Color changing coaxial polymer fibers

Patent metadata

Field	Value
Publication number	US-12590204-B2
Application number	US-202218045142-A
Country	US
Kind code	B2
Filing date	Oct 7, 2022
Priority date	Oct 7, 2021
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

Disclosed herein is a fiber having a sheath including a polymer and a core including a non-cholesteric liquid crystal. The sheath is transparent to visible light. The fiber may an average diameter of no more than 10 microns, and at least 90% of the fiber has a diameter within 20% of the average diameter. The sheath may include a compound capable of photoisomerization that extends into the core. The interference color of the fiber may be reversibly changed by exposure to light or a temperature change.

First claim

What is claimed is:

1 . A fiber comprising:
a sheath comprising a polymer;
wherein the sheath is transparent to visible light; and
a core comprising a non-cholesteric liquid crystal;
wherein the fiber has an average diameter of no more than 10 microns; and
wherein at least 90% of the fiber has a diameter within 20% of the average diameter.

2 . The fiber of claim 1 , wherein the polymer is polyvinylpyrrolidone.

3 . The fiber of claim 1 , wherein the liquid crystal is 4-cyano-4′-n-pentylbiphenyl.

4 . The fiber of claim 1 ;
wherein the fiber has an average interference color wavelength within the visible spectrum; and wherein at least 90% of the fiber has an interference color wavelength within 10% of the average interference color wavelength.

5 . A nanofibrous mat comprising:
one or more of the fibers of claim 4 .

6 . A method comprising:
providing the fiber of claim 1 at a first temperature;
wherein the fiber exhibits a first interference color at the first temperature; and
changing the temperature of the fiber to a second temperature that causes the fiber to exhibit a second interference color different from the first interference color.

7 . A fiber comprising:
a sheath comprising:
a polymer; and
a compound capable of photoisomerization;
wherein the sheath is transparent to visible light; and

a core comprising a non-cholesteric liquid crystal;
wherein the compound capable of photoisomerization extends into the core.

8 . The fiber of claim 7 , wherein the polymer is polyvinylpyrrolidone.

9 . The fiber of claim 7 , wherein the liquid crystal is 4-cyano-4′-n-pentylbiphenyl.

10 . The fiber of claim 7 , wherein the compound capable of photoisomerization is an azobenzene.

11 . The fiber of claim 7 , wherein the compound capable of photoisomerization is

12 . The fiber of claim 7 ;
wherein the fiber has an average interference color wavelength within the visible spectrum; and wherein at least 90% of the fiber has an interference color wavelength within 10% of the average interference color wavelength.

13 . A nanofibrous mat comprising:
one or more of the fibers of claim 7 .

14 . A method comprising:
providing the fiber of claim 7 ;
wherein the fiber exhibits a first interference color; and
exposing the fiber to light of a wavelength that causes the fiber to exhibit a second interference color different from the first interference color.

15 . A method comprising:
providing the fiber of claim 7 at a first temperature;
wherein the fiber exhibits a first interference color at the first temperature; and
changing the temperature of the fiber to a second temperature that causes the fiber to exhibit a second interference color different from the first interference color.

16 . A method comprising:
providing a first solution comprising:
15-20 wt. % of a polymer;
0.01-0.1 wt. % sodium chloride; and
ethanol;
providing a second solution comprising a liquid crystal; and electrospinning the first solution and the second solution to form a fiber comprising:
a sheath comprising the polymer; and
a core comprising the liquid crystal;
wherein the electrospinning is performed at:
5-13 kV;
8-14 cm from a substrate; and
no more than 20% relative humidity.

17 . The method of claim 16 , wherein the polymer is polyvinylpyrrolidone.

18 . The method of claim 16 , wherein the liquid crystal is 4-cyano-4′-n-pentylbiphenyl.

19 . The method of claim 16 , wherein the first solution further comprises:
a compound capable of photoisomerization.

20 . The method of claim 17 , wherein the compound capable of photoisomerization is:

21 . A compound having the formula:

Assignees

• Us Gov Sec Navy

Inventors

• Lundin Jeffrey G
• Thum Matthew D
• Kolacz Jakub
• Ratchford Daniel

Classifications

• D01F8/04

  from synthetic polymers · CPC title

• D01F1/10

  Other agents for modifying properties · CPC title

• D01D5/34

  Core-skin structure; Spinnerette packs therefor · CPC title

• C08K5/315

  Compounds containing carbon-to-nitrogen triple bonds · CPC title

• C08K5/23 Primary

  Azo-compounds · CPC title