Method for solution coating of inorganic superhydrophilic thin film

Patent metadata

Field	Value
Publication number	US-12570871-B2
Application number	US-202118019003-A
Country	US
Kind code	B2
Filing date	Aug 3, 2021
Priority date	Aug 5, 2020
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

A method of producing a silica-based superhydrophilic film. A coating formulation is provided, where the coating formulation includes an alkali metal silicate having a substantial portion of water removed therefrom, where the alkali metal silicate has a formula of M 2 O·nSiO 2 , and where M represents an alkali metal and n is a positive real number greater than zero. Furthermore, the coating formulation and an alcohol including a curing agent are mixed, where the curing agent includes an acid or an alkaline earth metal halide. Additionally, the coating formulation is dried to form the silica-based superhydrophilic film. Furthermore, a silica-based superhydrophilic film is produced according to such a method, where the silica-based superhydrophilic film includes an amine stabilizer.

First claim

The invention claimed is:

1 . A method of producing a silica-based superhydrophilic film, the method comprising:
providing a coating formulation comprising an alkali metal silicate, wherein the alkali metal silicate has a formula of M 2 O·nSiO 2 , wherein M represents an alkali metal and n is a positive real number greater than zero; depositing the coating formulation on a substrate prior to mixing the coating formulation and an alcohol, wherein the alcohol comprises a curing agent, wherein the curing agent comprises an aqueous acid or an alkaline earth metal halide; and drying the coating formulation, which contains the alcohol, to form the silica-based superhydrophilic film.

2 . The method of claim 1 , wherein n ranges from 0.4 to 40.

3 . The method of claim 1 , wherein providing the coating formulation comprises dissolving the alkali metal silicate in an aqueous solvent, wherein the aqueous solvent comprises water.

4 . The method of claim 1 , wherein the alkali metal comprises potassium, sodium, or lithium.

5 . The method of claim 1 , further comprises adding an aqueous amine stabilizer to the coating formulation and/or the alcohol prior to mixing the coating formulation and the alcohol.

6 . The method of claim 5 , wherein the aqueous amine stabilizer comprises methenamine in water, formamide in water, acetamide in water, or ethanolamine in water.

7 . The method of claim 1 , further comprises adding silica particles to the coating formulation prior to mixing the coating formulation and the alcohol.

8 . The method of claim 1 , wherein mixing the coating formulation and the alcohol comprises (i) applying the alcohol to the coating formulation or (ii) contacting the coating formulation with the alcohol.

9 . The method of claim 1 , wherein the alcohol comprises methanol, ethanol, isopropanol, 1-propanol, butanol, or 2-methoxyethanol.

10 . The method of claim 1 , wherein the aqueous acid comprises hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, or acetic acid.

11 . The method of claim 1 , wherein the alkaline earth metal halide is soluble in the alcohol, and wherein the alkaline earth metal halide comprises calcium chloride or magnesium chloride.

12 . The method of claim 1 , wherein mixing the coating formulation and the alcohol is carried out in a duration of 10 seconds or less.

13 . The method of claim 1 , wherein drying the coating formulation to form the silica-based superhydrophilic film is carried out at a temperature ranging from 20° C. to 150° C.

14 . The method of claim 1 , further comprising annealing of the silica-based superhydrophilic film.

Assignees

• Agency Science Tech & Res
• Univ London

Inventors

• Lim Yee Fun
• Goh Gregory Kia Liang
• Chapman-Fortune John

Classifications

• B05D1/36

  Successively applying liquids or other fluent materials, e.g. without intermediate treatment · CPC title

• C09D1/04

  with organic additives · CPC title

• C08G77/02

  Polysilicates · CPC title

• C09D5/00

  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 title

• C09D183/02 Primary

  Polysilicates · CPC title