Structured nanoporous materials, manufacture of structured nanoporous materials and applications of structured nanoporous materials

Patent metadata

Field	Value
Publication number	US-2021003915-A1
Application number	US-201916979367-A
Country	US
Kind code	A1
Filing date	Mar 13, 2019
Priority date	Mar 13, 2018
Publication date	Jan 7, 2021
Grant date	—

Abstract

A method is disclosed for manufacturing a structured polymeric material. In the method, a body is provided comprising a substantially homogenous precursor polymeric material. An interference pattern of electromagnetic radiation is set up within the body to form a partially cross-linked polymeric material, the interference pattern comprising maxima and minima of intensity of the electromagnetic radiation, the interference pattern thereby causing spatially differential cross linking of the precursor polymeric material to form crosslinked regions having relatively high cross linking density and non-crosslinked regions having relatively low cross linking density, the crosslinked regions and non-crosslinked regions corresponding to the maxima and minima of intensity of the electromagnetic radiation, respectively. The partially cross-linked polymeric material is then contacted with a solvent to cause expansion and crazing of at least some of the non-crosslinked regions to form a structured polymeric material containing pores.

First claim

1 - 32 . (canceled)

33 . A polymeric structure having a plurality of lamellae, adjacent lamellae being spaced apart by an intervening spacing layer wherein the spacing layer comprises an array of spacing elements integrally formed with and extending between the adjacent lamellae, the spacing layer having interconnected porosity extending within the spacing layer.

34 . The polymeric structure according to claim 33 wherein the lamellae are substantially non-porous.

35 . The polymeric structure according to claim 33 and having a first region and a second region, adjacent the first region, wherein the first region differs from the second region in that the first region is a nanoporous material having the plurality of lamellae, adjacent lamellae being spaced apart by the intervening spacing layer.

36 . The polymeric structure according to claim 33 and having a first region and a second region, each having the plurality of lamellae, adjacent lamellae spaced apart by the intervening spacing layer wherein in the first region the adjacent lamellae are spaced apart by a first characteristic spacing and in the second region the adjacent lamellae are spaced apart by a second characteristic spacing, different to the first characteristic spacing so that the first and second regions display different structural color under white light illumination at the same angle of incidence.

37 . The polymeric structure according to any one of claim 35 wherein the first region and the second region have substantially the same composition.

38 . The polymeric structure according to any one of claim 35 wherein the polymeric structure is in the form of a layer, the first and second regions extending through the thickness of the layer.

39 . The polymeric structure according to claim 33 wherein the degree of porosity of the spacing layer is greater than that of the lamellae.

40 . The polymeric structure according to claim 33 wherein the nanoporous material is a cross linked polymeric material.

41 . A method for manufacturing a structured polymeric material, the method comprising:
providing a body comprising a precursor polymeric material; setting up an interference pattern of electromagnetic radiation within the body comprising precursor polymeric material to form a partially cross-linked polymeric material, the interference pattern comprising maxima and minima of intensity of the electromagnetic radiation, the interference pattern thereby causing spatially differential cross linking of the precursor polymeric material to form crosslinked regions having relatively high cross linking density and non-crosslinked regions having relatively low cross linking density, the crosslinked regions and non-crosslinked regions corresponding to the maxima and minima of intensity of the electromagnetic radiation, respectively, contacting the partially cross-linked polymeric material with a solvent to cause expansion and crazing of at least some of the non-crosslinked regions to form a structured polymeric material containing pores,
wherein the precursor polymeric material is substantially homogenous.

42 . The method according to claim 41 wherein the precursor polymeric material, at the time of setting up the interference pattern of electromagnetic radiation within the body of precursor polymeric material, consists of a single phase.

43 . The method according to claim 41 wherein the precursor polymeric material, at the time of setting up the interference pattern of electromagnetic radiation within the body of precursor polymeric material, comprises one or more homopolymer, one or more copolymer and/or one or more block copolymer.

44 . The method according to claim 41 wherein the precursor polymeric material comprises a photo-initiator, operable to cause cross linking of the precursor polymeric material on exposure to visible light.

45 . The method according to claim 41 wherein the solvent used to cause expansion and crazing falls outside the Hansen solubility sphere for the precursor polymeric material when plotted in Hansen space but lies close enough to the Hansen solubility sphere for the precursor polymeric material to plasticize and expand the precursor polymeric material.

46 . The method according to claim 41 wherein the precursor polymeric material is formed as a layer on a substrate, a surface of the substrate providing a reflection interface for setting up the interference pattern.

47 . The method according to claim 41 wherein a first region of the precursor polymeric material is selectively exposed to the electromagnetic radiation and a second region of the precursor polymeric material is not exposed to the electromagnetic radiation so that the expansion and crazing takes place only in the first region at which there is formed the structured polymeric material containing pores.

48 . The method according to claim 47 wherein the second region is shielded from the electromagnetic radiation by a mask.

49 . The method according to claim 47 wherein the first region is selectively exposed to the electromagnetic radiation by a laser.

50 . The method according to claim 41 wherein a first region of the precursor polymeric material is selectively exposed to electromagnetic radiation to form a first interference pattern having a characteristic first periodicity to form a stratified porous structure having a corresponding first periodicity, and a second region of the precursor polymeric material is selectively exposed to electromagnetic radiation to form a second interference pattern having a characteristic second periodicity, different to the first periodicity, to form a stratified porous structure having a corresponding second periodicity.

51 . A method for manufacturing a structured polymeric material, the method comprising:
providing a body comprising a precursor polymeric material; selectively exposing a first region of the precursor polymeric material to electromagnetic radiation to form a first interference pattern having a characteristic first periodicity; selectively exposing a second region of the precursor polymeric material to electromagnetic radiation to form a second interference pattern having a characteristic second periodicity, different to the first periodicity,
wherein the first and second interference patterns interact with the precursor polymeric material to form a partially cross-linked polymeric material, each interference pattern comprising maxima and minima of intensity of the electromagnetic radiation, the interference patterns thereby causing spatially differential cross linking of the precursor polymeric material to form crosslinked regions having relatively high cross linking density and non-crosslinked regions having relatively low cross linking density, the crosslinked regions and non-crosslinked regions corresponding to the maxima and minima of intensity of the electromagnetic radiation, respectively,
the method further comprising:
contacting the partially cross-linked polymeric material with a solvent to cause expansion and crazing of at least some of the non-crosslinked regions to form a stratified porous structure in the first region having a corresponding first stratified porous structure periodicity, and a stratified porous structure in the second region having a corresponding second stratified porous structure periodicity, different to the first stratified porous structure periodicity.

52 . The method according to claim 51 wherein the first and second interfe

Assignees

• Univ Kyoto

Inventors

• Sivaniah Easan
• Ito Masateru
• Yamamoto Daisuke

Classifications

• B29C35/0894

  provided with masks or diaphragms · CPC title

• B29C35/0805 Primary

  using electromagnetic radiation · CPC title

• C08J7/02

  with solvents, e.g. swelling agents · CPC title

• C08J3/28

  Treatment by wave energy or particle radiation · CPC title

• C08J2369/00

  Characterised by the use of polycarbonates; Derivatives of polycarbonates · CPC title