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US-12624191-B2 - Polymeric opal

US12624191B2US 12624191 B2US12624191 B2US 12624191B2US-12624191-B2

Abstract

The present disclosure provides a polymeric opal comprising a polymer and an additive. The additive comprises a two-dimensional (2D) material and/or a carbon nanotube and the weight ratio of the polymer to the additive is between 100:0.001 and 00:0.1.

Inventors

  • Izabela JUREWICZ
  • Alan DALTON

Assignees

  • UNIVERSITY OF SURREY

Dates

Publication Date
20260512
Application Date
20191205
Priority Date
20181205

Claims (20)

  1. 1 . A polymeric opal consisting of comprising: a polymer consisting of a plurality of polymer particles defining interstitial sites between the polymer particles; an additive disposed in the interstitial sites, the additive comprising a two-dimensional (2D) material and/or a carbon nanotube, wherein the weight ratio of the polymer to the additive is between 100:0.001 and 100:0.1; a fluid disposed in the interstitial sites; optionally one or more surfactants; and optionally a polymer coating.
  2. 2 . The polymeric opal of claim 1 , wherein the additive consists of a 2D material.
  3. 3 . The polymeric opal of claim 2 , wherein the 2D material comprises a plurality of 2D material particles having a mean thickness of less than 50 nm and a largest lateral dimension with a mean size of less than 30 μm and/or wherein the 2D material is selected from the group consisting of graphene, hexagonal boron nitride (h-BN) and a transition metal dichalcogenide.
  4. 4 . The polymeric opal of claim 1 , wherein the polymeric opal comprises a surfactant.
  5. 5 . The polymeric opal of claim 4 , wherein the surfactant comprises a non-ionic surfactant.
  6. 6 . The polymeric opal of claim 5 , wherein the non-ionic surfactant comprises wherein n is an integer between 1 and 50, and/or a polysorbate.
  7. 7 . The polymeric opal of claim 5 , wherein the volumetric ratio of the polymer to the non-ionic surfactant is between 100:0.0001 and 100:2.
  8. 8 . The polymeric opal of claim 1 , wherein the polymer has a dry glass transition temperature (Tg) between 0° C. and 100° C.
  9. 9 . The polymeric opal of claim 1 , wherein the plurality of particles have an average particle size of between 50 nm and 1,000 nm.
  10. 10 . The polymeric opal of claim 1 , wherein the polymer comprises a carboxylic acid group.
  11. 11 . The polymeric opal of claim 1 , wherein the fluid is an interstitial liquid.
  12. 12 . The polymeric opal of claim 11 , wherein the polymeric opal comprises a polymer coating, optionally wherein the polymer coating is configured to modify the rate of evaporation of the interstitial liquid.
  13. 13 . The polymeric opal of claim 11 , wherein the interstitial liquid comprises between 0.5 wt % and 30 wt % of the polymeric opal.
  14. 14 . The polymeric opal of claim 11 , wherein the interstitial liquid comprises water, an alcohol, or an amine.
  15. 15 . The polymeric opal of claim 1 , wherein the polymeric opal exhibits a stopband at a wavelength between 200 nm and 1000 nm.
  16. 16 . A photonic paper, an item of jewelry, a time-temperature indicator, a mechano-chromic sensor, a waveguide, a scaffold for tissue engineering, or a sensor, comprising a polymeric opal as defined in claim 1 .
  17. 17 . An anti-counterfeiting kit comprising a photonic paper, as defined by claim 16 , and a pen comprising a solvent.
  18. 18 . The polymeric opal of claim 1 , wherein the two-dimensional (2D) material and/or the carbon nanotube are disposed in the interstitial sites.
  19. 19 . The polymeric opal of claim 1 , wherein the plurality of polymer particles are assembled in a close-packed structure.
  20. 20 . The polymeric opal of claim 19 , wherein the plurality of polymer particles are assembled in a hexagonal close-packed structure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a 35 U.S.C. § 371 application of International Application No. PCT/GB2019/053435, filed on Dec. 5, 2019, which claims the benefit of European Patent Application GB 1819852.3, filed on Dec. 5, 2018, the entireties of which are hereby incorporated by reference. The present invention relates to a polymeric opal. The invention extends to a method of producing the polymeric opal and various uses of the polymeric opal. Nature has presented us with incredible examples of functional materials. Structural colour, as found in butterfly wings or opal gem stones, is particularly fascinating. Mimicking such behaviour using synthetic photonic crystals consisting of highly ordered assemblies of monosize colloidal particles is promising for a range of novel and emerging applications. One of the major limiting factors for colloidal photonic crystals requiring colour perceptibility, is their opaque nature. The origin of the opacity is structural disorder causing strong incoherent scattering that generates diffuse light as well as a low refractive index contrast. The present invention arises from the inventors' attempts in producing synthetic colloidal photonic crystals. In accordance with a first aspect of the invention, there is provided a polymeric opal comprising a polymer and an additive, wherein the additive comprises a two-dimensional (2D) material and/or a carbon nanotube and the weight ratio of the polymer to the additive is between 100:0.001 and 100:0.1. Advantageously, the inventors have found that polymeric opals as defined in the first aspect are mechanically robust, free-standing, flexible and thick synthetic opals containing an additive locked in a colloidal polymer crystal lattice. In particular, the additive markedly increases iridescence and reduces deleterious scattering producing a strong angle-dependent structural colour and a stopband that can be reversibly shifted across the visible spectrum. For the graphene and polymers used in the examples, a weight ratio of between 100:0.001 and 100:01 corresponds to a volumetric ratio of between about 100:0.0005 and 100:005. The weight ratio of the polymer to the additive may be between 100:0.002 and 100:0.08, more preferably between 100:0.004 and 100:0.06, between 100:0.006 and 100:0.04 or between 100:0.007 and 100:0.02, and most preferably between 100:0.008 and 100:0015 or between 100:0.009 and 100:0.0125. Alternatively, or additionally, the volumetric ratio of the polymer to the additive may be between 100:0.001 and 100:001, more preferably between 100:0.002 and 100:0.08 or between 100:0.003 and 100:0.007, and most preferably between 100:0.004 and 100:0.006. The additive may consist of a 2D material. The term “2D material” can refer to a material with a thickness of a few nanometres or less. Accordingly, the material could have a thickness of 10 nm or less, 5 nm or less or 2 nm or less. The 2D material may comprise of a single layer of atoms. It may be appreciated that a single layer could comprise multiple strata. For instance, molybdenum disulphate comprises a plane of molybdenum ions sandwiched between two planes of sulphide ions. Alternatively, all of the carbon atoms in a layer of graphene are disposed in the same plane, so a single layer of graphene may be viewed as having one stratum. Accordingly, a single layer could comprise between 1 and 5 strata, preferably between 1 and 3 strata. An atom within the single layer of atoms may be covalently bonded to one or more other atoms within the single layer of atoms. In embodiments where the single layer comprises multiple strata, an atom may be covalently bonded to one or more atoms in a different stratum within the single layer of atoms. However, an atom within the single layer of atoms may not be covalently bonded to a further atom with is not in the single layer of atoms. Accordingly, the 2D material may comprise a plurality of layers. The plurality of layers may be adjacent to each other. The plurality of layers may not be connected by covalent bonds. The 2D material preferably comprises a plurality of particles. The plurality of particles may have a mean thickness of less than 50 nm, less than 40 nm, less than 30 nm or 2 less than 0 nm, more preferably less than 10 nm, less than 7.5 nm, less than 5 nm or less than 2.5 nm, and most preferably less than 2 nm, less than 1.5 nm or less than 1 nm. Alternatively, or additionally, the plurality of particles may have a mean number of layers between 1 and 20, more preferably between 1 and 15 or between 1 and 10 and most preferably between 1 and 5. The plurality of particles may comprise a largest lateral dimension with a mean size of less than 30 μm, less than 20 μm, less than 15 μm or less than 10 μm, more preferably a mean size of less than 5 μm or less than 4 μm, and most preferably less than 3.5 μm. The plurality of particles may comprise a largest lateral dimension with a mean size of at least 20 nm, a