# US 2019/0168204 A1 · Photocatalytic surface systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0168204 A1 - Document ID: US20190168204A1 - Status: Published application - Kind: A1 - Application number: 16/212,663 - Filed: 2018-12-06 - Published: 2019-06-06 - Earliest claimed: 2017-12-06 - Assignees: Sonata Scientific LLC - Inventors: Peter C. Van Buskirk; Maryam Golalikhani; Melissa A. Petruska; Jeffrey F. Roeder - Web page: https://patentgrep.com/patent/US20190168204A1 ## CPC - B01J 35/39: Photocatalytic properties - A61L 9/205: {using a photocatalyst or photosensitiser} - B01J 21/063: {Titanium; Oxides or hydroxides thereof} - B01J 23/745: Iron - B01J 35/23: in a colloidal state - B01J 35/396: {Distribution of the active metal ingredient} - B01J 35/397: {Egg shell like} - B01J 35/45: Nanoparticles - B01J 35/77: Compounds characterised by their crystallite size - B01J 37/0209: {involving a reaction between the support and a fluid} - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - 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) ## Abstract The Invention describes integration of photocatalytic materials into composite surfaces in order to achieve antimicrobial properties. Aspects of the invention include types of photocatalytic materials and methods to achieve long lifetimes, high durability and mechanical robustness, for application to medical and sanitary uses, among others. ## Claims ### Claim 1 A photocatalytic surface system that incorporates a UV-A or visible light activated titania-based photocatalytic material in contact with a matrix, where the photocatalytic material is designed to reduce oxidation of the matrix. ### Claim 2 (depends on 1) The photocatalytic surface system of claim 1, where the photocatalytic material is a colloidal nanocrystal capped with solubilizing ligands ### Claim 3 (depends on 2) The photocatalytic material of claim 2, where the solubilizing ligands include alkoxysilanes, phosphonic acids, carboxylic acids, alcohols, and sulfonic acids. ### Claim 4 (depends on 2) The photocatalytic material of claim 2, where the colloidal nanocrystals are 2-15 nm in diameter. ### Claim 5 (depends on 1) The photocatalytic surface system of claim 1, where the photocatalytic material is a monolithic composite photocatalyst. ### Claim 6 (depends on 5) The photocatalytic surface system of claim 5, where the monolithic composite photocatalyst incorporates a core-shell geometry, where the shell layer has been at least partially removed at the matrix surface to enable greater antimicrobial efficacy. ### Claim 7 (depends on 6) The photocatalytic surface system of claim 6, where the shell layer is comprised of silica, alumina, zirconia, hafnia, SixNy, Si—C—O—N, or silicon. ### Claim 8 (depends on 5) The photocatalytic surface system of claim 5, where the external surface of the monolithic composite photocatalyst is greater than 50% free of active photocatalyst nanoparticles by areal percent, wherein photocatalyst is present in the interior pores of the monolithic composite photocatalyst, wherein a portion of the monolithic composite photocatalyst has been at least partially removed at the matrix surface to enable greater antimicrobial efficacy. ### Claim 9 (depends on 1) The photocatalytic surface system of claim 1, where the photocatalytic material is bulk titania particles coated with a shell layer, where the shell layer has been removed or partially removed at the matrix surface to enable greater antimicrobial efficacy. ### Claim 10 (depends on 9) The surface system of claim 9, where the shell layer is comprised of silica, alumina, zirconia, hafnia, SixNy, Si—C—O—N, or silicon. ### Claim 11 (depends on 1) The photocatalytic surface system of claim 1, where the matrix is comprised of polyurethanes, epoxies or silicones. ### Claim 12 (depends on 11) The photocatalytic surface system of claim 11, where the matrix contains inorganic nanocrystals, particles or fibers that modify the mechanical properties of the matrix. ### Claim 13 (depends on 1) The photocatalytic surface system of claim 1, where the matrix is comprised of silicon oxide, aluminum oxide, titanium oxide, or refractory oxide forming precursors. ### Claim 14 (depends on 1) The use of the photocatalytic surface system of claim 1 as an antimicrobial layer. ### Claim 15 (depends on 14) The photocatalytic surface system of claim 14 that is used as an antimicrobial layer on any of medical equipment, hospital furniture, light switches, medical instruments, toys, kitchen surfaces, touch pad covers and screens, the surface of a catheter, the surface of an implanted in vivo device, cardiac defibrillators or joint implant surfaces. ### Claim 16 A method of manufacturing a photocatalytic surface system, the method comprising; forming a titania-based photocatalytic material designed to reduce oxidation in a matrix, mixing the photocatalytic material into a paste or liquid thereby dispersing the photocatalytic material in the paste or liquid, dispensing the paste or liquid in a controlled pattern, hardening the paste or liquid to form a solid matrix having a defined shape based on the controlled pattern, thereby suspending the photocatalytic material in the matrix, exposing at least a portion of the photocatalytic material at a surface of the matrix thereby forming a photocatalytic surface system, and exposing the photocatalytic surface system to UV-A or visible light, thereby stimulating photocatalytic activity. ### Claim 17 (depends on 16) The method of claim 16, where the concentration of photocatalytic materials in the matrix is controlled at the surface of the photocatalytic surface system to achieve improved antimicrobial efficacy at the surface of the finished item. ### Claim 18 (depends on 16) The method of claim 16, where optical elements are formed in the defined shape. ### Claim 19 A liquid cleaning agent for cleaning a solid surface, that provides photocatalytic enhancing species to the surface. ### Claim 20 (depends on 19) The liquid cleaning agent of claim 19, where the agent is applied by cloths, fibrous implements, mops, sprays, jets, misters or nebulizers. ### Claim 21 (depends on 19) The cleaning agent of claim 19, where the photocatalytic enhancing species enable Fenton or photo-Fenton reactions. ### Claim 22 (depends on 19) The cleaning agent of claim 19, where the photocatalytic enhancing species includes Fe. ### Claim 23 (depends on 19) The cleaning agent of claim 19, where the cleaning agent combines photocatalytic enhancing species and halide containing species. ### Claim 24 (depends on 19) The cleaning agent of claim 19, where the surface contains photocatalytic antimicrobial materials.