METHOD OF CREATING COLORED MATERIALS BY FIXING ORDERED STRUCTURES OF MAGNETITE NANOPARTICLES WITHIN A SOLID MEDIA

• US 20130146788A1
• Filed: 04/14/2010
• Published: 06/13/2013
• Est. Priority Date: 04/14/2009
• Status: Abandoned Application

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Yin, Yadong, Ge, Jianping, Kwon, Sunghoon
• Application Number:
  US13/264,411
• Publication Number:
  US 20130146788A1
• Time in Patent Office: Days
• US Class Current: 250/492.1
• CPC Class Codes: B01J 19/12 employing electromagnetic waves
• CPC Class Codes: B01J 19/123 Ultraviolet light
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: C01P 2006/42 Magnetic properties
• CPC Class Codes: C08K 2201/01 Magnetic additives
• CPC Class Codes: C08K 2201/011 Nanostructured additives
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 9/08 Ingredients agglomerated by treatment with a binding agent
• CPC Class Codes: C09C 1/24 Oxides of iron
• CPC Class Codes: C09C 3/10 Treatment with macromolecular organic compounds C09C3/006 takes precedence
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: C09D 7/62 modified by treatment with other compounds
• CPC Class Codes: C09D 7/69 Particle size larger than 1000 nm
• CPC Class Codes: G02B 1/005 made of photonic crystals or photonic band gap materials photonic band-gap structures or photonic lattices in integrated optics G02B6/1225; photonic band-gap structures or photonic lattices in optical fibres G02B6/02295
• CPC Class Codes: G02B 2207/101 Nanooptics
• CPC Class Codes: G02B 5/201 in the form of arrays
• CPC Class Codes: G02F 1/09 based on magneto-optical elements, e.g. exhibiting Faraday effect
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection
• CPC Class Codes: H01F 1/0063 in a non-magnetic matrix, e.g. granular solids granular films H01F10/007
• CPC Class Codes: H01F 1/344 : Ferrites, e.g. having a cubic spinel structure (X2+O)(Y23+O3), e.g. magnetite Fe3O4
• CPC Class Codes: Y10T 428/24802 : Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]

Abstract

Compositions and methods wherein ordered structures of photonic nanocrystals are created in a liquid medium and then such structures are fixed by converting the liquid medium to a solid. In addition, compositions and methods of reversibly fixing such structures, so that ordered structures can be reversibly created in a liquid medium, converted to solid, and then converted back to liquid, wherein new ordered structures can be created and again fixed.

Claims

1. A method of creating colored materials, comprising:

fixing ordered structures of magnetically responsive nanoparticles within a media, such that the ordered structures diffract light to create colors.

2. The method of claim 1, further comprising creating the ordered structures of magnetically responsive nanoparticles with an external magnetic field.

3. The method of claim 2, wherein the ordered structures of magnetically responsive nanoparticles are created in a liquid media and the ordered structures are fixed by converting the liquid media to a solid media.

4. The method of claim 3, wherein the liquid media is a photocurable solution.

5. The method of claim 4, further comprising fixing the ordered structures of magnetically responsive nanoparticles with an UV source having a wavelength of approximately 240 nm to approximately 365 nm.

6. The method of claim 1, wherein the ordered structures are created in a reversible media, wherein the reversible media is reversible from a solid to a liquid, such that the color can be changed.

7. A method of generating multicolored patterns comprising:

fixing a structural color from a superparamagnetic colloidal nanocrystal clusters (CNC); and

introducing a high resolution patterning of multiple structural colors using a single material.

8. The method of claim 7, further comprising repetitive tuning and fixing of the structural color from a mixture of superparamagnetic photonic crystals and photocurable resin.

9. The method of claim 7, wherein the superparamagnetic photonic crystals consists of a plurality of domain magnetite nanoparticles, which are coated.

10. The method of claim 7, further comprising adding an external magnetic field to the photonic crystals, and wherein the external magnetic field assembles the photonic crystals in a chain-like structures along the magnetic field lines.

11. The method of claim 7, wherein the attractive magnetic force due to the superparamagnetic core is balanced with repulsive solvation force, both of which determine the inter-particle distance under any given magnetic field strength.

12. The method of claim 7, wherein the inter-particle distance in a chain determines the color of the light diffracted from the chain.

13. The method of claim 7, wherein the color can be tuned by simply varying the inter-particle distance using external magnetic fields.

14. The method of claim 7, wherein once the desired color is obtained, the desired color is fixed by solidifying the photocurable resin through UV exposure.

15. The method of claim 7, wherein the particle chains are frozen in the solidified polymer network without distorting its periodic arrangements, thus retaining the structural color.

16. The method of claim 7, further comprising adding a hydrogen bonding solvent, which forms a solvation layer around the particle surface, and which provides a strong repulsion when two solvation layers overlap.

17. The method of claim 16, wherein the hydrogen bonding solvent is an alkanol.

18. The method of claim 17, further comprising adding ethanol to the system.

19. (canceled)

20. (canceled)

21. (canceled)

22. (canceled)

23. (canceled)

24. (canceled)

25. (canceled)

26. (canceled)

27. (canceled)

28. (canceled)

29. (canceled)

30. (canceled)

31. A method of forming magnetochromatic microspheres comprising:

coating a plurality of magnetite nanocrystals with a surface medium;

dispersing the plurality of coated magnetite nanocrystals in a curable solution;

placing the magnetite nanocrystals and curable solution in an immiscible solution to form an emulsion;

exposing the emulsion to an external magnetic field, which aligns the coated magnetite nanocrystals in one-dimensional chains within emulsion droplets within the curable solution; and

curing the emulsion droplets within the curable solution into magnetochromatic microspheres.

32. The method of claim 31, wherein the step of curing the emulsion droplets is by exposing the curable solution to a UV illumination source.

33. The method of claim 32, wherein the step of exposing the curable solution to the UV illumination source fixes the ordered structures within the microspheres.

34. The method of claim 31, wherein the plurality of magnetite nanocrystals have a chemical composition of γ

-Fe₂O₃Fe₂O₃ and/or Fe₃O₄.

39. The method of claim 31, further comprising microspheres immersed in a phase-changeable matrix, the phase-changeable matrix having a liquid phase and a solid phase.

40. The method of claim 39, wherein when the matrix is the liquid phase, adjusting an angle of the external magnetic field to change an orientation of the microspheres.

47. The method of claim 31, wherein the immiscible liquid is a viscous non-polar solvent, mineral oil and/or silicone oil and/or paraffin oil.

52. The method of claim 39, wherein the phase-changeable matrix is a polyethylene glycol (PEG) film, paraffin, long-chain alkanes, esters, primary alcohols and/or a non-crosslinked polymers such as polyethylene, poly(ethylene oxide), polyethylene-block-poly(ethylene glycol) and/or polyesters.

35. (canceled)

36. (canceled)

37. (canceled)

38. (canceled)

41. (canceled)

42. (canceled)

43. (canceled)

44. (canceled)

45. (canceled)

46. (canceled)

48. (canceled)

49. (canceled)

50. (canceled)

51. (canceled)

53. (canceled)

54. (canceled)

55. (canceled)

56. (canceled)

57. (canceled)

58. (canceled)

59. A method of forming magnetochromatic microspheres comprising:

a simultaneous magnetic assembly and UV curing process of an emulsion system comprised of superparamagnetic Fe₃O₄@SiO₂ colloidal particles, which are self-organized into ordered structures inside emulsion droplets of UV curable resin.

60. The method of claim 59, wherein the ordered structures are fixed by an immediate UV curing process to polymerize the droplets.

61. The method of claim 59, further comprising rotating the microspheres using an external magnetic field to change the orientation of the magnetic chains and thereby the diffractive colors of the microspheres.

62. A display comprising:

microspheres containing ordered structures of photonic crystals, which are rotated, which changes the angle of diffraction of light passing through the microspheres.

63. The display of claim 62, further comprising rotating the microspheres, which changes the angle of diffraction of light passing through the microspheres, which changes a first color to a second color.

64. The display of claim 62, further comprising microspheres immersed in a phase-changeable matrix, the phase-changeable matrix having a liquid phase and a solid phase.

65. The display of claim 64, wherein when the matrix is the liquid phase, adjusting an angle of the external magnetic field to change an orientation of the microspheres.

66. The display of claim 65, wherein the orientation of the microspheres are fixed when the matrix goes to the solid phase.

67. The display of claim 62, wherein the field strength required to rotate the microspheres is dependent on an amount magnetite nanocrystals in each of the microspheres.

68. The display of claim 64, wherein the phase-changeable matrix is a polyethylene glycol (PEG) film.

69. The display of claim 64, wherein the phase-changeable matrix is paraffin, long-chain alkanes, esters, primary alcohols and/or a non-crosslinked polymers such as polyethylene, poly(ethylene oxide), polyethylene-block-poly(ethylene glycol) and/or polyesters.