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 .
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 (i.e., changing from AIA to pre-AIA ) 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 1-10 and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Klassen et al (WO 2020/176888 A1) in view of Wu et al (Synergistic effects of CNT and GO on enhancing mechanical properties…, Materials and Design, 2017) and Bakajin et al (US PGPub 2011/0220574 A1).
With respect to claim 1, Klassen teaches filters for purification of biological fluids [Abs] – examiner notes that whether such a material is used for treatment of wastewater or any other type of filtration is drawn to the intended use and does not distinguish structurally. The filters are membranes that may be made of a matrix material of e.g. polylactic acid (PLA) [0023]. Further, these membranes may be formed with modifier components such as nanotubes to provide improved properties [0025]. Klassen is silent to the specific use of self-assembled MWCN/GO nanohybrids.
However, Wu teaches that graphene oxide and carbon nanotubes can be combined to form a three-dimensional integrated network which is useful for membrane modification [Abs] to improve both membrane stability and strength as well as separation; absent clarification of the specific requirements, such a 3D network would be interpreted as a nanohybrid. Wu teaches that there is synergy between the two in combination (even improved compared to just GO or just CNT alone) due to the pi-pi bond interactions between the two [pg. 43, Sec. 3.2; Conclusions]. Wu teaches that the nanotubes employed are multiwalled nanotubes [pg. 40, Sec. 2.1].
It would have been obvious to one of ordinary skill in the art to modify the membranes taught by Klassen to feature MWCNT/GO nanohybrids because, as in Wu, the combination of the two provides a great synergistic improvement compared even to the use of nanotubes alone, and thus would be expected to provide both further improved strength as well as improved separation performance to the membranes of Klassen.
Regarding the nanotubes being “f-MWCNT” i.e. functionalized, Wu and Klassen are silent to such a feature. However, Bakajin teaches methods of incorporating nanotubes such as MWCNTs into membranes [Abs] and teaches that they can be functionalized with groups such as carboxylic acids, amines, and the like [0076] and that they can be selectively charged in such a way i.e. positively or negatively [0070] to facilitate various separations. It would have been obvious to incorporate such functionalization because, as in Bakajin, this can enhance ion rejection (including via charge, as above), selectivity, and fouling resistance [0077]. Provision of an overall positively charged membrane in this way would similarly have been obvious e.g. by incorporation of suitable functionalization.
With respect to claims 2-3, Wu teaches ranges of CNT/GO content of between 0.5-5.0 wt% [pgs. 40-41, Sec. 2.2] which lies within or overlaps the claimed ranges, such that the claimed ranges are at minimum obvious.
With respect to claims 4-6, see MPEP 2113; the claims are directed to a product, and limitations regarding the process of making such product in the product claims do not necessarily distinguish the scope of the product itself over the prior art. Regardless, Klassen teaches that the nanotubes or the like can be present in the solution which forms the membrane [0025], as does Wu [pg. 40, Sec. 2.2].
With respect to claims 7-10, Wu teaches GO:CNT ratios of approximately, 1:3 (i.e. 75:25 in claim terms, referring to CNT:GO), 1:1 (50:50), and 3:1 (25:75) [pg. 40-41, Sec. 2.2]. As such, providing ranges as claimed e.g. about 80:20, 60:40, or 70:30 would represent an obvious optimization of values which are already very close to the proportions taught by Wu.
See MPEP 2144.05 II.A; "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
With respect to claims 18-20, see the rejections of claims 1, 2-3, and 7-10 above. The combination of Klassen and Wu suggests a PLA membrane with integrated MWCNT/GO nanohybrid; in view of Bakajin, this could be functionalized specifically with species such a COOH and specifically to achieve e.g. a negative charge for ion rejection as well as for enhanced separation and fouling resistance. Wu suggests the same range of GO/CNT content within the membrane, and similar or overlapping ranges for the ratio of MWCNT and GO; as such, the claimed invention would have been obvious over such combination.
Claims 11-17 are rejected under 35 U.S.C. 103 as being unpatentable over Klassen et al in view of Wu et al and Bakajin et al, further in view of Mou et al (CN 107381970 A).
With respect to claim 11, see the rejection of e.g. claim 1 above. Klassen teaches adding e.g. nanotubes to a solution for forming a membrane of PLA or the like, and in view of Wu providing a combined CNT/GO composite to allow self-assembly and 3D structures for greatly improved properties would have been obvious; further, as in Bakajin, providing functionalized CNTs such as positively charged CNTs would have been obvious to improve the resulting membrane properties and allow for selection rejection of ions and the like. As above, both Klassen and Wu teach dispersing the nanocarbons in a solvent in combination with the membrane material and casting to form a membrane. They are silent to the use of PVP in such a solution, although Klassen does suggest incorporating a porogen [0034] in the membrane solution.
However, the use of PVP as a porogen is well known in the art for casting of membranes, and Mou teaches example membranes which may include a base material of PLA or similar, and which may include PVP as the porogen [pg. 5, third paragraph]. It would have been obvious to one of ordinary skill in the art to include a well-known, useful porogen such as PVP in the modified membrane of Klassen to perform its well-known and expected function, particularly when it is known to be useful for membranes made from PLA or the like as in Mou.
With respect to claim 12, Klassen is silent to a specific solvent, and Wu is silent to DMAc. However, as above, Mou teaches membranes which may be formed from PLA or the like and use PVP porogens, and teaches that DMAc may be the solvent [pg. 5, third paragraph]. Selection of an appropriate solvent for casting a polymer membrane would have been an obvious engineering choice for one of ordinary skill in the art, particularly when the prior art in Mou demonstrates the utility of a particular solvent for a particular polymer and combination of materials.
With respect to claims 13-14, Wu teaches ranges of CNT/GO content of between 0.5-5.0 wt% [pgs. 40-41, Sec. 2.2] which lies within or overlaps the claimed ranges, such that the claimed ranges are at minimum obvious.
With respect to claim 15, as above at least in view of Bajakin it would have been obvious to provide functionalized nanotubes with e.g. positively charged functionalization for enhanced properties.
With respect to claims 16 and 17, as above Wu examines combinations in which there are provided more CNTs than GO e.g. 75:25 mixtures (3:1 ratio of CNT:GO).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Zheng (CN 111330456 A) teaches composite films for wastewater treatment as well as biomedical separations, and which employes a biodegradable material with nanotube components integrated within. The material may be a matrix of polylactic acid or similar.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRADLEY R SPIES whose telephone number is (571)272-3469. The examiner can normally be reached Mon-Thurs 8AM-4PM.
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, Jennifer Dieterle can be reached at (571)270-7872. 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.
/BRADLEY R SPIES/Primary Examiner, Art Unit 1777