Low-voltage haze tuning assembly and method

Patent metadata

Field	Value
Publication number	US-2024402557-A1
Application number	US-202418732384-A
Country	US
Kind code	A1
Filing date	Jun 3, 2024
Priority date	Jun 2, 2023
Publication date	Dec 5, 2024
Grant date	—

Abstract

Haze tunable assemblies and methods of forming and using the assemblies are disclosed. Exemplary assemblies include two or more substrates and a composite liquid crystal material interposed between at least two of the substrates. Exemplary assemblies exhibit large variation in haze upon application of a relatively low voltage and can retain desired transmission of visible light transmission.

First claim

1 . A haze tunable assembly comprising:
a first substrate; a second substrate; a composite liquid crystal material interposed between the first substrate and the second substrate; a first contact layer between the first substrate and the composite liquid crystal material; and a second contact layer between the second substrate and the composite liquid crystal material, wherein the composite liquid crystal material comprises:
liquid crystal material; and
a cross-linked unaligned network of nanofibers, and
wherein a haze of the composite liquid crystal material can be tuned by applying a bias across the first contact layer and the second contact layer.

2 . The assembly of claim 1 , wherein the liquid crystal material is nematic liquid crystal material.

3 . The assembly of claim 1 , wherein an average diameter of the nanofibers is between about 3 nm and about 6 nm.

4 . The assembly of claim 1 , wherein an average pore size of pores within the cross-linked unaligned network of nanofibers is between about 50 nm and about 200 nm.

5 . The assembly of claim 1 , wherein emergent domains of the liquid crystal material are larger than the average pore size.

6 . The assembly of claim 5 , wherein the emergent domains of the liquid crystal material are between about 1 μm and about 10 μm.

7 . The assembly of claim 1 , wherein a total transmission of light of the assembly in the visible and/or near infrared region of the of the electromagnetic spectrum is greater than 80%, greater than 85%, or greater than 89% in both an off state and in an on state.

8 . The assembly of claim 7 , wherein a difference of the total transmission of light in the visible and/or near infrared region of the of the electromagnetic spectrum in the off state of the assembly is within 10% or within 5% of a transmission of light in the visible and/or near infrared region of the of the electromagnetic spectrum of the assembly in the in on state.

9 . The assembly of claim 1 , wherein light transmitted through the assembly is color neutral.

10 . The assembly of claim 1 , wherein the liquid crystal material comprises 4-cyano-4′-pentylbiphenyl (5CB), MLC-9200-000, MLC-9200-100, MLC-6608, MLC-6241-000, 5PCH, 5CB, TL-216, E7, or E44.

11 . The assembly of claim 1 , wherein a haze coefficient of the composite liquid crystal material is less than 10% in an on state and greater than 80% in an off state.

12 . The assembly of claim 1 , wherein a difference of a haze coefficient of the composite liquid crystal material in an off state and a haze coefficient of the composite liquid crystal material in an on state is greater than 75 absolute percent.

13 . The assembly of claim 1 , wherein a driving voltage of the assembly is less than 5 V.

14 . The assembly of claim 1 , wherein the nanofibers comprise cellulose nanofibers.

15 . The assembly of claim 1 , wherein the composite liquid crystal material further comprises spacers.

16 . The assembly of claim 1 , wherein a distance between the first substrate and the second substrate is greater than zero and less than 30 micrometers.

17 . A method of tuning a haze of a tunable assembly, the method comprising the steps of:
providing an assembly of claim 1 ; and applying a bias across the first contact layer and the second contact layer to thereby affect a change in a haze coefficient of the composite liquid crystal material of greater than 75 absolute percent.

18 . The method of claim 17 , wherein a difference of a transmission of light in the visible and/or near infrared region of the of the electromagnetic spectrum in the off state of the assembly is within 10% or within 5% of a transmission of light in the visible and/or near infrared region of the of the electromagnetic spectrum of the assembly in the in on state.

19 . The method of claim 17 , wherein a total transmission of light in the visible and/or near infrared region of the of the electromagnetic spectrum is greater than 80% in both an off state and in an on state.

20 . A window comprising the haze tunable assembly of claim 1 .

Assignees

• Univ Colorado Regents

Inventors

• Ghosh Souvik
• Smalyukh Ivan I
• Abraham Eldho

Classifications

• G02F1/1334

  based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals · CPC title

• G02F1/1339

  Gaskets; Spacers; Sealing of cells · CPC title

• G02F2201/02

  fibre · CPC title

• G02F1/139 Primary

  based on orientation effects in which the liquid crystal remains transparent · CPC title