Chiral polymers for the self-assembly of photonic crystals

Patent metadata

Field	Value
Publication number	US-9575212-B2
Application number	US-201414188961-A
Country	US
Kind code	B2
Filing date	Feb 25, 2014
Priority date	Feb 26, 2013
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

Described herein are copolymers constructed from chiral, non-racemic monomers, which self-assemble to photonic crystals. The difficulty of incorporating chiral elements into photonic crystals has limited the ability to generate unique bandstructures for different circular polarizations of light. The materials and methods described herein relate to easily, predictably fabricating chiral photonic crystals having desirable optical properties.

First claim

The invention claimed is:

1. A chiral photonic crystal, comprising:
a copolymer having a main chain and a plurality of side groups, each side group bound to a monomer unit of the main chain; wherein
the main chain comprises polynorbornene or polyacetylene;
each side group comprises (i) a chiral, non-racemic polyisocyanate or (ii) a dendrimer;
the copolymer self-assembles into a chiral photonic crystal through microphase segregation; and
the chiral photonic crystal reflects circularly polarized light of a first wavelength to a different extent depending on the direction of circular polarization of the circularly polarized light.

2. The chiral photonic crystal of claim 1 , wherein the photonic crystal has a photonic bandgap in the ultraviolet spectrum, in the visible spectrum, in the near-infrared spectrum, or in the infrared spectrum.

3. The chiral photonic crystal of claim 1 , wherein each side group comprises a chiral, non-racemic polyisocyanate.

4. The chiral photonic crystal of claim 1 , wherein each side group comprises a chiral, non-racemic polyisocyanate; and the chiral non-racemic polyisocyanate forms a one-handed helical strand.

5. The chiral photonic crystal of claim 1 , wherein each side group comprises a chiral, non-racemic polyisocyanate; and the main chain is polyacetylene polymerized from substituted 1,6-heptadiyne monomer units.

6. The chiral photonic crystal of claim 1 , wherein each side group comprises a chiral, non-racemic polyisocyanate resulting from copolymerizing hexyl isocyanate with (R)-2,6-dimethylheptyl isocyanate.

7. The chiral photonic crystal of claim 1 , wherein the side groups of the copolymer are covalently linked to chiral moieties.

8. The chiral photonic crystal of claim 1 , wherein the side groups of the copolymer are covalently linked to chiral macromolecules.

9. The chiral photonic crystal of claim 1 , wherein the copolymer has a chirality resulting from supramolecular organization of the side groups.

10. The chiral photonic crystal of claim 1 , wherein the main chain comprises polynorbornene.

11. The chiral photonic crystal of claim 1 , wherein the main chain comprises polyacetylene.

12. The chiral photonic crystal of claim 1 , wherein the side groups are dendrimers.

13. A thin film comprising a chiral photonic crystal of claim 1 .

14. A method of forming a chiral photonic crystal according to claim 1 , comprising:
providing a plurality of polymeric molecules that rotate polarized light, each molecule containing a reactive terminal monomer unit;
polymerizing the reactive terminal monomer units to form a copolymer comprising a main chain comprising polynorbornene or polyacetylene formed by the polymerized terminal monomer units and polymeric side groups comprising (i) a chiral, non-racemic polyisocyanate or (ii) a dendrimer; and
fostering self-assembly of the copolymer into a chiral photonic crystal through microphase segregation.

15. The method of claim 14 , wherein the chiral photonic crystal has a photonic bandgap in the ultraviolet spectrum, in the visible spectrum, in the near-infrared spectrum, or in the infrared spectrum.

16. The method of claim 14 , wherein polymerizing is conducted by ring-closing alkyne polymerization or by ruthenium-mediated ring-opening metathesis polymerization.

17. The method of claim 14 , further comprising forming a thin film of the copolymer.

18. The method of claim 17 , wherein forming the thin film comprises evaporating a solution of the copolymer.

Assignees

• California Inst Of Techn

Inventors

• Grubbs Robert H
• Miyake Garret M
• Weitekamp Raymond
• Piunova Victoria

Classifications

• G02B5/3016

  involving passive liquid crystal elements (optical properties of liquid crystals G02F1/0063; polarising elements associated with active liquid crystal devices G02F1/133528) · CPC title

• G02B1/005 Primary

  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 title

• G02B6/1225

  comprising photonic band-gap structures or photonic lattices · CPC title