Method to create hydrophilic antimicrobial diamond coating

Patent metadata

Field	Value
Publication number	US-12325660-B1
Application number	US-202418414761-A
Country	US
Kind code	B1
Filing date	Jan 17, 2024
Priority date	Jan 17, 2024
Publication date	Jun 10, 2025
Grant date	Jun 10, 2025

Abstract

A method for creating a hydrophilic antimicrobial diamond coating on a silicon or glass surface includes providing a silicon or glass surface, creating a second surface by seeding a plurality of nanodiamond particles on the silicon or glass surface by microwave plasma chemical vapor deposition (MPCVD), and forming a silver nitrate and hydroxylamine solution. A third surface may be created by seeding a plurality of silver nanoparticles onto the second surface by spraying the silver nitrate and hydroxylamine solution onto the second surface and maintaining the silver nitrate and hydroxylamine solution on the second surface for a predetermined time. The third surface may then be exposed to an oxygen plasma treatment.

First claim

The invention claimed is:

1. A method for creating a hydrophilic antimicrobial diamond coating on a silicon or glass surface comprising the steps of:
providing a silicon or glass surface;
creating a second surface by seeding a plurality of nanodiamond particles on the silicon or glass surface by microwave plasma chemical vapor deposition (MPCVD) such that each of the plurality of nanodiamond particles has a grain size of approximately 2-5 nm;
forming a silver nitrate and hydroxylamine solution by mixing a silver nitrate solution of approximately 0.03-0.08 mg/L with hydroxylamine at a predetermined temperature;
creating a third surface comprising:
seeding a plurality of silver nanoparticles onto the second surface by spraying the silver nitrate and hydroxylamine solution onto the second surface, and
maintaining the silver nitrate and hydroxylamine solution on the second surface for a predetermined time; and

exposing the third surface to an oxygen plasma treatment for 10-40s, at a power of approximately 40 W, a pressure of 100-200 mTorr, and an oxygen flow rate of 20-25 sccm.

2. The method of claim 1 , wherein the MPCVD includes a chamber having a pressure lower than atmospheric pressure and a mixture of gases flowing into the chamber, the mixture of gases comprising:
methane at a flow rate of 1.2 sccm,
hydrogen at a flow rate of 17 sccm, and
argon at a flow rate of 400 sccm; and
the chamber generating a plasma ball from a microwave plasma source wherein the plasma has a temperature of between approximately 400-800° C. with an input power of 2100 W and a frequency of 915 MHz.

3. The method of claim 1 wherein each of the plurality of nanodiamond particles has a grain size of approximately 5 nm.

4. The method of claim 1 wherein the second surface has a thickness between approximately 200 nm to 600 nm.

5. The method of claim 1 wherein the predetermined time for maintaining the silver nitrate and hydroxylamine solution on the second surface is approximately 2 hours.

6. The method of claim 1 wherein the predetermined temperature is 25° C.

7. The method of claim 1 wherein the step of exposing the third surface to an oxygen plasma treatment includes exposing the third surface to the oxygen plasma treatment for 40s, at a power of 40 W, a pressure of 160 mTorr, and an oxygen flow rate of 22 sccm.

8. The method of claim 1 wherein the hydrophilic antimicrobial diamond coating on the silicon or glass surface transmits light up to 90% in the visible spectrum.

9. The method of claim 1 wherein the hydrophilic antimicrobial diamond coating on the silicon or glass surface is optically transparent while maintaining at least 87% optical transmission throughout the visible spectrum.

10. The method of claim 1 wherein the hydrophilic antimicrobial diamond coating on the silicon or glass surface comprises a superhydrophilic antimicrobial diamond coating (SADC) on the silicon or glass surface.

11. The method of claim 10 wherein the SADC is anti-fogging and reduces bacterial attachment to approximately zero percent coverage.

12. A method for creating a hydrophilic antimicrobial diamond coating on a silicon or glass surface comprising the steps of:
providing a silicon or glass surface;
creating a second surface by seeding a plurality of nanodiamond particles on the silicon or glass surface by microwave plasma chemical vapor deposition (MPCVD) such that each of the plurality of nanodiamond particles has a grain size of approximately 2-5 nm;
creating a third surface by exposing the second surface to an oxygen plasma treatment for 10-40s, at a power of approximately 40 W, a pressure of 100-200 mTorr, and an oxygen flow rate of 20-25 sccm;
forming a silver nitrate and hydroxylamine solution by mixing a silver nitrate solution of approximately 0.03-0.08 mg/L with hydroxylamine at a predetermined temperature;
seeding a plurality of silver nanoparticles onto the third surface by spraying the silver nitrate and hydroxylamine solution onto the third surface; and
maintaining the silver nitrate and hydroxylamine solution on the third surface for a predetermined time.

13. The method of claim 12 wherein the MPCVD includes a chamber having a pressure lower than atmospheric pressure and a mixture of gases flowing into the chamber, the mixture of gases comprising:
methane at a flow rate of 1.2 sccm,
hydrogen at a flow rate of 17 sccm, and
argon at a flow rate of 400 sccm; and
the chamber generating a plasma ball from a microwave plasma source wherein the plasma has a temperature of between approximately 400-800° C. with an input power of 2100 W and a frequency of 915 MHz.

14. The method of claim 12 wherein each of the plurality of nanodiamond particles has a grain size of approximately 5 nm.

15. The method of claim 12 , wherein the second surface has a thickness between approximately 200 nm to 600 nm.

16. The method of claim 12 wherein the predetermined time for maintaining the silver nitrate and hydroxylamine solution on the third surface is approximately 2 hours.

17. The method of claim 12 wherein the predetermined temperature is 25° C.

18. The method of claim 12 wherein the step of creating a third surface by exposing the second surface to an oxygen plasma treatment further includes exposing the second surface to the oxygen plasma treatment for 40s, at a power of 40 W, a pressure of 160 mTorr, and an oxygen flow rate of 22 sccm.

19. The method of claim 12 wherein the hydrophilic antimicrobial diamond coating on the silicon or glass surface transmits light up to 90% in the visible spectrum.

20. The method of claim 12 wherein the hydrophilic antimicrobial diamond coating on the silicon or glass surface is optically transparent while maintaining at least 87% optical transmission throughout the visible spectrum.

Assignees

• Us Energy

Inventors

• Sumant Anirudha V
• Deng Shikai

Classifications

• C03C2217/78

  Coatings specially designed to be durable, e.g. scratch-resistant · CPC title

• C03C2217/42

  consisting of particles only · CPC title

• C03C2217/75

  Hydrophilic and oleophilic coatings · CPC title

• C03C17/3607 Primary

  Coatings of the type glass/inorganic compound/metal · CPC title

• C03C17/36

  at least one coating being a metal · CPC title