FIELD OF INVENTION

The present invention relates to the field of disinfection technology. More particularly, the present invention relates to an apparatus for surface and air disinfection.

BACKGROUND OF THE INVENTION

Infectious diseases can be transmitted from contaminated surfaces or space via physical contact or airborne transmission. This can be prevented by cleaning or disinfecting the contaminated surfaces or space. Cleaning involves the use of soap or detergent, whereas disinfection involves the use of a product or process to inactivate microbes responsible for the infectious diseases. Disinfection technology is vital in preventing and controlling the spread of infectious diseases such as COVID-19 caused by SARS-CoV- 2 virus.

Conventionally, ultraviolet (UV) irradiation is used for disinfection. In particular, the UV irradiation inactivates microbes by destroying their nucleic acids and disrupting their DNA, thereby leaving the microbes unable to perform cellular functions. For example, US Patent No. US11040121B2 discloses a portable UV device for disinfection. The portable UV device comprises a germicidal UV light source disposed within a housing comprising a motorized unit, a hydraulic system, and an actuator. When not in use, the germicidal UV light source resides within the housing. When in use, the germicidal UV light source is released from the housing in a vertical and rotational manner. However, UV irradiation technology for surface disinfection can be costly due to the use of UV light bulb. Additionally, UV irradiation can damage structures of human eyes. Side effects are such as corneal damage, cataracts, and macular degeneration. Alternatively, Hwang et al. (doi: 10.1038/s41467-020-15004-6) discloses a photob acteri ci dal polymer containing crystal and thiolated gold nanocluster for killing microbes on a polymer upon activated by a light source. However, this technology requires the polymer to be in direct contact with the microbes, thereby rendering it inconvenient for use.

Therefore, it is desirable to provide a disinfection technology that is affordable and convenient to use while not inducing the aforementioned side effects. The present invention provides a solution to the problems.

SUMMARY OF INVENTION

One aspect of the present invention is to provide a disinfection apparatus that is affordable and convenient to use while not inducing the side effects such as corneal damage, cataracts, and macular degeneration.

Another aspect of the present invention is to provide a readily available disinfecting apparatus in which common light emitting device can be modified thereinto. For instance, the light-emitting device is a portable handheld electrical device such as torch light and mobile phone or a non-portable electrical device such as streetlight and wall lamp. The light can be provided by light emitting diode (LED), fluorescent light bulb, and incandescent light bulb.

Yet, another aspect of the present invention is to provide a disinfecting apparatus having a protective layer that protects the light emitting device from contaminants.

More particularly, the present invention aims to provide an apparatus for disinfecting a target surface or air comprising a light-emitting device, a transparent film deposited onto the light-emitting device, and a coating deposited onto the film. The coating comprises vibration-energy-containing nanoparticles in which atoms of the nanoparticles are in a state of energy excitation that vibrate for a period of time upon being subjected to a vibration force. When in use, the apparatus illuminates through the film and the coating thereby transferring the vibration energy of the vibration-energy- containing nanoparticles onto the target surface for disinfection.

At least one of the preceding aspects is met, in whole or in part, in which the embodiment of the present invention describes an apparatus for disinfecting a target surface or air comprising (a) a light-emitting device; (b) a transparent film being deposited onto the light-emitting device; and (c) a coating deposited onto the film in which the coating is derived from a mixture comprising a nanoparticle solution and an acrylic polymer solution, wherein the nanoparticle solution comprises vibration- energy-containing nanoparticles, a binder, an acid-based surface additive, and a first organic solvent selected from the group consisting of alcohol, silicone oil, and a combination thereof, and the acrylic polymer solution comprises an acrylic polymer and a second organic solvent selected from the group consisting of alkane, cyclohexane, ketone, ester, and any combinations thereof, whereby the acrylic polymer solution promotes attachment of the vibration-energy-containing nanoparticles onto the film, wherein upon activating the light-emitting device light illuminates through the film and the coating thereby transferring the vibration energy of the vibration-energy-containing particles onto the target surface or air for disinfection, in which the film protects of the light-emitting device from contaminants.

In a preferred embodiment of the present invention, the transparent film is derived from polypropylene, polyethylene terephthalate, polyurethane, polyethylene, or polypropylene.

According to the preferred embodiment of the present invention, the nanoparticle solution is present at about 1% to about 20% by volume of the mixture and the acrylic polymer solution is present at about 80% to about 99% by volume of the mixture.

Still, according to the preferred embodiment of the present invention, the vibration- energy-containing particles are present at about 0.1% to about 10% by weight of the nanoparticle solution, the binder is present at about 0.1% to about 30% by weight of the nanoparticle solution, the surface additive is present at about 0.1% to about 8% by weight of the nanoparticle solution, and the first organic solvent is present at about 75% to about 94% by weight of the nanoparticle solution.

Yet, according to the preferred embodiment of the present invention, the vibration- energy-containing particles are in a state of energy excitation that vibrate at a frequency of 1 to 1000 kHz for a predetermined period upon being subjected to a vibration force at the frequency for at least 6 hours.

Preferably, the vibration-energy-containing particles are metal-based nanoparticles, rare earth-based nanoparticles, graphene, or a combination thereof.

Further to the preferred embodiment of the present invention, the acrylic polymer is present at about 5% to about 70% by volume of the acrylic polymer solution and the second organic solvent is present at about 30% to about 95% by volume of the acrylic polymer solution.

According to another preferred embodiment of the present invention, the acrylic polymer solution further comprises a siloxane polymer to improve texture of the coating.

Still, according to another preferred embodiment of the present invention, acrylic polymer solution further comprises a hardener. Preferably, the coating has a thickness of about 1 gm to about 10 gm.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description. However, it is to be understood that limiting the description to the preferred embodiments of the present invention is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claim.

The present invention is an apparatus for disinfecting a target surface or air. Preferably, the apparatus comprises a light-emitting device, a transparent film deposited onto the light-emitting device, and a coating deposited onto the film. Preferably, the lightemitting device is a portable handheld electrical device such as torch light and mobile phone or a non-portable electrical device such as streetlight and wall lamp. The light can be provided by light emitting diode (LED), fluorescent light bulb, or incandescent light bulb. The light-emitting device can be powered by a built-in power source (such as a battery) and/or an external power source (with connections to existing power outlets). Wherever necessary, an existing light-emitting device can be converted into the disinfecting apparatus by applying the transparent film onto the light-emitting device followed by depositing the coating onto the film.

According to a preferred embodiment of the present invention, the transparent film is derived from polypropylene, polyethylene terephthalate, polyurethane, polyethylene, or polypropylene. The transparent film can be a commercial film made from any of the aforementioned materials. Preferably, the film has a thickness of about 25 pm to about 300 pm. According to the preferred embodiment of the present invention, the coating is derived from a mixture comprising a nanoparticle solution and an acrylic polymer solution. Preferably, the nanoparticle solution is present at about 1% to about 20% by volume of the mixture and the acrylic polymer solution is present at about 80% to about 99% by volume of the mixture.

Still, according to the preferred embodiment of the present invention, the nanoparticle solution comprises vibration-energy-containing nanoparticles, a binder, an acid-based surface additive, and a first organic solvent. Preferably, the vibration-energy-containing nanoparticles are present at about 0.1% to about 10% by weight of the nanoparticle solution, the binder is present at about 0.1% to about 30% by weight of the nanoparticle solution, the surface additive is present at about 0.1% to about 8% by weight of the nanoparticle solution, and the first organic solvent is present at about 75% to about 94% by weight of the nanoparticle solution. A lower amount of vibration-energy-containing nanoparticles is not preferable as it may not provide sufficient vibration for disinfection when in use, whereas a higher amount of vibration-energy-containing nanoparticles does not provide notable improvement.

Preferably, the vibration-energy-containing nanoparticles are in a state of energy excitation that vibrate at a frequency of 1 to 1000 kHz for a predetermined period upon being subjected to a vibration force. The vibration force is preferably provided for a sufficiently long period of time to ensure that atoms of the nanoparticles capture and hold the energy from the vibration force for the predetermined period of time. Preferably, the vibration force is provided for at least 6 hours. During the process, the atoms are excited to vibrate vigorously for a period of time at a frequency similar to the frequency of the vibration force. By way of example, the vibration force can be provided by means of ultrasonication. In some embodiments of the present invention, the vibration-energy-containing nanoparticles can hold vibration energy and vibrate for 6 months.

Preferably, the vibration-energy-containing nanoparticles are metal-based nanoparticles, rare earth-based nanoparticles, graphene nanoparticles, or any combinations thereof. More preferably, the metal-based nanoparticles are derived from metal, metal oxide, metal nitrate, metal sulfate, or any combinations thereof. For example, the metal-based nanoparticles are colloidal copper, platinum oxide, silver oxide, titanium oxide, tin oxide, gold oxide, silver nitrate, silver citrate, copper sulfate, or a combination thereof. On the other hand, the rare earth-based nanoparticles are preferably derived from scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or any combinations thereof.

Preferably, the first organic solvent serves as a medium for distributing the vibration- energy-containing nanoparticles onto the film during deposition of the coating. Preferably, the first organic solvent used herein does not react with the vibration- energy-containing nanoparticles so that it does not alter the vibration energy stored in the vibration-energy-containing nanoparticles. Preferably, the first organic solvent is selected from the group consisting of an alcohol, a silicone oil, and a combination thereof. By way of example, the alcohol is methanol, ethanol, propanol, or any combinations thereof, whereas the silicone oil is hexamethyldisiloxane, octamethyltrisiloxane, decamethylcyclopentasiloxane, polydimethylsiloxane, octamethylcyclotetrasiloxane, or any combinations thereof. Advantageously, the silicone oil provides a smooth appearance and anti-stick characteristics to the coating to prevent adherence of solid impurities such as dusts.

Preferably, the binder is used to enhance binding of the vibration-energy-containing nanoparticles onto the film during the deposition. Additionally, the binding allows the coating to be cured at room temperature. Preferably, the binder is a silane. Preferably, the acid-based surface additive is an acid which enhances binding of the vibration-energy-containing nanoparticles onto the film. In particular, the acid lowers pH of the mixture, thereby promoting etching of the vibration-energy-containing nanoparticles onto the film by forming bonds therebetween. Preferably, the pH of the mixture is adjusted to about 5 to about 6 for the aforementioned purpose. A pH lower than 5 is not preferable as it may cause corrosion to the film. On the other hand, an alkaline mixture having a pH of 8 or higher is not desirable as the coating derived therefrom may detach from the film. Preferably, the acid-based surface additive is sulphuric acid, phosphoric acid, nitric acid, citric acid, or hydrochloric acid.

Yet, according to the preferred embodiment of the present invention, the acrylic polymer solution comprises an acrylic polymer and a second organic solvent. Preferably, the acrylic polymer is present at about 5% to about 70% by volume of the acrylic polymer solution and the second organic solvent is present at about 30% to about 95% by volume of the acrylic polymer solution.

Preferably, the acrylic polymer is polyacrylate or polyvinyl ester. For example, the polyacrylate is poly(methacrylate), poly(methyl methacrylate), poly(ethyl methacrylate), or poly(2-hydroxyethyl methacrylate), whereas the polyvinyl ester is polyvinyl acetate or polyvinyl propionate.

Preferably, the second organic solvent is selected from the group consisting of alkane, cyclohexane, ketone, ester, and any combinations thereof. In an exemplary embodiment of the present invention, the second organic solvent is hexane, cyclohexane, acetone, acetyl acetate, or any combinations thereof. Advantageously, the acrylic polymer solution promotes attachment of the vibration-energy-containing nanoparticles onto the film. In some embodiments of the present invention, the acrylic polymer solution further comprises a siloxane polymer to improve texture of the coating. In particular, the siloxane polymer improves wettability of the mixture by reducing its surface tension. This aids in spreading of the mixture throughout the film, thereby forming the coating with smooth texture. For example, the siloxane polymer is boroxo siloxane, 1,3- Bis(glycidyloxypropyl)-1, 1,3,3 tetramethyldisiloxane, or polymethyl(3- glycidyloxypropyl) siloxane.

In some embodiments of the present invention, the acrylic polymer solution further comprises a hardener to enhance curing of the mixture. By way of example, the hardener is anhydride-based, amine-based, polyamide, aliphatic, or cycloaliphatic hardener.

In one embodiment of the present invention, the acrylic polymer solution comprises 62% by volume of the acrylic polymer, 3.5% by volume of the siloxane polymer, 3% by volume of methyl ethyl ketone, 3% by volume of cyclohexane, 26% by volume of ethyl acetate.

The present invention further provides a method for converting a light-emitting device into the apparatus as hereinbefore described. Preferably, the light-emitting device is a portable handheld electrical device such as torch light and mobile phone or a nonportable electrical device such as streetlight and wall lamp. The light can be provided by light emitting diode (LED), fluorescent light bulb, and incandescent light bulb.

Preferably, the transparent film as hereinbefore described is firstly deposited onto a surface of the light-emitting device. Commercial film has a sticky surface which allows direct deposition of the film without the need of adhesive. Advantageously, the transparent film acts as a protective layer to protect the surface of the light-emitting device from contaminants. Additionally, a user can remove the film, such as by means of peeling, from the light-emitting device and replace with a new transparent film with the coating as hereinbefore described after prolonged usage.

Following this, the mixture as hereinbefore described can be prepared. The nanoparticle solution is preferably subjected to ultrasonication to provide vibration energy to the nanoparticles therein. The acrylic polymer or the acrylic polymer solution is preferably not to mixed with the nanoparticle solution before the ultrasonication of the nanoparticle solution to prevent curing of the acrylic polymer prior to depositing the mixture onto the film. Then, the mixture can be deposited onto the film. Preferably, the deposition is performed by using spraying means such as an atomizer. Subsequently, the mixture can be cured at room temperature to form a coating thereon. Prior to the deposition, the film is preferably cleaned to remove impurities such as dust or oil stain, thereby enhancing binding of the mixture thereonto. Preferably, the coating has a thickness of about 1 pm to about 10 pm.

Advantageously, the apparatus in the present invention does not require to come into direct contact with the target surface or air containing microbes for disinfection. When in use, the apparatus illuminates through the film and the coating thereby transferring the vibration energy of the vibration-energy-containing nanoparticles onto the target surface or air for disinfection via irradiation provided by the light-emitting device. The vibration energy is then transferred to the microbes. In this process, microbial cell walls or cell membranes are induced to vibrate at that frequency. The microbial cell membranes or cell walls have a natural frequency in which upon vibrated at such frequency will cause it to shatter or break. When the frequency transferred to the microbes matches with the natural frequency of the microbial cell membranes or cell walls, such vibration causes them to shatter and break apart, thereby killing the microbes. Based on the aforementioned, the apparatus in the present invention is affordable and convenient to use. EXAMPLE

The following non-limiting examples have been carried out to illustrate the preferred embodiments of the present invention.

Example 1

Some exemplary compositions of the nanoparticle solution are tabulated in Tables 1-5.

Table 1 : First exemplary composition of the nanoparticle solution in the present invention.

Table 2: Second exemplary composition of the nanoparticle solution in the present invention. Table 3: Third exemplary composition of the nanoparticle solution in the present invention.

Table 4: Fourth exemplary composition of the nanoparticle solution in the present invention. Table 5: Fifth exemplary composition of the nanoparticle solution in the present invention.

Example 2

A first experiment was conducted to determine the disinfection capability of the present invention. A transparent film was deposited onto a 36 W LED lamp. Then, the mixture described in the present invention was deposited onto the film to form a coating thereon. The resulting 36 W LED lamp is referred herein as “36 W LED lamp A”. 36 W LED lamp A was compared to a conventional 36 W LED lamp without the film and the coating, referred herein as “36 W LED lamp B” to determine their disinfection capability. Each of the lamps was positioned at 600 mm on top of an inoculum culture having an initial concentration of 9.5 - 9.6 * 10 ⁴ cfu/ml of Klebsiella pneumoniae.

Then, the inoculum cultures were separately exposed to irradiation provided by the lamps for 1, 2, 5, and 10 minutes. Subsequently, the exposed inoculum cultures were incubated at 35 °C for 24 - 48 hours. Lastly, remaining microbes were determined. The reduction (%) was calculated based on Equation 1. The results were tabulated in Table 6. (Equation 1) where A = remaining microbes after irradiation by the 36 W LED lamp A

B = remaining microbes after irradiation by the 36 W LED lamp B

Table 6: Disinfection capability of 36 W LED lamps A and B at a distance of 600 mm from the inoculum cultures.

The microbes in the inoculum cultures were reduced by the irradiation provided by 36 W LED lamp A. Additionally, the reduction was higher after a longer exposure. On the contrary, the irradiation provided by 36 W LED lamp B did not reduce the number of microbes in the inoculum cultures. The results show that the apparatus in the present invention is capable of providing disinfection capability. In particular, vibration energy of vibration-energy-containing nanoparticles is transferred onto a target surface (the inoculum culture) via irradiation provided by a light-emitting device (36 W LED lamp) for disinfection. It should be noted that the 36 W LED lamp used herein does not provides germicidal UV light which by itself is capable of disinfecting microbes.

Example 3

A second experiment was conducted to determine the disinfection capability of the present invention. A transparent film was deposited onto a 18 W LED lamp. Then, the mixture described in the present invention was deposited onto the film to form a coating thereon. The resulting 18 W LED lamp is referred herein as “18 W LED lamp A”. 18 W LED lamp A was compared to a conventional 18 W LED lamp without the film and the coating, referred herein as “18 W LED lamp B” to determine their disinfection capability. Each of the lamps was positioned at 600 mm on top of an inoculum culture having an initial concentration of 9.5 - 9.6 * 10 ⁴ cfu/ml of Klebsiella pneumoniae. Then, the inoculum cultures were separately exposed to irradiation provided by the lamps for 1, 2, 5, 10, 30, and 60 minutes. Subsequently, the exposed inoculum cultures were incubated at 35 °C for 24 - 48 hours. Lastly, remaining microbes and reduction were determined. The experiment was repeated using 36 W LED lamps. The results were tabulated in Table 7.

Table 7: Disinfection capability of 18 W and 36 W LED lamps A and B at a distance of 600 mm from the inoculum cultures.

The microbes in the inoculum cultures were reduced by the irradiation provided by 18 W LED lamp A and 36 W LED lamp A. Additionally, the reduction was higher after a longer exposure. On the contrary, the irradiation provided by 18 W LED lamp B and 36 W LED lamp B did not reduce the number of microbes in the inoculum cultures. The results are in accordance with the findings in the first experiment. It should be noted that the LED lamps used herein do not provides germicidal UV light which by itself is capable of disinfecting microbes.

Example 4

A third experiment was conducted to determine the disinfection capability of the present invention. The transparent film was deposited onto a 36 W LED lamp. Then, the mixture described in the present invention was deposited onto the film to form a coating thereon. The resulting 36 W LED lamp is referred herein as “36 W LED lamp A”. 36 W LED lamp A was compared to a conventional 36 W LED lamp without the film and the coating, referred herein as “36 W LED lamp B” to determine their disinfection capability. Each of the lamps was positioned at 150 mm on top of an inoculum culture having an initial concentration of 2.3 - 2.6 * 10 ⁷ cfu/ml of Klebsiella pneumoniae. Then, the inoculum cultures were separately exposed to irradiation provided by the lamps for 1 minute, 2 minutes, 5 minutes, 10 minutes, 30 minutes, 60 minutes, 3 hours, 6 hours, and 24 hours. Subsequently, the exposed inoculum cultures were incubated at 35 °C for 24 - 48 hours. Lastly, remaining microbes and reduction were determined. The results were tabulated in Table 8.

Table 8: Disinfection capability of 36 W LED lamps A and B at a distance of 150 mm from the inoculum cultures.

The microbes in the inoculum cultures were reduced by the irradiation provided by 36 W LED lamp A. Additionally, the reduction was higher after a longer exposure. On the contrary, the irradiation provided by 36 W LED lamp B did not reduce the number of microbes in the inoculum cultures. The results are in accordance with the findings in the first and second experiments. It should be noted that the LED lamps used herein do not provides germicidal UV light which by itself is capable of disinfecting microbes.

Example 5 A fourth experiment was conducted to determine the disinfection capability of the present invention. The transparent film was deposited onto a 24 W LED light. Then, the mixture described in the present invention was deposited onto the film to form a coating thereon. The resulting 24 W LED light is referred herein as “24 W LED light A”. 24 W LED light A was compared to a conventional 24 W LED light without the film and the coating, referred herein as “24 W LED light B” to determine their disinfection capability. Each of the lights was positioned at 1200 mm on top of an inoculum culture having an initial concentration of 1.5 - 1.6 * 10 ⁶ cfu/ml of Klebsiella pneumoniae. Then, the inoculum cultures were separately exposed to irradiation provided by the lamps for 1 minute, 2 minutes, 5 minutes, 10 minutes, 30 minutes, 60 minutes, 3 hours, 6 hours, and 24 hours. Subsequently, the exposed inoculum cultures were incubated at 35 °C for 24 - 48 hours. Lastly, remaining microbes and reduction were determined. The results were tabulated in Table 9.

Table 9: Disinfection capability of 24 W LED lights A and B at a distance of 1200 mm from the inoculum cultures.

The microbes in the inoculum cultures were reduced by the irradiation provided by 24 W LED light A. Additionally, the reduction was higher after a longer exposure. On the contrary, the irradiation provided by 24 W LED light B did not reduce the number of microbes in the inoculum cultures. The results are in accordance with the findings in the abovementioned experiments. It should be noted that the LED lights used herein do not provides germicidal UV light which by itself is capable of disinfecting microbes.

One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiment described herein is not intended as limitations on the scope of the present invention.