Smart glass using guided self-assembled photonic crystal

Patent metadata

Field	Value
Publication number	US-9733467-B2
Application number	US-201514863440-A
Country	US
Kind code	B2
Filing date	Sep 23, 2015
Priority date	Dec 3, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A smart glass uses a guided self-assembled photonic crystal, including a photonic crystal layer that is interposed between a pair of conductive glass plates. The smart glass includes a first material and a second material having a different refractive index from the first material and surrounding the first material. Thereby, the smart glass has a color, even when a dye is not included, by strongly reflecting light in a specific wavelength range incident to the photonic crystal layer. This is because the first material is formed regularly to have a constant distance by guided self-assembly, and the smart glass thereby may obtain a target color by randomly adjusting the distance between the first materials.

First claim

What is claimed is:

1. Smart glass having a specific color comprising:
a pair of conductive glass plates; and
a photonic crystal layer interposed between the glass plates,
wherein the photonic crystal layer includes a first material regularly arranged by guided self-assembly and a second material having a different refractive index from the first material and surrounding the first material, thereby reflecting light only in a specific wavelength range, and
wherein the first material is a liquid crystal droplet and the second material is a silica-titanium alkoxide.

2. The smart glass of claim 1 attaining a target color by adjustment of a distance between the first materials.

3. The smart glass of claim 1 , wherein a distance between the first materials is 200 to 400 nm.

4. The smart glass of claim 1 , wherein the first material has a hexagonal close-packed structure (hcp) or a face-centered cubic structure (fcc).

5. The smart glass of claim 1 , wherein a thickness of the photonic crystal layer is 3 times to 5 times a distance between the first materials.

6. A method for preparing smart glass comprising:
(a) preparing a mixed liquid by mixing a first material and a second material having a different refractive index from that of the first material; and
(b) forming a photonic crystal layer by interposing the mixed liquid between a pair of conductive glass plates so that the first material is regularly arranged by guided self-assembly
wherein the first material is a liquid crystal droplet and the second material is a silica-titanium alkoxide, and the step (b) forms and regularly arranges the liquid crystal droplet as the liquid crystal of the mixed liquid is phase-separated by applying the mixed liquid on one surface of the conductive glass plate and drying the result.

7. The method for preparing smart glass of claim 6 , wherein the liquid crystal and the silica-titanium alkoxide are mixed in a volume ratio of 1:2 to 2:1.

8. The method for preparing smart glass of claim 6 , wherein the mixed liquid further includes a surfactant in 1 to 5 vol %.

9. The method for preparing smart glass of claim 8 , wherein the surfactant includes a functional group including a metal atom and a solvophilic functional group.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp
• Univ Sejong Ind Acad Coop Found

Inventors

• Kim Hyun Sub
• Kong Nak Kyoung
• Oh Young Sub
• Lee Jin Hee
• Seo Yong Ho

Classifications

• G02B26/001 Primary

  based on interference in an adjustable optical cavity (interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26) · CPC title

• G02F2202/32

  Photonic crystals · CPC title

• E06B9/24

  Screens or other constructions affording protection against light, especially against sunshine; Similar screens for privacy or appearance; {Slat blinds}(operating, guiding or securing devices or arrangements for roll-type closures E06B9/56; free-hanging flexible screens A47H23/00) · CPC title

• 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

• E06B2009/2464

  featuring transparency control by applying voltage, e.g. LCD, electrochromic panels · CPC title