Prosecution Insights
Last updated: April 19, 2026
Application No. 17/579,633

Purification and Enrichment of Boron Nitride Nanotube Feedstocks

Non-Final OA §102§112
Filed
Jan 20, 2022
Examiner
MCCULLOUGH, ERIC J.
Art Unit
1773
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Government Of The United States AS Represented By The Secretary Of The Air Force
OA Round
1 (Non-Final)
30%
Grant Probability
At Risk
1-2
OA Rounds
4y 2m
To Grant
74%
With Interview

Examiner Intelligence

Grants only 30% of cases
30%
Career Allow Rate
120 granted / 393 resolved
-34.5% vs TC avg
Strong +43% interview lift
Without
With
+43.4%
Interview Lift
resolved cases with interview
Typical timeline
4y 2m
Avg Prosecution
45 currently pending
Career history
438
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
55.3%
+15.3% vs TC avg
§102
13.9%
-26.1% vs TC avg
§112
23.1%
-16.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 393 resolved cases

Office Action

§102 §112
DETAILED ACTION This action is in response to an application filed with the US on 01/20/2022 and having an Effective Filing Date of 01/11/2019, in which claims 1-8 are pending and ready for examination. 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 . Information Disclosure Statement The information disclosure statement(s) (IDS) submitted on 20 JANUARY 2022 is/are in compliance with the provisions of 37 CFR 1.97 and has/have been considered. An initialed copy of Form 1449 is enclosed herewith. 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 3 is rejected under 35 U.S.C. 112(b) 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 3 recites the limitation “the retentate”. There is insufficient antecedent basis for this limitation in the claim. Claim Rejections - 35 USC § 102 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 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. 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. (a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention. Claims 1-4 and 6 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by H.M. Kyllönen, et al., Membrane filtration enhanced by ultrasound: a review, Desalination, Volume 181, Issues 1–3, 2005, Pages 319-335 (hereinafter “Kyllönen”). Regarding Claim 1 Kyllönen discloses a system for purifying a fluid comprising: a treatment vessel having an interior volume for receiving a feed liquid mixture, a membrane with pore sizes of 0.25, 1, and 3 µm (i.e. nanoporous according to claim 6) in flow communication with the treatment vessel interior volume; and an ultrasound horn (i.e. ultrasonic mixing probe) disposed within the treatment vessel interior volume, wherein the system is capable of sonicating the liquid mixture within the treatment vessel interior volume while, while at the same time, at least a portion of the liquid mixture is filtered across the nanoporous membrane and out of the treatment vessel to provide a filtrate; Fig. 3 PNG media_image1.png 419 567 media_image1.png Greyscale With regard to the system being “for purifying a boron nitride nanotube feedstock”, the treatment vessel being “for receiving an initial mixture of a boron nitride nanotube (BNNT) feedstock with a solvent, the BNNT feedstock comprising hexagonal boron nitride (h-BN) particles and less than about 50 weight percent BNNTs on a dry basis” and “wherein the initial mixture of the boron nitride nanotube (BNNT) feedstock with the solvent is sonicated within the treatment vessel interior volume while, at the same time, at least a portion of the mixture is filtered across the nanoporous membrane and out of the treatment vessel to provide a filtrate”; these are functional limitations which attempt to define this apparatus claim’s structure in terms of its functional abilities. Claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function (see MPEP 2114), and thus the prior art need only disclose structure capable of achieving the recited function(s) to read on the functional limitations. It is specifically noted that the claim thus does not positively claim “an initial mixture”, “a filtrate” or the process of sonicating or filtering said initial mixture. These functional limitations do not further define over the prior art because the structure disclosed by Kyllönen would be capable of the noted functional limitation(s), i.e. even though the specific functions are not disclosed. Further, the claimed “an initial mixture” and “a filtrate” are material worked upon, “inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims”; MPEP 2115. Regarding Claim 2 Kyllönen discloses the system of Claim 1, and with regard to the limitation “wherein the initial mixture further comprises a non-metal containing surfactant”, as the initial mixture is not positively claimed, as discussed above, this is merely a functional limitation which does not further define over the prior art because the structure disclosed by Kyllönen would be capable of the noted functional limitation. Regarding Claim 3 Kyllönen discloses the system of Claim 1, and with regard to the limitation “wherein the retentate comprises at least 90 weight percent BNNTs on a dry basis”, as the initial mixture is not positively claimed, as discussed above, this is merely a functional limitation which does not further define over the prior art because the structure disclosed by Kyllönen would be capable of the noted functional limitation. Regarding Claim 4 Kyllönen discloses the system of Claim 1, and with regard to the limitation “wherein the solvent comprises at least one polar aprotic solvent”, as the initial mixture is not positively claimed, as discussed above, this is merely a functional limitation which does not further define over the prior art because the structure disclosed by Kyllönen would be capable of the noted functional limitation. Regarding Claim 6 Kyllönen discloses the system of Claim 1, wherein the nanoporous membrane comprises a plurality of pores, the pores having an average pore size of 0.25, 1, and 3 µm. Claims 1-8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2012/0118824 A1 (hereinafter “Kashihara”). Regarding Claim 1 Kashihara discloses a system for purifying a fluid comprising: a treatment vessel having an interior volume (raw water side 3) for receiving a feed liquid mixture, a membrane having an average pore diameter of 1 μm or more (i.e. nanoporous according to claim 6) in flow communication with the treatment vessel interior volume; and an ultrasonic vibrators 21 and 22 (i.e. ultrasonic mixing probes) disposed within the treatment vessel interior volume, wherein the system is capable of sonicating the liquid mixture within the treatment vessel interior volume while, while at the same time, at least a portion of the liquid mixture is filtered across the nanoporous membrane and out of the treatment vessel to provide a filtrate; Abstract, Fig. 2, [0077]-[0081]. PNG media_image2.png 477 802 media_image2.png Greyscale With regard to the system being “for purifying a boron nitride nanotube feedstock”, the treatment vessel being “for receiving an initial mixture of a boron nitride nanotube (BNNT) feedstock with a solvent, the BNNT feedstock comprising hexagonal boron nitride (h-BN) particles and less than about 50 weight percent BNNTs on a dry basis” and “wherein the initial mixture of the boron nitride nanotube (BNNT) feedstock with the solvent is sonicated within the treatment vessel interior volume while, at the same time, at least a portion of the mixture is filtered across the nanoporous membrane and out of the treatment vessel to provide a filtrate”; these are functional limitations which attempt to define this apparatus claim’s structure in terms of its functional abilities. Claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function (see MPEP 2114), and thus the prior art need only disclose structure capable of achieving the recited function(s) to read on the functional limitations. It is specifically noted that the claim thus does not positively claim “an initial mixture”, “a filtrate” or the process of sonicating or filtering said initial mixture. These functional limitations do not further define over the prior art because the structure disclosed by Kashihara would be capable of the noted functional limitation(s), i.e. even though the specific functions are not disclosed. Further, the claimed “an initial mixture” and “a filtrate” are material worked upon, “inclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims”; MPEP 2115. Regarding Claim 2 Kashihara discloses the system of Claim 1, and with regard to the limitation “wherein the initial mixture further comprises a non-metal containing surfactant”, as the initial mixture is not positively claimed, as discussed above, this is merely a functional limitation which does not further define over the prior art because the structure disclosed by Kashihara would be capable of the noted functional limitation. Regarding Claim 3 Kashihara discloses the system of Claim 1, and with regard to the limitation “wherein the retentate comprises at least 90 weight percent BNNTs on a dry basis”, as the initial mixture is not positively claimed, as discussed above, this is merely a functional limitation which does not further define over the prior art because the structure disclosed by Kashihara would be capable of the noted functional limitation. Regarding Claim 4 Kashihara discloses the system of Claim 1, and with regard to the limitation “wherein the solvent comprises at least one polar aprotic solvent”, as the initial mixture is not positively claimed, as discussed above, this is merely a functional limitation which does not further define over the prior art because the structure disclosed by Kashihara would be capable of the noted functional limitation. Regarding Claim 5 Kashihara discloses the system of Claim 1, wherein the nanoporous membrane may comprise polytetrafluoroethylene [0028]. Regarding Claim 6 Kashihara discloses the system of Claim 1, wherein the nanoporous membrane comprises a plurality of pores, the pores having an average pore size/diameter of 1 µm or more [0013], including PTFE with a pore diameter of 2-5 µm [0036]. Regarding Claim 7 Kashihara discloses the system of Claim 1, further comprising a receiving vessel (the second membrane filtration means, Fig. 1, [0079]) for collecting filtrate from the nanoporous membrane, and with regard to the limitation “wherein the receiving vessel is maintained at a sub-atmospheric pressure in order to draw filtrate across the membrane”, this is directed to how the apparatus is used and is therefore a functional limitation, as discussed above, which does not further define over the prior art because the structure disclosed by Kashihara would be capable of the noted functional limitation. Regarding Claim 8 Kashihara discloses the system of Claim 1, further comprising a solvent supply line (i.e. 11), which supplies that raw water feed and is there for suitable for adding makeup solvent to the mixture in the treatment vessel. And while no specific supply reservoir is discussed, the raw water feed must necessarily and inherently be supplied from somewhere, that inherent supply may thus be considered a solvent supply reservoir. See MPEP 2112 with regard to inherency. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Eric J. McCullough whose telephone number is (571)272-8885. The examiner can normally be reached Monday-Friday 10:00-6:00. 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, Magali Slawski can be reached at 571-270-3960. 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. /ERIC J MCCULLOUGH/ Examiner, Art Unit 1773 /Magali P Slawski/ Supervisory Patent Examiner, Art Unit 1773
Read full office action

Prosecution Timeline

Jan 20, 2022
Application Filed
Aug 07, 2025
Non-Final Rejection — §102, §112
Jan 08, 2026
Response after Non-Final Action
Jan 08, 2026
Response Filed

Precedent Cases

Applications granted by this same examiner with similar technology

Patent 12595396
ACID RESISTANT FILTER MEDIA
2y 5m to grant Granted Apr 07, 2026
Patent 12533640
POLYTETRAFLUOROETHYLENE COMPOSITE FILTER MATERIAL AND PREPARATION METHOD AND USES THEREOF
2y 5m to grant Granted Jan 27, 2026
Patent 12528050
BIOCIDE COMPOSITION AND METHOD
2y 5m to grant Granted Jan 20, 2026
Patent 12528723
PLASMA ACTIVATED WATER PRODUCTION WITH MEMBRANE CONCENTRATION
2y 5m to grant Granted Jan 20, 2026
Patent 12497737
Filter Media
2y 5m to grant Granted Dec 16, 2025
Study what changed to get past this examiner. Based on 5 most recent grants.

AI Strategy Recommendation

Get an AI-powered prosecution strategy using examiner precedents, rejection analysis, and claim mapping.
Powered by AI — typically takes 5-10 seconds

Prosecution Projections

1-2
Expected OA Rounds
30%
Grant Probability
74%
With Interview (+43.4%)
4y 2m
Median Time to Grant
Low
PTA Risk
Based on 393 resolved cases by this examiner. Grant probability derived from career allow rate.

Sign in with your work email

Enter your email to receive a magic link. No password needed.

Personal email addresses (Gmail, Yahoo, etc.) are not accepted.

Free tier: 3 strategy analyses per month