Removal of biocontaminants using compositions containing rare earth oxides and precious metals

Abstract

An antimicrobial composition comprising approximately 99.95% to approximately 50% by mass of a particulate oxide composition in which a noble metal is dispersed on the surface of the particulate oxide composition. In the antimicrobial composition, the noble metal is selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof. The particulate oxide composition comprises a trivalent dopant selected from the group consisting of cerium oxide, yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and optionally additional oxides selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), and mixtures thereof, where cerium oxide is present in a greater amount than the trivalent dopant. Furthermore, a method for removing biological contaminants using this composition is also described.

Description

Technical Field

[0001] Related Applications This application was filed as a PCT international application on March 1, 2024, claiming the priority and benefit of U.S. Provisional Application No. 63 / 449,242, filed on March 1, 2023, the entire content of which is incorporated herein by reference.

[0002] Field of the Invention The present invention relates to an antimicrobial composition comprising cerium oxide (CeO2) microparticle oxide composition containing a trivalent dopant, on the surface of which a noble metal is dispersed. The present invention also relates to the use of these compositions in the removal of biofouling substances, including as antibacterial / antibacterial / antiviral agents. Therefore, these compositions have uses for removing bacteria, viruses, protozoa (e.g., amoeba), fungi (e.g., mold), algae, yeast, etc. In particular, these compositions can be used in methods for treating fluids including liquids or air and methods for treating by contact with solid surfaces.

[0003] Background Art Various techniques have been used to remove biofouling substances from air and aqueous streams. Examples of such techniques include adsorption onto high surface area materials such as alumina, filters having pore sizes smaller than the biofouling substances, and the use of strongly oxidizing substances such as chlorine and bromine. Certain metals have also been utilized to exhibit the oligodynamic action, which is the biocidal effect of the metal. Metals known to exhibit oligodynamic action are Al, Sb, As, Ba, Si, B, Cu, Au, Pb, Hg, Ni, Ag, Th, Sn, and Zn. Incorporating these into air or aqueous stream treatment technologies remains a problem because toxicity to humans and animals and cost are major concerns.

[0004] There remains a need for effective and inexpensive antimicrobial materials for removing bacteria, viruses, and other microbial contaminants from fluids including air, water, and other aqueous streams.

Summary of the Invention

[0005] Abstract The present invention relates to an antibacterial composition comprising a particulate oxide composition in which a noble metal (PGM) is dispersed on the surface, and the use of this composition for removing bacteria, viruses and other microbial contaminants by contact. The particulate oxide composition is cerium oxide (CeO2) containing a trivalent dopant, and is described herein as the particulate oxide composition. Therefore, the compositions disclosed herein can remove biological contaminants from air and aqueous liquid streams, and in particular can remove bacteria and viruses from air and water even when the microorganisms are present at high or extremely low concentrations.

[0006] The antibacterial composition contains from about 99.95% to about 50% by mass of a particulate oxide composition in which a noble metal is dispersed on the surface. In certain embodiments, the noble metal is present in an amount of from about 0.05% to about 25% by mass based on the total weight of the antibacterial composition. In this antibacterial composition, the noble metal is selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh) and mixtures thereof. The particulate oxide composition optionally contains a trivalent dopant selected from the group consisting of cerium oxide, yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr) and mixtures thereof, and an additional oxide selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si) and mixtures thereof, and in the particulate oxide composition, cerium oxide is present in a greater amount than the trivalent dopant.

[0007] The particulate oxide composition has a unique depth profile, and the average dopant / cerium ratio at about 0 nm to about 3.5 nm from the surface of the particulate composition is greater than the dopant / cerium ratio at about 15 nm from the surface of the particulate composition.

[0008] In certain embodiments of the particulate oxide composition, the average dopant / cerium ratio from about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is about 10% to about 250% greater than the dopant / cerium ratio from about 15 nm from the surface of the particulate oxide composition. In other embodiments, the average dopant / cerium ratio from about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is about 15% to about 250% greater than the dopant / cerium ratio from about 15 nm from the surface of the particulate oxide composition.

[0009] In certain embodiments of the particulate oxide composition, the particulate oxide comprises about 99.95% to about 20% by mass of cerium oxide based on the total weight of the particulate oxide composition, about 0.1% to about 50% by mass of trivalent dopant based on the total weight of the particulate oxide composition, and about 70% to about 0% by mass of additional oxide based on the total weight of the particulate oxide composition. In certain embodiments, the additional metal oxide is about 0% by mass.

[0010] The antimicrobial compositions disclosed herein include particulate oxide compositions in which a noble metal is dispersed on the surface. The antimicrobial compositions contain about 0.1% to about 50% by mass of the noble metal based on the total weight of the composition. In certain embodiments, the antimicrobial compositions contain about 1% to about 25% by mass of the noble metal based on the total weight of the composition. In other embodiments, the antimicrobial compositions contain about 1% to about 10% by mass of the noble metal based on the total weight of the composition. As described above, the noble metal is selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof. In certain embodiments, the noble metal is silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), or a mixture thereof.

[0011] In one particular embodiment, the precious metal is silver (Ag) and is present in an amount of about 0.05% to about 0.3% by mass based on the total weight of the antimicrobial composition. In another particular embodiment, the precious metal is ruthenium (Ru) and is present in an amount of about 0.05% to about 5% by mass based on the total weight of the antimicrobial composition.

[0012] These compositions, which include particulate oxide compositions in which noble metals are dispersed on the surface, have biocontaminant removal properties and are therefore used to remove bacteria or viruses from fluids and / or surfaces, including air and water. The biocontaminants to be removed include bacteria, viruses, protozoa (e.g., amoebas), fungi (e.g., molds or fungi), etc.

[0013] This specification also discloses supported compositions comprising support materials and antimicrobial compositions. The supported compositions have biocontaminant removal properties and are therefore used to remove bacteria or viruses from fluids and / or surfaces, including air and water. The biocontaminants to be removed include bacteria, viruses, protozoa (e.g., amoebas), fungi (e.g., molds or fungi), and the like.

[0014] The supported compositions for removing biocontaminants disclosed herein comprise a support material comprising an organic polymer, cotton, glass fiber, or a mixture thereof, and the antimicrobial composition described herein. In the supported composition, the antimicrobial composition is supported on or within the support material.

[0015] In certain embodiments, these supported compositions contain an antimicrobial composition in an amount ranging from about 0.5% to about 80% by mass, based on the total weight of the supported composition.

[0016] The supported composition, comprising a support material and an antimicrobial composition, is in a rigid or elastic form and can be molded into articles that remove biological contaminants, such as filters, fixed-bed filter systems, plastic or glass bottles or containers, and plastic or glass contact surfaces.

[0017] In one embodiment, a plastic article is disclosed. This plastic article comprises a supported composition for removing biocontaminants, the supported composition comprising (i) an organic polymer selected from the group consisting of polyethylene, polyvinyl chloride, nylon, polypropylene, polyester, polyurethane, polyamide, polyolefin, polycarbonate, copolymers thereof and mixtures thereof, and (ii) an antimicrobial composition described herein, the antimicrobial composition being supported on or inside the organic polymer, and the plastic article containing about 50% to about 100% by mass of the supported composition. The plastic article may be a filter, a fixed floor filter system, a plastic bottle or container, a plastic contact surface, a plastic door knob or handle cover, a plastic elevator button cover, and the like.

[0018] The antimicrobial compositions themselves, the supported compositions, and the articles can be used in methods for removing biological contaminants. These biological contaminants include bacteria, viruses, protozoa (e.g., amoebas), fungi (e.g., molds or fungi), and the like.

[0019] In one embodiment, a method for removing a biocontaminant comprises (i) providing an antimicrobial composition disclosed herein, (ii) contacting the antimicrobial composition with a biocontaminant, the biocontaminant being selected from the group consisting of bacteria, viruses, fungi, protozoa (e.g., amoebas) and mixtures thereof, and (iii) removing at least about 90% of the biocontaminant by contact with the antimicrobial composition. In some embodiments, the antimicrobial composition is contained within a filter material or plastic.

[0020] In certain embodiments, the method treats aquatic flow, and the biocontaminants are present in the aquatic flow. In other embodiments, the method treats gaseous flow, and the biocontaminants are present in the gaseous flow. In yet another embodiment, contact is performed by bringing a solid into contact with an antimicrobial composition, thereby treating the solid surface by contact. In certain embodiments of these embodiments, contact is performed by bringing a solid into contact with an article containing an antimicrobial composition.

[0021] In certain embodiments of treating a fluid (i.e., a gaseous or aqueous flow), the method may further include a step of setting a target concentration of a biocontaminant. In these embodiments, the biocontaminant may be identified and a target concentration of that biocontaminant may be set. The method may further include a step of monitoring the biocontaminant in the treated flow.

[0022] In some embodiments, these methods are methods for removing biocontaminants from a fluid or for treating a fluid. In these embodiments, the fluid may be a gaseous flow or a water system flow. In these embodiments, the method comprises (i) providing an antimicrobial composition disclosed herein, (ii) contacting a fluid containing biocontaminants with the antimicrobial composition, wherein the biocontaminants are selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas) and mixtures thereof, and (iii) removing the biocontaminants from the fluid by contact with the antimicrobial composition. The biocontaminants may be removed by an amount of 90% or more. If the fluid is a liquid, the antimicrobial composition may be used as is, and the method may further include filtering the fluid / liquid.

[0023] In certain embodiments, these methods are methods for removing biocontaminants from a fluid using a supported composition. In these embodiments, the fluid may be a gaseous flow or a water system flow. In these embodiments, the method includes (i) providing a supported composition comprising a support material comprising an organic polymer, cotton, glass fiber or a mixture thereof, and an antimicrobial composition disclosed herein; (ii) contacting a fluid containing biocontaminants with the supported composition, wherein the biocontaminants are selected from the group comprising bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas) and mixtures thereof; and (iii) removing the biocontaminants from the fluid by contact with the supported composition. The biocontaminants may be removed by an amount of 90% or more.

[0024] These methods for treating a fluid, gaseous, or aqueous flow using the antimicrobial composition itself or a supported composition may further include a step of setting a target concentration of a biocontaminant. In these methods, the target biocontaminant is identified, and then a target concentration of that biocontaminant is set. The method may further include a step of monitoring the biocontaminant in the treated flow. Monitoring may be performed by sampling or continuously.

[0025] In methods for treating aqueous flows, the antimicrobial composition may be used directly by slurring it with the aqueous flow. These methods, including slurring, may further include a filtering step.

[0026] In certain embodiments, the method comprises the following steps: (i) providing a support material comprising an organic polymer, cotton, glass fiber, or a mixture thereof, and a supported composition comprising an antimicrobial composition disclosed herein; (ii) setting a target concentration of a biocontaminant; (iii) contacting a gaseous or aqueous flow containing the biocontaminant with the supported composition to obtain a treated flow by removing the biocontaminant through contact with the supported composition; and (iv) monitoring the biocontaminant in the treated flow, the biocontaminant being selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas), and mixtures thereof. The target concentration may be set by a specific amount of the contaminant (e.g., virus, bacteria, protozoa / amoeba, or fungus) or by a detection limit. Monitoring may be performed by sampling or continuously. [Brief explanation of the drawing]

[0027] Simple description of the drawing [Figure 1] Figure 1 is an SEM image of the composition of Example 1, with a 200 nm scale bar.

[0028] [Figure 2]Figure 2 is an SEM image of the composition of Example 1, with a 2 μm scale bar.

[0029] [Figure 3] Figure 3 is a TEM image of the composition of Example 1, with a 10 nm scale bar. The bright-field image is on the left and the dark-field image is on the right.

[0030] [Figure 4] Figure 4 is a TEM image of the composition of Example 1, with a 20 nm scale bar. The bright-field image is on the left and the dark-field image is on the right.

[0031] [Figure 5A] Figure 5A shows the temperature-induced desorption of CO2 from the composition of Example 1.

[0032] [Figure 5B] Figure 5B shows the temperature-induced desorption of CO2 from the composition of Example 2.

[0033] [Figure 5C] Figure 5C shows the temperature-induced desorption of CO2 from the composition of Example 3.

[0034] [Figure 6] Figure 6 shows the temperature-induced desorption of H2 in the compositions of Example 1, Example 2, and Example 3.

[0035] [Figure 7] Figure 7 is a graph of the zeta potential as a function of pH for the compositions of Example 1, Example 2, and Example 3.

[0036] [Figure 8] Figure 8 is a graph showing the relationship between the LaO+ / CeO+ ratio and depth for the compositions of Example 1 and Example 2.

[0037] [Figure 9]Figure 9 is a graph showing the relationship between the PrO+ / CeO+ ratio and depth for the compositions of Example 4 and Example 5.

[0038] [Figure 10] Figure 10 is an SEM image of the composition of Example 2, with a 200 nm scale bar.

[0039] [Figure 11] Figure 11 is an SEM image of the composition of Example 2, with a 20 nm scale bar.

[0040] [Figure 12A] Figure 12A is a bright-field TEM image of the composition of Example 2, with a 200 nm scale bar. The box indicates the zoom area for Figure 12B.

[0041] [Figure 12B] Figure 12B is a bright-field TEM image of the composition of Example 2, with a 20 nm scale bar. The box indicates the zoom area for Figure 12C.

[0042] [Figure 12C] Figure 12C is a bright-field TEM image of the composition of Example 2, with a 5 nm scale bar.

[0043] [Figure 12D] Figure 12D is a dark-field TEM image of the composition of Example 2, with a 5 nm scale bar.

[0044] [Figure 13A] Figure 13A shows the temperature-induced desorption of CO2 from the compositions of Examples 6-9, which are the antimicrobial compositions of Example 1 in which PGM is dispersed on the surface.

[0045] [Figure 13B] Figure 13B shows the temperature-induced desorption of CO2 from the compositions of Examples 10-13, which are the antimicrobial compositions of Example 2 in which PGM is dispersed on the surface.

[0046] [Figure 13C] Figure 13C shows the temperature-induced desorption of CO2 from the compositions of Examples 14-16, which are the antimicrobial compositions of Example 3 in which PGM is dispersed on the surface.

[0047] [Figure 14A] Figure 14A shows a comparison of the logarithmic reduction of E. coli in Examples 3, 15, and 9, which contain 1% Ru.

[0048] [Figure 14B] Figure 14B shows a comparison of the logarithmic reduction of Staphylococcus aureus in Examples 3, 15, and 9, which contain 1% Ru.

[0049] [Figure 15A] Figure 15A shows a comparison of the logarithmic reduction of E. coli in Examples 3, 10, 13, and 7, which contain 0.1% Ru.

[0050] [Figure 15B] Figure 15B shows a comparison of the logarithmic reduction of Staphylococcus aureus in Examples 3, 16, 10, 13, and 7, which contain 0.1% Ru. [Modes for carrying out the invention]

[0051] Detailed description Before disclosing and describing compositions, articles, and methods, it should be understood that the present invention is not limited to any specific structure, process step, or material disclosed herein, but also extends to its equivalents as recognized by those skilled in the art. It should also be understood that the terms used herein are used solely for the purpose of describing specific embodiments and are not intended to be limiting. It should be noted that the singular forms “a,” “an,” and “the” used herein include the plural unless the context clearly indicates otherwise. Therefore, for example, “trivalent dopant” does not imply a quantitative or source limitation, “step” may include multiple steps, “product of reaction or treatment” does not imply all products of the reaction / treatment, and “treatment” may mean one or more such treatment steps. Thus, a treatment step may include treating the same material / flow multiple or repeatedly to obtain a specific treatment product.

[0052] The singular form of "biological pollutant" also includes the plural. For example, "amoeba" and "virus" mean "amoeba species" and "virus species," respectively.

[0053] Numerical values ​​accompanied by "approximately" or "about" include typical experimental error. In this specification, the terms "approximately" and "about" are used synonymously and mean a statistically meaningful range for values ​​such as weight percentages, surface areas, concentration ranges, timeframes, distances, molecular weights, temperatures, and pH. Such ranges are of the order of one order of magnitude and can typically be within 10%, and more typically within 5% of the indicated value or range. In some cases, such ranges may be within the typical experimental error of the standard method used to measure and / or determine a particular value or range. The permissible variation encompassed by the term "approximately" depends on the specific system under consideration and can be readily understood by those skilled in the art. Where a range is described herein, at least each integer within that range is also assumed to be one embodiment of the present invention.

[0054] The terms "precious metals," "precious metal group," and "PGM" are used synonymously and refer to metals selected from copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), or mixtures thereof.

[0055] A "low antibacterial substrate" refers to a substrate that has antibacterial activity such that the logarithmic reduction of the target contaminant is less than 0.2.

[0056] The compositions according to the present invention have the activity to remove biological contaminants. These compositions comprise a CeO2 particulate composition containing a trivalent dopant and a noble metal, the noble metal being dispersed on the surface of the particulate composition. Therefore, the noble metal is associated with / adhered to the surface of the particulate composition. The CeO2 particulate composition containing a trivalent dopant is also described as a particulate oxide composition, and these terms are used synonymously herein. This particulate oxide composition consists of a mixed oxide of Ce and a trivalent dopant.

[0057] The compositions disclosed herein may be used as slurries or as supported compositions and / or articles intended for the removal of biocontaminants, and may be used in methods for removing biocontaminants. These biocontaminants include bacteria, viruses, fungi, protozoa (e.g., amoebas), yeasts, and mixtures thereof.

[0058] The antimicrobial compositions disclosed herein comprise a noble metal and about 99.95% to about 50% by mass of a particulate oxide composition, the noble metal being dispersed on the surface of the particulate oxide composition and selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof. As the mass percentage of the noble metal increases, the amount to which the surface of the particulate oxide composition is coated with the noble metal also increases. Those skilled in the art will understand that when the composition comprises about 50% by mass of the particulate oxide composition and about 50% by mass of the noble metal, the entire surface of the particulate oxide composition is approximately coated with the noble metal.

[0059] The antimicrobial compositions disclosed herein exhibit unexpectedly superior activity compared to the particulate oxide compositions alone. Furthermore, the antimicrobial compositions exhibit unexpectedly superior activity compared to noble metals dispersed on low-antimicrobial substrates. Moreover, the combined activity shows an unexpected synergistic effect, thus exceeding simple additive activity.

[0060] The antimicrobial compositions disclosed herein contain more than about 50% by mass and up to about 99.95% by mass of particulate oxide composition based on the total weight of the composition. Precious metals are present in small amounts compared to the particulate oxide composition, and therefore the antimicrobial compositions contain more particulate oxide composition than precious metals.

[0061] In some embodiments, the antimicrobial composition contains about 0.05% to about 50% by mass of precious metals based on the total weight of the composition. In certain embodiments, the antimicrobial composition contains about 0.1% to about 50% by mass of precious metals based on the total weight of the composition.

[0062] In certain embodiments, the antimicrobial composition contains about 0.05% to about 25% by mass or about 0.1% to about 25% by mass of precious metals based on the total weight of the composition. In other embodiments, the antimicrobial composition contains about 0.05% to about 10% by mass or about 0.1% to about 10% by mass of precious metals based on the total weight of the composition. In yet another embodiment, the antimicrobial composition contains about 0.05% to about 8% by mass or about 0.1% to about 8% by mass of precious metals based on the total weight of the composition. In yet another embodiment, the antimicrobial composition contains about 0.05% to about 5% by mass or about 0.1% to about 5% by mass of precious metals based on the total weight of the composition. These embodiments of mass percent of precious metals can be combined with any embodiment of the particulate oxide compositions described herein. It is advantageous to achieve acceptable removal of the target biocontaminants while using the lowest possible mass percent of precious metals.

[0063] The noble metals dispersed on the surface exist in metallic or oxide form. In certain embodiments, the noble metal is silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), or a mixture thereof.

[0064] In certain embodiments, the noble metal dispersed on the surface of the particulate oxide composition is ruthenium. In certain embodiments of these embodiments, the antimicrobial composition contains ruthenium in an amount of about 0.05% to about 5% by mass, or about 0.05% to about 3% by mass, or about 0.1% to about 3% by mass, based on the total weight of the composition. These ruthenium-containing embodiments can be combined with any embodiment of the particulate oxide composition described herein.

[0065] In another specific embodiment, the noble metal dispersed on the surface of the particulate oxide composition is silver. In certain of these embodiments, the antimicrobial composition contains about 0.05% to about 0.3% by mass of silver based on the total weight of the composition, or about 0.1% by mass of silver based on the total weight of the composition. These silver-containing embodiments can be combined with any of the embodiments of particulate oxide compositions described herein.

[0066] The antimicrobial compositions described herein exhibit effective activity while reducing the amount of precious metal, and their activity shows an unexpected synergistic effect (i.e., not merely additive) compared to the activity of the particulate oxide composition alone or the activity when a similar amount of precious metal is supported on a low-antimicrobial substrate.

[0067] As described above, the antimicrobial composition comprises a particulate oxide composition in which a noble metal is dispersed on the surface. The particulate oxide composition comprises a trivalent dopant (as an oxide) selected from the group consisting of cerium oxide, yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and optionally additional metal oxides selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof. In this particulate oxide, cerium oxide is present in greater quantities than the trivalent dopant, and the average dopant / cerium ratio from about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is greater than the dopant / cerium ratio at about 15 nm from the surface of the particulate oxide composition.

[0068] In certain embodiments of the particulate oxide composition, it comprises about 99.9% to about 20% by mass of cerium oxide based on the total weight of the particulate oxide composition, about 0.1% to about 50% by mass of a trivalent dopant based on the total weight of the particulate oxide composition, and about 70% to about 0% by mass of an additional metal oxide based on the total weight of the particulate oxide composition.

[0069] Within the antimicrobial composition, the particulate oxide composition mainly consists of a mixed oxide of Ce and a trivalent dopant. These particulate oxide compositions are also described herein as a CeO2 composition containing a trivalent dopant or a CeO2 particulate composition containing a trivalent dopant.

[0070] Therefore, a CeO2 particulate matter composition containing a trivalent dopant is a mixed oxide of Ce and a trivalent dopant. In the particulate matter oxide composition, the trivalent dopant is selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof.

[0071] In certain embodiments, the particulate oxide composition includes an additional metal oxide. This additional metal oxide is selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof.

[0072] Within the antimicrobial composition, a CeO2 composition or particulate oxide composition containing a trivalent dopant comprises cerium oxide and one or more trivalent dopants (as oxides), and optionally one or more additional metal oxides. Therefore, a particulate oxide composition comprises a trivalent dopant (as oxide) selected from the group consisting of cerium oxide, yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, optionally cerium oxide, additional metal oxides other than trivalent dopants, and trace amounts of impurities.

[0073] The additional metal oxide in the particulate oxide composition is selected from the group consisting of aluminum, titanium, zirconium, hafnium, and mixtures thereof. In certain embodiments, the particulate oxide composition contains no additional metal oxide. In other embodiments, the particulate oxide composition contains additional metal oxide.

[0074] The cerium in the cerium oxide in the particulate oxide composition is Ce(IV). The trivalent rare earth dopant may be selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), cerium (Ce), and mixtures thereof. In certain embodiments, the trivalent dopant is selected from yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and in certain embodiments, the trivalent dopant is Nd, La, or a mixture thereof. In other embodiments, the trivalent dopant is La. In yet another embodiment, the trivalent dopant is Pr. As described above, the trivalent dopant exists as an oxide in the particulate matter composition, and therefore the particulate matter oxide composition contains at least a mixed oxide of cerium and the trivalent dopant.

[0075] Trivalent dopants are present in smaller amounts compared to cerium oxide, and therefore particulate oxide compositions contain more cerium oxide than trivalent dopants (as oxide).

[0076] The particulate oxide composition may optionally contain additional metal oxides other than cerium oxide and trivalent dopants. These additional metal oxides may be selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof.

[0077] Therefore, particulate oxide compositions are mixed oxide compositions (i.e., mixtures of oxides of at least cerium and trivalent dopants). In this specification, this composition is also referred to as cerium oxide containing a trivalent dopant, in which case it means a mixed cerium-trivalent dopant oxide. However, this does not exclude additional metal oxides unless the composition is specified to contain about 0 additional metal oxides other than cerium oxide and trivalent dopants.

[0078] In certain embodiments of the particulate oxide composition, the trivalent dopant is La, and the particulate oxide composition contains about 0 additional metal oxides. In these embodiments, the particulate oxide composition is a mixed cerium-lanthanum oxide (or La-doped cerium oxide).

[0079] The particulate oxide composition contains about 0.1% to about 50% by mass of trivalent dopant (as oxide) based on the total weight of the particulate oxide composition. As described above, the trivalent dopant is present in small amounts compared to cerium oxide. In certain embodiments, the particulate oxide composition contains about 0.5% to about 40% by mass or about 1% to about 40% by mass of trivalent dopant based on the total weight. In certain embodiments, the particulate oxide composition contains about 2% to about 35% by mass or about 2% to about 30% by mass of trivalent dopant based on the total weight. In yet another embodiment, the particulate oxide composition contains about 2% to about 25% by mass or about 5% to about 20% by mass of trivalent dopant based on the total weight. In certain of these embodiments, the particulate oxide composition contains about 15% by mass of trivalent dopant based on the total weight. The trivalent dopant is present in the particulate composition as an oxide, and these mass percent are based on the trivalent dopant as an oxide. In all of the embodiments described above, the trivalent dopant is lanthanum, and the particulate oxide composition is lanthanum-doped cerium oxide (i.e., a mixed oxide of cerium and lanthanum).

[0080] When the particulate oxide composition contains about 0 cerium oxide, one or more trivalent dopants, and additional metal oxides, the amount of cerium oxide varies in proportion to the amount of trivalent dopants, and the total amount of trivalent dopants (as oxides) and cerium oxide is about 100% of the particulate oxide composition. In certain embodiments of these additions containing about 0 metal oxides, the trivalent dopant is lanthanum, and the particulate oxide composition is lanthanum-doped cerium oxide.

[0081] In particulate oxide compositions, cerium oxide is present in greater quantities than trivalent dopants. The particulate oxide compositions disclosed herein generally contain about 99.9% to about 20% by mass of cerium oxide based on the total weight of the particulate oxide composition. In certain embodiments, the particulate oxide composition contains about 99.9% to about 50% by mass of cerium oxide. In certain embodiments, the particulate oxide composition contains about 99.5% to about 25% by mass or about 99% to about 30% by mass of cerium oxide based on the total weight. In certain embodiments, the particulate oxide composition contains about 98% to about 65% by mass or about 98% to about 70% by mass of cerium oxide based on the total weight. In yet another embodiment, the particulate oxide composition contains about 98% to about 75% by mass or about 95% to about 80% by mass of cerium oxide based on the total weight. In certain embodiments of these embodiments, the particulate oxide composition contains about 85% by mass of cerium oxide based on the total weight. The amount of cerium oxide varies in accordance with the amount of trivalent dopant and any additional metal oxide, with the total amount accounting for approximately 100% of the particulate composition.

[0082] In certain embodiments, the particulate oxide composition contains about 0% by mass of additional metal oxides, and in these embodiments, the particulate oxide composition contains cerium oxide in an amount that is about 100% of the particulate oxide composition based on the mass percentage of trivalent dopant. For example, in embodiments containing about 0.1% to about 50% by mass of trivalent dopant based on the total weight of the particulate oxide composition, the composition contains about 99.9% to about 50% by mass of cerium oxide. In embodiments containing about 1% to about 40% by mass of trivalent dopant based on the total weight of the particulate oxide composition, the composition contains about 99% to about 60% by mass of cerium oxide. In embodiments containing about 2% to about 30% by mass of trivalent dopant based on the total weight of the particulate oxide composition, the composition contains about 98% to about 70% by mass of cerium oxide, and so on.

[0083] As described herein, particulate oxide compositions may optionally contain additional metal oxides other than cerium oxide and trivalent dopants. These additional metal oxides may be selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof. The particulate oxide compositions disclosed herein generally contain about 70% to about 0% by mass of additional metal oxides based on the total weight of the particulate oxide composition.

[0084] In certain embodiments, the particulate oxide comprises about 99.9% to about 20% by mass of cerium oxide based on the total weight of the particulate oxide composition, about 0.1% to about 50% by mass of trivalent dopant based on the total weight of the particulate oxide composition, and about 70% to about 0% by mass of additional metal oxide based on the total weight of the particulate oxide composition. In the particulate oxide composition, cerium oxide is present in greater amounts than the trivalent dopant.

[0085] When additional metal oxides are present, the particulate oxide composition generally contains about 70% to about 0.1% by mass of additional metal oxides based on the total weight of the particulate oxide composition. In certain embodiments, the particulate oxide composition contains about 50% to about 0.1% by mass or about 30% to about 0.1% by mass of additional metal oxides based on the total weight. In certain embodiments, the particulate oxide composition contains about 10% to about 0.1% by mass of additional metal oxides based on the total weight. In other embodiments, the particulate oxide composition contains about 0% by mass of additional metal oxides. The amount of additional metal oxides varies in correspondence with the amounts of trivalent dopant and cerium oxide, with the total amount being about 100% of the particulate oxide composition.

[0086] In one embodiment, the particulate oxide composition contains about 2% to about 25% by mass of trivalent dopant, about 20% to about 30% by mass of cerium oxide, and about 45% to about 78% by mass of additional metal oxide, based on the total weight of the particulate oxide. In the particulate oxide composition, cerium oxide is present in greater amounts than the trivalent dopant, and the amounts of the components vary accordingly, with the total amount accounting for about 100% of the particulate composition.

[0087] In another embodiment, the particulate oxide composition comprises about 2% to about 25% by mass of trivalent dopant, about 45% to about 78% by mass of cerium oxide, and about 20% to about 30% by mass of additional metal oxide, based on the total weight of the particulate oxide. In the particulate oxide composition, cerium oxide is present in greater amounts than the trivalent dopant, with the amounts of the components fluctuating in correspondence, and the total amount being about 100% of the particulate composition.

[0088] The particulate oxide composition may optionally contain small amounts of impurities. These impurities are typically present at about 1% by mass or less (up to about 0 or undetectable amounts) based on the total weight of the particulate oxide composition. These impurities include residual solvents, salts, other metals, etc. These other metals include magnesium, iron, calcium, silicon, sodium, etc., which are commonly found in water. These impurities (from about 1% by mass to about 0 or undetectable amounts) may be present in the particulate oxide compositions of any of the embodiments described above and below. If present and detectable, the impurities are generally present at about 100 ppm or less.

[0089] The particulate oxide compositions disclosed herein have a unique depth profile with respect to the distribution of cerium oxide and trivalent dopants. This unique depth profile means that a higher trivalent dopant / Ce ratio exists near the surface of the particulate oxide composition than in the interior.

[0090] With respect to the depth profile, those skilled in the art will understand that these particulate oxide compositions have a surface, which is referred to as approximately 0 nm. Those skilled in the art will understand how to measure Ce and trivalent dopants from this surface (i.e., 0 nm) to the depth (measured in nm units) inside the particulate oxide composition, and from these measurements they can calculate the trivalent dopant / Ce ratio and the average trivalent dopant / Ce ratio at different depths.

[0091] The unique depth profile of the particulate oxide composition is characterized by the fact that the average trivalent dopant / Ce ratio from the surface of the particulate oxide composition (i.e., approximately 0 nm) to approximately 3.5 nm is greater than the trivalent dopant / Ce ratio from the surface of the particulate oxide composition to approximately 15 nm. Measurements of Ce and trivalent dopant are performed at regular intervals from 0 nm (i.e., the surface) to approximately 3.5 nm, and then averaged. Measurements of Ce and trivalent dopant are also performed at approximately 15 nm from the surface of the particulate oxide composition. Figure 8 shows LaO + / CeO + This graph shows the relationship between the ratio and depth, illustrating the unique depth profile in an example of a particulate oxide composition used in an antimicrobial composition.

[0092] The depth profiles of the distribution of cerium oxide and trivalent dopants are measured by time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profilometry, as described in Noel, C. et al., ToF-SIMS Depth Profiling of Organic Delta Layers with Low-Energy Cesium Ions: Depth Resolution Assessment, Journal of The American Society for Mass Spectrometry, Vol. 30 (2019) pp. 1537-1544. The contents of this document are incorporated herein by reference in their entirety. As those skilled in the art will understand, a square region of particles in the sample material is selected and analyzed by ToF-SIMS to obtain an analysis at 0 nm (i.e., the surface). ToF-SIMS works by irradiating the material with an ion beam, causing the material to sputter. Sputtering is the phenomenon in which microscopic particles are emitted from the surface of a solid material. The emitted particles are analyzed by mass spectrometry. In this specification, the ion source for ToF-SIMS analysis is a cesium ion source operating at 2 keV, with a target current of 130 nA and a sputtering size of 500 μm. 2 The analysis area is 200 μm. 2The process involved 2-frame analysis followed by 6-frame sputtering, with a sputtering time of 60 seconds. The selected square region was etched with an ion beam to remove surface atoms. In this specification, the primary ion beam is a bismuth liquid metal ion gun operating at 30 keV, with a pulsed target current of approximately 0.6 pA and a sputtering size of 250 μm. 2 The analysis area is 100 μm. 2 The process involved 50 sputtering frames after 2 frame analysis, with a sputtering time of 20,000 seconds. The etching time corresponds to the etching depth, and therefore the depth can be controlled. In this specification, the sputtering depth was calibrated to 1 nm / second. The exposed surface is then re-analyzed by ToF-SIMS to obtain analysis at a new depth. The particulate composition can be analyzed at any interval in nm units, for example, at intervals of approximately 0.2 nm, approximately 0.5 nm, approximately 1 nm, etc. This process is repeated until the desired depth is reached. The obtained mass spectrometry data is associated with the depth at which it was acquired. In this invention, it is important to determine the trivalent dopant / Ce ratio, and therefore this ratio becomes the reported data.

[0093] The unique depth profile of the particulate oxide composition imparts distinctive structural (i.e., physical) and electrochemical properties, which may contribute to improved biocontamination removal activity when used in antimicrobial compositions.

[0094] In one embodiment, the particulate oxide composition of the antimicrobial composition comprises a trivalent dopant (as an oxide) selected from the group consisting of cerium oxide, yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and optionally an additional metal oxide selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof, wherein cerium oxide is present in greater proportion than the trivalent dopant, and the average trivalent dopant / Ce ratio at about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is greater than the trivalent dopant / Ce ratio at about 15 nm from the surface of the particulate oxide composition. In one embodiment of this particulate oxide composition, the composition contains about 0.1% to about 50% by mass of trivalent dopant. In a particular embodiment, the composition further contains about 99.9% to about 50% by mass of cerium oxide based on the total weight of the particulate oxide composition.

[0095] Another embodiment disclosed herein is a particulate oxide composition comprising cerium oxide and a trivalent dopant selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and optionally an additional metal oxide selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof, wherein cerium oxide is present in greater proportion than the trivalent dopant, and the average trivalent dopant / Ce ratio at about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is greater than the trivalent dopant / Ce ratio at about 15 nm from the surface of the particulate oxide composition, and further comprising about 2% to about 30% by mass of trivalent dopant. In one embodiment of this particulate oxide composition, the composition comprises about 98% to about 70% by mass of cerium oxide based on the total weight of the particulate oxide composition.

[0096] It is understood that a particulate oxide composition containing trivalent doped CeO2 and having the depth profile described above may have any of the above amounts of trivalent dopant, cerium oxide, and any additional metal oxide.

[0097] In certain embodiments, the particulate oxide composition comprises cerium oxide and a trivalent dopant, contains small amounts to none (i.e., about 0) of additional metal oxides, and impurities are present at 1% to none (i.e., 0 or undetectable). If present and detectable, impurities are generally present at concentrations of about 100 ppm or less.

[0098] In certain embodiments, the particulate oxide composition has an average trivalent dopant / Ce ratio from about 0 nm to about 3.5 nm from the surface of the particulate oxide composition that is about 10% to about 250% greater than the trivalent dopant / Ce ratio from about 15 nm from the surface of the particulate oxide composition. In other embodiments, the particulate oxide composition has an average trivalent dopant / Ce ratio from about 0 nm to about 3.5 nm from the surface that is about 15% to about 250% greater than the trivalent dopant / Ce ratio from about 15 nm from the surface. As described above, it is understood that about 0 nm from the surface of the particulate oxide composition refers to the surface of the particulate oxide composition itself.

[0099] It is understood that a particulate oxide composition containing trivalent doped CeO2 and having the depth profile described above may have any of the above amounts of trivalent dopant, cerium oxide, and any additional metal oxide, and may also have additional properties described later.

[0100] Particulate oxide compositions containing trivalent doped CeO2 and having a unique depth profile may also exhibit unique physical properties. For example, they exhibit both physicoadsorption and chemiadsorption of CO2 (see Figures 5A, 5B, and 5C). Physicoadsorption, also known as physical adsorption, is a weak bond formed by van der Waals forces, etc. Chemiadsorption, also known as chemical adsorption, occurs, and the adsorbed substance is bonded by chemical bonds. This is a much stronger adsorption than physicoadsorption. Exhibiting physicoadsorption and chemiadsorption is a unique property of particulate oxide compositions containing trivalent doped CeO2 with the aforementioned depth profile. Since the adsorbed substance is CO2 (acid), exhibiting chemiadsorption indicates that the material is more basic, which may lead to improved biocontaminant removal activity. These properties of physicoadsorption and chemiadsorption may be combined with any of the depth profiles described above, as well as the amounts of trivalent dopant, cerium oxide, and any additional metal oxides, and additional properties described later.

[0101] Particulate oxide compositions with a unique depth profile are more oxidative because they can be reduced more easily than compositions produced by conventional methods. Figure 6 shows graphs of the temperature-controlled hydrogen reduction of materials in Examples 1, 2, and 3. Example 1 has a large, sharp peak at low temperatures. This peak indicates that this novel particulate oxide composition (Example 1) is reduced more easily than the compositions of Example 2 or 3. Therefore, particulate oxide compositions with a unique depth profile are more oxidative and thus may be more effective in removing / reducing biocontaminants. The graph for Example 2 is basically the same shape as Example 1, but shifted to the high-temperature side, indicating that the material requires more energy to react with hydrogen, and therefore has lower oxidizing power than Example 1. The graph for Example 3, which is undoped cerium oxide, shows two peaks for hydrogen reduction, which are spread out and not very high. This indicates that two types of reduction can occur in this material, and that the reduction on the high-temperature side is much more difficult to achieve.

[0102] This hydrogen reduction temperature and more oxidative properties may be combined with any of the depth profiles, physical properties, and amounts of trivalent dopants, cerium oxide, and any additional metal oxides described above, as well as additional properties described later.

[0103] Particulate oxide compositions containing trivalent doped CeO2 and having a unique depth profile may exhibit even higher basicity, as indicated by their isoelectric point and zeta potential (see Figure 7). In certain embodiments, the particulate oxide compositions described herein have an isoelectric point at pH about 8 to about 9. In yet another embodiment, the particulate oxide compositions described herein have a zeta potential of about 20 mV to about 40 mV at pH about 7. Having a higher isoelectric point indicates that the material is more basic, which may result in improved biocontaminant removal activity. This property may be combined with any of the depth profiles, physical properties, and amounts of trivalent dopant, cerium oxide, and any additional metal oxides described above, and may also be combined with additional properties described later.

[0104] A particulate oxide composition containing trivalent doped CeO2 may have a surface area that helps noble metals adhere to the surface and improves the removal properties of biological contaminants.

[0105] The surface area described herein is the apparent surface area of ​​the composition measured under nitrogen at approximately 77 K using the Micromeritics ASAP 2000 system. The procedure described in ASTM International Test Method D 3663-03 (re-approved in 2008) was used, with one important exception. It is well known that it is impossible to measure the "BET surface area" for materials containing micropores. Recognizing that the surface area is an approximation, the reported value is presented as an "apparent surface area" value, not a "BET surface area" value. Following generally accepted procedures, the application of the BET equation in the measurement of apparent surface area was limited to the pressure range in which the term na(1-P / P0) in the equation increases continuously with increasing P / P0. Degassing of the sample was performed under a nitrogen atmosphere at approximately 300°C for approximately 2 hours.

[0106] The particulate oxide composition containing trivalent-doped CeO2 may have a surface area of about 70 m 2 / g to about 300 m 2 / g. It is understood that the particulate oxide composition having this surface area may be combined with the average pore volume described below, any one or more of the depth direction profiles described above and other characteristics, and the amounts of the trivalent dopant, cerium oxide and any additional metal oxide described above.

[0107] The particulate oxide composition usually has an average (arithmetic mean, median and mode) pore volume measured by nitrogen adsorption of about 0.01 cm 3 / g to about 1.5 cm 3 / g. Without wishing to be bound by theory, it is considered that the average pore volume affects and can improve the removal of biological contaminants from an aqueous or gas stream.

[0108] It is understood that the particulate oxide composition may combine the above-described average pore volume with any one or more of the above-described surface areas, depth direction profiles and other characteristics, and the amounts of the trivalent dopant, cerium oxide and any additional metal oxide described above.

[0109] The particulate oxide composition containing cerium oxide and one or more trivalent dopants and having noble metals dispersed on its surface can effectively remove biological contaminants. These antibacterial compositions contain a particulate oxide composition having noble metals dispersed on its surface and can remove approximately 90% or more of biological contaminants. In certain embodiments, these antibacterial compositions can remove approximately 99% or more of biological contaminants.

[0110] These antimicrobial compositions exhibit unexpectedly superior activity compared to noble metals dispersed on a low-antimicrobial substrate or on a particulate oxide composition alone. Furthermore, their activity shows an unexpected synergistic effect (i.e., not merely additive) compared to the activity of the particulate oxide composition alone or the activity of a similar amount of noble metal supported on a low-antimicrobial substrate. Therefore, the antimicrobial compositions disclosed herein make it possible to maintain the effectiveness of removing biocontaminants while reducing the amount of noble metals used (e.g., silver or ruthenium).

[0111] The antimicrobial composition can be slurried with a water system containing biocontaminants to effectively remove them. In certain embodiments, slurriing the antimicrobial composition with a water system containing biocontaminants removes at least about 90% of the biocontaminants. In other embodiments, slurriing removes at least 95%, preferably 99%, or more of the biocontaminants.

[0112] The antimicrobial compositions described herein may be incorporated into supporting compositions and / or articles for removing biocontaminants as described later.

[0113] Support compositions and articles Further disclosed herein are support compositions comprising a support material and an antimicrobial composition comprising a trivalent-doped CeO2 particulate composition on which a noble metal is dispersed on the surface. These support compositions are for removing biological contaminants. The support composition comprises a support material and an antimicrobial composition comprising a noble metal, and a particulate oxide composition comprising cerium oxide doped with a trivalent dopant selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and optionally comprising an additional metal oxide selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof, wherein cerium oxide is present in greater quantities than the trivalent dopant, and the noble metal is dispersed on the surface of the particulate oxide composition.

[0114] As described above, the particulate oxide composition comprises cerium oxide, one or more trivalent dopants (as oxides), and optionally additional metal oxides other than cerium oxide and trivalent dopants, and trace amounts of impurities. In certain embodiments, the particulate oxide composition contains about 0 additional metal oxides. The particulate oxide composition has a unique depth profile in which cerium oxide is present in greater proportions than trivalent dopants, and the average trivalent dopant / Ce ratio from about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is greater than the trivalent dopant / Ce ratio at about 15 nm from the surface. The particulate oxide composition contained in the antimicrobial composition within the supporting composition includes all embodiments of the particulate oxide composition described above.

[0115] The antimicrobial composition contains approximately 50% to 99.95% by mass of particulate oxide composition based on the total weight of the antimicrobial composition. In the antimicrobial composition, the particulate oxide composition is present in greater quantities than the precious metal.

[0116] The precious metal is selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof. In certain embodiments, the precious metal is silver, ruthenium, or a mixture thereof. The antimicrobial composition in the supporting composition includes all embodiments relating to the aforementioned precious metals.

[0117] The support composition for removing biological contaminants further comprises a support material, which includes an organic polymer, cotton, glass fiber, or a mixture thereof.

[0118] The organic polymer may be a homopolymer or copolymer of organic monomers. The organic polymer may also be a silicone or polysiloxane (i.e., a polymer composed of siloxanes (-R2Si-O-SiR2-, where R is an organic group)). The organic polymer may also be a thermosetting polymer, such as a thermoplastic elastomer. In certain embodiments, the organic polymer is selected from the group consisting of polyethylene, polycarbonate, polyvinyl chloride, nylon, polypropylene, polyester, polyurethane, polyamide, polyolefin, copolymers thereof, and mixtures thereof. In certain embodiments, the organic polymer is a silicone.

[0119] In the support compositions disclosed herein, the antimicrobial composition is supported on or inside the support material.

[0120] In one embodiment of the support composition, the particulate oxide composition of the antimicrobial composition comprises about 99.9% to about 20% by mass of cerium oxide, about 0.1% to about 50% by mass of trivalent dopant (as oxide), and about 70% to about 0% by mass of additional metal oxide, based on the total weight of the particulate oxide composition.

[0121] In another embodiment of this support composition, the particulate oxide composition of the antimicrobial composition comprises about 0.1% to about 50% by mass of trivalent dopant and about 99.9% to about 50% by mass of cerium oxide, based on the total weight of the particulate oxide composition.

[0122] In the supporting composition, it is understood that the antimicrobial composition may have any of the above-described embodiments of the particulate oxide composition and the noble metal.

[0123] These support compositions comprise a support material containing an organic polymer, cotton, glass fiber, or a mixture thereof, and an antimicrobial composition containing a particulate oxide composition having a unique depth profile and a noble metal, the noble metal being dispersed on the surface of the particulate oxide composition. As described above, this particulate oxide composition is a mixed oxide composition (i.e., a mixture of oxides of cerium, a trivalent dopant, and any additional metal oxide). In these support compositions, the antimicrobial composition containing the noble metal and the particulate oxide composition (i.e., trivalent doped cerium oxide having a unique depth profile) is supported on or inside the support material.

[0124] In all embodiments, the support composition comprises about 0.5% to about 80% by weight of the antimicrobial composition based on the total weight of the support composition. In certain embodiments, the support composition comprises about 0.5% to about 50% by weight of the antimicrobial composition based on the total weight. In other embodiments, the support composition comprises about 0.5% to about 25% by weight of the antimicrobial composition based on the total weight. In yet another embodiment, the support composition comprises about 0.5% to about 10% by weight of the antimicrobial composition based on the total weight. In an additional embodiment, the support composition comprises about 0.5% to about 5% by weight of the antimicrobial composition based on the total weight. In these support compositions, it is understood that the antimicrobial composition may have any of the embodiments of the particulate oxide composition and the precious metal described above.

[0125] The support composition, which includes the support material and the antimicrobial composition, may be in a rigid or elastic form. The support composition may form an article for removing biological contaminants, such as a filter or plastic (e.g., a plastic container). This article may be in a rigid or elastic form.

[0126] If the support composition forms an article, the article contains about 50% to about 100% by weight of the support composition, which includes the support material and the antimicrobial composition, based on the total weight of the article. In certain embodiments, the article contains about 75% to about 95% by weight of the support composition, which includes the support material and the antimicrobial composition, based on the total weight of the article.

[0127] When the antimicrobial composition and support material are molded into an elastic or rigid article, the article may further contain a binder, gravel, sand, glass wool, a metal or plastic container, etc.

[0128] In some embodiments, the support material may be an organic polymer. In the specifics of these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or a mixture thereof, and the noble metal is Ag, Ru, or a mixture thereof. When this support composition using an organic polymer as the support material forms an article, the article may be a plastic article. In these embodiments, the organic polymer may be selected from the group consisting of polyethylene, polyvinyl chloride (PVC), nylon, polypropylene, polyester, polyurethane, polyamide, polyolefin, polycarbonate, copolymers thereof, and mixtures thereof. In certain embodiments, the organic polymer is polyethylene, polycarbonate, or a mixture thereof. If it is plastic, the article may be in the form of a filter, bottle, container, or plastic cover for high-touch services. The filter may be a fixed floor. The bottle or container may be for liquids. High-touch surfaces include escalator or stair railing covers, elevator button covers, doors, door handles or knobs or covers thereof, public transport covers, electronic transaction touchpads, etc.

[0129] In some embodiments, the support material may be cotton. In these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or a mixture thereof, and the noble metal is Ag, Ru, or a mixture thereof. When this support composition uses cotton as the support material to form an article, the article may be a filter or a fibrous article.

[0130] In some embodiments, the support material may be glass fiber. In these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or a mixture thereof, and the noble metal is Ag, Ru, or a mixture thereof. When this support composition using glass fiber as the support material forms an article, the article may be a filter, bottle, container, or high-touch surface. The filter may be a fixed floor. High-touch surfaces include elevator button covers, doors, public transport covers, and electronic transaction touchpads.

[0131] In certain embodiments, the support material may be cotton or an organic polymer. In these embodiments, the organic polymer may be selected from the group consisting of nylon, polyester, polyamide, and mixtures thereof. In these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or a mixture thereof, and the noble metal is Ag, Ru, or a mixture thereof. When this mixture is used as the support material, the article may be a filter or a fibrous article.

[0132] In certain embodiments, the support material may be glass fiber and an organic polymer. The organic polymer may be selected from the group consisting of polyethylene, polyvinyl chloride (PVC), nylon, polypropylene, polyester, polyurethane, polyamide, polyolefin, polycarbonate, copolymers thereof, and mixtures thereof. In the specification of these embodiments, the organic polymer may be selected from the group consisting of polyethylene, polycarbonate, and mixtures thereof. In the specification of these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or a mixture thereof, and the noble metal is Ag, Ru, or a mixture thereof. When this mixture is used as the support material, the article may be a filter, bottle, container, or high-touch surface. The filter may be a fixed floor. High-touch surfaces include escalator or stair railing covers, elevator button covers, door, door handle or knob covers, public transport covers, electronic transaction touchpads, etc.

[0133] In some embodiments, the support material may be polyethylene or polycarbonate. In these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or a mixture thereof, and the noble metal is Ag, Ru, or a mixture thereof. When the support composition forms an article, the article is a plastic article and may be in the form of a filter, bottle, container, or plastic cover for a high-touch surface. The filter may be a fixed bed.

[0134] In certain embodiments, the support material may be silicone. In these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or a mixture thereof, and the noble metal is Ag, Ru, or a mixture thereof.

[0135] In certain embodiments, the article is a plastic article. The plastic article may be in the form of a filter, bottle, container, or plastic cover for a high-touch surface. The plastic article comprises a support composition for removing biocontaminants, the support composition comprising (i) an organic polymer selected from the group consisting of polyethylene, polyvinyl chloride, nylon, polypropylene, polyester, polyurethane, polyamide, polyolefin, polycarbonate, copolymers thereof, and mixtures thereof. The plastic article further comprises (ii) an antimicrobial composition, the antimicrobial composition comprising (a) a noble metal selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof, and (b) a particulate oxide composition. The particulate oxide composition comprises a trivalent dopant selected from the group consisting of cerium oxide, yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and optionally an additional metal oxide selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), and mixtures thereof, wherein cerium oxide is present in greater quantities than the trivalent dopant, and the average trivalent dopant / Ce ratio from about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is greater than the trivalent dopant / Ce ratio at about 15 nm from the surface. The noble metal is dispersed on the surface of the particulate oxide composition, and is present in greater quantities than the noble metal. In the specification of these embodiments, the trivalent dopant of the particulate oxide composition is Pr, La, or mixtures thereof, and the noble metal is Ag, Ru, or mixtures thereof. In addition, in these embodiments of plastic articles, the organic polymer may be selected from the group consisting of polyethylene, polycarbonate, and mixtures thereof.

[0136] In all embodiments of the plastic article, the antimicrobial composition is supported on or within the organic polymer. In certain embodiments, the plastic article contains, based on its total weight, about 50% to about 100% by weight of the support composition for removing biocontaminants.

[0137] In certain embodiments of the plastic article, the article comprises an antimicrobial composition comprising (i) a noble metal selected from the group consisting of silver, ruthenium, or mixtures thereof, and (ii) a particulate oxide composition comprising about 99.95% to about 50% by mass, based on the total weight of the particulate oxide composition, in the form of a particulate oxide composition comprising about 0.1% to about 50% by mass of a trivalent dopant and about 99.9% to about 50% by mass of cerium oxide. This particular particulate oxide composition encompasses all embodiments relating to the particulate oxide composition described above.

[0138] Antimicrobial compositions, support compositions, and articles disclosed herein, including noble metal and trivalent doped cerium oxide microparticle compositions in which noble metals are dispersed on the surface of the microparticle composition, can remove about 90% or more of biocontaminants. In certain embodiments, these antimicrobial compositions, support compositions, and articles can remove about 99% or more of biocontaminants.

[0139] The biocontaminants removed by the articles, supporting compositions, antimicrobial compositions, and methods disclosed herein include viruses, bacteria, fungi (e.g., molds or mycelium), protozoa (e.g., amoebas), algae, yeasts, and mixtures thereof. In certain embodiments, the biocontaminants removed by the articles, compositions, and methods disclosed herein are selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas), and mixtures thereof. In certain embodiments, the biocontaminants removed by the articles, compositions, and methods disclosed herein are bacteria, viruses, amoebas, and mixtures thereof. In other embodiments, the biocontaminants are bacteria, viruses, and mixtures thereof.

[0140] In certain embodiments, the biological contaminants to be removed include those that pose a problem in water systems such as wastewater, and those that pose a problem when suspended in the air.

[0141] Bacteria include Gram-positive and Gram-negative bacteria. Bacteria include fecal coliforms commonly found in water. Examples of bacteria include Streptococcus, Staphylococcus, Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), Legionella pneumophila, Campylobacter Jejuni, Salmonella, Mycobacterium tuberculosis, Corynebacterium diphtheriae, Listeria monocytogenes, and Bordetella pertussis. Viruses include, for example, rhinovirus, coronavirus, vaccinia virus, poliovirus, varicella zoster virus, paramyxovirus, influenza virus, measles virus (morbillivirus), hepatitis A virus (HAV), adenovirus (HAdV), rotavirus (RoV), sapovirus, respiratory syncytial virus (RSV), paramyxovirus, varicella zoster virus (VZV), smallpox virus (variola virus, including smallpox and monkeypox), as well as other enteric viruses such as norovirus (NoV), coxsackievirus, echovirus, reovirus and astrovirus. Other microbial contaminants include protozoa (e.g., Cryptosporidium) and especially amoebas (e.g., Naegleria fowleri). Furthermore, fungi among the microbial contaminants include Trichophyton mentagrophytes and Aspergillus.

[0142] The articles, compositions, and methods disclosed herein reduce the concentration or amount of these biocontaminants.

[0143] Method for producing antimicrobial composition and trivalent doped cerium oxide particulate oxide composition Known methods exist for producing trivalent-doped cerium oxide compositions (e.g., U.S. Patent Application No. 17 / 870,068, the contents of which are fully incorporated herein). Furthermore, known methods exist for producing trivalent-doped cerium oxide compositions having the aforementioned unique depth profile and other unique properties (e.g., U.S. Patent Application No. 17 / 895,942, the contents of which are fully incorporated herein).

[0144] An antimicrobial composition in which a precious metal is dispersed as a metal or oxide on the surface of a particulate oxide composition is prepared by the method described in the examples below.

[0145] A method for producing an antimicrobial composition generally includes the steps of wetting a particulate oxide composition with a solution of a soluble noble metal salt, optionally exposing the mixture to a reducing agent, drying it under reduced pressure, and optionally drying or calcining the resulting solid at a high temperature.

[0146] As an example, trivalent doped cerium oxide is wetted with a ruthenium(III) nitrosyl nitrate solution in an amount that ultimately results in 1 mass% Ru. Then, an amount of hydrazine is added to reduce the ruthenium to metallic ruthenium, and the liquid is removed by evaporation under reduced pressure.

[0147] In one embodiment, the antimicrobial composition comprises about 1% by weight of ruthenium and about 99% by weight of the particulate oxide composition. Wetting of the particulate oxide can be performed by placing the particulate oxide in a container, stirring or rotating the container, and then spraying, dropping, pumping, or injecting a soluble noble metal salt solution into the container. The rate of addition of the soluble noble metal salt solution and the mixing time should be sufficient to adequately wet and mix the material. Any reducing agent may be any reagent having a reduction potential sufficient to reduce the noble metal to its metallic state, such as hydrazine, hydrogen, carboxylic acids (i.e., citric acid, acetic acid, oxalic acid, etc.), alcohols, metal hydrides, hydrogen peroxide, etc. Drying of the antimicrobial material can be performed under reduced pressure, at high temperature, or a combination thereof. Further heating or calcination is optional and, if used, can be performed in a furnace, rotary kiln, etc.

[0148] Preparation of support compositions and articles The support composition comprises a support material and an antimicrobial composition comprising a noble metal and a particulate oxide composition, wherein the noble metal is dispersed on the surface of the particulate oxide composition. The particulate oxide composition comprises cerium oxide and a trivalent dopant and has the distinctive depth-direction profile described above. The particulate oxide composition, antimicrobial composition, support composition and articles encompass all embodiments described herein. In the support composition, the support material is selected from an organic polymer, cotton, glass fiber, or a mixture thereof.

[0149] The support composition may be used alone to process gaseous or aqueous mixtures. Alternatively, the support composition may be incorporated into an article specifically designed for processing gaseous or aqueous mixtures, such as a filter or plastic container. The filter may be a fixed bed. The filter is used with gaseous or aqueous mixtures or flows, and is therefore used to filter them.

[0150] In a support composition and an article containing the support composition, the antimicrobial composition is supported on or within the support material, and the support composition is provided for removing biological contaminants.

[0151] The antimicrobial composition may be supported on one or more external and / or internal surfaces of a support material. Those skilled in the art will generally understand that the internal surface of a support material is referred to as a pore. The antimicrobial composition may be supported on the surface of the support material or incorporated into its surface. The antimicrobial compositions described herein may be supported on a support material with or without a binder. In some embodiments, the antimicrobial composition may be applied to the support material using conventional techniques such as slurry support.

[0152] The process for manufacturing the support composition is not limited to a specific step or method, but generally any process that results in incorporating the antimicrobial composition into or supporting the support material. The process for incorporating the antimicrobial composition into the support material includes mixing the antimicrobial composition during the manufacturing process of the support material. For example, the antimicrobial composition can be added to molten polypropylene in the molding process. Alternatively, the antimicrobial composition can be added to a mixture of polyvinyl chloride resin, a plasticizer, and a stabilizer, passed through a hot mixer, and then through an extruder.

[0153] The process of supporting an antimicrobial composition on a support material involves mixing the antimicrobial composition with an organic binder in liquid or aqueous solution. The mixture of the antimicrobial composition and the organic binder is bonded to the support material by immersion in the support material or by coating (spreading or airbrushing) the mixture. The organic binder can also be used in slurry support techniques.

[0154] In certain embodiments, the organic binder is selected from citric acid, polyurethane diol, polyvinyl alcohol, polyvinylpyrrolidone, linseed oil, and mixtures thereof. After the antimicrobial composition is bonded to the support, the coated support may optionally be washed with water before drying to remove any residue not bonded to the support. The coated support may then optionally be dried at a temperature greater than about 20°C and less than about 300°C for about 1 to 12 hours or until fully dry. In certain embodiments, the coated support may then optionally be dried at a temperature greater than about 20°C and less than about 120°C.

[0155] In the case of molten support materials such as glass or plastic, the support material can be heated until its surface begins to soften slightly, and then the antimicrobial composition can be placed on the surface so that the antimicrobial composition begins to mix with the semi-molten material. Through cooling and re-solidification, the antimicrobial composition is incorporated into the surface of the support material. The temperature used depends on the support material being used. Those skilled in the art can easily determine the appropriate temperature for the support material being used. For example, it is over 1000°C for quartz glass, about 500-600°C for borosilicate glass, and about 200-300°C for PVC.

[0156] These solid supports can be used to form articles, including filters and plastic articles.

[0157] Antimicrobial compositions may also be incorporated into articles for high-frequency contact surfaces, which may come into direct contact with biological contaminants. Therefore, articles for high-frequency contact surfaces can be used not only for fluid handling but also for reducing bacteria and / or viruses that adhere via contact. These articles include liquid containers, elevator buttons, escalator or stair railing covers, doors, door handles, door knobs, covers in public transport, touchpads for electronic transactions, and fabrics.

[0158] A support composition comprising an antimicrobial composition and a support material can be molded into elastic or rigid articles such as filters, fixed-bed filtration systems, bottles or containers, and high-frequency contact surfaces. In certain embodiments, the article is a plastic article. In other embodiments, the article is a filter. These articles may include other necessary components that are commonly found in such articles, as is widely recognized by those skilled in the art. Techniques for molding these articles are well known to those skilled in the art.

[0159] Method of using antibacterial composition This application relates to a method for removing biocontaminants using any of the above-mentioned antimicrobial compositions comprising trivalent-doped cerium oxide with a noble metal dispersed on its surface. This method may utilize the antimicrobial composition itself, or it may utilize the antimicrobial composition as part of a support composition or article. This method can treat fluids including air, water-based flows, and gaseous flows.

[0160] In these methods, the antimicrobial composition exhibits remarkably superior activity compared to the particulate oxide composition alone or to noble metals dispersed on a low-antimicrobial substrate. Furthermore, this activity is unexpectedly synergistic (i.e., not merely additive), and is superior to the activity of the particulate oxide composition alone or to the activity of a similar amount of noble metal supported on a low-antimicrobial substrate.

[0161] In one embodiment, a support composition comprising an antimicrobial composition and a support material may be used alone in a method for removing biological contaminants, or the support composition of the antimicrobial composition and the support material may be incorporated into an article specifically designed for processing gaseous or aqueous mixtures, such as a filter or plastic (e.g., a plastic container).

[0162] The antimicrobial composition used in these methods comprises (a) about 99.95% to about 50% by mass of the particulate oxide composition based on the total weight of the particulate oxide composition, the particulate oxide composition comprising trivalent dopants (as oxides) selected from the group consisting of cerium oxide, yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof, and optionally additional oxides selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), and mixtures thereof, wherein cerium oxide is present in greater amounts than the trivalent dopants, and the average trivalent dopant / Ce ratio at about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is greater than the trivalent dopant / Ce ratio at about 15 nm from the surface. The antimicrobial composition further comprises (b) a noble metal dispersed on the surface of the particulate oxide composition, the noble metal being selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof.

[0163] The antimicrobial composition may have any of the above-described embodiments of the noble metal and particulate oxide compositions.

[0164] In a particular embodiment, the present application relates to a method for removing biocontaminants and maintaining their concentration below a target level using a disclosed antimicrobial composition comprising a precious metal and trivalent doped cerium oxide. These biocontaminants include bacteria, viruses, protozoa (e.g., amoebas), fungi, algae, yeast, and the like. These methods may utilize the antimicrobial composition itself, a supporting composition containing the antimicrobial composition, or articles containing these supporting compositions.

[0165] This method may involve treating the surface of a fluid (e.g., a water-based flow, a gas-based flow, or a mixture thereof) or a solid object by contact / direct contact. Therefore, the methods disclosed herein include methods for treating fluids (e.g., water-based flows and / or gas-based flows).

[0166] In certain embodiments, an aqueous or gaseous flow is brought into contact with an antimicrobial composition comprising a noble metal and a particulate oxide composition. The particulate oxide composition comprises all embodiments described above and includes the aforementioned amounts of trivalent dopant, cerium oxide, and any additional metal oxide, as well as the aforementioned properties. The antimicrobial composition comprises all embodiments described above and includes any of the aforementioned amounts of noble metal and noble metal.

[0167] In other embodiments, a water-based or gaseous flow is brought into contact with a support composition containing the antimicrobial composition described herein. In yet another embodiment, a potentially contaminated surface is brought into contact with a support composition or article containing the antimicrobial composition described herein. These potentially contaminated surfaces include, for example, skin (e.g., hands, fingers, palms, etc.), and the contact occurs by touching the support composition or article containing the antimicrobial composition described herein. In the methods disclosed herein, the biological contaminants to be removed may be contained in a water-based or gaseous flow, or they may be present on the surface of a physical object.

[0168] While the present invention is not intended to be bound by any particular theory, it is believed that, as described herein, by contacting an antimicrobial composition comprising a particulate oxide composition on which a noble metal is dispersed on the surface with a biocontaminant, the biocontaminant is adsorbed and / or reacted with, or inactivated by contact with, the noble metal and / or trivalent-doped cerium oxide. By adsorbing, reacting with, and / or inactivating the biocontaminant with the noble metal and / or trivalent-doped cerium oxide, the biocontaminant is removed from the fluid (air or water system flow) or solid surface containing the biocontaminant.

[0169] Biocontaminants can be removed to or below a target level. In some embodiments, biocontaminants can be removed to an undetectable level. The target level may be a specific amount or a detection limit. As part of the method herein, the biocontaminant to be removed may be identified, and a target amount or target level of that contaminant may be set. For the specific biocontaminants assumed herein, the target amount or target level may be a detectable amount. The method may optionally further include the step of monitoring the contaminant in the treated fluid.

[0170] The methods disclosed herein may be used to treat air or water, or to treat contaminants by contact. When used to treat contaminants by contact, the disclosed antimicrobial composition is incorporated into a high-frequency contact surface.

[0171] By treating biocontaminated air and / or water using the antimicrobial compositions disclosed herein, air and / or water treatment methods can be operated efficiently, and a treated flow with reduced concentrations of biocontaminants can be obtained. As disclosed herein, the antimicrobial compositions are incorporated into a support composition, which may be incorporated into articles specifically designed for treating gaseous or aqueous mixtures, such as filters, fixed-bed filtration systems, or container plastics. In methods for treating aqueous flows, the antimicrobial compositions may be used as themselves or contacted by slurring. These slurring methods may further include a step of filtering the fluid / liquid.

[0172] In any of these methods, the antimicrobial composition may contain any of the types and amounts of precious metals described above, as well as any of the embodiments and amounts of particulate oxide compositions described above. Therefore, the particulate oxide composition may contain any of the amounts of the trivalent dopant, cerium oxide, and any additional metal oxides described above, and may have the properties described above. The particulate oxide composition in the antimicrobial composition has a unique depth profile.

[0173] The method of the present invention is intended to remove biological contaminants (e.g., bacteria, viruses, amoebas, etc.) from air and / or drinking water and groundwater, but it will be understood that the method can be used to treat any gaseous or aqueous feedstream containing undesirable amounts of biological contaminants. The method is also intended to remove biological contaminants from contaminated surfaces by direct contact with an article containing an antimicrobial composition disclosed herein. In certain embodiments, a method for removing these biological contaminants comprises the step of providing an antimicrobial composition comprising: (i) a particulate oxide composition comprising cerium oxide; a trivalent dopant selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr) and mixtures thereof; and optionally an additional metal oxide selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf) and mixtures thereof, here (i) cerium oxide is present in greater quantities than trivalent dopants, and the average trivalent dopant / Ce ratio from about 0 nm to about 3.5 nm from the surface of the particulate oxide composition is greater than the trivalent dopant / Ce ratio at about 15 nm from the surface; (b) a noble metal dispersed on the surface of the particulate oxide composition, where the noble metal is selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof. The method further comprises (ii) contacting the antimicrobial composition with a biocontaminant, where the biocontaminant is selected from the group consisting of bacteria, viruses, fungi, protozoa, and mixtures thereof; and (iii) removing the biocontaminant by contact with the antimicrobial composition. The biocontaminant may be contained in an aqueous or liquid system, or may be present on the surface of an object that is in physical contact with the antimicrobial composition. These methods remove at least about 90% of biocontaminants upon contact with the antimicrobial composition. In certain embodiments, the method removes about 99% or more of biocontaminants upon contact with the antimicrobial composition.

[0174] In some embodiments, the antimicrobial composition may be contained within a supporting composition, and in some of these embodiments, the supporting composition may be incorporated into an article. These methods may further include a step of monitoring for biocontaminants after contact. Monitoring may be performed by sampling or continuously.

[0175] In certain embodiments, these methods include the steps of: (i) providing a support composition comprising a support material comprising an organic polymer, cotton, glass fiber or a mixture thereof as a support material, and an antimicrobial composition (as disclosed herein) comprising (a) a particulate oxide composition and (b) a noble metal dispersed on the surface of the particulate oxide composition; (ii) contacting the support composition with a biocontaminant, the biocontaminant being selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas) and mixtures thereof; and (iii) removing the biocontaminant by contact with the support composition. These methods remove at least about 90% of the biocontaminant.

[0176] In some of these methods, the particulate oxide composition in the antimicrobial composition comprises about 99.9% to about 20% by mass of cerium oxide, about 0.1% to about 50% by mass of a trivalent dopant, and about 70% to about 0% by mass of an additional metal oxide, based on the total weight of the particulate oxide composition. In certain embodiments of these methods, the antimicrobial composition comprises a noble metal selected from silver, ruthenium, or a mixture thereof.

[0177] The biocontaminants may be present in a water system or liquid flow, or on the surface of an object that is in physical contact with the support composition. These methods may further include a step of monitoring the biocontaminants after contact. Monitoring may be performed by sampling or continuously.

[0178] The antimicrobial composition includes any embodiment of the noble metal and particulate oxide compositions described above.

[0179] Contact between the antimicrobial composition and a biocontaminant removes a measurable amount of the biocontaminant. In one embodiment, contact removes at least about 90% of the biocontaminant. In other embodiments, contact removes at least 95%, or more preferably 99% or more than 99% of the biocontaminant.

[0180] Contact between an antimicrobial composition and a biocontaminant effectively reduces the amount of the biocontaminant, and in certain embodiments, effectively reduces the amount of the biocontaminant in a gaseous or aqueous flow. This removal can also be expressed as a percentage reduction in the concentration of the biocontaminant. In some embodiments, contact between an antimicrobial composition and a biocontaminant can reduce its concentration by more than about 75%. More typically, it can reduce its concentration by more than about 80%, more typically more than about 85%, more typically more than about 90%, more typically more than about 95%, more typically more than about 97.5%, more typically more than about 99%, and even more typically more than about 99.5%.

[0181] In certain embodiments, these methods may be methods for removing biocontaminants from a fluid or for treating a fluid. In these embodiments, the fluid may be a gas, a water flow, or a mixture thereof. In these embodiments, the method may use the antimicrobial composition itself, a support composition, or an article disclosed herein. Thus, the method includes (i) a step of providing an antimicrobial composition, a support composition, or an article disclosed herein. If it is a support composition, the support material includes an organic polymer, cotton, glass fiber, or a mixture thereof, and also includes the antimicrobial composition. The method further includes (ii) a step of contacting a gas or water flow containing a biocontaminant with the antimicrobial composition, the biocontaminant being selected from the group consisting of bacteria, viruses, fungi (e.g., mold), protozoa (e.g., amoebas), and mixtures thereof; and (iii) a step of removing the biocontaminant from the gas or water flow by contact with the antimicrobial composition. The biocontaminant may be removed by 90% or more. These methods may further include a step of monitoring the biocontaminant after contact. Monitoring may be performed by sampling or continuously.

[0182] In these methods, the antimicrobial composition and the noble metal and particulate oxide composition within the antimicrobial composition include all embodiments described above.

[0183] These methods for treating gaseous or aqueous flows may further include a step of setting a target concentration of a biological contaminant. In these methods, the target biological contaminant is identified and a target concentration of the biological contaminant is set. These methods may further include a step of monitoring the biological contaminant in the treated flow. Monitoring may be performed by sampling or continuously.

[0184] In certain embodiments, these methods include the steps of: (i) providing a composition comprising a support material comprising an organic polymer, cotton, glass fiber, or a mixture thereof, and an antimicrobial composition disclosed herein, wherein the antimicrobial composition comprises a particulate oxide composition and a noble metal; (ii) setting a target concentration of a biocontaminant; (iii) contacting a gaseous or aqueous stream with the antimicrobial composition to remove the biocontaminant through contact with the antimicrobial composition and obtain a treated stream; and (iv) monitoring the biocontaminant in the treated stream, wherein the biocontaminant is selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas) and mixtures thereof. The antimicrobial composition and the noble metal and particulate oxide composition within the antimicrobial composition include all embodiments described above. The target concentration may be a specific amount (e.g., virus, bacteria, protozoa / amoeba, or fungus) or may be set to a detection limit. Monitoring of the biocontaminant can be carried out by techniques well known to those skilled in the art. Monitoring may be carried out by sampling or continuously. Those skilled in the art understand real-time and continuous monitoring techniques for microbial contaminants such as viruses, bacteria, protozoa / amoebas, and fungi. These techniques include optical techniques and cell counters.

[0185] In certain embodiments for treating aquatic flow, the method comprises the steps of: (i) providing an antimicrobial composition as described herein, comprising a particulate oxide composition and a noble metal; the method further comprises (ii) contacting the aquatic flow with the antimicrobial composition to remove biocontaminants by contact with the antimicrobial composition to obtain a treated aquatic flow, wherein the biocontaminants are selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas) and mixtures thereof; these methods may further comprise the step of monitoring the biocontaminants after contact; monitoring may be performed by sampling or continuously; in certain embodiments, the method may further comprise the step of setting a target concentration of biocontaminants and monitoring the biocontaminants in the treated aquatic flow; the target concentration may be a specific amount or a detection limit; in these methods, the antimicrobial composition may be contained in a support composition, contained in a support composition within an article, or the antimicrobial composition may be directly slurryed and brought into contact with the aquatic flow; in methods involving slurring, the step of filtering the fluid / liquid may further comprise the step of filtering the fluid / liquid. In these methods, the antimicrobial composition and the particulate oxides and precious metals within the antimicrobial composition include all embodiments described above.

[0186] In certain embodiments for treating aquatic flow, the method comprises the steps of: (i) providing a support material comprising an organic polymer, cotton, glass fiber, or a mixture thereof, and an antimicrobial composition described herein, comprising (a) a particulate oxide composition and (b) a noble metal dispersed on the surface of the particulate oxide composition. The method further comprises (ii) contacting the aquatic flow with the antimicrobial composition to remove biocontaminants by contact with the antimicrobial composition to obtain a treated aquatic flow, in which case the biocontaminants are selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas) and mixtures thereof. In these methods, the antimicrobial composition and the particulate oxides and noble metals in the antimicrobial composition include all embodiments described above. These methods may further comprise the step of monitoring the biocontaminants after contact. Monitoring may be performed by sampling or continuously. In certain embodiments, the method may further comprise the step of setting a target concentration of biocontaminants and monitoring the biocontaminants in the treated aquatic flow. The target concentration may be a specific amount or a detection limit.

[0187] In certain embodiments of processing a gaseous flow, the method includes: (i) providing a support material comprising an organic polymer, cotton, glass fiber, or a mixture thereof, and an antimicrobial composition as described herein, comprising (a) a particulate oxide composition and (b) a noble metal dispersed on the surface of the particulate oxide composition. The method further includes (ii) contacting the gaseous flow with the antimicrobial composition to remove biocontaminants by contact with the antimicrobial composition to obtain a treated gaseous flow, in which case the biocontaminants are selected from the group consisting of bacteria, viruses, fungi (e.g., molds), protozoa (e.g., amoebas) and mixtures thereof. In these methods, the antimicrobial composition and the particulate oxides and noble metals in the antimicrobial composition include all embodiments described above. These methods may further include monitoring the biocontaminants after contact. Monitoring may be performed by sampling or continuously. In certain embodiments, the method may further include setting a target concentration of biocontaminants and monitoring the biocontaminants in the treated gaseous flow. The target concentration may be a specific amount or a detection limit.

[0188] When the biological contaminant is bacteria or fungi / mold, its removal can be expressed as a percentage reduction determined using colony-forming units (CFU). In these embodiments, the concentration of bacterial contaminants after contact with the antimicrobial composition or a supporting composition or article containing the antimicrobial composition ranges from approximately 45 colony-forming units CFU / ml to 5 × 10⁻⁶. 5 It can be CFU / ml.

[0189] When the biological contaminants are bacteria and / or viruses, their removal can be expressed as a percentage reduction determined using the Most Probable Number (MPN) method. The MPN method is used to estimate the concentration of viable microorganisms in a sample by repeating growth in liquid media at 10-fold serial dilutions.

[0190] The target concentration of the biocontaminant can also be set as a percentage reduction in the contaminant between before and after the method is implemented. In certain embodiments, this percentage reduction may be about 75% to about 100%. In other embodiments, this percentage reduction may be about 80% to about 99.9%.

[0191] The target concentration of a biological contaminant can be set to the detection limit of that contaminant. As described above, in embodiments for setting a target concentration of a biological contaminant, the method may further include one or more of the following additional steps: identifying the biological contaminant to be targeted; setting a target concentration; and monitoring the biological contaminant after the contact step to determine or confirm that the biological contaminant is below the target concentration. Depending on the biological contaminant, the target concentration may be a detectable amount of that contaminant, and the methods disclosed herein are effective for treating the water or gaseous flow as long as no contaminant is detected in the treated flow.

[0192] In these specific embodiments, the flow being treated may be an aqueous flow, and the targeted contaminant may be bacteria, viruses, or protozoa (e.g., amoebas). For example, the flow being treated may be an aqueous or gaseous flow, and the targeted contaminant may be Escherichia coli (E. coli), poliovirus, coronavirus, Naegleria fowleri, paramyxovirus, Mycobacterium tuberculosis, Legionella pneumophila, coronavirus, or a mixture thereof. In a specific embodiment, the flow being treated is an aqueous flow, and the targeted contaminant is Escherichia coli, poliovirus, Naegleria fowleri, Legionella pneumophila, coronavirus, or a mixture thereof. In a specific embodiment, the flow being treated is a gaseous flow, and the targeted contaminant is paramyxovirus, Mycobacterium tuberculosis, coronavirus, or a mixture thereof. In certain embodiments, the targeted viruses are primarily transmitted by contact and include varicella-zoster virus (VZV), variola virus (including smallpox and monkeypox).

[0193] These specific methods include (i) providing an antimicrobial composition disclosed herein, the antimicrobial composition comprising: (a) a particulate oxide composition, and (b) a noble metal dispersed on the surface of the particulate oxide composition. The method further includes (ii) setting a target concentration of a biocontaminant, in which case the biocontaminant is selected from the group consisting of Escherichia coli, poliovirus, coronavirus, Naegleria fowleri, paramyxovirus, Mycobacterium tuberculosis, Legionella pneumophila, coronavirus, or mixtures thereof; (iii) contacting a gaseous or aqueous flow with the antimicrobial composition to remove the biocontaminant by contact with the antimicrobial composition to obtain a treated flow; and (iv) monitoring the biocontaminant in the treated flow. The target concentration may be a specific amount or a detection limit. The method may also include a step of identifying the target contaminant before setting the target concentration.

[0194] In these methods, the antimicrobial composition and the particulate oxides and precious metals within the antimicrobial composition encompass all embodiments described above. The antimicrobial composition of step (i) may be provided as part of a support composition, in which case it may further include a support material consisting of an organic polymer, cotton, glass fiber or a mixture thereof, or it may be provided as part of an article containing the support composition.

[0195] Examples of gaseous supply streams that can be treated according to the methods disclosed herein include building ventilation systems, aircraft or vehicle ventilation systems, and indoor air. On the other hand, examples of liquid supply streams that can be treated according to the methods disclosed herein include surface water such as tap water, well water, water from lakes, ponds and wetlands, water for recreational activities, agricultural water, wastewater from industrial processes, and geothermal fluids. Other applications involving physical contact with biocontaminants rather than filtration include incorporation into plastic containers or plastics incorporated into high-contact surfaces, such as elevator buttons, escalator handrail covers, stair railing covers, touchpads for electronic transactions, doors, and doorknobs. These high-contact surfaces may also include glass or mixtures of glass and plastic.

[0196] The antimicrobial composition can remove bacteria, viruses, protozoa (e.g., amoebas), fungi (e.g., molds), and other microbial contaminants, and in certain embodiments, remove bacteria, viruses, protozoa (e.g., amoebas), fungi (e.g., molds), and mixtures thereof from a gaseous or liquid supply stream.

[0197] In one embodiment, the method envisions removing biological contaminants from a gaseous or water-based flow using an antimicrobial composition (as disclosed herein) containing a particulate oxide composition and a noble metal dispersed on its surface. The gaseous flow may be an ambient air source or supply air for a ventilation system that contains, or may contain, undesirable amounts of biological contaminants and / or other pollutants. The water-based flow may be a drinking water source or groundwater source that contains, or may contain, undesirable amounts of biological contaminants and / or other pollutants. Furthermore, the water-based flow may, without limitation, include well water, surface water (including water from lakes, ponds and wetlands, natural and artificial, as well as water for recreational purposes), agricultural water, wastewater from industrial processes, and geothermal water.

[0198] In some embodiments, a gaseous stream containing biocontaminants is introduced into a container through an inlet and treated under conditions that maintain the gaseous state, usually at room temperature and pressure. Within this container, the gaseous stream containing biocontaminants comes into contact with an antimicrobial composition. Contact between the antimicrobial composition and the gaseous stream containing biocontaminants removes the biocontaminants. Contact between the antimicrobial composition and the gaseous stream containing biocontaminants results in the removal of a measurable amount of biocontaminants, and in some embodiments, at least 90%, more preferably 95%, and even more preferably 99% or more of the biocontaminants. In this method, the antimicrobial composition and the particulate oxides and precious metals in the antimicrobial composition encompass all embodiments described above.

[0199] In some embodiments, a water stream containing biocontaminants is introduced into a container via an inlet and treated under conditions that maintain a liquid state, typically at room temperature and pressure. Within this container, the water stream containing biocontaminants comes into contact with an antimicrobial composition. Contact between the antimicrobial composition and the water stream containing biocontaminants removes the biocontaminants. Contact between the antimicrobial composition and the water stream containing biocontaminants results in the removal of a measurable amount of biocontaminants, and in some embodiments, at least 90%, more preferably 95%, and even more preferably 99% or more of the biocontaminants. In this method, the antimicrobial composition and the particulate oxides and precious metals in the antimicrobial composition encompass all embodiments described above.

[0200] In some embodiments, the antimicrobial composition is in the form of a fixed bed. Furthermore, the fixed bed containing the antimicrobial composition typically includes particles containing trivalent doped cerium oxide and noble metals dispersed on its surface. The antimicrobial composition may have a shape and / or form that allows gaseous or aqueous fluids to flow through the fixed bed with minimal back pressure while maximizing the surface area of ​​the trivalent doped cerium oxide particles with noble metals dispersed on their surface. If necessary, the antimicrobial composition may be in the form of molded bodies such as beads, extruded bodies, porous polymer structures, or monoliths. The antimicrobial composition may be supported as a layer and / or coating on these beads, extruded bodies, porous polymer structures, or monolithic supports.

[0201] Contact between the antimicrobial composition and a fluid containing biocontaminants typically occurs at temperatures ranging from approximately 1°C to 100°C, and more commonly from approximately 5°C to 40°C. Furthermore, contact between the antimicrobial composition and a water system containing biocontaminants typically occurs in a pH range of approximately 1 to 11, and more commonly from approximately 3 to 9. Contact between the antimicrobial composition and the fluid containing biocontaminants generally lasts for a period of time between approximately 30 seconds and 24 hours.

[0202] In general, antimicrobial compositions can be used to treat any biological contaminants, particularly bacteria, viruses, protozoa (e.g., amoebas), fungi, yeasts, and mixtures thereof.

[0203] Contact between an antimicrobial composition and a gas or water system containing biocontaminants can effectively reduce the level of biocontaminants in the gas or water system. Typically, contact between an antimicrobial composition and a biocontaminant can reduce its concentration by more than 75%, more typically by more than 80%, more typically by more than 85%, more typically by more than 90%, more typically by more than 95%, more typically by more than 97.5%, more typically by more than 99%, and even more typically by more than 99.5%. If the biocontaminant is bacteria or fungi, the concentration reduction rate (%) can be measured using colony-forming units (CFU). If the biocontaminant is bacteria or viruses, the concentration reduction rate (%) can be measured using the most probable number (MPN).

[0204] A method for treating air or water to remove biological contaminants includes passing an airflow or waterflow having a first concentration of one or more unwanted biological contaminants through a material, article, or support composition containing an antimicrobial composition to obtain a treated airflow or waterflow in which the concentration of one or more unwanted biological contaminants is lower than the first concentration.

[0205] In certain embodiments, the biological contaminant to be removed is a virus. After contact with an article or supporting composition containing the antimicrobial composition, the concentration of the virus may be below the target virus concentration. When treating an airflow or gaseous flow, the fluid in contact (or treated) will have a virus concentration below the target virus concentration. In the specifics of these embodiments, the virus to be removed is a coronavirus.

[0206] In certain embodiments, the biological contaminants to be removed are bacteria. After contact with an article or supporting composition containing the antimicrobial composition, the bacterial concentration may be below the target bacterial concentration. When treating an airflow or gaseous flow, the contacted (or treated) fluid will have a bacterial concentration below the target bacterial concentration. In the specifics of these embodiments, the bacteria to be removed are fecal coliforms.

[0207] In certain embodiments, the biological contaminants to be removed are protozoa (e.g., amoebas). After contact with an article or supporting composition containing an antimicrobial composition, the concentration of protozoa (e.g., amoebas) may be less than or equal to a target protozoa (e.g., amoeba) concentration. When treating an airflow or gaseous flow, the fluid in contact (or treated) will have a protozoa (e.g., amoeba) concentration less than or equal to a target protozoa (e.g., amoeba) concentration. In the specifics of these embodiments, the protozoa (e.g., amoebas) to be removed are Naegleria fowleri and / or Cryptosporidium.

[0208] In certain embodiments, the biological contaminants to be removed are fungi (e.g., mold). After contact with an article or supporting composition containing the antimicrobial composition, the concentration of fungi may be below the target fungal concentration. When treating an airflow or gaseous flow, the contacted (or treated) fluid will have a concentration of fungi below the target fungal concentration. In the specifics of these embodiments, the fungi to be removed are Trichophyton mentagrophytes and / or Aspergillus.

[0209] The concentration of contaminants after contact with a supporting composition, material, or article containing an antimicrobial composition ranges from approximately 45 CFU / ml to 5 × 10⁻⁶. 5 The concentration may be CFU / ml. The target concentration may be set to a specific amount as the number of CFUs per ml of contaminant (e.g., virus, bacteria, amoeba, fungus), or it may be set to the detection limit.

[0210] In certain embodiments, the antimicrobial composition itself is slurried with a water system containing biocontaminants. When the antimicrobial composition, which includes the precious metal and particulate oxide composition, and the water system containing biocontaminants are slurried, it is understood that they come into contact. Although the present invention is not bound by any particular theory, it is believed that by slurring and / or contacting the antimicrobial composition with a water system containing biocontaminants as described above, some, almost all, or all of the biocontaminants contained in the water system containing biocontaminants are removed. After slurring and / or contacting the antimicrobial composition with a water system containing biocontaminants, the slurry is filtered by known solid-liquid separation methods. The antimicrobial compositions and the particulate oxides and precious metals therein used in these methods include all embodiments described above.

[0211] Examples The following examples are provided to illustrate in more detail the trivalent doped cerium oxide composition and the method thereof, but the scope of the present invention is not limited in any way thereto.

[0212] Scanning electron microscope (SEM) images were acquired using a FEG Zeiss ultra 55 (resolution 1 nm). Transmission electron microscope (TEM) images were acquired using an FEI Titan Themis 200 (resolution 0.09 nm). Surface area, pore radius, and pore volume were measured by the BET / BJH method (ASTM D3663-20). Hg porosity and total Hg pore volume were measured using a Micromeritics Autopore IV 9500 system, following the procedure specified in ASTM D4284-07. Grain size was measured using a Microtrac S3500. X-ray diffraction was performed using a Bruker D2 Phaser X-ray diffractometer. Crystallite size was determined by the full width at half maximum. Zeta potential versus pH was measured using a Malvern Panalytical (Zetasizer Nano ZS) ZEN3600 in a procedure similar to ASTM E2865-12 (2018). As those skilled in the art will understand, crystallite size was measured by XRD or TEM and is the size of individual crystals. Dxx size is the size of the particles composed of individual crystallites and is measured by laser diffraction. Temperature-controlled desorption of CO2 was carried out according to the method described by Hakim, A. et al., "Temperature Programmed Desorption of Carbon Dioxide for Activated Carbon supported Nickel Oxide: The Adsorption and Desorption Studies, Advanced Materials Research, Vol. 1087 (2015) pp 45-49". Temperature-controlled reduction of hydrogen was carried out according to the method described by Hurst, NW et al., "Temperature Programmed Reduction. Catalysis Reviews Science and Engineering, 24:2, 233-309".Depth profiling was performed according to the method described by Noel, C. et al., "ToF-SIMS Depth Profiling of Organic Delta Layers with Low-Energy Cesium Ions: Depth Resolution Assessment, Journal of The American Society for Mass Spectrometry, Vol. 30 (2019) pp 1537-1544".

[0213] Example 1 A trivalent-doped cerium oxide composition was prepared by the following method: 68 g (0.297 mol) of lanthanum carbonate and 464 g (2.7 mol) of cerium oxide were mixed with 200 ml of 1.0 mol / L lanthanum nitrate solution. The components were mixed for 2 hours. The mixture was then heated in a furnace at 550°C for 2 hours to obtain 542 g of mixed cerium lanthanum oxide. This contains approximately 15% lanthanum oxide by weight. This composition is also called La-doped cerium oxide.

[0214] SEM images were collected from a sample of the composition and are shown in Figures 1 and 2. These images show a porous material with a certain degree of spherical structure. TEM images were collected from a sample of the composition of Example 1 and are shown in Figures 3 and 4. These images show spherical clusters. Analysis of the sample of the composition of Example 1 for surface area, pore radius, and pore volume yielded a result of 98.332 m². 2 / g(BET), 135.268m 2 The values ​​were / g(BJH), pore radius 3.235 nm, and pore volume 0.248 cc / g. Hg-porosity was measured at 0.21 cc / g, pore size <1 μm was 0.46 cc / g, and total pore volume was 0.96 cc / g. The particle size distribution was measured by the method described above, and the results are D 10 =3.552μm, D 50 =12.1μm, D 90The depth was 43.12 μm. The crystallite size measured by XRD was 9.77 nm. The temperature-controlled desorption profile is shown in Figure 5A. CO2 desorption had three peaks at 172°C, 350°C, and 735°C, indicating both physicoadsorption and chemiadsorption of CO2. H2-TPR is shown in Figure 6, showing a strong peak around 500°C, in stark contrast to the broad peaks shown in Examples 2 and 3. The zeta potential against pH is shown in Figure 7, and the isoelectric point (IEP) was 8.1. LaO against depth + / 140 CeO + The ratio is shown in Figure 8. At shallow depths, LaO + / CeO + It is noteworthy that the ratio is high and approaches a constant value as the depth increases. This indicates that in the material of Example 1, the La concentration is high at and near the surface. The material of Example 1 is one embodiment of trivalent-doped cerium oxide having a unique depth-direction profile.

[0215] Example 2 A trivalent-doped cerium oxide composition was prepared by the following method (also described in U.S. Patent Application No. 17 / 870,068): 129 ml of 1 mol / L Ce(NO3)4 solution was mixed with 24 ml of 1 mol / L La(NO3)3 solution. The resulting solution was refluxed for at least 2 hours. Then, 5.5 mol / L NH4OH was added until the pH reached 10. The resulting solid was filtered and washed with pure water until the conductivity of the washing water was <15 mS / cm. The resulting powder was heated in air in a furnace at 550°C for at least 2 hours to obtain a mixed cerium lanthanum oxide containing approximately 15% lanthanum oxide by weight. This composition is also known as La-doped cerium oxide.

[0216] Figures 10 and 11 are SEM images. These images show a porous material with a certain degree of spherical structure. Figures 12A-12D are TEM images, showing spherical clusters and diffraction planes. The surface area is 120.464 m². 2 / g(BET), 143.087m 2The particle size was / g(BJH), pore radius was 3.245 nm, and pore volume was 0.285 cc / g. The pore volume for pore size <0.1 μm was 0.23 cc / g, the pore volume for pore size <1 μm was 0.45 cc / g, and the total pore volume was 0.99 cc / g. The particle size distribution was measured by the method described above, and the results are D 10 =1.301μm, D 50 = 5.545 μm, D 90 The crystallite size was 13.109 μm. The crystallite size measured by XRD was 9.03 nm. The temperature-controlled desorption profile is shown in Figure 5B. CO2 desorption had one peak at 175°C, indicating only physiadsorption of CO2. The peak at the higher temperature was indistinguishable from the background, and no chemiadsorption of CO2 was detected. H2-TPR is shown in Figure 6, showing a broad peak around 566°C. The zeta potential against pH is shown in Figure 7, and the isoelectric point (IEP) was 7.34.

[0217] LaO for depth + / 140 CeO + The ratio is shown in Figure 8. This material has LaO from the surface to the maximum measurement depth. + / CeO + It is noteworthy that the ratio is almost constant. This indicates that the La concentration is almost the same at the surface and in the deeper layers.

[0218] Example 3 A cerium(IV) oxide composition was prepared by the following method: In a sealed stirring vessel, 1 liter of 0.12 M cerium(IV) ammonium nitrate solution was prepared from cerium(IV) ammonium nitrate crystals dissolved in nitric acid and held at approximately 90°C for approximately 24 hours. In a separate container, 200 ml of 3 M aqueous ammonia solution was prepared and held at room temperature. The two solutions were then mixed and stirred for approximately 1 hour. The resulting precipitate was filtered using a Buchner funnel equipped with filter paper. The resulting solid was thoroughly washed with pure water in a Buchner funnel. After the washing / filtration step, the wet hydrate was calcined in a muffle furnace at approximately 450°C for 3 hours to form a cerium(IV) oxide composition.

[0219] The surface area is 126 m².2 / g(BET), 167m 2 The particle size was / g(BJH), pore radius was 3.62 nm, and pore volume was 0.309 cc / g. The pore volume for pore size <0.1 μm was 0.24 cc / g, the pore volume for pore size <1 μm was 0.35 cc / g, and the total pore volume was 0.85 cc / g. The particle size distribution was measured by the method described above, and the results are D 10 =2μm, D 50 =9μm, D 90 The crystallite size was 25 μm. The crystallite size measured by XRD was 8.43 nm. The temperature-controlled desorption profile is shown in Figure 5C. CO2 desorption had one peak at 175°C, indicating only physiadsorption of CO2. The peak at the higher temperature was indistinguishable from the background, and no chemiadsorption of CO2 was detected. The H2-TPR is shown in Figure 6, showing broad peaks around 500°C and 900°C. The zeta potential against pH is shown in Figure 7, and the isoelectric point (IEP) was 7.22.

[0220] Since this sample contains only Ce, depth profiling was not performed. This sample does not contain trivalent dopants.

[0221] Example 4 A trivalent-doped cerium oxide composition was prepared by the following method: In a sealed stirring vessel, 1 liter of 0.12 M cerium(IV) ammonium nitrate solution was prepared from cerium(IV) ammonium nitrate crystals dissolved in nitric acid. 199.5 g (0.5 mol) of commercially available aluminum nitrate (Al(NO3)3) was added to this solution, and it was held at approximately 90°C for approximately 24 hours. In a separate container, 200 ml of 3 M aqueous ammonia solution was prepared and held at room temperature. The two solutions were then mixed and stirred for approximately 1 hour. The resulting precipitate was filtered using a Buchner funnel equipped with filter paper. The resulting solid was thoroughly washed in a Buchner funnel with pure water. After the washing / filtration step, the wet hydrate was calcined in a muffle furnace at approximately 450°C for 3 hours to form an aluminum cerium(IV) oxide composition. This oxide was suspended in a praseodymium nitrate solution containing praseodymium carbonate. The ratio of Pr to cerium(IV) aluminum oxide was adjusted so that the praseodymium oxide content in the final product was 4%, 8%, 12%, or 20%. The components were mixed for 2 hours. Then, this mixture was heated in a furnace at 550°C for 2 hours to obtain mixed cerium aluminum praseodymium oxide. This composition is also called Pr-doped cerium oxide.

[0222] Next, measure the depth profile of each of these materials, and PrO + versus 140 CeO + The relationship between the ratio and depth is shown in Figure 9. Similar to Example 1, in this case PrO + trivalent pair 140 CeO + The ratio was high at the surface and shallow depths, and approached a constant level as the depth increased. The material of Example 4 is one embodiment of trivalent-doped cerium oxide having a unique depth-direction profile.

[0223] Example 5 A praseodymium-doped cerium oxide composition was prepared by the following method. This method is similar to that of Example 2. 129 ml of 1 M Ce(NO3)4 solution was mixed with 82 ml of 1 M Pr(NO3)3 solution and 63.9 g (0.3 mol) of commercially available aluminum nitrate (Al(NO3)3). The resulting solution was refluxed and held for at least 2 hours. Then, 5.5 M NH4OH was added to adjust the pH to 10. The resulting solid was filtered and washed with pure water until the conductivity of the washing water was <15 mS / cm. The resulting powder was heated in air in a furnace at 550°C for at least 2 hours to obtain mixed cerium aluminum praseodymium oxide. This composition contains approximately 16% Pr oxide by weight and is also called Pr-doped cerium oxide.

[0224] The depth profile was measured, and the data is shown in Figure 9. Similar to Example 2, in this case PrO + versus 140 CeO + The ratio remained nearly constant from the surface to the maximum measurement depth. This indicates that the Pr concentration is approximately the same at the surface and at deeper depths.

[0225] Next, the depth profile data of Examples 1, 2, 4, and 5 were compared. Specifically, the trivalent to Ce ratio (LaO) at a depth of 0 to 3.5 nm was compared. + / CeO + or PrO + / CeO + The average value of ) was calculated. This average value was compared with the same ratio at a depth of 15 nm. Next, the % increase rate was calculated using the following formula. % Increase Rate = {(Average value between 0 and 3.5 nm) - (Ratio at 15 nm)} / (Ratio at 15 nm) × 100 [Table 1]

[0226] Example 6 A silver-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 1 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Next, 542 g of silver nitrate solution containing 1% silver by weight was added to the flask under reduced pressure. Then, 3.10 g of 50% citric acid solution was added to the flask under reduced pressure. The slurry turned metallic silver / gray. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. Furthermore, it was dried in an oven at 90°C until the weight was constant (approximately 30 minutes).

[0227] When a sample of the composition in Example 6 was analyzed for surface area, pore radius, and pore volume, it was found to be 103.184 m². 2 / g(BET), 120.897m 2 The concentration was found to be / g(BJH), with a pore radius of 2.992 nm and a pore volume of 0.206 cc / g. The crystallite size measured by XRD was 10.2 nm. The temperature-programmed desorption profile is shown in Figure 13A, and the desorption of CO2 had three peak temperatures at 172°C, 350°C, and 735°C, indicating both physicoadsorption and chemiadsorption of CO2. The desorption of CO2 was similar to that of Example 1, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0228] Example 7 A silver and ruthenium-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 1 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Then, 542 g of a ruthenium(III) nitrosyl nitrate solution containing 0.09996% ruthenium and 0.00004% silver by weight was added to the flask under reduced pressure. Subsequently, 0.31 g of a 50% citric acid solution was added to the flask under reduced pressure. The slurry turned metallic silver / gray. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. Furthermore, it was dried in an oven at 90°C until the weight stabilized (approximately 30 minutes).

[0229] When a sample of the composition in Example 7 was analyzed for surface area, pore radius, and pore volume, it was found to be 104.323 m². 2 / g(BET), 127.824m 2 The concentration was found to be / g(BJH), with a pore radius of 2.537 nm and a pore volume of 0.232 cc / g. The crystallite size measured by XRD was 10.5 nm. The temperature-programmed desorption profile is shown in Figure 13A, and the desorption of CO2 had three peak temperatures at 172°C, 350°C, and 735°C, indicating both physicoadsorption and chemiadsorption of CO2. The desorption of CO2 was similar to that of Example 1, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0230] Example 8 A silver oxide-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 1 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Then, 542 g of a silver nitrate solution containing 0.1% silver by weight was added to the flask under reduced pressure. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. The powder was further heated at 500°C for 2 hours. The precipitated silver was expected to be silver oxide.

[0231] When a sample of the composition in Example 8 was analyzed for surface area, pore radius, and pore volume, it was found to be 89.964 m². 2 / g(BET), 138.397m 2 The concentration was found to be / g(BJH), with a pore radius of 2.346 nm and a pore volume of 0.299 cc / g. The crystallite size measured by XRD was 11 nm. The temperature-programmed desorption profile is shown in Figure 13A, and the desorption of CO2 had three peak temperatures at 172°C, 350°C, and 735°C, indicating both physicoadsorption and chemiadsorption of CO2. The desorption of CO2 was similar to that of CO2 in Example 1, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0232] Example 9 A ruthenium oxide-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 1 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Then, 542 g of a ruthenium(III) nitrosyl nitrate solution containing 1% by weight of ruthenium was added to the flask under reduced pressure. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. The powder was further heated at 500°C for 2 hours. The precipitated ruthenium was expected to be ruthenium oxide.

[0233] When a sample of the composition in Example 9 was analyzed for surface area, pore radius, and pore volume, it was found to be 98.745 m². 2 / g(BET), 126.338m 2 The values ​​were found to be / g(BJH), pore radius 2.536 nm, and pore volume 0.214 cc / g. The crystallite size measured by XRD was 10.6 nm. The temperature-programmed desorption profile is shown in Figure 13A, and the desorption of CO2 had three peak temperatures at 172°C, 350°C, and 735°C, indicating both physicoadsorption and chemiadsorption of CO2. The desorption of CO2 was similar to that of CO2 in Example 1, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0234] Example 10 A ruthenium-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 2 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Next, 542 g of a ruthenium(III) nitrosyl nitrate solution containing 0.1% ruthenium by weight was added to the flask under reduced pressure. Furthermore, 0.310 g of a 50% citric acid solution by weight was added to the flask under reduced pressure. The slurry turned metallic silver / gray. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. Then, it was further dried in a 90°C oven until the weight stabilized (approximately 30 minutes).

[0235] When a sample of composition Example 10 was analyzed for surface area, pore radius, and pore volume, it was found to be 131.926 m². 2 / g(BET), 167.993m 2 The values ​​were found to be / g(BJH), pore radius 2.988 nm, and pore volume 0.338 cc / g. The crystallite size measured by XRD was 7.7 nm. The temperature-programmed desorption profile is shown in Figure 13B, and CO2 desorption had one peak at 175°C, indicating only physioadsorption of CO2. The CO2 desorption was similar to that of Example 2, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0236] Example 11 A silver ruthenium-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 2 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Next, 542 g of a silver nitrate and ruthenium(III) nitrosyl nitrate solution containing 0.5% silver and 0.5% ruthenium by weight was added to the flask under reduced pressure. Furthermore, 4 g of hydrazine monohydrate was added to the flask under reduced pressure. The slurry turned metallic silver / gray. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. Then, it was further dried in a 90°C oven until the weight stabilized (approximately 30 minutes).

[0237] When a sample of the composition in Example 11 was analyzed for surface area, pore radius, and pore volume, it was found to be 105.810 m². 2 / g(BET), 127.365m 2 The values ​​were found to be / g(BJH), pore radius 2.744 nm, and pore volume 0.212 cc / g. The crystallite size measured by XRD was 10.5 nm. The temperature-programmed desorption profile is shown in Figure 13B, and CO2 desorption had one peak at 175°C, indicating only physioadsorption of CO2. The CO2 desorption was similar to that of Example 2, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0238] Example 12 A silver oxide-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 2 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Then, 542 g of a silver nitrate solution containing 1% silver by weight was added to the flask under reduced pressure. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. The powder was further heated at 500°C for 2 hours. The precipitated silver was expected to be a mixed silver oxide.

[0239] When a sample of composition Example 12 was analyzed for surface area, pore radius, and pore volume, it was found to be 125.703 m². 2 / g(BET), 157.473m 2 The values ​​were found to be / g(BJH), pore radius 2.988 nm, and pore volume 0.293 cc / g. The crystallite size measured by XRD was 7.8 nm. The temperature-programmed desorption profile is shown in Figure 13B, and CO2 desorption had one peak at 175°C, indicating only physioadsorption of CO2. The CO2 desorption was similar to that of Example 2, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0240] Example 13 A ruthenium oxide-doped trivalent dopant cerium oxide composition was prepared by the following method. 542 g of La-doped cerium oxide from Example 2 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Then, 542 g of a ruthenium(III) nitrosyl nitrate solution containing 0.1% ruthenium by weight was added to the flask under reduced pressure. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. The powder was further heated at 500°C for 2 hours. The precipitated ruthenium was expected to be ruthenium oxide.

[0241] When a sample of composition Example 13 was analyzed for surface area, pore radius, and pore volume, it was found to be 130.804 m². 2 / g(BET), 165.211m 2The values ​​were found to be / g(BJH), pore radius 2.999 nm, and pore volume 0.307 cc / g. The crystallite size measured by XRD was 7.7 nm. The temperature-programmed desorption profile is shown in Figure 13B, and CO2 desorption has one peak at 175°C, indicating only physioadsorption of CO2. The CO2 desorption is similar to that of Example 2, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0242] Example 14 A silver-doped cerium(IV) oxide composition was prepared by the following method. 542 g of the cerium(IV) oxide composition from Example 3 was placed in a round-bottom flask on a rotary evaporator, rotated for mixing, and heated to 60°C. Next, 542 g of a silver nitrate solution containing 0.1% silver by weight was added to the flask under reduced pressure. Furthermore, 0.310 g of a 50% citric acid solution by weight was added to the flask under reduced pressure. The slurry turned metallic silver / gray. Rotation, heating, and reduced pressure were maintained until the material became a free-flowing powder. Then, it was further dried in a 90°C oven until the weight stabilized (approximately 30 minutes).

[0243] When a sample of composition Example 14 was analyzed for surface area, pore radius, and pore volume, it was found to be 151.333 m². 2 / g(BET), 198.860m 2 The values ​​were found to be / g(BJH), pore radius 1.892 nm, and pore volume 0.207 cc / g. The crystallite size measured by XRD was 8.5 nm. The temperature-programmed desorption profile is shown in Figure 13C, and CO2 desorption had one peak at 175°C, indicating only physioadsorption of CO2. The CO2 desorption was similar to that of Example 3, and therefore it can be seen that the PGM dopant has only minimal effect on the physical properties of the material.

[0244] Example 15 A ruthenium-doped cerium(IV) oxide composition was prepared by the following method. 542 g of the cerium(IV) oxide composition of Example 3 was placed in a round flask on a rotary evaporator, rotated for mixing, and heated to 60 °C. Then, 542 g of a ruthenium(III) nitrosyl nitrate solution containing 1% ruthenium by weight was added to the flask under reduced pressure. Further, 4 g of hydrazine monohydrate was added to the flask under reduced pressure. The slurry turned metal silver / grey. Rotation, heating and reduced pressure were maintained and the material was processed until it became a free-flowing powder. Thereafter, it was further dried in an oven at 90 °C until the weight became constant (for about 30 minutes).

[0245] When a sample of the Example 15 composition was analyzed for surface area, pore radius and pore volume, it was found to be 150.679 m 2 / g (BET), 189.460 m 2 / g (BJH), pore radius 1.769 nm, pore volume 0.192 cc / g. The crystallite size measured by XRD was 8.3 nm. The temperature-programmed desorption profile is shown in Figure 13C. The desorption of CO2 had one peak at 175 °C and showed only physical adsorption of CO2. The desorption of CO2 was similar to that of CO2 in Example 3, and thus it can be seen that the PGM dopant has only a minimal effect on the physical properties of the material.

[0246] Example 16 A ruthenium oxide-doped cerium(IV) oxide composition was prepared by the following method. 542 g of the cerium(IV) oxide composition of Example 3 was placed in a round flask on a rotary evaporator, rotated for mixing, and heated to 60 °C. Then, 542 g of a ruthenium(III) nitrosyl nitrate solution containing 0.1% ruthenium by weight was added to the flask under reduced pressure. Rotation, heating and reduced pressure were maintained and the material was processed until it became a free-flowing powder. The powder was further heated at 500 °C for 2 hours. The precipitated ruthenium was expected to be ruthenium oxide.

[0247] When a sample of the Example 16 composition was analyzed for surface area, pore radius and pore volume, it was 144.278 m2 / g(BET), 187.392 m 2 / g(BJH), the pore radius was found to be 1.891 nm and the pore volume was 0.199 cc / g. The crystallite size measured by XRD was 8.5 nm. The temperature-programmed desorption profile is shown in Fig. 13C. The desorption of CO2 had one peak at 175 °C, indicating only physical adsorption of CO2. The desorption of CO2 was similar to that of CO2 in Example 3, and thus it can be seen that the PGM dopant has only a minimal impact on the physical properties of the material.

[0248] Example 17 The bactericidal properties of the compositions of Example 3 and Examples 6 - 16 were tested using the ASTM International method E2149. A 1.0 ± 0.1 g amount of the test material was added to 50 ml of a suspension of Staphylococcus aureus ATCC 6538 or Escherichia coli ATCC 8739. The suspensions of these microorganisms were initiated with tryptic soy broth and cultured under conditions that allowed sufficient growth before testing, and then diluted to a target concentration of approximately 2×10 5 CFU / ml (colony-forming units). The inoculated suspension was fixed to a wrist-action shaker and cultured dynamically for 30 minutes. A portion of the test and control suspensions was collected and counted and cultured using standard dilution and plate-spreading techniques. The plates were cultured for 18 - 24 hours under optimal culture conditions for the test microorganisms of interest. [Table 2] [Table 3]

[0249] Table 3 summarizes the logarithmic removal rates of Escherichia coli (E. coli) or Staphylococcus aureus (S. aureus) upon exposure to particulate oxides with 1% PGM (platinum group metal) dispersed on their surface. When cerium oxide from Example 3 was included for comparison, the antimicrobial performance was low. When 1% Ru was supported on the cerium oxide from Example 3 (material from Example 15), the antimicrobial performance improved slightly. When 1% Ru was supported on the material from Example 1 (material from Example 9), the antimicrobial performance improved significantly. When 1% PGM (Ru / Ag split 50 / 50) was supported on the material from Example 2 (material from Example 11), the antimicrobial performance also improved, but this improvement is likely largely due to the presence of Ag. Materials supported with 1% Ag (materials from Examples 12 and 6) showed very high activity, regardless of whether Example 1 or Example 2 was doped with Ag. Therefore, Ag exhibited high antimicrobial activity, and 1% Ag was too active to distinguish the differences between the materials in Example 1 and Example 2. [Table 4]

[0250] The results summarized in Table 4 show the logarithmic removal rates of Escherichia coli (E. coli) or Staphylococcus aureus (S. aureus) upon exposure to particulate oxide particles with 0.1% PGM (platinum group metals) dispersed on their surface. For comparison, when cerium oxide from Example 3 was included, the antimicrobial performance was low. When 0.1% Ru was supported on the cerium oxide from Example 3 (material from Example 16), the antimicrobial performance did not significantly improve. When 0.1% Ru was supported on the material from Example 2 (material from Example 10), the antimicrobial performance improved slightly, and when 0.09996% Ru and 0.00004% Ag (total PGM 0.1%) were supported on the material from Example 1 (material from Example 7), the performance improved significantly. These results indicate that doping with 0.1% Ag is also highly active. When 0.1% Ag was supported on the material of Example 1 (the material of Example 8), it showed higher antimicrobial performance than when 0.1% Ag was supported on the material of Example 3 (the material of Example 14). Therefore, the observed antimicrobial activity was not attributable to the PGM dopant alone. It was expected that 0.1% PGM support would show lower performance than 1% support, and the results were consistent. However, the performance differences when similar PGM support was applied to the particulate oxide materials of Example 1, Example 2, and Example 3 were not expected. When PGM was supported on the material of Example 1, it showed higher antimicrobial performance than the materials of Example 2 or Example 3, which were similarly supported with PGM.

[0251] Example 19 The materials of Example 7 were suspended in pure water, and a binder such as citric acid was added to the water. Next, a substrate such as cotton fabric was immersed in the suspension at least once. After removing the substrate, it was dried. The resulting fabric had a coating of the composition of Example 1 on its surface. This coated fabric was placed on an air filter so that the fabric covered the surface of the air filter and allowed air to pass through the fabric. The filter was installed in an HVAC or indoor air purification unit, and when the unit was operated, air contaminated with coronavirus passed through the filter. Analysis of the air discharged from the unit revealed a decrease in coronavirus concentration.

[0252] Example 20 Polyethylene granules or powder were mechanically mixed with the material of Example 7 until the material of Example 7 constituted approximately 1% by weight. This mixture was placed in a heating chamber to form an end-use article, such as a bottle. The surface of the bottle formed from polyethylene containing the material of Example 7 was exposed to Escherichia coli (E. coli) to test for antimicrobial or bacteriostatic properties. Subsequent surface analysis revealed fewer E. coli colony-forming units compared to the control. Furthermore, pasteurized milk was placed in the formed bottles, and the time until the milk spoiled was observed. Compared to polyethylene bottles without the material of Example 1, the time until the milk spoiled was extended.

[0253] Unless otherwise specified, all numerical values ​​representing the quantities, molecular weights, and other properties of the components used in this specification and claims, as well as reaction conditions, are understood to be modified by the word "approximately." Therefore, unless otherwise stated, the numerical parameters described in the following specification and the attached claims are approximations that vary depending on the desired properties.

[0254] While the numerical ranges and parameters defining the broad scope of the technology are approximations, the values ​​described in specific examples are reported as accurately as possible. However, any values ​​inevitably include errors arising from the standard deviation associated with the measurement.

[0255] It is clear that the compositions and methods described herein are suitable for achieving the advantages and essential benefits mentioned. Those skilled in the art will understand that the methods and systems described herein can be implemented in a variety of embodiments and are therefore not limited to the examples described herein. In this regard, some features of the different embodiments described herein can be combined into one embodiment, and fewer or more alternative embodiments having all the features described herein are also possible.

[0256] While various embodiments have been described for the purposes of the present invention, various changes and modifications are possible within the scope envisioned in the present invention. Numerous other modifications that are obvious to those skilled in the art and that are included in the spirit of the present invention can be readily conceived.

Claims

1. An antibacterial composition characterized by comprising the following: (a) A particulate oxide composition comprising approximately 99.95% by mass to approximately 50% by mass, the particulate oxide composition comprising the following: Cerium oxide; A trivalent dopant selected from the group consisting of yttrium (Y), lanthanum (La), neodymium (Nd), praseodymium (Pr), and mixtures thereof; and Optionally, additional oxides selected from the group consisting of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), silicon (Si), and mixtures thereof; Here, cerium oxide is present in greater quantities than trivalent dopant, and the average trivalent dopant / cerium ratio from approximately 0 nm to approximately 3.5 nm from the surface of the particulate oxide composition is greater than the trivalent dopant / cerium ratio from approximately 15 nm from the surface of the particulate oxide composition; and (b) A noble metal dispersed on the surface of a particulate oxide composition, selected from the group consisting of copper (Cu), nickel (Ni), silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), gold (Au), osmium (Os), rhodium (Rh), and mixtures thereof.

2. The antimicrobial composition according to claim 1, wherein the precious metal is present in an amount of about 0.05% to about 25% by mass based on the total weight of the antimicrobial composition.

3. The antimicrobial composition according to claim 1 or 2, wherein the precious metal is present in an amount of about 0.05% to about 10% by mass based on the total weight of the antimicrobial composition.

4. The antimicrobial composition according to claim 3, wherein the aforementioned precious metal is present in an amount of about 0.05% to about 8% by mass based on the total weight of the antimicrobial composition.

5. The antimicrobial composition according to any one of claims 1 to 4, wherein the precious metal is silver (Ag), palladium (Pd), platinum (Pt), ruthenium (Ru), or a mixture thereof.

6. The antimicrobial composition according to claim 5, wherein the precious metal is silver (Ag), ruthenium (Ru), or a mixture thereof.

7. The antimicrobial composition according to claim 6, wherein the aforementioned precious metal is silver (Ag) and is present in an amount of about 0.05% to about 0.3% by mass based on the total weight of the antimicrobial composition.

8. The antimicrobial composition according to claim 6, wherein the noble metal is ruthenium (Ru) and is present in an amount of about 0.05% to about 5% by mass based on the total weight of the antimicrobial composition.

9. The antimicrobial composition according to any one of claims 1 to 8, wherein the noble metal is dispersed on the surface of the particulate oxide composition as a metal or as an oxide.

10. The antimicrobial composition according to any one of claims 1 to 9, wherein the particulate oxide composition comprises the following: Approximately 99.9% to 20% by mass of cerium oxide based on the total weight of the particulate oxide composition; A trivalent dopant in an amount of approximately 0.1% to approximately 50% by mass based on the total weight of the particulate oxide composition; and Approximately 70% to 0% by mass of additional oxides based on the total weight of the particulate oxide composition.

11. The antimicrobial composition according to any one of claims 1 to 9, wherein the particulate oxide composition comprises the following: Approximately 20% to 30% by mass of cerium oxide based on the total weight of the particulate oxide composition; A trivalent dopant in an amount of approximately 2% to 25% by mass based on the total weight of the particulate oxide composition; and An additional oxide of approximately 45% to 78% by mass, based on the total weight of the particulate oxide composition.

12. The antimicrobial composition according to any one of claims 1 to 9, wherein the particulate oxide composition comprises the following: Approximately 45% to 78% by mass of cerium oxide based on the total weight of the particulate oxide composition; A trivalent dopant in an amount of approximately 2% to 25% by mass based on the total weight of the particulate oxide composition; and An additional metal oxide of approximately 20% to 30% by mass, based on the total weight of the particulate oxide composition.

13. The antimicrobial composition according to claim 1 or 2, wherein the average trivalent dopant / cerium ratio at approximately 0 nm to approximately 3.5 nm from the surface of the microparticle oxide composition is approximately 10% to approximately 250% greater than the trivalent dopant / cerium ratio at approximately 15 nm from the surface of the microparticle oxide composition.

14. The antimicrobial composition according to claim 1, wherein the noble metal is present in an amount of about 0.05% to about 10% by mass based on the total weight of the antimicrobial composition, and the particulate oxide composition contains about 2% to about 30% by mass of a trivalent dopant.

15. A supported composition for removing biological contaminants, comprising the following: Support materials comprising organic polymers, cotton, glass fibers, or mixtures thereof; and The antimicrobial composition according to claim 1 or 2; Here, the antibacterial composition is a supported composition that is supported on or within the support material.

16. The support material is an organic polymer, and the organic polymer is selected from the group consisting of polyethylene, polyvinyl chloride, nylon, polypropylene, polyester, polyurethane, polyamide, polyolefin, polycarbonate, copolymers thereof, and mixtures thereof, as described in claim 15.

17. The support material is cotton, according to claim 15.

18. The supported composition according to claim 15, wherein the supported composition comprises about 0.5% by mass to about 80% by mass of an antimicrobial composition based on the total weight of the supported composition.

19. The supported composition according to claim 15, wherein the supported composition is a filter material or a plastic.

20. A method for removing biological contaminants, characterized by comprising the following: A step of providing the antimicrobial composition according to claim 1 or 2; The steps of bringing the composition into contact with a biological contaminant selected from the group consisting of bacteria, viruses, protozoa, fungi, and mixtures thereof; and A step of removing at least about 90% of the biological contaminants through contact with the composition.

21. The method according to claim 20, wherein the antibacterial composition is contained in a filter material or plastic.

22. The method according to claim 20, wherein the antimicrobial composition is supported on or within a support material comprising an organic polymer, cotton, glass fiber, or a mixture thereof.

23. The method according to claim 20, wherein the antimicrobial composition removes approximately 99% or more of biological contaminants.

24. The method according to claim 20, wherein the biocontaminant is present in a water system flow, a gas flow, or a mixture thereof.

25. The method according to claim 20, wherein the contact is made via solid contact with an article containing an antimicrobial composition.

26. The method according to claim 20, further comprising the steps of setting a target biocontaminant concentration and monitoring the biocontaminant after contact.

27. A plastic article comprising the following: (a) A supported composition for removing biological contaminants, comprising the following: Organic polymers selected from the group consisting of polyethylene, polyvinyl chloride, nylon, polypropylene, polyester, polyurethane, polyamide, polyolefin, polycarbonate, copolymers thereof and mixtures thereof; and The antimicrobial composition according to claim 1 or 2; Here, in the supported composition, the antimicrobial composition is supported on or within the organic polymer; and The aforementioned plastic article is a plastic article that contains, based on the total weight of the plastic article, about 50% to about 100% by mass of a supported composition that removes biological contaminants.

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