DESC:The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

FIELD OF INVENTION
[0001] The present invention relates to surface coating substances, and more specifically to an antimicrobial coating on surface for inactivating micro-organisms which come in contact with the surface. The present application is based on, and claims priority from an Indian Application Number 202041019979 filed on 12th May 2020 the disclosure of which is hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] Textiles form part of our daily life and is used in clothing, decorations, covering surfaces, bandaging, etc. in a variety of environments. However, in some environments such as hospitals, laboratories, industrial environments, military, animal caregivers, etc. there is imminent danger of microbiological contamination on textile surfaces. The prevalent environment in the locations can result in the textile being not only a fertile breeding ground for pathogens, but also a perfect substrate from which the pathogens can spread to others resulting in infections, maybe even death, higher operational costs and waste through redundancy and rot.
[0003] The 2020- 2021 COVID-19 pandemic rapidly spread throughout the world. There are two main issues which need to be addressed, first is to slow down the transmission of the COVID-19 virus and other is to treat the infected patients. In treating the COVID-19 infected patients frontline workers including doctors, nurses, sanitation workers, played a very important role. However, there is a need to ensure that the frontline workers themselves are not infected.
[0004] Further, there have been research publications stating that the COVID-19 virus may stay in air and surfaces like metals, plastic, fabric etc. from hours to days in an infectious state. Therefore, the people can acquire the COVID-19 virus from the surfaces without being aware of the same. The COVID-19 virus can also stay on the textiles such as clothes, bed sheets etc. for up to 24 hours. Further, pores on the textiles can only prevent particulate matter from entering the textile, but allows the COVID-19 viruses through the textile. Also, sweat and other fluids released from a user can get trapped in the textile pores which provide enough warmth and humidity to turn the textile into breeding grounds for the COVID-19 virus.
[0005] However, there is no one method or product which can be used to address both the problems of slowing the infections and protecting the frontline workers/people from acquiring the virus from textiles.
[0006] Thus, it is desired to address the above mentioned disadvantages or other shortcomings or at least provide a useful alternative.
OBJECT OF INVENTION
[0007] The principal object of the embodiments herein is to provide an antimicrobial coating of nanoparticles for coating surfaces to inactivate micro-organisms which come in contact with the surface. This helps in securing the surfaces and curbing the role of surfaces as spreading agents of the micro-organisms.
[0008] Another object of the embodiments herein is to prepare a nanoparticles solution using one of doped nanoparticles and polymeric mixture of nanoparticles for providing a multi-mode mechanism for inactivating a microbe or viruses on the surface.

SUMMARY
[0009] Accordingly the embodiments herein provide an antimicrobial coating for a surface, wherein the antimicrobial coating is a nanoparticle solution coated on the surface for providing a multi-mode mechanism for inactivating a microbe or viruses on the surface. The nanoparticle solution is prepared using one of doped nanoparticles and polymeric mixture of nanoparticles. The doped nanoparticles and the polymeric mixture of nanoparticles include at least one nano-metal substances and one nano-metal oxides.
[0010] In an embodiment, the multi-mode mechanism comprises at least one of a reactive oxygen species (ROS) mechanism, light activated mechanism, and cationic charge induced mechanism.
[0011] In an embodiment, the nanoparticle solution is prepared using the doped nanoparticles by obtaining a first solution by adding at least one surfactant in an aqueous solvent and applying ultrasonic irradiation for to the first solution for a period of 5 min. Further, the method includes obtaining a second solution by adding a mixture of nanoparticle powders into the first solution during the ultrasonic irradiation of the first solution, adding sodium citrate of 1 to 10gm into the second solution and obtaining the nanoparticle solution by mixing and irradiating the for 30 min the second solution with the sodium citrate.
[0012] In an embodiment, the nanoparticle solution prepared using the doped nanoparticles are maintained at a pH above 8.
[0013] In an embodiment, the at least one surfactant comprises dodecyl trimethyl ammonium bromide (DTAB), Polyethylenimine (PEI) and polyethylene glycol (PEG).
[0014] In an embodiment, the mixture of nanoparticle powders comprises 97.5% - 98 % of ZnO Nanoparticles of size in a range of 20nm - 100 nm and 2-2.5 % of Cu Nanoparticles of size in the range of 1nm - 30 nm.
[0015] In an embodiment, the at least one surfactant in the nanoparticle solution are in a weight % between 5% - 20% and the mixture of nanoparticle powders in the nanoparticle solution are in weight % between 0.1 wt% - 10 wt% with the aqueous solvent in the weight % between 70% - 95% in the nanoparticle solution.
[0016] In an embodiment, the at least one surfactant in the nanoparticle solution are adsorbed by on surface of the nanoparticles and forms one of vesicle structures and micelle structures.
[0017] In an embodiment, the formation of one of the vesicle structures and the micelle structures prevents an agglomeration of the nano particles in the antimicrobial coating.
[0018] In an embodiment, the nanoparticle solution is prepared using the polymeric mixture of nanoparticles by preparing a solvent by mixing a 20% of the PEG with 80% of water and preparing a mixture by adding DTAB of weight % 5 -20% to the solvent. Further, the method includes adding an Epoxy Resin to the mixture; and obtaining the nanoparticle solution by adding a mixture of nanoparticle powders to the Epoxy Resin mixture and irradiating the nanoparticle solution for a period of 45 minutes.
[0019] In an embodiment, the mixture of nanoparticle powders comprises 97.5% - 98 % of ZnO Nanoparticles of size in a range of 20nm - 100 nm and 2-2.5 % of Cu Nanoparticles of size in the range of 1nm - 30 nm.
[0020] In an embodiment, the epoxy resin is added with a weight % between 1% - 10% of the nanoparticle solution.
[0021] In an embodiment, the nanoparticle solution is dip coated on the surface.
[0022] In an embodiment, the nanoparticle solution is prepared using the polymeric mixture of nanoparticles by mixing in one of a magnetic stirrer and an ultrasonic irradiation chamber an isopropyl Alcohol of 70% - 80%, the DTAB Chemical belonging to a cation group of 20%, an Epoxy Resin of 1% - 4 % and a fragrance oils.
[0023] In an embodiment, the nanoparticle solution is coated onto the surface using spray coating technique.
[0024] In an embodiment, the nanoparticle solution is coated onto the surface using an ultrasonic cavitation technique.
[0025] In an embodiment, the antimicrobial coating comprises one of hydrophobic properties and hydrophilic properties based on the two nano-metal substances and the nano-metal oxides used in the nanoparticle solution.
[0026] In an embodiment, the antimicrobial coating adheres to the surface up to 60-100 wash cycles depending on the nanoparticles used to coat the surface.
[0027] In an embodiment, the antimicrobial coating inactivates micro-organisms within 5 minutes of contact and wherein the antimicrobial coating inactivates micro-organisms even in size range of 20 to 30 nm.
[0028] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

DETAILED DESCRIPTION OF INVENTION
[0029] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0030] Accordingly the embodiments herein provide an antimicrobial coating for a surface, wherein the antimicrobial coating is a nanoparticle solution coated on the surface for providing a multi-mode mechanism for inactivating a microbe or viruses on the surface. The nanoparticle solution is prepared using one of doped nanoparticles and polymeric mixture of nanoparticles. The doped nanoparticles and the polymeric mixture of nanoparticles include at least one nano-metal substances and one nano-metal oxides.
[0031] Some of the main advantages of the antimicrobial coating using the nanoparticles solutions include but are not limited to:
1. Ease of usage of the antimicrobial coating and applications that can fit in existing methodology.
2. No chemical binders used when the nanoparticles solution is prepared using doped nanoparticles.
3. Inactivation of various viruses including various strains of the deadly Coronavirus and bacteria by the coated surfaces with all the compositions of the nanoparticle solution.
4. Multimode mechanisms are induced to destroy viruses and bacteria which mean a variety of the bacteria and the viruses can be destroyed using the nanoparticle solution. The multi-mode mechanism is the main principle why the surfaces coated with the proposed antimicrobial coating of nanoparticle solution are superior to any conventional chemical compositions of the coatings. The multi-mode mechanisms include but are not limited to reactive oxygen species (ROS) mechanism, light activated mechanisms, cationic charge induced mechanisms etc.
5. The antimicrobial coating helps in inactivation of the microorganisms and viruses in less than 5 minutes of contact with the coated surface.
6. The multimode mechanism induced using the chemical composition helps in destroying bacteria that develop chemical resistance over a period of time. Hence proven much more effective than any current methods.
7. The use of nanoparticles increases various inactivation methods and has proven effective against different microbes and viruses.
8. All three chemical compositions have been proven effective on all types of virus which have an envelope shape.
[0032] The invention deals with different antimicrobial agents and preparation methods of the antimicrobial agents that can be coated on various surfaces such as for example but not limited to textiles, fabric, rubber, tissues, soft surfaces and hard surfaces. The coated textile provides a high inactivation rate on viruses such as corona-virus. The textiles include but are not limited to cotton, cotton-polyester, polyester or any other fabric that is activated through antiviral nanoparticle based agents. These textiles can be utilized in making daily wear, masks, PPE equipment, furniture covers, hospital, and bed linings. Cushion linings in flights/automotive applications and more. Also our innovation includes high reusability of the textiles and will retain the inactivation properties for 60-100 wash cycles. Also, these textiles are not harmful for humans, kids, pets and environment.
[0033] The antimicrobial coating for the surface basically is a nanoparticle solution which is coated on the surface to provide a multi-mode mechanism to the surface. The multi-mode mechanism helps in inactivating a microbe or viruses which comes in contact with the surface. The nanoparticle solution is prepared using one of the below mentioned chemical compositions and can be coated on the surface using a specific coating technique. However, the specific coating technique may not be considered as a limitation for the specific chemical composition of the nanoparticle solution.
[0034] The chemical compositions of the nanoparticle solution and the specific coating techniques are:
1. Ultrasonic irradiation of textiles or other surfaces using doped nanoparticles.
2. A standard method called DIP Coating/PAD dry cure method using a first chemical composition of the polymeric mixture of nanoparticles.
3. A spray coating methodology using the second chemical composition of the polymeric mixture of nanoparticles.
Doped Nanoparticles solution for coating textiles using ultrasonic irradiation:
[0035] The nanoparticle solution is prepared using Doped Nanoparticles solution for coating textiles using ultrasonic irradiation. This composition is utilized to coat textiles using ultrasonic irradiation method. There are no chemical Binders utilized in this technique.
[0036] The chemical composition of the nanoparticle solution prepared using doped nanoparticles includes:
1. 97.5% - 98 % of ZnO Nanoparticles of sizes (20nm - 100 nm) - 2-2.5 % of Cu Nanoparticles (1nm - 30 nm) powders are mixed together to form a first mixture.
2. The first mixture is dissolved into a distilled water solution in ratios of 0.1 wt% - 10 wt%.
3. One or two surfactants are mixed into the solvent. The surfactants may include - PEI or DTAB or PEG or a mixture of any two of them and is called as a second mixture.
4. The weight % of second mixture may be between 5% - 20%.
5. The main solvent is an aqueous solution - where distilled water is utilized. The weight % of the distilled water is between 70% - 95% in the nanoparticles solution.
[0037] The method for preparing the nanoparticle solution using the doped nanoparticles based on the above mentioned chemical composition includes:
1. Distilled water is added to a chamber
2. Then the second mixture of the surfactants is added to the aqueous solution.
3. Ultrasonic irradiation is applied to the second mixture in the aqueous solution for a period of 5 min.
4. Then the first mixture of the Nanoparticle powders is added into the solution in (3) while ultrasonic irradiation is on-going.
5. Sodium citrate of 10gm is added into the mixture in (4).
6. Mix the solution in (5) and leave it under irradiation for a period of 30 min to obtain the nanoparticle solution.
[0038] The nanoparticles in the nanoparticle solution along with the surfactants form Vesicle or micelle structures. The formation of one of the vesicle structures and the micelle structures prevents an agglomeration of the nano particles in the antimicrobial coating. The form vesicle or micelle structures are stable at room temperature up to 12 hours. The overall PH of the nanoparticle solution is maintained above 8.
Polymeric mixture of nanoparticles for coating the surfaces using standard coating techniques:
[0039] The nanoparticle solution is prepared using polymeric mixture of nanoparticles for coating textiles using any standard coating technique like DIP coating technique.
[0040] The chemical composition of the nanoparticle solution prepared using polymeric mixture of nanoparticles includes:
1. 97.5% - 98 % of ZnO Nanoparticles of sizes (20nm - 100 nm) - 2-2.5 % of Cu Nanoparticles (1nm - 30 nm) powders are mixed together to form nanoparticles mixture.
2. DTAB weight % of 5 - 20%.
3. An Epoxy Resin is added with a weight % between 1% - 10%.
4. PEG 20% and Distilled water 80% mixture is used as solvent.
[0041] The method for preparing the nanoparticle solution using the polymeric mixture of the nanoparticles includes:
1. The PEG is mixed with water and is used as a solvent for other mixtures.
2. The DTAB of weight % 5 -20% are added to the solvent.
3. Then the epoxy resin is added to the mixture
4. Then the desired nano particles mixture is added to the mixture.
[0042] Further, the mixture is irradiated for 45 min for perfect mixing of all the added chemicals and for the nanoparticle solution to be ready to be coated on the surface.
Polymeric mixture for coating the surfaces using Spray Coating technique:
[0043] The nanoparticle solution is prepared using polymeric mixture of nanoparticles for coating textiles using spray coating technique.
[0044] The chemical composition of the nanoparticle solution prepared using polymeric mixture of nanoparticles includes
1. Isopropyl Alcohol - 70% - 80%
2. DTAB - Chemical belonging to a cation group - 20%
3. Epoxy Resin - 1% - 4 %
4. Fragrance creating Oils Like Lavender oil etc.
[0045] The method for preparing the nanoparticle solution using the polymeric mixture of the nanoparticles includes adding the above mixtures one after the other and mixing using a magnetic stirrer or ultrasonic irradiation.
[0046] Further, the textiles are also treated with Mixture 1 and Mixture 2 together with the Mixture 2 used as a pretreatment process for the textile and mixture one is used for ultrasonication.
[0047] The above compositions 2 &3 can also be used for other soft and hard surfaces other than textiles and are generic in nature.
[0048] The multi-Mode mechanism for inactivating the viruses and bacteria means the antimicrobial coating on the surface displays multiple mechanisms like Light activated ROS, Lipid peroxidation, Positive Charge attraction of the envelope etc. which help in inactivating the microbes which come in contact with the coated surface.
[0049] The advantage of having multi-mode mechanism is that due to the multi-mode mechanism being provided by the nanoparticles solution the antimicrobial coating includes:
1. Faster inactivation rates
2. Applicable for all types of bacteria and viruses
3. No bacterial resistance
4. Both Biocidal and Biostatic (Bactericidal and bacteriostatic) properties can be observed.
[0050] When the textile is coated with the antimicrobial coating, the coated textile exhibits significant properties which include but are not be limited to:
1. Once coronavirus comes in contact with the textiles, a 99% inactivation of coronavirus has been observed in 5, 10, 15, 30, 60 minutes - depending on the specific nanoparticles used.
2. The coated textiles are reusable and SEM analysis of the coated textiles shows a strong adhesion to the nanoparticles resulting in the retainment of the virus inactivation property up to 60-100 wash cycles depending on the nanoparticles used to coat the textiles. This has been tested under sterile washing conditions of 75 degrees Centigrade.
3. The coated textiles do not show any significant leaching while washing in water and thereby do not contaminate the water or the environment.
4. The coated textiles have also shown promise on inactivating other bacteria, viruses as small as 30 nm.
5. The coated textiles have been proved to not cause any toxicity to humans or pets.
6. As a byproduct, the coated textiles have also shown properties of UV Protection, skin health enhancement and faster skin wound recoveries upon contact. The textiles can show both hydrophobic (water resistant) and hydrophilic (water absorption) properties depending on the specific nanoparticles used.
[0051] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.
,CLAIMS:CLAIMS
We claim:
1. An antimicrobial coating for a surface, wherein the antimicrobial coating is:
a nanoparticle solution coated on the surface for providing a multi-mode mechanism for inactivating a microbe or viruses on the surface,
wherein the nanoparticle solution is prepared using one of doped nanoparticles and polymeric mixture of nanoparticles, wherein the doped nanoparticles and the polymeric mixture of nanoparticles comprises a nano-metal substances and a nano-metal oxides.
2. The antimicrobial coating as claimed in claim 1, wherein the multi-mode mechanism comprises at least one of a reactive oxygen species (ROS) mechanism, light activated mechanism, cationic charge induced mechanism.
3. The antimicrobial coating as claimed in claim 1, wherein the nanoparticle solution is prepared using the doped nanoparticles by:
obtaining a first solution by adding at least one surfactant in an aqueous solvent;
applying ultrasonic irradiation for to the first solution for a period of 5 min;
obtaining a second solution by adding a mixture of nanoparticle powders into the first solution during the ultrasonic irradiation of the first solution;
adding sodium citrate of 1 to 10gm into the second solution;
obtaining the nanoparticle solution by mixing and irradiating for 30 min the second solution with the sodium citrate.
4. The antimicrobial coating as claimed in claim 3, wherein the nanoparticle solution prepared using the doped nanoparticles is maintained at a pH above 8.
5. The antimicrobial coating as claimed in claim 3, wherein the at least one surfactant comprises dodecyl trimethyl ammonium bromide (DTAB), Polyethylenimine (PEI) and polyethylene glycol (PEG).
6. The antimicrobial coating as claimed in claim 3, wherein the mixture of nanoparticle powders comprises 97.5% - 98 % of ZnO Nanoparticles of size in a range of 20nm - 100 nm and 2-2.5 % of Cu Nanoparticles of size in the range of 1nm - 30 nm.
7. The antimicrobial coating as claimed in claim 3, wherein the at least one surfactant in the nanoparticle solution are in a weight % between 5% - 20% and the mixture of nanoparticle powders in the nanoparticle solution are in weight % between 0.1 wt% - 10 wt% with the aqueous solvent in the weight % between 70% - 95% in the nanoparticle solution.
8. The antimicrobial coating as claimed in claim 3, wherein the at least one surfactant in the nanoparticle solution are adsorbed by on surface of the nanoparticles and forms one of vesicle structures and micelle structures.
9. The antimicrobial coating as claimed in claim 8, wherein the formation of one of the vesicle structures and the micelle structures prevents an agglomeration of the nano particles in the antimicrobial coating.
10. The antimicrobial coating as claimed in claim 1, wherein the nanoparticle solution is prepared using the polymeric mixture of nanoparticles by:
preparing a solvent by mixing a 20% of the PEG with 80% of water;
preparing a mixture by adding DTAB of weight % 5 -20% to the solvent;
adding an Epoxy Resin to the mixture; and
obtaining the nanoparticle solution by adding a mixture of nanoparticle powders to the Epoxy Resin mixture and irradiating the nanoparticle solution for a period of 45 minutes.
11. The antimicrobial coating as claimed in claim 3 and claim 10, wherein the mixture of nanoparticle powders comprises 97.5% - 98 % of ZnO Nanoparticles of size in a range of 20nm - 100 nm and 2-2.5 % of Cu Nanoparticles of size in the range of 1nm - 30 nm.
12. The antimicrobial coating as claimed in claim 10, wherein the epoxy resin is added with a weight % between 1% - 10% of the nanoparticle solution.
13. The antimicrobial coating as claimed in claim 10, wherein the nanoparticle solution is dip coated on the surface.
14. The antimicrobial coating as claimed in claim 1, wherein the nanoparticle solution is prepared using the polymeric mixture of nanoparticles by:
mixing in one of a magnetic stirrer and an ultrasonic irradiation chamber an isopropyl Alcohol of 70% - 80%, the DTAB Chemical belonging to a cation group of 20%, an Epoxy Resin of 1% - 4 % and a fragrance oils.
15. The antimicrobial coating as claimed in claim 14, wherein the nanoparticle solution is coated onto the surface using spray coating technique.
16. The antimicrobial coating as claimed in claim 3, wherein the nanoparticle solution is coated onto the surface using an ultrasonic cavitation technique.
17. The antimicrobial coating as claimed in claim 1, wherein the antimicrobial coating comprises one of hydrophobic properties and a hydrophilic properties based on the two nano-metal substances and the nano-metal oxides used in the nanoparticle solution.
18. The antimicrobial coating as claimed in claim 1, wherein the antimicrobial coating adheres to the surface up to 60-100 wash cycles depending on the nanoparticles used to coat the surface.
19. The antimicrobial coating as claimed in claim 1, wherein the antimicrobial coating inactivates micro-organisms within 5 minutes of contact and wherein the antimicrobial coating inactivates micro-organisms even in size range of 20 to 30 nm.

Dated this 12th Day of May, 2021

Signature:
Arun Kishore Narasani
(Patent Agent IN/PA 1049)