ELECTROCHROMIC WO3 NANOPARTICLES, A METHOD FOR THEIR PRODUCTION AND INK USING SAID PARTICLES

• US 20140139576A1
• Filed: 07/13/2012
• Published: 05/22/2014
• Est. Priority Date: 07/14/2011
• Status: Abandoned Application

• Current Assignee: Universidade Nova de Lisboa, YD Ynvisible, SA (Ynvisible Interactive, Inc.)
• Original Assignee: Universidade Nova de Lisboa, YD Ynvisible, SA (Ynvisible Interactive, Inc.)
• Inventors: Costa, Claudia Brito da, Baptista, Carlos Alberto Pinheiro, Henriques, Ins Domingues da Silva, Laia, Csar Antnio Tonicha
• Application Number:
  US14/232,501
• Publication Number:
  US 20140139576A1
• Time in Patent Office: Days
• US Class Current: 347/10
• CPC Class Codes: C09D 11/32 characterised by colouring agents
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C09D 11/50 Sympathetic, colour changing or similar inks
• CPC Class Codes: C09D 11/52 Electrically conductive inks
• CPC Class Codes: C09K 9/00 Tenebrescent materials, i.e. materials for which the range of wavelengths for energy absorption is changed as a result of excitation by some form of energy
• CPC Class Codes: G02F 1/1524 Transition metal compounds
• CPC Class Codes: G02F 2201/083 infrared absorbing
• CPC Class Codes: G02F 2203/11 involving infrared radiation

Abstract

Tungsten trioxide (WO3) nanoparticles are synthesized via a sol-gel route using metallic tungsten as precursor and printed on a flexible electrode using inkjet printing in order to build solid-state electrochromic cells. A method for separate control of different spectral regions of the electrochromic device (near infrared and visible) is disclosed.

Claims

1. Method for producing electrochromic particles, wherein there are the sequential steps of

mixing 5-10% metallic tungsten with 95-90% of hydrogen peroxide

allowing the mix to react until a colorless solution is achieved

stirring the colorless solution in a closed vessel at 100°

C. until a yellow precipitate powder is formed.

2. The method of claim 1, wherein the mix is allowed to react for 3 minutes.

3. The method of claim 1, wherein the colorless solution is stirred for 5 hours.

4. The method of claim 1, wherein the aqueous solution is heated for 2 hours.

5. Electrochromic particles produced by the method of claim 1, wherein an ink which coloring agent is the electrochromic particles exhibits the following behavior

when subject to an electric potential up to −

1.1 V (+/−

0.5 V) it displays color alteration in the near-infrared and not in the visible range of light

when subject to an electrical potential of 1.1 V (+/−

0.5 V) and higher it displays color alteration both in the near-infrared and the visible ranges of light.

6. Method for producing an ink, wherein there are the sequential steps of:

mixing 5-10% metallic tungsten with 95-90% of hydrogen peroxide

allowing the mix to react until a colorless solution is achieved

stirring the colorless solution in a closed vessel at 100°

C. until a yellow precipitate powder is formed

dispersing the sintered powder in water until a stable colloidal suspension is achieved.

7. The method of claim 6, wherein the mix is allowed to react for 3 minutes.

8. The method of claim 6, wherein the colorless solution is stirred for 5 hours.

9. The method of claim 6, wherein the aqueous solution is heated for 2 hours.

10. Ink produced by the method of claim 6, wherein the following behavior is observed

when subject to an electric potential up to −

1.1 V (+/−

0.5 V) it displays color alteration in the near-infrared and not in the visible range of light

when subject to an electrical potential of −

1.1 V (+/−

0.5 V) and higher it displays color alteration both in the near-infrared and the visible ranges of light.

11. Method for inkjet printing the ink produced by the process in claim 6, wherein a waveform is used with the following parameters:

applied voltage of 14 V

firing drop sequence of 6 KHz

drop spacing of 20 μ

m.

12. An electrochromic ink, wherein

metallic tungsten particles are components of the ink

the following behavior is observed

when subject to an electric potential up to −

1.1 V (+/−

0.5 V) it displays color alteration in the near-infrared and not in the visible range of light

when subject to an electrical potential of −

1.1 V (+/−

0.5 V) and higher it displays color alteration both in the near-infrared and the visible ranges of light.