DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. 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
2. 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 04 February 2026 has been entered.
Response to Amendments
3. The applicant’s response dated 04 February 2026 has been entered into the record. The examiner agrees with the applicant’s assertion that no new matter was added in the amendments as per pg. 5. Claim 21 is now the independent Claim. Claims 12, 13, 14, 15, 16, 20, 21, and 22 are currently pending and under examination in the instant application. The applicant has cancelled Claims 11, 17, 18, 19, and 23.
Claim Rejections - 35 USC § 103
4. 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.
5. 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.
6. Claims 12, 13, 14, 20, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. in view of Su et al. and Kullapere et al.
Claim 21 is the independent claim from which Claims 12, 13, 14, and 20 all directly or indirectly depend.
Wu et al. (“Corrosion damage evolution and mechanical properties of carbon fiber reinforced aluminum laminate,” J. Cent. South Univ. 2021, 28, 657-668) is directed toward corrosion in mixed materials (pg. 657: title and abstract). Su et al. (“Electrografting of 4-Nitrobenzenediazonium Salts on Al-7075 Alloy Surfaces-The Role of Intermetallic Particles. Nanomaterials 2021, 11(4), article 894, pg. 1-22) is directed toward treatment of aluminum alloys with an organic film (pg. 1: title and abstract). Kullapere et al. (“Oxygen electroreduction on chemically modified glassy carbon electrodes in alkaline solution,” J. Electroanal. Chem. 2007, 599(2), 183-193).
Regarding Claim 21, Wu et al. discloses a method of inhibiting formation of a galvanic couple (i.e.: corrosion) between a pre-formed carbon reinforced polymeric composite having exposed carbon fibers at a cut edge thereof and a metal substrate that is formed of a metal or alloy material fixed to the polymeric composite as supported by Figure 1, Table 1, and Table 2. Figure 1a shows a cross section of a CARALL, which is defined as carbon fiber reinforced aluminum laminate and is made of alternating layers of carbon fiber/epoxy (T800/X850) and aluminum alloy (Al 2024-T3). The materials are either joined by an adhesive (G2 in Table2) or pressed together as per Figure 2 (pg. 659).
[AltContent: textbox ([img-media_image1.png]
Figure 1a. from Wu et al. showing mixed material assembly)]
Wu et al. further discloses coating the (cut) edges by using epoxy resin or coating all of the exposed surfaces with a polyurethane as a means to prevent corrosion as discussed in section 3.3. Exfoliation corrosion characterization. In both cases, the application of an organic coating significantly reduced the corrosion of the CARALL composite material (Figure 6, Figure 7, and Figure 8). The organic coating provided by Wu et al. prevents or inhibits the cathodic reduction of oxygen by blocking chemisorption of the oxygen by the carbon fibers to prevent or inhibit formation of the galvanic couple between the polymeric composite and the metal substrate as supported by Figure 10 which shows the mechanism of crevice corrosion and is discussed on pg. 666. However, Wu et al. does not disclose the corrosion inhibition of the mixed material assembly of Claim 21 resulting from the formation of an adlayer using diazonium salts.
The use of an adlayer resulting from the formation of a film from a diazonium salt to prevent corrosion or reduce oxidative activity of either conductive substrates and/or electrodes is well-established in the prior art.
For example, Su et al. is directed toward the formation of an electrografted layer formed from diazonium salt (pg. 1: abstract) on an aluminum alloy (7075). In the introduction on pg.2, Su et al. indicated that deposited phenylene layers (i.e.: adlayer) on the surfaces of Cu and the 2024 T3 aluminum alloy reduced the corrosion processes on these metal surfaces and could potentially replace toxic corrosion inhibitors (i.e.: chrome-based materials). Furthermore, Su et al. indicated that electrografting on the substrate occurred using cyclic voltammetry by the applying a potential scanning between −0.1 and −1.0 V vs. Ag/AgCl at 50 mV/s with the maximum negative vertex occurring at a potential of −0.4 V (pg. 3: 2.2. Electrografting of 4-NBD on the Al-7075 Substrate). The electrolyte used for the deposition is comprised of 3 mM 4-nitrophenyldiazonium tetrafluoroborate (i.e.: “NP” or “4-NBD”) dissolved in 0.1 M Bu4NBF4 supporting electrolyte in acetonitrile (pg. 3: 2.2. Electrografting of 4-NBD on the Al-7075 Substrate). On pg. 7, Su et al. further explains that an irreversible diffusion-controlled voltametric peak observed peak around −0.6 V (vs. Ag/AgCl) is attributed to the electrochemical reduction of the diazonium salt (3.2. 4-NBD Electrografting of the Treated Al-7075 Substrates). The electroreduction of the diazonium subsequently generates the aryl radical species in the vicinity of the electrode that bind to the metal or oxide surface, release N2, and covalently attach nitrophenylene layers on the substrate surface (pg. 7: 3.2. 4-NBD Electrografting of the Treated Al-7075 Substrates). In the discussion, Su et al. concluded that the ultra-thin organic film deposited on the surface of the Al alloy represents an efficient way to improve the corrosion resistance and adhesive properties of such alloys (pg. 19).
Kullapere et al. is directed toward the oxygen reduction activity of carbon treated with aryl diazonium salts (pg. 183: title and abstract). An adlayer was deposited using cyclic voltammetry onto a glassy carbon electrode. The application conditions were a scanning window of -1.2 V to 0.6 V and a sweep rate of 100 mV/s using an electrolyte comprised of 1 mM solution aryl diazonium salt (e.g.: C6H5N2BF4) and 0.1 M nBu4NBF4 in acetonitrile (pg. 185: 2. Experimental Section). Kullapere et al. further indicated that the barrier properties of covalently attached phenyl layers (i.e.: adlayer) are of considerable interest to study the reduction of oxygen on GC electrodes modified with barrier layers of various organic compounds (pg. 184). Kullapere et al. also indicated that nitro-substitution on the aryl diazonium salt is known to form very compact films (pg. 184: 1. Introduction) which likely improve barrier properties (i.e.: corrosion resistance) of the adlayer. Kullapere et al. found that the highest blocking efficiency (of oxygen) was observed for phenyl-modified glassy carbon electrodes with respect to the oxygen reduction reaction (pg. 192: 4. Conclusion). The behavior would reasonably be expected to operate on the carbon fiber of a carbon fiber epoxy.
It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to replace the polyurethane or epoxy film applied to the composite (aluminum + carbon fiber/epoxy) in Wu et al. by using the electrografting method to deposit diazonium salts as described by the combination of Su et al. and Kullapere et al. with the reasonable expectation of inhibiting corrosion of the assembly. Electrografting improves the adlayer coverage and quality as phenylene film is deposited on the (exposed) surfaces and into recessed areas as compared to the epoxy/polyurethane film that can only be applied to visible areas (i.e.: line of sight). Moreover, the adlayer deposited using electrografting would provide a barrier to oxygen and salt electrolyte thus reducing corrosion of mixed material assemblies.
Regarding Claim 12, Xu et al. in view of Su et al. and Kullapere et al. disclose the method according to Claim 21, wherein the solution includes 3 mM diazonium salt (e.g.: “NP”) dissolved in 0.1 M Bu4NBF4 supporting electrolyte in acetonitrile (Su et al. on pg. 3: 2.2. Electrografting of 4-NBD on the Al-7075 Substrate). A prima facie case of obviousness exists when an example disclosed in the prior art overlaps with the claimed range (i.e.: concentration of diazonium salt and supporting electrolyte). See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
Regarding Claim 13, Xu et al. in view of Su et al. and Kullapere et al. disclose the method according to Claim 21, wherein the molecular adlayer is formed using an electrochemically-assisted mechanism as described in Su et al. where the electrografting of the diazonium salt is achieved using cyclic voltammetry with the applied potential ranging from −0.1 and −1.0 V vs. Ag/AgCl at sweep rate of 50 mV/s with the maximum negative vertex occurring at a potential of −0.4 V (pg. 3: 2.2. Electrografting of 4-NBD on the Al-7075 Substrate
A prima facie case of obviousness exists when an example disclosed in the prior art overlaps with the claimed range (i.e.: voltage range and scan rate). See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
Regarding Claim 14, Xu et al. in view of Su et al. and Kullapere et al. disclose the method according to Claim 13, wherein the potential electrochemically reduces “NP” and attaches via an aryl radical to the carbon fibers to form the adlayer as discussed Su et al. Su et al. indicates the electroreduction of the diazonium subsequentially generates the aryl radical species in the vicinity of the electrode that bind to the surface (of the carbon fiber), release N2, and covalently attach nitro-phenylene layers on the surface of the substrates (pg. 7: 3.2. 4-NBD Electrografting of the Treated Al-7075 Substrates).
Regarding Claim 20, Xu et al. in view of Su et al. and Kullapere et al. disclose the method according to Claim 21, wherein the adlayer is covalently bonded to the plurality of exposed carbon fiber as discussed Su et al. Su et al. indicates the electroreduction of the diazonium subsequentially generates the aryl radical species in the vicinity of the electrode that bind to the surface (of the carbon fiber), release N2, and covalently attach nitro-phenylene layers on the surface of the substrates (pg. 7: 3.2. 4-NBD Electrografting of the Treated Al-7075 Substrates).
7. Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. Su et al. and Kullapere et al. as applied to Claim 13 above, and further in view of Bureau et al.
Wu et al. (“Corrosion damage evolution and mechanical properties of carbon fiber reinforced aluminum laminate,” J. Cent. South Univ. 2021, 28, 657-668) is directed toward corrosion in mixed materials (pg. 657: title and abstract). Su et al. (“Electrografting of 4-Nitrobenzenediazonium Salts on Al-7075 Alloy Surfaces-The Role of Intermetallic Particles. Nanomaterials 2021, 11(4), article 894, pg. 1-22) is directed toward treatment of aluminum alloys with an organic film (pg. 1: title and abstract). Kullapere et al. (“Oxygen electroreduction on chemically modified glassy carbon electrodes in alkaline solution,” J. Electroanal. Chem. 2007, 599(2), 183-193). Bureau et al. (US Patent No. 7,736,484 – previously presented) is directed toward the growing and grafting of an organic film onto substrates (title).
Regarding Claim 15, Xu et al. in view of Su et al. and Kullapere et al. disclose the method according to Claim 13, wherein the potential is applied to the carbon fibers resulting in the formation of the adlayer. However, the combination of references fails to explicitly disclose a film with a total thickness range of 1 micron to 10 microns deposited over multiple cycles.
Like Su et al. and Kullapere et al., Bureau et al. is directed toward a method of grafting and growing an organic film on a substrate (title). According to Col 4 Lines 45-67, Bureau et al. discloses that an organic film can be grown onto a substrate when a more cathodic potential is applied to the surface of the substrate than required for electro-reduction of a diazonium salt. For example, Bureau et al. indicates the 4-nitrophenyl diazonium tetrafluoroborate, “NP,” is electro-reduced at -0.1 V vs. Ag/Ag+ as depicted in FIG. 1 during a voltage sweep between +0.3 V and -2.9 V vs. Ag/Ag+ at scan rate of 50 mV/s (Col 4 Lines 64-67 through Col 5 Lines 1-5. Bureau et al. discloses that the thickness of the adlayer can be controlled by increasing the number of sweeps according to Ex. 1 showing that one sweep results in a film thickness of 3 nm, ten sweeps results in a film thickness of 30 nm, and sweeps results in a film thickness of 100 nm when using 4-nitrophenyldiazomium tetrafluoroborate as the aryl radical source (Col 11 Lines 39-43). Bureau et al. further indicates that films between 2 nm and 500 nm can easily be formed when using 4-nitrophenyldiazomium tetrafluoroborate, “NP,” (Col 6 Lines 31-34) as per the disclosed application method. Therefore, the film thickness is a result-effective variable, i.e., a variable which achieves a recognized result, and the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation (See MPEP 2144.0.II.B.). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have discovered the optimum or workable ranges of the film thickness including values within the claimed range, through routine experimentation (by changing the number of voltage sweeps). One would have been motivated to do so in order to have formed an adlayer of sufficient thickness for improving the corrosion protection of the carbon fiber/conductive surface as indicated in Bureau et al. (Col 7 Lines 52-58).
8. Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. Su et al. and Kullapere et al. as applied to Claim 13 above, and further in view of Bureau et al. and Allongue et al.
Wu et al. (“Corrosion damage evolution and mechanical properties of carbon fiber reinforced aluminum laminate,” J. Cent. South Univ. 2021, 28, 657-668) is directed toward corrosion in mixed materials (pg. 657: title and abstract). Su et al. (“Electrografting of 4-Nitrobenzenediazonium Salts on Al-7075 Alloy Surfaces-The Role of Intermetallic Particles. Nanomaterials 2021, 11(4), article 894, pg. 1-22) is directed toward treatment of aluminum alloys with an organic film (pg. 1: title and abstract). Kullapere et al. (“Oxygen electroreduction on chemically modified glassy carbon electrodes in alkaline solution,” J. Electroanal. Chem. 2007, 599(2), 183-193). Bureau et al. (US Patent No. 7,736,484) is directed toward a method for grafting and growing a conductive organic film on a surface (title). Allongue et al. (“Covalent Modification of Carbon Surfaces by Aryl Radicals Generated from the Electrochemical Reduction of Diazonium Salts,” J. Am. Chem. Soc. 1997, 119, 201-207 – previously presented) is directed toward functionalizing carbon surfaces using electrochemically reduced diazonium salts (pg. 201: title and abstract).
Regarding Claim 16, Xu et al. in view of Su et al. and Kullapere et al. disclose the method according to Claim 13, wherein the potential is applied to the carbon fibers resulting in the formation of the adlayer. However, the combination of references fails to explicitly disclose multiple deposition cycles to deposit the adlayer in an amount ranging up to 10 nmol/cm2.
Like Su et al. and Kullapere et al., Bureau et al. is directed toward a method of grafting and growing an organic film on a substrate (title). According to Col 4 Lines 45-67, Bureau et al. discloses that an organic film can be grown onto a substrate when a more cathodic potential is applied to the surface of the substrate than required for electro-reduction of a diazonium salt. Bureau et al. further discloses that the thickness of the adlayer can be controlled by increasing the number of sweeps according to Ex. 1 showing that one sweep results in a film thickness of 3 nm, ten sweeps results in a film thickness of 30 nm, and sweeps results in a film thickness of 100 nm when using 4-nitrophenyldiazomium tetrafluoroborate as the aryl radical source (Col 11 Lines 39-43). Bureau et al. further indicates that films between 2 nm and 500 nm can easily be formed when using 4-nitrophenyldiazomium tetrafluoroborate, “NP,” (Col 6 Lines 31-34) as per the disclosed application method.
Therefore, it would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the deposition method Wu et al., Su et al, and Kullapere et al. by controlling the thickness of the deposited adlayer by modulating the number of cycles to ensure appropriate coverage to improve corrosion resistance of the multi-material assembly. However, the combination of Wu et al. Su et al. Kullapere et al. and Bureau et al. fail to disclose the amount of adlayer deposited in nmol/cm2.
Allongue et al. discloses the electrochemical reduction of 4-nitrophenyldiazonium tetrafluoroborate on highly oriented pyrolytic graphite (HOPG) as the carbon substrate (pg. 201: abstract and title). Allongue et al. applies a grafted film to the surface of the carbon substrate using a similar electrochemical deposition method (i.e.: supporting electrolyte and diazonium salt) as disclosed by Su et al., Kullapere et al., or Bureau et al.
Allongue et al. further discloses the surface functionalization of carbon with nitro-substituted aryl groups can be derivatized to allow further chemical functionalization of said carbon surface (pg. 206). When 4-nitrophenyldiazonium salt is used as the aryl source, the nitro-group can be converted to an amine, which would allow for further chemical reaction with epoxy polymers as discussed on pg. 206. Allongue et al. suggests this derivatization of the carbon surface may strengthen the carbon (fiber) composite interface (pg. 206). Therefore, maximizing the coverage of the carbon surface with the adlayer from the electro-reduction of the diazonium salt is important. Allongue et al. discusses on pg. 205 in the “Results and Discussion” section that the deposition of an adlayer from 4-nitrophenyldiazonium tetrafluoroborate reaches a saturation level around 41 x 10-10 mol/cm2 which converts to 4.1 nmol/cm2.
It would be obvious for one of ordinary skill in the art prior to the effective filing date of the claimed invention to apply the adlayer using the deposition method of Wu et al. Su et al. Kullapere et al. and Bureau et al. to cover the carbon surface with the loading level taught in Allongue et al. with the reasonable expectation of forming a carbon (fiber) composite with improved interfacial properties as discussed in Allongue et al. on pg. 206 and likely an improvement in corrosion resistance.
It has been held that a prima facie case of obviousness exists when an example (surface loading level of ~4 nmol/cm2) disclosed in the prior art is contained within the claimed range (surface loading level up to 10 nmol/cm2) of the instant application. See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
9. Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. Su et al. and Kullapere et al. as applied to Claim 21 above, and further in view of Palani et al.
Wu et al. (“Corrosion damage evolution and mechanical properties of carbon fiber reinforced aluminum laminate,” J. Cent. South Univ. 2021, 28, 657-668) is directed toward corrosion in mixed materials (pg. 657: title and abstract). Su et al. (“Electrografting of 4-Nitrobenzenediazonium Salts on Al-7075 Alloy Surfaces-The Role of Intermetallic Particles. Nanomaterials 2021, 11(4), article 894, pg. 1-22) is directed toward treatment of aluminum alloys with an organic film (pg. 1: title and abstract). Kullapere et al. (“Oxygen electroreduction on chemically modified glassy carbon electrodes in alkaline solution,” J. Electroanal. Chem. 2007, 599(2), 183-193). Palani et al. (“Modeling Galvanic Corrosion Behavior of Carbon Fiber Composite/AL 7050 Joints Under Extended Exposure,” 2017 Department of Defense – Allied Nations Technical Corrosion Conference, Paper No. 2017-867530, pg. 1-9 – previously presented) is directed toward studying galvanic corrosion of CFC and Al assemblies (pg. 1: abstract).
Regarding Claim 22, Wu et al. Su et al. and Kullapere et al. disclose the method of Claim 21 where the carbon fiber has a cut edge as per Wu et al. on pg. 659 in section 2.1 Materials and specimen preparation. However, the combination of references is silent on abrading the exposed carbon fiber.
Palani et al. discloses that galvanic corrosion is an issue between dissimilar metal including CFC (first substrate) and AL 7075 (second substrate) (pg. 1: abstract and pg. 1-2: introduction) like noted for the CARALL substrate of Wu et al. Palani et al. investigated the material degradation from these assemblies joined by titanium fasteners. Palani et al. further indicated providing a preformed CFC (carbon fiber composite) that cut and machined in order to provide exposed carbon fiber for corrosion testing (pg. 2: materials). Palani et al. also disclosed that the cut CFC edges were machined down (analogous to abrading of Claim 22) to about 100 microns in order to remove the outer resin layer and expose the surface-parallel carbon fibers to create a defined CFC surface and a worst-case galvanic condition when coupled with aluminum (pg. 2: materials). The application of the adlayer film as in Wu et al. Su et al. and Kullapere et al. would reasonably be expected to inhibit the galvanic couple between the two substrates owing to the electrically insulating nature of the organic film (i.e.: the adlayer) formed by coating (at least) the exposed carbon fiber from the electrochemical application diazonium salt electrolyte solution.
It would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method of coating carbon fiber of Wu et al. Su et al. and Kullapere et al. by providing a cut piece of carbon fiber composite that was abraded as taught in Palani et al. with the reasonable expectation of providing an adlayer with that would provide adhesion improvements and corrosion resistance to the cut carbon fiber representative of the worst case corrosion scenario.
Response to Arguments
10. The examiner agrees with the applicant’s arguments that Delamar et al. (previously presented) and Hurley et al. (previously presented) does not expressly disclose a method of reducing corrosion/preventing corrosion as per (amended) independent Claim 21; hence, the previous rejections under 103 are withdrawn. However, new grounds for rejection pertaining to the method are discussed in detail above.
Conclusion
11. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KEVIN SYLVESTER whose telephone number is (703)756-5536. The examiner can normally be reached Mon - Fri 8:15 AM to 4:30 PM EST.
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/KEVIN SYLVESTER/Examiner, Art Unit 1794
/JAMES LIN/Supervisory Patent Examiner, Art Unit 1794