RADIATIVE COOLING SUBSTRATE AND MANUFACTURING METHOD OF THE SAME

• US 20200131660A1
• Filed: 02/22/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: National Tsing Hua University
• Original Assignee: National Tsing Hua University
• Inventors: CHEN, YU-BIN, HAN, HUNG-SHENG
• Granted Patent: US 11,078,593 B2
• Time in Patent Office: Days
• CPC Class Codes: C09D 5/00 Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced electrically insulating plastics, resins or waxes H01B3/30; Filling pastes
• CPC Class Codes: C09D 5/44 for electrophoretic applications processes for coating by electrophoresis C25D13/00
• CPC Class Codes: C25D 13/06 with polymers not used, see C09D5/44
• CPC Class Codes: C25D 13/12 characterised by the article coated
• CPC Class Codes: C25D 13/20 Pretreatment
• CPC Class Codes: C25D 13/22 Servicing or operating apparatus or multistep processes
• CPC Class Codes: F28F 13/18 by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
• CPC Class Codes: F28F 2245/06 having particular radiating, reflecting or absorbing features, e.g. for improving heat transfer by radiation

Abstract

A radiative cooling substrate and a manufacturing method of the radiative cooling substrate are provided. The radiative cooling substrate includes a metallic substrate and a chitosan layer disposed on the metallic substrate with a thickness of 0.5 μm to 10 μm. The chitosan layer emits radiation within a waveband between 8 μm and 13 μm.

Claims

1. A manufacturing method of a radiative cooling substrate, comprising:

preparing a chitosan solution, the chitosan solution comprising chitosan and a solvent, wherein the solvent is selected from a group consisting of water, C1-C4 alcohols, organic acids and inorganic acids, and a pH-value of the chitosan solution is less than seven;

providing a metallic substrate into an electrophoresis cell loaded with the chitosan solution;

applying a voltage to the metallic substrate for a predetermined time period;

depositing a chitosan layer comprising the chitosan with a first thickness on the metallic substrate in an electrophoretic process; and

obtaining the radiative cooling substrate;

wherein the first thickness is a value from 0.5 μ

m to 10 μ

m.

2. The method of claim 1, further comprising:

before providing the metallic substrate into the electrophoresis cell loaded with the chitosan solution, forming the metallic substrate by depositing an adhesive layer with a second thickness on a silicon substrate and depositing a metal layer on the adhesive layer in an evaporation process;

wherein the adhesive layer comprises chromium or titanium, and the second thickness is 10 nm to 50 nm.

3. The method of claim 1, wherein a ratio of a weight of the chitosan and a volume of the solvent is 0.01 g:

1000 mL to 20 g;

1000 mL.

4. The method of claim 1, wherein the solvent comprises water and ethyl alcohol, and a volume ratio of the water and the ethyl alcohol is less than 2:

8.

5. The method of claim 1, wherein the solvent comprises acetic acid or hydrochloric acid.

6. The method of claim 1, wherein the voltage is less than 30 V.

7. The method of claim 1, wherein the predetermined time period is less than five minutes.

8. A radiative cooling substrate, comprising:

a metallic substrate; and

a chitosan layer, disposed on the metallic substrate and having a thickness of 0.5 μ

m to 10 μ

m;

wherein the chitosan layer emits radiation within a waveband between of 8 μ

m and 13 μ

m.

9. The radiative cooling substrate of claim 8, wherein the metallic substrate comprises:

a silicon substrate;

a metal layer, disposed on the silicon substrate; and

an adhesive layer, disposed between the silicon substrate and the metal layer with a thickness of 10 nm to 50 nm and comprising chromium or titanium.