidyl ether or epichlorohydrin/glutaraldeyde being used as crosslinking agent(s). Neither citation teaches the present invention, especially an ion exchange membrane comprising: a plurality of chitosan molecular chains crosslinked with a crosslinking agent selected from the group consisting of multivalent cations and mixtures thereof. Correspondence Any inquiry concerning this communication or earlier communications from the examiner should be directed to Examiner F. M. Teskin whose telephone number is (571) 272-1116. The examiner can normally be reached on Monday through Friday from 9:00 AM - 5:30 PM. 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, Robert Jones, can be reached at (571) 270-7733. The appropriate fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center for authorized users only. Should you have questions about access to Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. 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) Form at https://www.uspto.gov/patents/uspto-automated- interview-request-air-form. /FRED M TESKIN/Primary Examiner, Art Unit 1762 /FMTeskin/03-19-26
Read full office action

Prosecution Timeline

Mar 31, 2023
Application Filed
Mar 19, 2026
Non-Final Rejection — §102 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
90%
Grant Probability
97%
With Interview (+7.8%)
2y 3m
Median Time to Grant
Low
PTA Risk
Based on 1313 resolved cases by this examiner. Grant probability derived from career allow rate.

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