Polymer-stabilized dual frequency blue phase liquid crystals
View Patent ↗A dual frequency liquid crystal may be stabilized in the blue phase by a polymer matrix to provide an improved blue phase temperature range having a magnitude of at least about 65° C. Polymer-stabilized, blue phase dual frequency liquid crystal compositions and methods for producing polymer-stabilized, blue phase dual frequency liquid crystals are disclosed.
1. A blue phase dual frequency liquid crystal composition comprising:
a polymer matrix comprising:
a dual frequency liquid crystal; and
at least one chiral reagent, wherein the polymeric matrix comprises:
a first monomer selected from the group consisting of 1,4-Bis-[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene, 2-EHA, hexanedioldiacrylate (HDDA), trimethylolpropanetrisacrylate (TMPTA), and tripropyleneglycoldiacrylate (TPGDA), and
a second monomer selected from the group consisting of 1,4-Bis-[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene, 2-EHA, hexanedioldiacrylate (HDDA), trimethylolpropanetrisacrylate (TMPTA), and tripropyleneglycoldiacrylate (TPGDA), and wherein the polymeric matrix is present in the composition at a concentration of about 5 weight % to about 15 weight %, the dual-frequency liquid crystal is present in the composition at a concentration of about 50 weight % to about 80 weight %, and the at least one chiral reagent is present in the composition at a concentration of about 5 weight % to about 40 weight %, and
wherein the composition has a magnitude of a blue phase temperature range of at least about 65° C.
2. The composition of claim 1 , wherein the composition comprises a lower blue phase temperature limit of about −35° C. and an upper blue phase temperature limit of about 45° C.
3. The composition of claim 1 , wherein the dual frequency liquid crystal and the at least one chiral reagent are present in a molar ratio of about 1:2 to about 3:1.
4. The composition of claim 1 , further comprising at least one UV initiator capable of initiating polymerization between the first monomer and the second monomer.
5. The composition of claim 1 , wherein the blue phase dual frequency liquid crystal composition has an electro-optic switching with a response time of about 10 microseconds (μs) to about 100 μs.
6. The composition of claim 1 , wherein the polymer matrix is at least interstitially disposed among the at least one chiral reagent and molecules of the dual frequency liquid crystal to suppress realignment of the molecules of the dual frequency liquid crystal.
7. The composition of claim 1 , wherein the at least one chiral reagent is present in the composition at a concentration of about 25 weight % to about 38 weight %, the dual frequency liquid crystal is present in the composition at a concentration of about 52 weight % to about 65 weight %, and the polymer matrix is present in the composition at a concentration of about 5 weight % to about 15 weight %.
8. A method of making a blue phase dual frequency liquid crystal composition, the method comprising:
combining about 5 weight % to about 15 weight % of a plurality of monomers, 50 weight % to about 80 weight % of a dual frequency liquid crystal, and about 5 weight % to about 40 weight % of at least one chiral reagent to form a mixture; and
polymerizing the plurality of monomers to form a polymer matrix at least around molecules of the dual frequency liquid crystal and the at least one chiral reagent to stabilize the dual frequency liquid crystal in the blue phase, wherein the plurality of monomers comprises:
a first monomer selected from the group consisting of 1,4-Bis-[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene, 2-EHA, hexanedioldiacrylate (HDDA), trimethylolpropanetrisacrylate (TMPTA), and tri propyleneglycoldiacrylate (TPGDA), and
a second monomer selected from the group consisting of 1,4-Bis[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene, 2-EHA, hexanedioldiacrylate (HDDA), trimethylolpropanetrisacrylate (TMPTA), and tripropyleneglycoldiacrylate (TPGDA).
9. The method of claim 8 , wherein the polymer matrix stabilizes the dual frequency liquid crystal in the blue phase over a temperature range of at least about 65° C.
10. The method of claim 8 , wherein stabilizing dual frequency liquid crystal in the blue phase comprises stabilizing at a temperature range having a lower blue phase temperature limit of about −35° C. and an upper blue phase temperature limit of about 45° C.
11. The method of claim 8 , wherein:
the plurality of monomers in the mixture further comprise at least one UV polymerizable group;
the method further comprises combining a UV initiator with the mixture; and
the polymerizing comprises irradiating the mixture with UV light to polymerize the plurality of monomers.
12. The method of claim 8 , wherein
the method further comprises:
combining a UV initiator with the mixture; and
polymerizing the plurality of monomers by irradiating the mixture with UV light.
13. The method of claim 12 , wherein combining the plurality of monomers comprises combining the first monomer and the second monomer at a molar ratio of about 3:1 to about 1:3.
14. The method of claim 12 , wherein combining the plurality of monomers comprises combining first monomer and the at least one second monomer at a molar ratio of about 1.25:1 to about 1:1.25.
15. The method of claim 8 , wherein the combining comprises combining a dual frequency liquid crystal and the at least one chiral reagent in a molar ratio of about 1:2 to about 3:1.
16. The method of claim 8 , wherein polymerizing the plurality of monomers comprises polymerizing at a temperature between an upper blue phase temperature limit and a lower blue phase temperature limit of the dual frequency liquid crystal.