# US 2021/0275838 A1 · Plasmonic photoelectrochemical oxidation face mask > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0275838 A1 - Document ID: US20210275838A1 - Status: Published application - Kind: A1 - Application number: 17/249,503 - Filed: 2021-03-03 - Published: 2021-09-09 - Earliest claimed: 2020-03-03 - Assignees: University of South Florida - Applicants: University of South Florida - Inventors: Dharendra Yogi Goswami; Dilip Neeraj Goswami - Web page: https://patentgrep.com/patent/US20210275838A1 ## CPC - A62B 7/10: with filter elements - A61L 9/205: {using a photocatalyst or photosensitiser} - A62B 7/12: with fresh-air hose - A62B 9/02: Valves {(non-return valves mounted in breathing masks or helmets A62B18/10)} - A62B 18/006: {with pumps for forced ventilation (A62B18/045 takes precedence)} - A62B 18/025: {Halfmasks (A62B23/02 takes precedence; surgical face masks A41D13/11)} - A62B 18/10: Valves - A62B 23/02: for respirators - B01D 53/8668: {Removing organic compounds not provided for in B01D53/8603 - B01D53/8665} - B01D 53/885: {Devices in general for catalytic purification of waste gases} - B01J 35/39: Photocatalytic properties - B01J 35/45: Nanoparticles - A61L 2209/111: Sensor means, e.g. motion, brightness, scent, contaminant sensors - A61L 2209/12: Lighting means - A61L 2209/14: Filtering means - B01D 2255/104: Silver - B01D 2255/20707: Titanium - B01D 2255/20792: Zinc - B01D 2255/802: Photocatalytic - B01D 2255/9202: Linear dimensions - B01D 2257/708: Volatile organic compounds V.O.C.'s - B01D 2257/91: Bacteria; Microorganisms - B01D 2258/06: Polluted air - B01D 2259/4533: for medical purposes - B01D 2259/4541: for portable use, e.g. gas masks - B01D 2259/802: Visible light - A62B: DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING (valves specially adapted for medical use A61M39/00; life-saving devices, apparatus or methods specially adapted for use in water B63C9/00; divers' equipment B63C11/00; specially adopted for use with aircraft, e.g. parachutes, ejector seats, {B64D17/00, B64D25/10}; rescue devices peculiar to mining E21F11/00) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract A breathing system for removing harmful contaminants, such as microbes and volatile organic compounds, is provided. The breathing system includes a face mask, an inhalation limb, and a plasmonic device. As a contaminated gas flows through an internal chamber of the plasmonic device, the contaminates are oxidized. Specifically, the internal chamber includes a source of photons spaced apart from the nanostructure. The nanostructure is coated in a plasmonic layer, including noble metal nanoparticles. The plasmonic layer is protected from oxidation through a photocatalyst layer disposed thereon. ## Claims ### Claim 1 A breathing purification system for delivering a gas from an environment to a user, the breathing system comprising: an inhalation limb including a first end in one way fluid communication with a face mask and a second opposite end in one way fluid communication with a plasmonic device; and the plasmonic device includes an internal compartment comprising: a source of photons having a wavelength and a filter, the filter including: a nanostructure having a length ⅓ to ¼ the wavelength; a plasmonic layer disposed on the nanostructure, the plasmonic layer including noble metal nanoparticles; a protective layer applied to the nanostructure, wherein the protective layer prevents the oxidization of the noble metal nanoparticles of the plasmonic layer; the plasmonic layer disposed between the nanostructure and the protective layer; wherein the photons emitted by the source of photons are incident on the filter; whereby the gas from the environment is filtered within the internal compartment before being supplied to the user via the face mask. ### Claim 2 (depends on 1) The breathing system of claim 1, wherein the source of photons is a light source having a wavelength of about 320 nm to 395 nm. ### Claim 3 (depends on 1) The breathing system of claim 1, wherein the source of photons is visible light having a wavelength of about 400 nm to 700 nm. ### Claim 4 (depends on 1) The breathing system of claim 1, wherein the plasmonic layer is applied to the nanostructure by e-beam deposition or plasma deposition. ### Claim 5 (depends on 1) The breathing system of claim 1, wherein the plasmonic layer is applied to the nanostructure by a reduction reaction of a salt of the noble metal nanoparticles of the plasmonic layer. ### Claim 6 (depends on 1) The breathing system of claim 1, wherein the filter includes a photocatalyst. ### Claim 7 (depends on 6) The breathing system of claim 6, wherein the photocatalyst is titanium dioxide, zinc oxide, silicon dioxide, or titanium oxide doped with nitrogen or a metal. ### Claim 8 (depends on 1) The breathing system of claim 1, further comprising: a switch in electrical communication with a fan configured to draw the gas from the environment through the filter and into the inhalation limb, a pressure sensor configured to continuously monitor a pressure within the inhalation limb, such that when the pressure within the inhalation limb exceeds a predetermined pressure, the pressure sensor sends an electrical signal to the switch to turn off the fan, thereby preventing the over pressurization of the inspiration limb. ### Claim 9 (depends on 1) The breathing system of claim 1, wherein the nanostructure is a carbon nanostructure, a titanium oxide nanostructure, a metal nanostructure, a metal nanostructure, or a silicon oxide nanostructure. ### Claim 10 (depends on 1) The breathing system of claim 1, wherein the nanostructure is crushed, thereby increasing the surface area of the plasmonic layer when the plasmonic layer is deposited onto the crushed nanotube. ### Claim 11 (depends on 1) The breathing system of claim 1, wherein the crushed nanostructure has a length between 50 nm to 100 nm. ### Claim 12 (depends on 1) The breathing system of claim 1, wherein the crushed nanostructure has a length between 20 nm to 100 nm. ### Claim 13 (depends on 1) The breathing system of claim 1, wherein the protective layer is less than 5 nm thick. ### Claim 14 (depends on 13) The breathing system of claim 13, wherein the protective layer is silicon oxide, a metal oxide, a salt, or a metal hydride. ### Claim 15 (depends on 1) The breathing system of claim 1, wherein the face mask comprises: an exhalation port disposed within a body of the face mask; and an exhalation limb including a first end in fluid communication with the exhalation portion and a second opposite end configured to exhaust an exhalation gas to the environment. ### Claim 16 (depends on 15) The breathing system of claim 15, wherein the exhalation limb includes an exhalation valve disposed between the first end and the second end of the exhalation limb, wherein the exhalation valve is configured to restrict the flow of the gas from the environment to an internal environment of the face mask. ### Claim 17 A breathing purification system for delivering a gas from an environment to a user, the breathing circuit comprising: an inhalation limb including a first end in fluid communication with a face mask and a second opposite end in fluid communication with a plasmonic device; the plasmonic device including an internal compartment disposed within the plasmonic device, the internal compartment comprising: a source of photons having a wavelength and a filter, the filter including: a nanostructure having a length ⅓ to ¼ the wavelength; a plasmonic layer disposed on the nanostructure via e-beam or plasma deposition, the plasmonic layer including noble metal nanoparticles; a protective layer including a non-porous photocatalyst, the protective layer having a thickness of less than 20 nm, wherein the protective layer prevents the oxidization of the noble metal nanoparticles of the plasmonic layer; wherein the plasmonic layer is disposed between the nanostructure and the protective layer; wherein the photons emitted by the source of photons are incident on the filter, thereby activating the photocatalyst; and a one-way valve disposed between the face mask and the plasmonic device, the one-way valve operable to transition between a closed configuration and an open configuration, wherein the close configuration occurring as a result of positive pressure in the inhalation limb, and the open configuration occurring as a result of negative pressure in the inhalation limb; wherein the gas from the environment flows through the internal compartment of the plasmonic device, such that when the user inhales, the filtered gas flows to the face mask via the inhalation limb as a result of the negative pressure created when the user inhales. ### Claim 18 (depends on 17) The breathing system of claim 17, further comprising a regulation valve disposed between the face mask and the plasmonic device, the regulation valve configured to adjust the speed of a fan, thereby adjusting a flow rate of the gas through the internal compartment. ### Claim 19 (depends on 17) The breathing system of claim 17, wherein at least a portion of the face mask and the inhalation limb are coated with a compound that is toxic to microorganisms, wherein the compound reduces the chance of the user being infected. ### Claim 20 A method of removing harmful contaminants from a gas supplied to a user for respiration, the method comprising the steps of: providing a breathing system configured to supply an amount of the gas to the user, the breathing system comprising: an inhalation limb having a first end in fluid communication with a face mask and a second opposite end in fluid communication with a plasmonic device having an internal compartment disposed therein, the internal compartment comprising: a source of photons having a wavelength and a filter, the filter including: a nanostructure having a length ⅓ to ¼ the wavelength; a plasmonic layer disposed on the nanostructure, the plasmonic layer including noble metal nanoparticles; a protective layer including a photocatalyst, the protective layer disposed on the nanostructure having a thickness of less than 20 nm, wherein the protective layer prevents the oxidization of the noble metal nanoparticles of the plasmonic layer; the plasmonic layer being disposed between the nanostructure and the protective layer; wherein the photons emitted by the source of photons are incident on the photocatalyst, thereby activating the photocatalyst; passing the gas from an environment through the internal compartment and into the inhalation limb, thereby removing harmful contaminants from the gas via catalytic oxidation of the harmful contaminants as the gas passes through the filter of the internal compartment; and operating a one-way valve disposed between the face mask and the plasmonic device, the one-way valve including a closed configuration and an open configuration, the close configuration occurring when there is positive pressure within the inhalation limb, and the open configuration occurring when there is negative pressure in the inhalation limb, wherein when in the open configuration, the gas flows from the internal compartment where the gas is filtered to remove harmful contaminants, through the inhalation limb, and to the face mask of the user, thereby permitting the user to breathe the filtered gas during respiration.