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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 26 JANUARY 2026 has been entered.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Status
Rejected Claims: 1-7
Withdrawn Claims: 9-20
Cancelled Claims: 8
Response to Amendment
The amendment filed on 26 JANUARY 2026 has been entered.
In view of the amendment to the claims, the amendment to claim 1 has been acknowledged.
In view of the amendment to claim 1, the rejection under 35 U.S.C. 103 has been modified.
Response to Arguments
Applicant’s arguments filed on 26 JANUARY 2026 have been fully considered.
Applicant argues, regarding claim 1, that Kulkarni in view of Nick fails to disclose the newly added limitations of claim 1 including “wherein each of the first continuous centrifuge and the second continuous centrifuge is configured to operate under conditions of: a reaction mixture input amount per minute in a range of 4 to 6 L/min, a G value in a range of 13,000 to 16,000 g, and a rotational speed in a range of 13,000 to 16,000 rpm and wherein the first mix tank, the first continuous centrifuge, the second mix tank, and the second continuous centrifuge are fluidly connected in series to form a continuous purification line” with Kulkarni explicitly describing centrifuges that are smaller and do not rotate as fast in the examples and Kulkarni repeatedly describes a batch centrifuge used multiple times manually and so claim 1 is allowable in view of the prior art (Arguments filed 26 JANUARY 2026, Page 6 to Page 8, Paragraph 2 and Page 9, Paragraph 3 to Page 10).
Regarding Applicant’s arguments, Applicant’s arguments with respect to “wherein each of the first continuous centrifuge and the second continuous centrifuge is configured to operate under conditions of: a reaction mixture input amount per minute in a range of 4 to 6 L/min, a G value in a range of 13,000 to 16,000 g, and a rotational speed in a range of 13,000 to 16,000 rpm” have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Furthermore, Kulkarni teaches some specific examples of centrifugation for particular nanoparticles, but Kulkarni explicitly teaches that the speed of the centrifuge can be within the range of 6,000 RPM and 20,000 RPM based upon the particle size and distribution of the desired particles (Paragraph 0033, Machine Translation) and that there can be multiple continuous centrifuges operated in series (Paragraph 0020, 0038, Machine Translation) and that it is known to scale up nanomaterial separation with industrial centrifuges (Paragraph 0014, Machine Translation). Therefore, claim 1 is not allowable.
Applicant argues that Kulkarni utilizes a different separation principle than the instant claimed invention (Arguments filed 26 JANUARY 2026, Page 8, Paragraph 3 and Page 9, Paragraph 2).
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., the specific mixture and separation principle for the nanoparticle separations) are not recited in the rejected claim. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Applicant argues, regarding claim 1 and Nick, that Nick simply teaches an inert gas environment and not a device for supplying an inert gas directly into the centrifuge and so does not teach the limitations of instant claim 1 because the general environment purging would not prevent the removal of organic solvent misting cause by high-speed centrifugation (Arguments filed 26 JANUARY 2026, Page 8, Paragraphs 4-5).
Regarding Applicant’s arguments, Nick specifically teaches the purging of equipment with inert gas such as nitrogen or argon into vessels or equipment in which the material is present (Paragraph 0048) and specifically mentions centrifugation as the isolation method (Paragraph 0045). Therefore, Nick teaches the instant limitation of purging equipment.
Applicant argues that there is no motivation to combine Nick and Kulkarni because Kulkarni does not relate to quantum dots and Nick does not disclose centrifugation systems (Arguments filed 26 JANUARY 2026, Page 9, Paragraph 1).
Regarding Applicant’s argument, Lim is now used as the primary reference and teaches multiple mixing and centrifuges steps in sequence for the isolation of quantum dots and Kulkarni is analogous to the claimed invention because it pertains to a process for continuously separating nanoparticles using centrifugal extractors (Paragraph 0002) while Nick is analogous to the claimed invention because it pertains to the technical field of quantum dot synthesis (Paragraph 0002) and mentions centrifugation separation (Paragraph 0045).
Applicant argues, regarding claims 2-7, that claim 1 is allowable and so claims 2-7 are allowable because they depend upon claim 1.
Regarding Applicant’s argument, claim 1 is not allowable and so claims 2-7 are also not allowable.
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.
Claims 1-2 are rejected under 35 U.S.C. 103 as being unpatentable over Lim et al US Patent Application No. 20200091557 A1 (hereinafter Lim) in view of Kulkarni et al Korean Patent Application No. KR 20190137882 A (hereinafter Kulkarni) in view of Nick et al US Patent Application No. 20140027673 A1 (hereinafter Nick) in view of Crown Machinery, Tubular Separator, 21 APRIL 2017, https://crown-machinery.com/tubular-separator/, accessed via Wayback Machine on 12 FEBRUARY 2026 (hereinafter Crown Machinery) with support from Mel Dorin and Judy Cummings, Beckman Coulter, Inc., Principles of Continuous Flow Centrifugation, 26 SEPTEMBER 2016, https://www.news-medical.net/whitepaper/20160926/Overview-of-Continuous-Flow-Centrifugation.aspx, accessed via Wayback Machine on 12 FEBRUARY 2026 (hereinafter Beckman Coulter).
Regarding Claim 1, Lim teaches the use of 2-3 centrifuge steps with mixing steps between each centrifuge step in sequence and the specific speed of centrifuge for quantum dot purification after synthesis. Kulkarni teaches the use of continuous centrifuges for nanoparticle separation and that it is known to scale up nanoparticle synthesis and purification with industrial equipment, Nick teaches inert gas purging for quantum dot synthesis, Crown Machinery teaches specific industrial equipment known to be used for fine particle separations from liquids that can operate at the parameters of instant claim 1, and Beckman Coulter demonstrates that reservoirs before and after each continuous centrifuge are well known in the art of continuous flow centrifugation.
Lim teaches that for the preparation of quantum dots (i.e., a system for purifying nanoparticles, the system comprising) with an average diameter in the range of 2-12 nanometers (i.e., wherein the nanoparticles are quantum dot nanoparticles; Abstract)
can be mixed with a water soluble organic solvent (i.e., a first mix tank configured to prepare a first reaction mixture by mixing a crude solution for synthesis of the nanoparticles and a first mix solvent)
to precipitate impurities and then centrifuged (i.e., a first centrifuge configured to primarily separate the nanoparticles and a first filtrate by centrifuging the first reaction mixture supplied from the first mix tank),
with the process repeated two or three times on the resulting supernatant until a precipitate is no longer produced (i.e., a second mix tank configured to prepare a second reaction mixture by mixing the first filtrate supplied from the first continuous centrifuge and a second mix solvent, and a second centrifuge configured to secondarily separate the nanoparticles and a second filtrate by centrifuging the second reaction mixture supplied from the second mix tank; wherein the capacity of the second centrifuge is equal to the capacity of the first centrifuge)
with the speed of the centrifuge operating at 13,000 RPM (i.e., wherein each of the first centrifuge and the second centrifuge is configured to operate under conditions of: a rotational speed in a range of 13,000 to 16,000 rpm; Paragraph 0054).
Lim does not teach the use of continuous centrifuges, and does not explicitly teach wherein the first mix tank, the first continuous centrifuge, the second mix tank, and the second continuous centrifuge are fluidly connected in series to form a continuous purification line.
However, Kulkarni teaches continuously supplying a suspension of nanoparticles in a solvent to a centrifuge (i.e., a system of purifying nanoparticles, the system comprising; Paragraph 0019, Machine Translation)
where the separation can be performed in a continuous flow mode (i.e., continuous centrifuge; Paragraph 0020, Machine Translation) with the number of steps of continuous centrifugation with continuous flow centrifuges being calculated from the stage efficiency of a batch run (Paragraph 0038, Machine Translation), that recovery rates of the nanoparticles are improved by increasing the number of alternating centrifugation and mixing steps (Paragraph 0042, Machine Translation), and continuous flow centrifuges increase the number of steps required for separation, but allow greater recovery of surfactant and potentially increasing the functionality of the nanoparticle (Paragraph 0043, Machine Translation).
Kulkarni further teaches that the speed of the centrifuge is within the range of 6,000 RPM and 20,000 RPM based upon the particle size and distribution of the desired particles (i.e., a rotational speed in a range of 13,000 to 16,000 rpm; Paragraph 0033, Machine Translation),
and an example with three centrifuges operating in series (i.e., wherein the first mix tank, the first continuous centrifuge, the second mix tank, and the second continuous centrifuge are fluidly connected in series to perform a continuous purification line; Paragraph 0059, Machine Translation) and that it is known to scale up nanomaterial separation with industrial centrifuges (Paragraph 0014, Machine Translation).
Kulkarni is analogous to the claimed invention because it pertains to a process for continuously separating nanoparticles using centrifugal extractors (Paragraph 0002). It would have been obvious to one of ordinary skill in the art at the time of filing of the instant claimed invention to modify the process for quantum dot synthesis as taught by Lim with the series continuous centrifugation as taught by Kulkarni because the continuous centrifugation would improve the surfactant recovery and the functionality of the nanoparticle.
Lim in view of Kulkarni does not teach wherein each of the first continuous centrifuge and the second continuous centrifuge includes an inert gas supply for supplying an inert gas into the first continuous centrifuge and the second continuous centrifuge, and are configured to centrifuge the respective reaction mixture under an inert gas atmosphere supplied by the inert gas supply.
However, Nick teaches that quantum dots can be grown, isolated from growth solution via centrifugation (i.e., wherein the nanoparticles are quantum dot nanoparticles), and redispersed all under inert gas conditions (i.e., wherein each of the first continuous centrifuge and the second continuous centrifuge includes an inert gas supply for supplying an inert gas into the first continuous centrifuge and the second continuous centrifuge, and are configured to centrifuge the respective reaction mixture under an inert gas atmosphere supplied by the inert gas supply) for the purpose of making quantum dots that are substantially free of oxygen and water (Paragraph 0045) with well-known methods for removing oxygen including purging the material with an inert gas and purging and backfilling the vessel containing the material with inert gas for several cycles, among other methods (Paragraph 0048).
Nick is analogous to the claimed invention because it pertains to the technical field of quantum dots (Paragraph 0002). According to KSR Rationale A, combining prior art elements according to known methods to yield predictable results, (1) the prior art teaches all of the claim limitations, with the only difference being the combination of elements in a single reference, (2) Lim in view of Kulkarni makes obvious the centrifugation process and Nick teaches that quantum dots can be centrifuged under inert gas, and (3) the results would predictably result in the separation of quantum dots that are also free of oxygen and water (MPEP 2143(I)(A)).
Lim in view of Kulkarni in view of Nick does not explicitly teach wherein the capacity of the first continuous centrifuge is in a range of 4 to 8 liters, based on the size of the bowl for collecting solids, wherein each of the first continuous centrifuge and the second continuous centrifuge is configured to operate under conditions of a reaction mixture input amount per minute in a range of 4 to 6 L/min, and a G value in a range of 13,000 to 16,000 g.
However, Crown Machinery teaches tubular separators used in continuous and semi-continuous operations for separating light concentration, fine particles from suspension (Page 2) with a number of sizes of separators having a bowl capacity of 6-10 liters, and maximum throughput of 20-41 L/min, with a maximum bowl speed from 14,000-16,000 rpm (Table, Page 3).
Crown Machinery is analogous to the claimed invention because it pertains to continuous centrifuges for the separation of fine particles from liquids (Page 2, Paragraph 6). It would have been obvious to one of ordinary skill in the art at the time of filing the instant claimed invention at the time of filing of the instant claimed invention to modify the centrifuges made obvious by Lim in view of Kulkarni in view of Nick with the tubular separators as taught by Crown Machinery because the tubular separators would allow for the scaling up of the process with industrial centrifuges as described by Kulkarni.
For more clarity regarding the mix tanks located between the continuous centrifuges, Beckman Coulter teaches an overview of continuous flow centrifugation in which Fig. 8 shows that standard arrangement of continuous flow centrifugation includes a reservoir for both the starting material and effluent on either side of the centrifuge (Page 7).
Furthermore, the limitation “wherein the nanoparticles are quantum dot nanoparticles” is directed toward materials or articles worked upon by the claimed invention and is therefore not subject to patentability. The inclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims (In re Young, 75 F.2d 996, 25 USPQ 69 (CCPA 1935) and thus holds no patentable weight. See MPEP §2115.
Regarding Claim 2, Lim further teaches that the mixing and centrifuging steps should be repeated 2-3 times (i.e., further comprising: a third mix tank configured to prepare a third reaction mixture by mixing the second filtrate supplied from the second continuous centrifuge and a third mix solvent; Paragraph 0054).
Kulkarni further teaches in an example that a third step is performed in a similar manner with supernatant separation from the second centrifuge followed by addition of solvent and mixing (i.e., further comprising: a third mix tank configured to prepare a third reaction mixture by mixing the second filtrate supplied from the second continuous centrifuge and a third mix solvent) and then finishing with another centrifugation step (Paragraph 0042).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter as applied to claim 2 above, and further in view of Kurz US Patent Application No. 20100152326 A1 (hereinafter Kurz).
Regarding Claim 3, Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter does not teach further comprising: a distillation device configured to separate, in a distillation manner, a mix solvent and the nanoparticles from the third reaction mixture of the third mix tank or from the second filtrate separated by the second continuous centrifuge.
However, Kurz teaches that it is well known to recycle a solvent containing dispersed nanoparticles by performing centrifugation to remove the particles followed by distillation to recover and separate the solvent (i.e., a distillation device configured to separate, in a distillation manner, a mix solvent and the nanoparticles from the third reaction mixture of the third mix tank or from the second filtrate separated by the second continuous centrifuge; Paragraph 0162).
Kurz is analogous to the claimed invention because it pertains to the field of preparing nanocomposite materials (Paragraph 0002). It would have been obvious to one of ordinary skill in the art at the time of filing the instant claimed invention to modify the continuous centrifugation process made obvious by Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter with the distillation as taught by Kurz because the distillation would allow solvent to be recycled and thus reduce waste of materials.
Claims 4-5 are rejected under 35 U.S.C. 103 as being unpatentable over Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz as applied to claim 3 above, and further in view of Shimizu et al US Patent Application No. 20190060782 A1 (hereinafter Shimizu).
Regarding Claim 4, Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz does not teach wherein the distillation device comprises: a distillation heat exchanger into which the third reaction mixture or the second filtrate is supplied; and at least one heater disposed in contact with the distillation heat exchanger.
However, Shimizu teaches a purification device (Fig. 1, #100) including a distillation column (i.e., wherein the distillation device comprises; Fig. 1, #101) with both a reboiler (i.e., a distillation heat exchanger into which the third reaction mixture or the second filtrate is supplied; and at least one heater disposed in contact with the distillation heat exchanger Fig. 1, #104) which heats the bottom product and a condenser (i.e., a distillation heat exchanger into which the third reaction mixture or the second filtrate is supplied; Fig. 1, #106) which cools the supplied vapor, and the purpose of the reboiler heat exchanger/heater is to supply the vapor to the distillation column (Paragraph 0071).
Shimizu is analogous to the claimed invention because it pertains to a purification device that obtains a solvent with a reduced impurity content (Abstract), especially of small metal particles (Paragraphs 0128-0131). It would have been obvious to one of ordinary skill in the art at the time of filing the instant claimed invention to modify the continuous centrifugation process as made obvious by Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz with the reboiler as taught by Shimizu because the reboiler would provide vapor for the distillation column to function.
Regarding Claim 5, Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz does not teach further comprising at least one solvent storage tank connected to the distillation device and configured to store a solvent recovered by distillation.
However, Shimizu teaches a filling portion (Fig. 2, #204) that includes a storage tank coated with a corrosion resistant material for the purpose of further reducing the impurities of the purified product (i.e., further comprising at least one solvent storage tank and configured to store a solvent recovered by distillation; Paragraphs 0285-0288) which is downstream of the distillation column (i.e., connected to the distillation device; Fig. 2, #202; Paragraph 0280).
It would have been obvious to one of ordinary skill in the art at the time of filing the instant claimed invention to modify the continuous centrifugation process made obvious by Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz with the storage tank as taught by Shimizu because the storage tank would further reduce impurities in the purified solvent.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz in view of Shimizu as applied to claim 5 above, and further in view of Spiegel et al US Patent Application No. 20180021791 A1 (hereinafter Spiegel).
Regarding Claim 6, Kurz further teaches that solvents can be recycled through centrifugation followed by distillation (i.e., such that the recovered solvent is reused; Paragraph 0162).
Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz in view of Shimizu does not teach further comprising a plurality of solvent supply tanks, wherein the solvent storage tank is connected to at least one of the plurality of solvent supply tanks and the first to third mix tanks.
However, Spiegel teaches a system (Fig. 1, #10) fluidly connected to an ultracentrifuge (Fig. 1, #12) that controls the flow of loading and filling reservoirs, jars, bottles, and other containers for the ultracentrifuge (i.e., a plurality of solvent supply tanks, wherein the solvent storage tank is connected to at least one of the plurality of solvent supply tanks and the first to third mix tanks; Figs. 3, 6; Paragraphs 0047-0052) for the purpose of automating the use of the ultracentrifuge and integrating with a customer’s network (Paragraph 0038).
Spiegel is analogous to the claimed invention because it pertains to a fluid handling system for ultracentrifuges (Paragraph 0002). It would have been obvious to one of ordinary skill in the art at the time of filing the instant claimed invention to modify the continuous centrifugation process made obvious by Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter in view of Kurz in view of Shimizu with the solvent supply tanks as taught by Spiegel because the solvent supply tanks would automate the loading of the centrifuges.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter as applied to claim 1 above, and further in view of Burgin International Patent Application No. WO 03106337 A1 (hereinafter Burgin).
Regarding Claim 7, Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter does not teach further comprising a monitoring unit installed at a predetermined position in a pipe where the first continuous centrifuge and the second mix tank are connected.
However, Burgin teaches the steps of mixing, centrifugating, and decanting and repeating said steps while monitoring the optical opacity of the supernatant to determine when to end the cycle (i.e., a monitoring unit installed at a predetermined position in a pipe where the first continuous centrifuge and the second mix tank are connected; Claims 1-3) for the purpose of determining when the nanoparticles are more completely removed by the centrifugation (Paragraph 0042).
Burgin is analogous to the claimed invention because it pertains to the separation of nanoparticles (Paragraph 0001). It would have been obvious to one of ordinary skill in the art at the time of filing the instant claimed invention to modify the continuous centrifugation process made obvious by Lim in view of Kulkarni in view of Nick in view of Crown Machinery with support from Beckman Coulter with the opacity monitor for the supernatant because the opacity monitor would determine if the nanoparticles have been effectively removed from the supernatant after a given number of centrifugation steps.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Flottweg-Nederland-Scheidingstechnologie, Class 1, Division 1 Liquid-Solid Separation Centrifuge, 26 AUGUST 2019, https://flottweg.nl/product-categorie/toepassingen/chemicalien-pharma-levensmiddelen/, Accessed 17 February 2026 by Wayback Machine teaches that it is known to use inert gas purging techniques in industrial centrifuge equipment when dealing with oxidation, combustibles, and/or hazardous materials.
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/A.A.G./ Examiner, Art Unit 1777
/IN SUK C BULLOCK/ Supervisory Patent Examiner, Art Unit 1772
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