Self-Disinfecting Photocatalyst Sheet

Abstract

A self-disinfecting photocatalyst sheet includes a substrate material and a photocatalyst layer with a primary photocatalyst and a secondary photocatalyst. The primary photocatalyst is a metal oxide photocatalyst, whereas the secondary photocatalyst is a metallic photocatalyst. The primary photocatalyst forms a covalent bond with the substrate material. The self-disinfecting photocatalyst sheet is activatable by a visible light and can self-disinfect against bacteria and viruses. A method of manufacturing the self-disinfecting photocatalyst sheet and means for alerting the user on the expiration of the self-disinfecting photocatalyst sheet are also presented.

Claims

1. A self-disinfecting photocatalyst sheet, comprising a substrate material with a first side and a second side opposite the first side; and a photocatalyst layer comprising a primary photocatalyst and a secondary photocatalyst, wherein: the primary photocatalyst comprises a metal oxide photocatalyst, the secondary photocatalyst comprises a metallic photocatalyst, a mass ratio of the primary photocatalyst to the secondary photocatalyst is between 10:1 to 100:1, and the primary photocatalyst forms a covalent bond with the substrate material at a molecular level on the first side of the substrate material.

2. The self-disinfecting photocatalyst sheet of claim 1, wherein an adhesive layer is coated on the second side of the substrate material.

3. The self-disinfecting photocatalyst sheet of claim 1, wherein the primary photocatalyst further comprises anatase titanium dioxide (TiO.sub.2).

4. The self-disinfecting photocatalyst sheet of claim 3, wherein the primary photocatalyst further comprises rhombus-shape anatase titanium dioxide (TiO.sub.2) and has a major axis of 10-15 nm and minor axis of 3-6 nm.

5. The self-disinfecting photocatalyst sheet of claim 1, wherein the secondary photocatalyst further comprises silver, gold, copper, zinc, nickel, cerium, or a combination thereof.

6. The self-disinfecting photocatalyst sheet of claim 5, wherein the secondary photocatalyst further comprises a third metallic photocatalyst and a fourth metallic photocatalyst with no other metallic photocatalysts.

7. The self-disinfecting photocatalyst sheet of claim 6, wherein the third metallic photocatalyst comprises silver nanoparticles (NPs) and the fourth metallic photocatalyst comprises cerium NPs.

8. The self-disinfecting photocatalyst sheet of claim 1, wherein the photocatalyst layer is activatable by a visible light in a wavelength range greater than 400 nm.

9. The self-disinfecting photocatalyst sheet of claim 1, wherein the substrate material comprises a glass.

10. The self-disinfecting photocatalyst sheet of claim 1, wherein the substrate material comprises a resin.

11. The self-disinfecting photocatalyst sheet of claim 2, wherein the adhesive layer comprises a pressure-sensitive adhesive (PSA) material.

12. The self-disinfecting photocatalyst sheet of claim 2, wherein the adhesive layer comprises an electrostatic-enhancing agent.

13. The self-disinfecting photocatalyst sheet of claim 1, further comprising: a color-changing dye coated on at least a portion of the photocatalyst layer, the color-changing dye configured to alert a user an expiration of the self-disinfecting photocatalyst sheet through a change of a color of the color-changing dye.

14. The self-disinfecting photocatalyst sheet of claim 13, wherein the color-changing dye comprises a phenol red.

15. The self-disinfecting photocatalyst sheet of claim 13, wherein the color-changing dye comprises silver nanoparticles (NPs).

16. The self-disinfecting photocatalyst sheet of claim 1, further comprising: a dye coated on at least a portion of the photocatalyst layer, wherein wearing-off or fading-away of the dye is a proxy to wear-and-tear of the photocatalyst layer.

17. The self-disinfecting photocatalyst sheet of claim 1, wherein the sheet has a transmission rate of visible light greater than 90%.

18. A method for producing a self-disinfecting photocatalyst sheet, comprising: forming the self-disinfecting photocatalyst sheet having a substrate material with a first side and a second side opposite the first side and a photocatalyst layer, with the photocatalyst layer comprising a primary photocatalyst and a secondary photocatalyst, by performing: applying a low-temperature air atmospheric plasma to the first side of the substrate material to improve a hydrophilic property of the substrate material; spraying a water-based photocatalyst solution on the first side of the substrate material, wherein the water-based solution comprises greater than 98 wt % in water, less than 2 wt % in the primary photocatalyst and secondary photocatalyst, and a mass ratio of the primary photocatalyst to the secondary photocatalyst is between 10:1 to 100:1; performing a heat curing process to create a hydroxyl group out of the primary photocatalyst to form a covalent bond with the substrate material on the first side of the substrate material; and coating an adhesive layer on the second side of the substrate material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are included to aid further understanding of the present disclosure and are incorporated in and constitute a part of the present disclosure. The drawings illustrate a select number of embodiments of the present disclosure and, together with the detailed description below, serve to explain the principles of the present disclosure. It is appreciable that the drawings are not necessarily to scale, as some components may be shown to be out of proportion to size in actual implementation in order to clearly illustrate the concept of the present disclosure.

[0020] FIG. 1 schematically depicts a diagram of an embodiment of the present disclosure with adhesive coating on the second side of a substrate material.

[0021] FIG. 2 schematically depicts a diagram of another embodiment of the present disclosure coated with a dye on the photocatalyst layer.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Overview

[0022] Various implementations of the present disclosure and related inventive concepts are described below. It should be acknowledged, however, that the present disclosure is not limited to any particular manner of implementation, and that the various embodiments discussed explicitly herein are primarily for purposes of illustration. For example, the various concepts discussed herein may be suitably implemented in a variety of the primary, the secondary photocatalyst, the substrate material, and the dye.

[0023] The present disclosure discloses a self-disinfecting photocatalyst sheet includes a substrate material and a photocatalyst layer with a primary photocatalyst and a secondary photocatalyst. The primary photocatalyst is a metal oxide photocatalyst, whereas the secondary photocatalyst is a metallic photocatalyst. The primary photocatalyst forms a covalent bond with the substrate material. The self-disinfecting photocatalyst sheet is activatable by a visible light and can self-disinfect against bacteria and viruses.

EXAMPLE IMPLEMENTATIONS

[0024] In FIG. 1, an embodiment 100 of the present disclosure is shown. A photocatalyst layer 102 is coated over a substrate material, polyvinyl chloride (PVC) 101. The photocatalyst layer contains a primary metal oxide photocatalyst TiO.sub.2 104 and two secondary metallic photocatalysts, silver nanoparticles (NPs) 105 and cerium NPs 106. The primary photocatalyst TiO.sub.2 104 forms a covalent bond with the PVC substrate material 101 along the boundary 103 where the photocatalyst layer 102 meets the substrate material 101. With the presence of the two secondary photocatalysts, the photocatalyst layer 102 is activatable by a visible light with a wavelength range greater than 400 nm. The second side of the PVC substrate material is coated with an adhesive layer 107 comprising a pressure-sensitive adhesive (PSA) material. With a PSA layer, the embodiment could be used as self-disinfecting window film, and it can be attached, removed, and even reattached to a glass window and provide self-disinfection protection for the glass window.

[0025] This embodiment is made firstly by treating the PVC substrate material 101 with an oxygen plasma at 50° C. Then one side of the plasma-treated substrate material PVC is sprayed with a water-based TiO.sub.2 solution that also contains silver NPs and cerium NPs. The TiO.sub.2, silver NPs, and cerium NPs, together has less than 2 wt % of the solution, and the water has 98 wt % of the solution. The mass ratio of the secondary photocatalysts, silver NPs and cerium NPs, to the primary photocatalyst TiO.sub.2 is 30:1. Thirdly, the substrate material being sprayed with a water-based TiO.sub.2 solution goes through a heat curing process for 30 minutes at 150° C. Lastly, the second side of the PVC substrate material is coated with an adhesive layer comprising a pressure-sensitive adhesive (PSA) material.

[0026] In FIG. 2, another embodiment 200 of the present disclosure is shown. Its substrate material, soda lime glass 201, is coated with a photocatalyst layer 202, comprising a primary metal oxide photocatalyst TiO.sub.2 204, and two secondary metallic photocatalysts, silver NPs 205 and cerium NPs 206. The primary photocatalyst TiO.sub.2 204 forms a covalent bond with the substrate material 201 along the boundary 203 where the photocatalyst layer 202 meets the substrate material 201. A layer of phenol red 208 is coated over a portion of the photocatalyst layer 202. The phenol red layer is red when this embodiment is first used under a visible light, since the photocatalyst layer 202 is activatable by the visible light and self-disinfect against bacteria, and therefore the phenol red layer detects no bacteria. As the photocatalyst layer 202 is worn off due the normal wear-and-tear, its photocatalytic effectiveness begins to drop and leaves some bacteria on its surface. When enough bacteria are accumulated on the surface of the photocatalyst layer 202, they will be detected by the phenol red layer 208, causing the phenol red to change its color to orange. By observing the color changing of the phenol red layer 208, a user can decide when it is necessary to replacement the self-disinfecting photocatalyst sheet with a new one.

[0027] The second side of the soda lime glass substrate material is coated with an adhesive layer comprising an electrostatic-enhancing agent 207 and this embodiment 200 has a transmission rate of visible light greater than 90%. This embodiment could be used as a cellphone screen protector for it could be adhered to the cellphone screen via the electrostatic-enhancing layer 207 without blocking the content of the cellphone screen, and more importantly, provide a self-disinfection protection for the cellphone screen.

Additional and Alternative Implementation Notes

[0028] Although the techniques have been described in language specific to certain applications, it is to be understood that the appended claims are not necessarily limited to the specific features or applications described herein. Rather, the specific features and examples are disclosed as non-limiting exemplary forms of implementing such techniques.

[0029] As used in this application, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise or clear from context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more,” unless specified otherwise or clear from context to be directed to a singular form.