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 Status
The Preliminary Amendment filed on 28 June 2024 has been entered; claims 1-14, 16, and 17 remain pending.
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.
Claims 1-14, 16, and 17 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, 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.
With respect to claim 1, the limitation “superhydrophobic” appears to be a relative term which renders the claim indefinite. The term “superhydrophobic” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. For the purposes of examination, the Examiner will interpret the limitation “superhydrophobic” as consistent with the contact angles recited in claim 4.
Regarding claims 2-14, 16, and 17, they are rejected for being dependent on or otherwise incorporating the limitations of a rejected base claim.
Claim Rejections - 35 USC § 103
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 1-5, 9-14, 16, and 17 are rejected under 35 U.S.C. 103 as being unpatentable over WO # 2013/074040 in view of Liao et al. (Journal of Membrane Science, 2020, 601, 117692), hereinafter “WO (‘040)” and “Liao”.
With respect to claims 1-3, 13, and 14, WO (‘040) discloses a nanofilament-coated membrane 200 having hierarchical porous structures (see below pore size range differences for microporous and nanoporous layers) comprising:
a microporous polymer support membrane 215 having through-going pores with a nominal pore diameter in the range from 0.01 to 1 µm (Page 10, lines 12-13, overlapping a portion of “0.2 µm to 50 µm” and touching the claimed range “1 µm to 10 µm” as recited in claim 2); and
an electrospun nanofiber layer 205 (“superhydrophobic fluorine-free nanoporous layer”) having through-going pores with a nominal pore diameter in the range of 0.05 µm and 5.0 µm or 50 to 5,000nm (overlapping “from 5 nm to 200 nm” and “from 10 nm to 100 nm” as recited in claim 2) (Page 10, lines 19-22) provided on said support membrane and comprising a porous network of nanofibers (“nanofilaments”) (see Page 12, lines 17-27) and a hydrophobic additive including polydimethylsiloxane (Page 13, lines 20-24), wherein the electrospun layer has a contact angle of 140-160° (see Page 14, lines 1-4, which overlaps “more than 150°” for the receding contact angle for water recited in claim 4 and therefore is considered to at least render obvious the limitation “superhydrophobic”). WO (‘040) teaches that the nanofilament-coated porous membrane of WO (‘040) is used in a membrane distillation system 300 (“device”) (Fig. 3; Page 4, lines 24-26; Page 10, lines 24-33), and that the microporous polymer support membrane comprises PVDF (Page 13, lines 29-30).
WO (‘040) teaches an electrospun nanofiber layer comprising PDMS as an additive, but does not specifically teach that the PDMS additive is in the form of nanofilaments.
Liao teaches a surface layer comprising PDMS nanofibers (Abstract; Section 2.2).
It would have been obvious to one of ordinary skill in the art at the time the invention was effectively filed to modify the PDMS additive of WO (‘040) with the PDMS nanofibers of Liao because both references teach membranes that are used in membrane distillation and WO (‘040) teaches a hydrophobic surface layer (see above), and because Liao teaches that the membrane with surface layer comprising PDMS nanofibers is robust and mitigates membrane scaling in fouling in membrane distillation (Title; Abstract). It is noted that the particular method of measuring the pore diameter is not assigned patentable weight in membrane claim 1, as the pore size should be the same no matter how it is measured, and because the limitations recite an implied method step of measuring pore size which does not further limit the membrane claims.
WO (‘040) in view of Liao and the claims differ in that WO (‘040) does not teach the exact same proportions for the pore size range of the microporous polymer support layer and the superhydrophobic fluorine-free nanoporous layer as recited in the instant claims.
However, one of ordinary skill in the art at the time the invention was made would have considered the invention to have been obvious because the range in pore sizes for the microporous polymer support layer and the superhydrophobic fluorine-free nanoporous layer taught by WO (‘040) overlap the instantly claimed proportions and therefore are considered to establish a prima facie case of obviousness. It would have been obvious to one of ordinary skill in the art to select any portion of the disclosed ranges including the instantly claimed ranges from the ranges disclosed in the prior art reference, particularly in view of the fact that; “The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages”, In re Peterson, 65 USPQ2d 1379 (CAFC 2003).
With respect to claim 4, WO (‘040) teaches a contact angle of 140-160 for the electrospun layer, while Liao teaches a contact angle of 170 ± 1° for the PDMS-3 layer, which has a sliding (“rolling off”) contact angle of 4.3 ± 0.1° (See Table 2). Although WO (‘040) in view of Liao does not teach a rolling contact angle of less than 10° after the recited hot water treatment; however, it has been held that where the claimed parameters/properties may be expressed differently and thus may be distinct from what is disclosed in the prior art, it is incumbent upon applicants to establish that such difference is unobvious. Therefore, it would have been obvious to one having ordinary skill in the art at the time of the invention to employ the particular parameters as claimed, since it is well-established that merely selecting proportions and ranges is not patentable absent a showing of criticality. In re Becket, 33 USPQ 33, and In re Russell, 169 USPQ 426.
With respect to claim 5, WO (‘040) in view of Liao teaches that the membrane has a liquid entry pressure of 350 kPa or 3.5 bar (“at least 2 bar”) (Page 9, lines 1-3).
With respect to claims 9-11, WO (‘040) in view of Liao renders obvious the membrane of claim 1, wherein in operation vapor from the heated distilland evaporates at the liquid-vapor interface located at the nanofiber layer 205. Due to the temperature gradient and the vapor pressure gradient across composite membrane 200, the water vapor permeates across composite membrane 200. The pores of microporous layer 215 filters the water vapor molecules. The filtered water vapor molecules then condenses at the vapor-liquid interface located at backing layer 210. The condensed liquid (water) is then collected at distillate area 130 (Page 14, lines 16-24, and see liquid feed or “solution” described on Page 1, lines 18-20 in general terms for membrane distillation).
With respect to claims 12, 16, and 17, WO (‘040) in view of Liao teaches that the distilland feed is a salt solution from which water is distilled, wherein the membrane distillation system 300 comprises distillate collection area 130, a condensing surface device, cold surface 125 (“cooling device”), and heating device for heating distilland 110 contained within a supply component for the aqueous salt solution distilland (see Page 9, large middle paragraph and see the paragraph spanning Pages 10-11).
Claims 6-8 are rejected under 35 U.S.C. 103 as being unpatentable over WO # 2013/074040 in view of Liao et al. (Journal of Membrane Science, 2020, 601, 117692) as applied to claim 1, and further in view of Rollings et al. (Langmuir, 2008, 24, 13653-13662) and Zhang et al. (Angew. Chem. Int. Ed., 2011, 50, 6652-6656), hereinafter “WO (‘040)”, “Liao”, “Rollings”, and “Zhang”.
With respect to claims 6-8, WO (‘040) in view of Liao discloses the membrane of claim 1, but forms the membrane via electrospinning the nanofilaments onto the microporous support, but that also that other methods of preparation can be used (see WO (‘040): Page 12, lines 17-21, see also Section 2.2 of Liao).
Rollings teaches formation of polysiloxane nanofibers on a surface, wherein the surface is first activated by oxygen plasma to remove contaminants, followed by immersion in an aqueous solution of octyltrichlorosilane, where surface -OH groups react with the octyltrichlorosilane to form polysiloxane nanofibers (nanofilaments) via condensation with reaction times ranging from 10 to 60 min (see Abstract; “Substrate Preparation and Activation” though “Polysiloxane Nanofiber Synthesis” Sections on Pages 13654-13655). Although Rollings teaches octyltrichlorosilane instead of trichloromethylsilane, Zhang teaches a similar method of forming self-assembled polysiloxane nanofilaments using trichloromethylsilane and employing toluene or alkane solvents (See Page 6652, right column, first full paragraph until the last line of the right column).
It would have been obvious to one of ordinary skill in the art at the time the invention was effectively filed to modify the method of preparation of the nanofiber/filament layer of WO (‘040) in view of Liao with the solution immersion and condensation methods disclosed by Rollings and Zhang because WO (‘040) teaches that the nanofiber layer can be prepared by other known methods and the methods of Rollings and Zhang also produce superhydrophobic polysiloxane nanofibers/filaments which are stable (see Zhang, paragraph spanning Pages 6652-6653).
Claim 7 is rejected with claim 6 as optional as the oxygen plasma activation embodiment was selected and taught by Rollings.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CLARE M PERRIN whose telephone number is (571)270-5952. The examiner can normally be reached 9AM-6PM EST M-F.
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/CLARE M. PERRIN/
Primary Examiner
Art Unit 1779
/CLARE M PERRIN/ Primary Examiner, Art Unit 1779
22 June 2026
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