DETAILED ACTION
This action is in response to the RCE with amendments and remarks filed 07/16/2026, in which claim 1 has been amended, claims 1-10, 12-14, 16-18, 20 and 23 are pending, claims 7-10 and 20 are withdrawn as directed to a Non-Elected Intention and claims 1-6, 12-14, 16-18 and 23 are ready for examination.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicants’ submission filed on 07/16/2026 has been entered.
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 18 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 18 recites the limitation “a thin film composite membrane … comprising the nanofilm of claim 1”. However, claim 1 is specifically limited to a freestanding membrane, and thus it is not clear how a freestanding membrane can be also a composite membrane. Correction is required.
Claim Rejections - 35 USC § 103
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 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 1-6, 12-14, 16, 18 and 21-23 are rejected under 35 U.S.C. 103 as being obvious over CN 107899429 A (hereinafter “Xu”) as evidenced by US 20150122800 A1 (hereinafter “Gallastegui”) and in view of Hao-Cheng Yang, Wei Xu, Yong Du, Jian Wu, Zhi-Kang Xu; Composite free-standing films of polydopamine/polyethyleneimine grown at the air/water interface. RSC Adv. 2014; 4 (85): 45415–45418. (hereinafter “Yang”).
Regarding Claim 1 Xu discloses a hollow fiber thin-layer composite nanofiltration membrane, (i.e. a nanofilm) comprising: a reaction product of polyphenol monomers and polyamine monomers, where the polyphenol monomer may be tannic acid and the polyamine monomers may be polyethyleneimine, polyallylamine, chitosan, diethylenetriamine, triethylenetetramine, triethylamine, piperazine, m-phenylenediamine, p-phenylenediamine (i.e. a natural building block type A including at least two functional groups and a natural building block type B including at least three functional groups, wherein at least one of the functional groups of the natural building block type A is an amine group and at least one of the functional groups of the natural building block type B is a catechol group); and which are reacted via a crosslinker which may be 1-ethyl-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (i.e. EDC); see Abstract, Pgs. 2-3 of the translation, and last paragraph and Claims 1-2;
wherein the natural building block type A and the natural building block type B react (Abstract, claims) to form a branched polymer network including solvent-resistant bonds (i.e. inherently due to EDC crosslinking), see MPE 2112.
Wherein EDC is known to be a coupling agent which facilitates the bonding link between two reagents, i.e. it allows the two reagents to react with each other, where specially it is noted that EDC is not included in the final material and only functions to form a coupling of the functionalities present in the reagents, where a coupler is differentiated from a linker that is included in the final material; as evidenced by Gallastegui [0038]-[0039]. Thus the polyphenol monomer and the polyamine monomer are seen to react directly. And as noted in the rejection this will inherently form “a branched polymer network including solvent-resistant bonds”, i.e. because the monomers include monomers which have more than two reactive functional groups which react and will thus be branched, and because they form covalent bonds which are seen to be broadly solvent resistant.
Xu does not disclose wherein the nanofilm is freestanding.
However Yang discloses a similar nanofilm formed from the reaction product of similar natural building blocks polyethyleneimine (polyamine) and polydopamine (polyphenol), wherein the film is formed free-standing, i.e. without a support layer, and may be used for nanofiltration; Abstract, Fig. 1, pgs. 45415-45417.
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the nanofilm of Xu by forming it as a freestanding film as disclosed by Yang because such freestanding/unsupported films are desirable for fields including nanofiltration.
Similarly, starting from Yang, it would have been prima facie obvious to one of ordinary skill in the art to modify the nanofilm of Yang by using the crosslinked polyamines and polyphenols as disclosed by Xu to form a freestanding membrane, because this involves the simple substitution of known polyamine and polyphenol reactants used to form a nanofilm for nanofiltration to obtain the predictable result of forming a successful nanofiltration nanofilm .
Regarding Claim 2 Xu in view of Yang discloses the nanofilm according to claim 1, wherein each of the at least two functional groups of the natural building block type A is an amine group; this is inherent to the polyamines polyethyleneimine, polyallylamine, chitosan, diethylenetriamine, triethylenetetramine, triethylamine, piperazine, m-phenylenediamine, p-phenylenediamine, Xu Claim 2.
Regarding Claim 3 Xu in view of Yang discloses the nanofilm of claim 1, wherein the at least three functional groups of the natural building block type B include a catechol group and a pyrogallol group; this is inherent to the polyphenol tannic acid; Xu claim 2.
Regarding Claim 4 Xu in view of Yang discloses the nanofilm of claim 1, wherein the at least two functional groups of the natural building block type A (polyamines) are different from the at least three functional groups of the natural building block type B (i.e. tannic acid), Xu Claim 2.
Regarding Claim 5 Xu in view of Yang discloses the nanofilm of claim 1, wherein the solvent-resistant bonds link at least a portion of the natural building block type A to at least a portion of the natural building block type B, i.e. inherently due to the coupling by EDC.
Regarding Claim 6 Xu in view of Yang discloses the nanofilm of claim 1, wherein the solvent-resistant bonds include an imine bond; i.e. because this would be inherent to tannic acid crosslinked with an amine (i.e. of the polyamines) by EDC, because EDC is known to cause the coupling/crosslinking of hydroxyl groups (i.e. on tannic acid) and amines (i.e. on the polyamines); and/or due to direct reaction in Yang, see Fig. 1
Regarding Claim 12 Xu in view of Yang discloses the nanofilm according to claim 1, wherein the amine group and the catechol group react to form an imine bond of the formula (3); i.e. because this would be inherent to tannic acid crosslinked with an amine (i.e. of the polyamines) by EDC, because EDC is known to cause the coupling/crosslinking of hydroxyl groups (i.e. on tannic acid) and amines (i.e. on the polyamines); and/or due to direct reaction in Yang, see Fig. 1
Regarding Claim 13 Xu in view of Yang discloses the nanofilm of claim 1, wherein at least one of the functional groups of the natural building block type B is a pyrogallol group, i.e. this is inherent o tannic acid, Xu Claim 2.
Regarding Claim 14 Xu in view of Yang discloses the nanofilm according to claim 13, wherein the amine group and the pyrogallol group react to form an imine bond and a carbon-nitrogen single bond of the formulas (4) and (5); i.e. because this would be inherent to tannic acid crosslinked with an amine (i.e. of the polyamines) by EDC, because EDC is known to cause the coupling/crosslinking of hydroxyl groups (i.e. on tannic acid) and amines (i.e. on the polyamines); and/or due to direct reaction in Yang, see Fig. 1
Regarding Claim 16 Xu in view of Yang discloses the nanofilm of claim 1, but is silent to the thickness of the nanofilm, and thus does not disclose a thickness of the nanofilm ranges from about 1 nm to about 2000 nm.
However, Yang discloses the thickness of the nanofilm ranges from about 80 nm to about 900 nm; Fig. 2.
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the nanofilm of Xu in view of Yang by forming it to have a thickness of from 80-900 nm as disclosed by Yang because this is a known useful and functional thickness for similar nanofilms.
Regarding Claim 18 Xu in view of Yang discloses the nanofilm of claim 1 which is used in a thin film composite membrane for nanofiltration by Xu (Abstract, Title), and thus it would have been obvious to use a support with the freestanding film in order to provide mechanical support. With regard to the filter being for organic solvent nanofiltration; these are intended use limitations which does not differentiate this apparatus claim from the prior art; see MPEP 2114(II).
Regarding Claim 23 Xu in view of Yang discloses the nanofilm of claim 1, wherein the natural building block type B is tannic acid, Xu Claim 2.
Claims 17 is rejected under 35 U.S.C. 103 as being unpatentable over Xu in view of Yang as evidenced by Gallastegui and further in view of US 5,945,000 (hereinafter “Skidmore”).
Regarding Claim 17 Xu in view of Yang discloses the nanofilm of claim 1, but is silent to the molecular weight cut off of the nanofilm, and thus does not disclose wherein a molecular weight cutoff of the nanofilm ranges from about 100 g mol 1 to about 2000 g mol 1.
However, nanofiltration membranes are known in the art to have pore sizes from 0.001-0.01 microns and can comprise for example a molecular weight cutoff of about 200 amu (i.e. g/mol); Skidmore C1/L52-57.
Therefore, before the effective filing date, it would have been prima facie obvious to one of ordinary skill in the art to modify the nanofilm of Xu in view of Yang by forming it to have a molecular weight cutoff of about 200 g/mol as disclosed by Skidmore because this is a known useful and functional molecular weight cutoff for nanofiltration.
Other Reference of Note
The following prior art is noted as relevant to the invention but not currently cited in a rejection:
Qin Li, Zhipeng Liao, Xiaofeng Fang, Dapeng Wang, Jia Xie, Xiuyun Sun, Lianjun Wang, Jiansheng Li, Tannic acid-polyethyleneimine crosslinked loose nanofiltration membrane for dye/salt mixture separation, Journal of Membrane Science, Volume 584, 2019, Pages 324-332
Response to Arguments
Applicants’ arguments filed 07/16/2026 have been fully considered, but they are now moot because they are directed in their entirety to grounds of rejection which are no longer cited in the current action and the new limitations of the amended claims which had not been previously addressed. See the updated rejection above citing a new combination of references to address the amended claims.
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, Benjamin L Lebron can be reached at 571-272-0475. 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
/BENJAMIN L LEBRON/ Supervisory Patent Examiner, Art Unit 1773
Prosecution Insights