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 .
Status of the Claims
This is a final Office action in response to Applicant’s amendments and remarks filed on 12/16/2025. Claims 1-20 are pending in the current Office action. Of these, claims 9-18 are withdrawn from consideration. Claims 1, 5, 8, and 19 were amended by Applicant.
Status of the Rejection
The objections to the drawings and specification are withdrawn in view of Applicant’s amendments.
The objection to claim 5 is withdrawn in view of Applicant’s amendments.
The rejections of claims 1-8 and 19-20 under 35 U.S.C. § 103 are withdrawn in view of Applicant’s amendments.
New rejections of claims 1-8 and 19-20 are necessitated by Applicant’s amendments.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-5, 7-8, and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Palakkal et al. (“Advancing electrodeionization with conductive ionomer binders that immobilize ion-exchange resin particles into porous wafer substrates” Clean Water (2020) 5 and SI) in view of Yamanaka (US Pat. Pub. 2004/0122117 A1) and Singh et al. (“Alkaline stable thermal responsive cross-linked anion exchange membrane for the recovery of NaOH by electrodialysis” Desalination 494 (2020) 114651) and as evidenced by, in the case of claim 7, ECOLAB (“Purolite™ Purofine™ PFA400” 2025).
Regarding claim 1, Palakkal teaches a membrane-wafer assembly comprising a core porous resin-wafer (RW) (“mixed resin wafer” Fig. 1c and see title and abstract);
wherein the resin-wafer comprises cation exchange resin beads and anion exchange resin beads bound together with a polymeric binder (see Fig. 1b-c and e.g., p. 1 col. 1 para. 1).
Palakkal does not teach the membrane-wafer assembly comprises a first ion-exchange surface comprising a thin anionic ionomer layer (AIL) bonded thereto, and a second ion exchange surface comprising a thin cationic ionomer layer (CIL) bonded thereto.
However, Yamanaka teaches a method for reducing internal resistance in electrodeionization systems (abstract and paras. 13 and 42) by replacing the cation-exchange and anion-exchange membranes (“The electrodeionization module was packed … so that the dense layers may function as ion exchange membranes integrated with the ion exchanger. Thus, no separate ion exchange membranes were used.” para. 64) with thin anionic ionomer and cationic ionomer layers (“a dense layer covering … and integrally formed with the porous polymer … functioning as an ion exchange membrane” para. 10 and see para. 62 and 21a,b in Fig. 3a) bonded to a porous ion exchange material (“a porous polymer functioning as an ion exchanger” para. 10 and 20a,b in Fig. 3a) on first and second ion-exchange surfaces thereof (“a dense layer containing cation exchange groups forming one side of the resulting plate and a dense layer containing anion exchange groups forming the other side” para. 62).
Palakkal teaches the resin-wafer is intended for use in an electrodialysis system disposed between cation and anion exchange membranes (CEMs and AEMs) (Fig. S9).
As Palakkal teaches an electrodeionization device comprising a porous resin-wafer ion exchange material, Palakkal is analogous art to the instant invention. As Yamanaka teaches a method for reducing internal resistance in electrodeionization systems, Yamanaka is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the system of Palakkal, by replacing the AEM and CEM with a thin anionic ionomer layer (AIL) bonded to a first ion-exchange surface of the ion exchange material and a thin cationic ionomer layer (CIL) bonded to a second ion-exchange surface of the ion exchange material, as taught by Yamanaka. A person having ordinary skill in the art would have been motivated to make this modification to achieve the predictable result of reducing the internal resistance of the electrodeionization module, as taught by Yamanaka. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)).
Modified Palakkal, via Yamanaka, further teaches the AIL and CIL each independently have a thickness in the range of about 10 µm to about 700 µm (“The thickness of the oil-soluble monomer layer (b1) may be arbitrary [sic] determined according to the thickness of the dense layer to be formed on the surface of the porous material, … preferably 10 to 700 μm.” para. 40), a range encompassing the claimed range. A range in the prior art encompassing a claimed range establishes a prima facie case of obviousness (MPEP § 2144.05).
Modified Palakkal does not teach the polymeric binder is a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder.
However, Singh teaches an anion exchange membrane for electrodialysis (title) comprising a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) (“Cross-linked AEMs (PSCr/x; x refer theoretical molar ratio of 1-methylimidazole to PVACN) were prepared via cross-linking, followed by quaternization with 1-methyl imidazole …” § 2.2.2. and see Scheme 1B), which provides the predictable benefit of enhanced stability (abstract and § 4).
As Singh teaches an anion exchange membrane composition for electrodialysis, Singh is analogous art to the instant application.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify system of Palakkal, such that the polymeric binder comprises a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder, as taught by Singh. A person having ordinary skill in the art would have been motivated to make this modification because Singh teaches this anion exchange material provides enhanced stability in the presence of alkaline media. Furthermore, use of a material known in the art as suitable for a purpose (i.e., use of a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) as an anion exchange material) establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 2, modified Palakkal, via Yamanaka, further teaches the AIL and CIL each independently have a thickness in the range of about 10 to about 700 µm, a range encompassing the claimed range (“The thickness of the oil-soluble monomer layer (b1) may be arbitrary [sic] determined according to the thickness of the dense layer to be formed on the surface of the porous material, … preferably 10 to 700 μm.” para. 40). A range in the prior art encompassing a claimed range establishes a prima facie case of obviousness (MPEP § 2144.05).
Regarding claim 3, modified Palakkal does not explicitly teach the AIL is a polymer bearing primary, secondary, tertiary, or quaternary amino groups, or tertiary phosphine or sulfone groups.
However, Yamanaka teaches polymers bearing primary, secondary, tertiary, or quaternary amino groups, or tertiary phosphine or sulfone groups are suitable for the AIL (“anionic exchange groups such as a quaternary ammonium group, tertiary amino group, secondary amino group, primary amino group, … tertiary sulfonium group, and phosphonium group;” para. 28 and see para. 27).
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the AIL of Palakkal such that the AIL is a polymer bearing primary, secondary, tertiary, or quaternary amino groups, or tertiary phosphine or sulfone groups, as taught by Yamanaka. A person having ordinary skill in the art would have been motivated to make this modification because Yamanaka teaches these materials are suitable anion exchange materials for use as the AIL. Use of a material known in the art as suitable for a purpose establishes a prima facie case of obviousness (MPEP § 2144.07).
Furthermore, modified Palakkal, via Singh, teaches the anion exchange material bears quaternary benzyl N-methyl imidazolium groups, a group differing from the claimed group (i.e., quaternary amino groups) only in that the quaternary amine is aromatic rather than aliphatic. It is therefore considered that, absent evidence of unexpected results, a person having ordinary skill in the art would have found it obvious to substitute a quaternary amino group for the quaternary benzyl N-methyl imidazolium group taught by Singh. Substitution of structurally similar chemical compounds, absent evidence of unexpected results, establishes a prima facie case of obviousness (MPEP § 2144.09).
Regarding claim 4, modified Palakkal teaches the limitations of claim 1, as described above.
Modified Palakkal does not explicitly teach the AIL comprises a quaternary benzyl n-methyl pyridinium chloride poly(arylene ether sulfone).
However, Palakkal further teaches quaternary benzyl n-methyl pyridinium chloride is a suitable anion exchange group for use in electrodeionization (see e.g., Fig. S1a), and poly(arylene ether sulfone) is a suitable backbone for anion exchange material (see e.g., Fig. 2a).
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to use a quaternary benzyl n-methyl pyridinium chloride poly(arylene ether sulfone) as the AIL in the system of modified Palakkal, because Palakkal teaches quaternary benzyl n-methyl pyridinium chlorides and poly(arylene ether sulfone) are suitable materials for use as an ion-exchange material. Use of materials known in the art as suitable for a purpose establishes a prima facie case of obviousness (MPEP § 2144.07).
Furthermore, modified Palakkal, via Singh, teaches the anion exchange material is a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone), a compound differing from the claimed compound only in the identity of the pendant quaternary ammonium group. It is therefore considered that, absent evidence of unexpected results, a person having ordinary skill in the art would have found it obvious to substitute a quaternary benzyl n-methyl pyridinium chloride for the quaternary benzyl N-methyl imidazolium taught by Singh. Substitution of structurally similar chemical compounds, absent evidence of unexpected results, establishes a prima facie case of obviousness (MPEP § 2144.09).
Regarding claim 5, modified Palakkal, via Yamanaka, further teaches the CIL is a polymer bearing sulfonic acid, phosphonic acid, and/or carboxylic acid groups (“cationic exchange groups such as a carboxylic acid group, … sulfonic acid group, phosphoric acid group, and phosphate group;” para. 28 and see para. 27).
Regarding claim 7, Palakkal further teaches the anionic ion exchange resin beads are polymer beads comprising quaternary amino groups on the surface thereof (“Purolite, PFA400” p. 8 Materials § and see below).
As evidenced by ECOLAB, Purolite™ PFA400 is an anion exchange resin comprising quaternary amino groups on the surface thereof (“Functional Group Type I Quaternary Ammonium” Table line 3).
Regarding claim 8, modified Palakkal, via Singh, further teaches the AIL is a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) (“Cross-linked AEMs (PSCr/x; x refer theoretical molar ratio of 1-methylimidazole to PVACN) were prepared via cross-linking, followed by quaternization with 1-methyl imidazole …” § 2.2.2. and see Scheme 1B).
Regarding claim 19, Palakkal teaches a membrane-wafer assembly electrodeionization (MWA-EDI) apparatus comprising a cathode, an anode, and a stack of membrane-wafer assemblies between the anode and the cathode (Fig. S9);
wherein the resin-wafer comprises cation exchange resin beads and anion exchange resin beads bound together with a polymeric binder (see Fig. 1b-c and e.g., p. 1 col. 1 para. 1);
each MWA is compressed between two gaskets (labelled “product capture” in Fig. S9) to form a diluate chamber (“feed/diluate compartments (~3.0mm thick) containing resin wafers” p. 9 para. bridging cols. 1 and 2 and see Fig. S9);
a concentrate chamber is positioned between each diluate chamber (open space in gaskets labelled “product capture” in Fig. S9);
each diluate chamber is oriented with an anion-exchange membrane (AEM) thereof facing the anode, and a cation exchange membrane (CEM) thereof facing the cathode (see Fig. S9);
and the concentrate chambers and diluate chambers configured and assembled for fluid flow therebetween (see p. 9 para. bridging cols. 1 and 2 and Fig. S9).
Palakkal does not teach each membrane-wafer assembly (MWA) in the stack comprises a thin anionic ionomer layer (AIL) bonded thereto, and a second ion exchange surface comprising a thin cationic ionomer layer (CIL) bonded thereto. Palakkal instead teaches the use of conventional AEMs and CEMs.
However, Yamanaka teaches a method for reducing internal resistance in electrodeionization systems (abstract and paras. 13 and 42) by replacing the cation-exchange and anion-exchange membranes (“The electrodeionization module was packed … so that the dense layers may function as ion exchange membranes integrated with the ion exchanger. Thus, no separate ion exchange membranes were used.” para. 64) with thin anionic ionomer and cationic ionomer layers (“a dense layer covering … and integrally formed with the porous polymer … functioning as an ion exchange membrane” para. 10 and see para. 62 and 21a,b in Fig. 3a) bonded to the ion exchange material (“a porous polymer functioning as an ion exchanger” para. 10 and 20a,b in Fig. 3a) on first and second ion-exchange surfaces thereof (“a dense layer containing cation exchange groups forming one side of the resulting plate and a dense layer containing anion exchange groups forming the other side” para. 62).
As Palakkal teaches an electrodeionization device comprising a porous resin-wafer ion exchange material, Palakkal is analogous art to the instant invention. As Yamanaka teaches a method for reducing internal resistance in electrodeionization systems, Yamanaka is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the system of Palakkal, by replacing the AEM and CEM with a thin anionic ionomer layer (AIL) bonded to a first ion-exchange surface of the ion exchange material and a thin cationic ionomer layer (CIL) bonded to a second ion-exchange surface of the ion exchange material, as taught by Yamanaka. A person having ordinary skill in the art would have been motivated to make this modification to achieve the predictable result of reducing the internal resistance of the electrodeionization module, as taught by Yamanaka. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)).
Modified Palakkal, via Yamanaka, further teaches the AIL and CIL each independently have a thickness in the range of about 10 µm to about 700 µm (“The thickness of the oil-soluble monomer layer (b1) may be arbitrary determined according to the thickness of the dense layer to be formed on the surface of the porous material, … preferably 10 to 700 μm.” para. 40) a range encompassing the claimed range. A range in the prior art encompassing a claimed range establishes a prima facie case of obviousness (MPEP § 2144.05).
Modified Palakkal does not teach the polymeric binder is a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder.
However, Singh teaches an anion exchange membrane for electrodialysis (title) comprising a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) (“Cross-linked AEMs (PSCr/x; x refer theoretical molar ratio of 1-methylimidazole to PVACN) were prepared via cross-linking, followed by quaternization with 1-methyl imidazole …” § 2.2.2. and see Scheme 1B), which provides the predictable benefit of enhanced stability (abstract and § 4).
As Singh teaches an anion exchange membrane composition for electrodialysis, Singh is analogous art to the instant application.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify system of Palakkal, such that the polymeric binder comprises a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder, as taught by Singh. A person having ordinary skill in the art would have been motivated to make this modification because Singh teaches this anion exchange material provides enhanced stability in the presence of alkaline media. Furthermore, use of a material known in the art as suitable for a purpose (i.e., use of a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) as an anion exchange material) establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 20, Palakkal further teaches bipolar membranes are positioned between the cathode and the stack and between the anode and the stack (see Fig. S9).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Palakkal in view of Yamanaka and Singh, as applied to claim 1 above, and further in view of Zhao et al. (“Novel low-cost cation exchange membrane containing hydrophilic cross-linked structure for enhanced electrodialysis properties” Journal of the Taiwan Institute of Chemical Engineers 100 (2019) 269-276).
Regarding claim 6, modified Palakkal teaches the limitations of claim 1, as described above.
Modified Palakkal does not teach the CIL comprises a sulfonated poly(arylene ether sulfone).
However, Zhao teaches a CEM comprising a sulfonated poly(arylene ether sulfone) (abstract) having good ion transport properties for water purification via electrodialysis (abstract) and a lower cost relative to commercial CEM materials (abstract).
As Zhao teaches membrane compositions for water purification by electrodialysis, Zhao is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the system of Palakkal, such that the CIL comprises a sulfonated poly(arylene ether sulfone), as taught by Zhao. A person having ordinary skill in the art would have been motivated to make this modification because Zhao teaches sulfonated poly(arylene ether sulfone) membranes have good ion transport properties for water purification, and are less expensive than other materials having comparable properties. Furthermore, use of a material known in the art as suitable for a purpose (i.e., a sulfonated poly(aryl ether sulfone) as a cation exchange material for use in an ion exchange barrier in an electrochemical water purification system) establishes a prima facie case of obviousness (MPEP § 2144.07).
Response to Arguments
Applicant’s arguments, see Remarks p. 8-9, filed 12/16/2025, with respect to the objections to the drawings, specification, and claims, have been fully considered and are persuasive. The objections to the drawings, specification, and claims are withdrawn.
Applicant’s arguments, see Remarks p. 9, filed 12/16/2025, with respect to the rejections of claims 1-8 and 19-20 under 35 U.S.C. § 103 have been fully considered and are persuasive in part. Therefore, the rejections have been withdrawn. However, new grounds of rejection are established in view of Applicant’s amendments.
Applicant’s Argument #1
Applicant argues on p. 9 that none of Palakkal, Yamanaka, or Zhao reasonably teach or render obvious “a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder”, as recited in amended claims 1 and 19.
Examiner’s Response #1
Examiner agrees. The rejections of record have therefore been withdrawn in view of Applicant’s amendments.
Applicant’s Argument #2
Applicant argues on p. 9 that, even if the use of a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder were determined prima facie obvious over the prior art, the specification provides evidence of unexpected results that would overcome any such determination. Specifically, Applicant argues that p. 16 and 17 of the specification report that the use of a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder provides enhanced lactate separation and an energy reduction relative to the use of a conventional non-ion exchanging binder i.e., a polyethylene binder, with or without the addition of the AIL and CIL membranes.
Examiner’s Response #2
Examiner respectfully disagrees. At issue is whether Applicant’s alleged beneficial results constitute unexpected results sufficient to overcome the prima facie case of obviousness established by Palakkal in view of Yamanaka and Singh.
In order for unexpected results to overcome a prima facie case of obviousness, Applicant must provide evidence that has a nexus to the claimed invention (MPEP § 716.01(b)), such evidence must be commensurate in scope with the claims (MPEP § 716.02(d)), such evidence must demonstrate a benefit over the closest prior art (MPEP § 716.02(e)), and Applicant must demonstrate that any such benefit demonstrated is, in fact, unexpected (MPEP § 716.02(b)(I) and 716.02(c)).
In the instant case, applicant has provided evidence that use of a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder provides a beneficial effect, regardless of whether or not the AIL and CIL are present. It is therefore considered that the provided evidence has a nexus to the invention as claimed, and is commensurate in scope with the claims.
However, Applicant has not provided evidence that the invention provides a benefit over the closest prior art, which is considered to be Palakkal. Instead, Applicant demonstrates that use of a quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) binder provides benefits relative to a non-ionic polyethylene binder. As Applicant has not compared the claimed invention to the closest prior art, Applicant’s evidence cannot be considered to constitute unexpected results capable of overcoming a prima facie case of obviousness.
Furthermore, Applicant’s asserted benefit i.e., reduced energy consumption when using an ionic binder rather than a non-ionic binder, is also described in Palakkal (see e.g., abstract). It is therefore unclear how the asserted benefits could reasonably be considered “unexpected” in view of the prior art of record.
Applicant’s argument is therefore not persuasive.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Zhang et al. (“Imidazolium functionalized polysulfone anion exchange membrane for fuel cell application” J. Mater. Chem., 2011, 21, 12744) teaches quaternary benzyl N-methyl imidazolium poly(arylene ether sulfone) is suitable for use as an anion exchange material (see abstract and Fig. 1). Sata et al. (“Preparation and Properties of Anion Exchange Membranes Having Pyridinium or Pyridinium Derivatives as Anion Exchange Groups” Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 36, 49–58 (1998)) teaches that quaternary benzyl N-methyl imidazolium groups are suitable anion exchange groups for use in anion exchange membranes (see e.g., Fig. 1).
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER R PARENT whose telephone number is (571)270-0948. The examiner can normally be reached M-F 11:00 AM - 6 PM EST.
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/ALEXANDER R. PARENT/Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795