阅读说明：本技术 包含纳米晶体纤维素和氧化镁的抗微生物涂层材料及其制备方法 (Antimicrobial coating material comprising nanocrystalline cellulose and magnesium oxide and method of making the same ) 是由 以斯拉·哈努卡 C·左尔科夫 尤瓦尔·尼沃 克拉里特·阿泽尔拉夫 于 2018-07-30 设计创作，主要内容包括：一种无毒的抗微生物化学捕集器,其包括膜,该膜包括抗微生物层,该抗微生物层包含纳米晶体纤维素(NCC)和选自MgO和Mg(OH)<Sub>2</Sub>所组成的组的抗微生物物质。在一些实施方案中,所述抗微生物捕集器在所述抗微生物层之上或之下包括至少一个附加的NCC层。本申请公开了制备所述抗微生物化学捕集器的方法和由此包被的制品,以及还公开了通过使用所述抗微生物化学捕集器控制微生物种群的方法。(A non-toxic antimicrobial chemical trap comprising a membrane comprising an antimicrobial layer comprising nanocrystalline cellulose (NCC) and a metal selected from MgO and Mg (OH) 2 An antimicrobial substance of the group. In some embodiments, the antimicrobial trap comprises at least one additional NCC layer above or below the antimicrobial layer. The application discloses the preparation of the antimicrobial chemistryMethods of traps and articles coated thereby, and methods of controlling microbial populations by using the antimicrobial chemical traps are also disclosed.)

1. An antimicrobial chemical trap, wherein the antimicrobial chemical trap comprises a film characterized by an upper surface and a lower surface, the film comprising an antimicrobial layer comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH)₂Particles of an antimicrobial material in the group consisting of mixtures thereof and combinations thereof, said particles being at least partially embedded within said film.

2. The antimicrobial chemical trap according to claim 1 wherein the antimicrobial substance particles are at least partially coated with NCC.

3. The antimicrobial chemical trap of claim 1, wherein the antimicrobial substance particles are at least partially exposed on the upper surface.

4. The antimicrobial chemical trap of claim 1, wherein at least a portion of the particles are arranged such that microorganisms in contact with the upper surface will come into contact with the particles.

5. The antimicrobial chemical trap of claim 1, wherein the membrane is characterized by a thickness between 0.5 μ ι η and 10 μ ι η.

6. The antimicrobial chemical trap of claim 1, wherein the antimicrobial substance comprises nanoparticles.

7. The antimicrobial chemical trap of claim 1, wherein the antimicrobial substance comprises particles characterized by a median diameter between 0.5 μ ι η and 10 μ ι η.

8. The antimicrobial trap of claim 1, wherein the membrane comprises at least one additive.

9. The antimicrobial trap of claim 8, wherein the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

10. The antimicrobial chemical trap of claim 1, comprising an NCC layer in contact with the lower surface, the NCC layer comprising NCC but no MgO or Mg (OH)₂。

11. The antimicrobial chemical trap of claim 10, wherein the NCC layer comprises at least one additive.

12. The antimicrobial chemical trap of claim 11, wherein the at least one additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

13. The antimicrobial chemical trap of claim 1, comprising a thin upper NCC layer in contact with the upper surface, the thin upper NCC layer comprising NCC but not comprising MgO or Mg (OH)₂。

14. The antimicrobial chemical trap according to claim 1 wherein said membrane comprises between 1% to 50% by weight of said antimicrobial substance.

15. The antimicrobial chemical trap of claim 14, wherein the membrane comprises between 10% to 20% by weight of the antimicrobial substance.

16. A method of controlling a microbial population, wherein the method comprises:

Obtaining an antimicrobial chemical trap according to any one of claims 1 to 15;

and the number of the first and second groups,

exposing a collection of microorganisms to the upper surface of the antimicrobial trap, thereby exposing the microorganisms to antimicrobial activity produced by the antimicrobial substance.

17. The method of claim 16, wherein the method comprises controlling a population of at least one microorganism selected from the group consisting of: escherichia coli, staphylococcus aureus, pseudomonas aeruginosa, salmonella, and listeria.

18. A method of producing an antimicrobial article, wherein the method comprises:

dispersing a first suspension on a substrate, the first suspension comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH)₂An antimicrobial substance from the group consisting of mixtures thereof and combinations thereof, thereby producing an antimicrobial layer comprising an upper surface and a lower surface, wherein the antimicrobial substance is at least partially embedded within the antimicrobial layer; and the number of the first and second groups,

drying the antimicrobial layer.

19. The method of claim 18, wherein the first suspension comprises at least one additive.

20. The method of claim 19, wherein the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

21. The method of claim 18, comprising:

dispersing a cellulose dispersion comprising nanocrystalline cellulose (NCC) but not MgO or Mg (OH)₂On said substrate, thereby producing a layer of NCC; and the number of the first and second groups,

drying the NCC layer;

wherein the step of dispersing the first suspension comprises dispersing the first suspension onto the NCC layer.

22. The method of claim 21, wherein at least one of the first suspension and the second suspension comprises at least one additive.

23. The method of claim 21, wherein the step of dispersing the first suspension is performed after the step of drying the NCC layer.

24. The method of claim 18, comprising dispersing a thin upper NCC layer on the upper surface, the thin upper NCC layer comprising NCC but not MgO or Mg (OH)₂。

25. The method of claim 18, wherein the substrate is not cationic.

26. The method of claim 18, wherein the antimicrobial substance is in the form of nanoparticles.

27. The method of claim 18, wherein the antimicrobial substance comprises particles having median diameters of 1 μ ι η and 10 μ ι η.

28. The method according to claim 18, wherein the first suspension comprises between 0.1% and 15% NCC (weight/volume).

29. The method according to claim 21, wherein at least one of the first suspension and the second suspension comprises between 0.1% and 3% NCC (weight/volume).

30. The method of claim 18, wherein the first suspension comprises a mixture of: 100 to 40: 100 (weight/weight) of the antimicrobial substance and NCC.

31. The method according to claim 18, wherein the first suspension comprises between 1% and 2% NCC (weight/volume) and the ratio of the antimicrobial substance and the NCC is between 10: 100 to 20: 100 (weight/weight).

32. The method of claim 18, comprising pretreating the substrate prior to the step of dispersing the first suspension.

33. The method of claim 18, wherein the antimicrobial substance is not located between the antimicrobial layer and the substrate.

34. The method of claim 18, wherein the substrate is selected from the group consisting of glass, polymers, hybrid materials, biomaterials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum, wood, surfaces of food, and any combination thereof.

35. The method of claim 18, wherein the dispersing step comprises dispersing the first suspension to produce an antimicrobial layer having a thickness between 0.5 μ ι η and 10 μ ι η.

36. A method for applying an antimicrobial chemical trap to a substrate, comprising:

dispersing a first suspension on the substrate, the first suspension comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH)₂An antimicrobial substance from the group consisting of mixtures thereof and combinations thereof, thereby producing an antimicrobial chemical trap comprising an antimicrobial layer; and the number of the first and second groups,

drying the antimicrobial layer.

37. The method of claim 36, wherein the dispersing step is preceded by:

will contain NCC but not MgO or Mg (OH)₂To the substrate, thereby producing a NCC layer; and the number of the first and second groups,

drying the NCC layer.

38. The method of claim 36, wherein the antimicrobial substance is in a form selected from the group consisting of nanoparticles, microparticles, mixtures thereof, and combinations thereof.

39. The method of claim 36, wherein the first suspension comprises at least one additive.

40. The method of claim 39, wherein the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

41. The method of claim 36, wherein the substrate is not cationic.

42. The method according to claim 36, wherein the first suspension comprises between 0.1% and 15% NCC (weight/volume).

43. The method according to claim 37, wherein at least one of the first suspension and the second suspension comprises between 0.1% and 3% NCC (weight/volume).

44. The method of claim 37, wherein at least one of the first suspensions comprises at least one additive.

45. The method of claim 36, wherein the first suspension comprises a mixture of water and a solvent in a ratio of 10: 100 to 20: between 100 (weight/weight) of the antimicrobial substance and NCC.

46. The method of claim 36, wherein the first suspension comprises between 1% and 2% NCC (weight/volume) and the ratio of the first substance and the NCC is between 10: 100 to 20: 100 (weight/volume).

47. The method of claim 36, comprising pretreating the substrate prior to the step of dispersing the first suspension.

48. The method of claim 36, wherein the substrate is selected from the group consisting of glass, polymers, hybrid materials, biomaterials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum, wood, food surfaces, and any combination thereof.

49. The method of claim 36, wherein the dispersing step comprises dispersing the first suspension to produce an antimicrobial layer having a thickness between 0.5 μ ι η and 10 μ ι η.

50. The method of claim 36, wherein the method does not include any step of dispersing the antimicrobial substance between the antimicrobial layer and the substrate.

51. An article comprising an antimicrobial coating, the article comprising:

a substrate; and the number of the first and second groups,

An antimicrobial chemical trap comprising a film characterized by an antimicrobial layer on an upper and lower surface, said antimicrobial chemical trap comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH) embedded within said film₂An antimicrobial substance in the group consisting of mixtures thereof and combinations thereof, said film being disposed on at least one surface of said substrate such that said lower surface is in contact with said substrate.

52. The article of claim 51, wherein the antimicrobial layer comprises at least one additive.

53. The article of claim 52, wherein the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

54. The article of claim 51, wherein said antimicrobial chemical trap comprises NCC but does not comprise MgO or Mg (OH)₂The layer of NCC disposed between the substrate and the antimicrobial layer.

55. The article of claim 51, wherein said antimicrobial chemical trap comprises a thin NCC-containing but not MgO or Mg (OH)₂The upper NCC layer disposed on the upper surface.

56. The article of claim 51, wherein the substrate is not cationic.

57. The article of any one of claims 51-56, wherein the antimicrobial substance is in a form selected from the group consisting of nanoparticles, microparticles, mixtures thereof, and combinations thereof.

58. The article of any of claims 51-56, wherein the antimicrobial chemical trap comprises a ratio of between 10: 100 to 20: between 100 (weight/weight) of the antimicrobial substance and NCC.

59. The article of any one of claims 51-56, wherein the substrate is selected from the group consisting of glass, polymers, hybrid materials, biomaterials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum, wood, food surfaces, and any combination thereof.

60. The article of any one of claims 51-56, wherein the substrate comprises at least one surface that is pre-treated to induce, allow, or accelerate the association of the surface with the layer.

61. The article of any one of claims 51-56, wherein the antimicrobial layer is characterized by a thickness of between 0.5 μm and 10 μm.

62. The article according to claim 54, wherein the layer comprising NCC is characterized by a thickness in the range of 0.5 μm to 10 μm.

63. The article of claim 51, produced according to the method of any one of claims 18-20, 24-28, or 30-35.

64. The article of claim 54, produced according to the method of any one of claims 21-23 or 29.

65. The article of any one of claims 51-56, wherein the article is selected from the group consisting of a cloth, a package, a container, a product for packaging and containing food, a wall coating, a work surface coating, a shelf coating, and a countertop coating.

66. An article comprising a substrate coated with an antimicrobial coating, wherein the antimicrobial coating is applied to the substrate according to the method of any one of claims 36-39.

67. A method for controlling a microbial population, the method comprising exposing a microbial population to the antimicrobial layer of the article of any one of claims 51-56.

68. A method of controlling a microbial population, the method comprising:

dispersing a first suspension on a substrate, the first suspension comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH) ₂An antimicrobial substance, mixtures thereof, and combinations thereof, thereby creating an antimicrobial layer characterized by an upper surface and a lower surface, such that the antimicrobial substance is disposed sufficiently close to the upper surface such that microorganisms impinging on the upper surface will be exposed to antimicrobial activity from the antimicrobial substance.

Drying the antimicrobial layer; and the number of the first and second groups,

placing the antimicrobial layer in a position such that the upper surface is accessible to microorganisms.

69. The method of claim 68, the method comprising:

dispersing a cellulose dispersion comprising nanocrystalline cellulose (NCC) but not MgO or Mg (OH)₂On said substrate, thereby producing a layer of NCC; and the number of the first and second groups,

drying the NCC layer;

wherein the step of dispersing the first suspension comprises dispersing the first suspension onto the NCC layer.

70. The method of any one of claims 68 or 69, comprising the step of exposing a collection of microorganisms to the antimicrobial layer.

71. The method of any one of claims 68 or 69, wherein the method comprises controlling a population of at least one microorganism selected from the group consisting of: escherichia coli, staphylococcus aureus, pseudomonas aeruginosa, salmonella, and listeria.

Technical Field

The present invention relates generally to antimicrobial coatings and films and articles comprising the coatings. The invention relates in particular to antimicrobial coatings and films made of nanocrystalline cellulose doped with magnesium oxide or magnesium hydroxide, to articles comprising at least one surface coated with said coating, and to methods for applying said coatings and for producing said articles.

Background

Bacterial resistance to antibiotics has become a significant problem. Much effort has been expended to find alternative methods of controlling bacteria.

Magnesium oxide is known to have antimicrobial properties. It is believed that MgO catalyzes the formation of reactive oxygen species (peroxides) in an aqueous environment, and these reactive oxygen species kill microorganisms in contact therewith.

Various articles incorporating MgO as an antimicrobial substance are known in the art. For example, U.S. Pat. No. 9315937A method for producing an antimicrobial fabric by sonochemical incorporation of MgO is disclosed. Sanuja et al (Int.J.Polym.Mater.Polym.Biomate.) -2014, 63,733 reported the preparation of clove oil-containing chitosan-magnesia based nanocomposite membranes by solution casting method. Zheng et al (university of Nanchang, Korea edition 2007, 29, 315; CA 152: 121924) have disclosed a precipitation method for extracting Na from₂CO₃And MgCl₂nano-MgO coating was initially prepared and calcined to obtain nano-particulate MgO.

Nanocrystalline cellulose (NCC) is a form of cellulose obtained under controlled conditions, resulting in the formation of high purity single crystals. These crystals exhibit extremely high mechanical strength, corresponding to the bonding of adjacent atoms. The Young's modulus of NCC is about 100-150 GPa, the tensile strength is about 10GPa, the value is similar to that of materials such as aramid fibers (Kevlar) and carbon fibers, and the surface area is about several hundred meters ²(ii) in terms of/g. These properties make NCC an attractive material for many applications. U.S. patent application publication No. 2015/00017432 discloses a method of making a coating comprising nanocrystalline cellulose, into which nanoparticles have been incorporated. This method requires that the substrate surface on which the coating is applied is positively charged in order to fix the coating in place by electrostatic interaction and to place the nanoparticles between the NCC layer and the substrate surface.

International patent application (PCT) publication No. WO2017/199252 discloses a modified NCC film in which properties such as hygroscopicity can be adjusted by adding one or more of a moisture-absorbing material, an OH-rich material such as an organic compound containing three or more OH groups, and a crosslinking agent.

As will be understood by those skilled in the art, it is not straightforward to control the position of particles, such as nanoparticles or microparticles, within or on the surface region of a material film that serves as a matrix for holding the particles. In many cases, in order to ensure a predetermined or partial exposure of the particles above the surface area, the thickness of the film of material must be limited, or the concentration of the particles must be increased to press the particles against the surface of the film. Although other methods may be used to ensure at least partial exposure, it has been found that reproducibility, particle distribution, and uniformity of the film are limited.

In the case where the surface activity is closely dependent on the surface density of the reactive functional groups, i.e. the activity increases with increasing surface functional groups, for example in the case of antimicrobial surfaces, and the degree of surface exposure of such functional groups is dependent inter alia on the processing conditions and material selection, this creates a technical need to minimize the impact or dependence on at least some of the processing conditions, thereby achieving activity independent of process constraints.

All the methods known in the art for the preparation of antimicrobial coatings incorporating MgO as active ingredient suffer from significant drawbacks, such as limited range of use or expensive or difficult preparation. Thus, a simple general method for producing robust and stable antimicrobial coatings has long been desired, but is still not met.

Disclosure of Invention

The present invention is designed to meet this need. The inventors of the present invention disclosed herein have developed a unique and innovative antimicrobial film comprising NCC as a substance known to have antimicrobial properties magnesium oxide (MgO) and/or magnesium hydroxide (Mg (OH)₂) The particles of a matrix material of (1). The inventors have found that no significant antimicrobial activity (i.e., no significant reduction in microbial population or reduction in growth rate of microbial population) is observed for MgO films in which the substrate is made of a polymer, such as polyethylene. In contrast, the MgO film of the matrix in which NCC is included not only shows significant antibacterial activity, but the film also maintains its antimicrobial properties without being constrained by any processing method and processing conditions. In some embodiments, the film retains its antimicrobial activity even if the antimicrobial particles are embedded in, contained in, or coated by the matrix material with limited or no direct exposure of the antimicrobial material on the surface of the film. In some embodiments, the film does not comprise any OH-rich material (OH-rich material) ). In some embodiments, the membrane does not comprise any crosslinking agent.

The inventors of the present invention have found that a catalyst comprising MgO or Mg (OH)₂And nanocrystalline cellulose or from MgO or Mg (OH)₂And nanocrystalline cellulose, to a variety of substrates, and can use a single general application of these films to coat all of these different substrates. An improved method of making an antimicrobial article comprising a substrate and a composition comprising nanocrystalline cellulose and MgO and/or Mg (OH)₂Or from a substrate and a coating comprising nanocrystalline cellulose and MgO and/or Mg (OH)₂The antimicrobial coating composition of (a); and an antimicrobial article comprising a substrate having dispersed on at least one surface thereof a composition comprising nanocrystalline cellulose and MgO and/or Mg (OH)₂The antimicrobial coating of (a); and methods of controlling a microbial population by exposing the microorganisms to an article of the invention.

It is therefore an object of the present invention to disclose an antimicrobial chemical trap, said trap comprising or consisting of a membrane characterized by an upper surface and a lower surface, said membrane comprising or consisting of: (a) an antimicrobial layer comprising nanocrystalline cellulose (NCC) and (b) a material selected from the group consisting of MgO, Mg (OH) ₂Particles of an antimicrobial substance in the group consisting of mixtures thereof and combinations thereof, said particles being at least partially embedded within said film. It is an object of the present invention to disclose an antimicrobial film characterized by an upper surface and a lower surface, said film comprising or consisting of: (a) an antimicrobial layer comprising nanocrystalline cellulose (NCC) and (b) a material selected from the group consisting of MgO, Mg (OH)₂Particles of an antimicrobial material in the group consisting of mixtures thereof and combinations thereof, said particles being at least partially embedded within said film. In some preferred embodiments of the invention, it does not contain any non-toxic substances. In some preferred embodiments of the invention, it does not contain any OH-rich material. In some preferred aspects of the inventionIn embodiments, it does not contain any crosslinking agent or catalyst or any product of the crosslinking reaction.

It is a further object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein said antimicrobial substance particles are at least partially coated with NCC.

It is a further object of this invention to disclose the antimicrobial chemical trap or membrane as defined above, wherein particles of said antimicrobial substance are at least partially exposed on said upper surface.

It is a further object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein said antimicrobial substance particles are at least partially coated with NCC.

It is a further object of this invention to disclose the antimicrobial chemical trap or membrane as defined above, wherein at least a portion of said particles are arranged such that microorganisms in contact with said upper surface will be in contact with said particles.

It is a further object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein said antimicrobial substance particles are at least partially coated with NCC.

It is another object of the current invention to disclose the antimicrobial chemical trap or membrane as defined above, wherein the membrane is characterized by a thickness between 0.5 μm and 10 μm.

It is a further object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein said antimicrobial substance particles are at least partially coated with NCC.

It is another object of the present invention to disclose the antimicrobial chemical trap or membrane as defined above, wherein the antimicrobial substance comprises particles selected from the group consisting of nanoparticles (nanoparticles), microparticles (microparticles), mixtures thereof and combinations thereof.

It is a further object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein said antimicrobial substance particles are at least partially coated with NCC.

It is a further object of this invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein the antimicrobial substance comprises particles characterized by a median diameter between 0.5 μm and 10 μm.

It is a further object of this invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein said membrane comprises at least one additive. In some embodiments of the invention, the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

It is another object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, comprising an NCC layer in contact with said lower surface, said NCC layer comprising NCC but not MgO or mg (oh)₂. In some embodiments of the invention, the NCC layer comprises at least one additive. In some preferred embodiments of the present invention, the at least one additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives and inert fillers.

It is another object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, comprising a thin upper NCC layer in contact with said upper surface, said thin upper NCC layer comprising NCC but not MgO or mg (oh)₂。

It is a further object of the present invention to disclose the antimicrobial chemical trap or membrane as defined in any of the above, wherein said membrane comprises between 1% and 50% by weight of said antimicrobial substance. In some preferred embodiments of the invention, the film comprises between 10% and 40% by weight of the antimicrobial substance. In some preferred embodiments of the invention, the film comprises between 10% and 20% by weight of the antimicrobial substance. In some preferred embodiments of the invention, the film comprises between 20% and 40% by weight of the antimicrobial substance.

In some embodiments, the NCC comprises a cellulose nanomaterial made into particles (e.g., fibrils, or otherwise as a crystalline material) from cellulose selected from a variety of sources at least about 100nm long. In other embodiments, the length of the particles is at most about 1000 microns. In other embodiments, the nanoparticles are between about 100nm and 1000 microns in length, between about 100nm and 900 microns in length, between about 100nm and 600 microns in length, or between about 100nm and 500 microns in length. In some embodiments, the NCC nanoparticles are between about 100nm and 1,000nm in length, between about 100nm and 900nm in length, between about 100nm and 800nm in length, between about 100nm and 600nm in length, between about 100nm and 500nm in length, between about 100nm and 400nm in length, between about 100nm and 300nm in length, or between about 100nm and 200nm in length.

The films disclosed herein are typically coatings of transparent, non-toxic materials formed directly on a surface region of a substrate material or article or directly on at least one preformed layer of material disposed between the surface of the substrate or article and the film. The thickness of the film can be adjusted to meet any desired characteristics, which properties depend, inter alia, on the method of application, the composition of the film, the concentration of the antimicrobial substance and the use of the article. Typically, the thickness of the film is between 0.5 μm and 10 μm. In some embodiments, the thickness is between 0.5 μm to 1 μm, between 0.5 μm to 2 μm, between 0.5 μm to 3 μm, between 0.5 μm to 4 μm, between 0.5 μm to 5 μm, between 0.5 μm to 6 μm, between 0.5 μm to 7 μm, between 0.5 μm to 8 μm, between 0.5 μm to 9 μm, between 1 μm to 10 μm, between 2 μm to 10 μm, between 3 μm to 10 μm, between 4 μm to 10 μm, between 5 μm to 10 μm, between 6 μm to 10 μm, between 7 μm to 10 μm, between 8 μm to 10 μm, or between 9 μm to 10 μm.

Antimicrobial substances (MgO or Mg (OH)₂) May also differ in the matrix material. In some embodiments, the film comprises between 1% to 50% (w/w) antimicrobial substance. In some embodiments, the film comprises (w /) between 1% and 45%, between 1% and 40%, between 1% and 35%, between 1% and 30%, between 1% and 25%, between 1% and 20% % of an antimicrobial substance, between 1% and 15%, between 1% and 10%, between 1% and 5%, between 5% and 50%, between 10% and 50%, between 15% and 50%, between 20% and 50%, between 25% and 50%, between 30% and 50%, between 35% and 50%, between 40% and 50%, between 45% and 50%, between 10% and 45%, between 10% and 40%, between 10% and 35%, between 10% and 30%, between 10% and 25%, between 10% and 20% or between 10% and 15%.

In some embodiments of the invention, antimicrobial substances (MgO and/or Mg (OH))₂) In the form of nanoparticles. In some embodiments of the invention, the nanoparticles are characterized by a size (dimension) between 1nm and 10nm, between 10nm and 20nm, between 20nm and 30nm, between 30nm and 40nm, between 40nm and 50nm, between 50nm and 60nm, between 60nm and 70nm, between 70nm and 80nm, between 80nm and 90nm, between 90nm and 100nm, between 100nm and 150nm, between 150nm and 200nm, between 250nm and 300nm, between 300nm and 350nm, between 350nm and 400nm, between 400nm and 450nm, between 450nm and 500nm, between 550nm and 600nm, between 600nm and 650nm, between 650nm and 700nm, between 700nm and 750nm, between 750nm and 800nm, between 800nm and 850nm, between 850nm and 900nm, between 900nm and 950nm or between 950nm and 999 nm.

In some embodiments of the invention, antimicrobial substances (MgO and/or Mg (OH))₂) In particulate form. In some embodiments, the microparticle is characterized by a size between 1 μm and 10 μm, between 10 μm and 20 μm, between 20 μm and 30 μm, between 30 μm and 40 μm, between 40 μm and 50 μm, between 50 μm and 60 μm, between 60 μm and 70 μm, between 70 μm and 80 μm, between 80 μm and 90 μm, between 90 μm and 100 μm, between 100 and 150 μm, between 150 and 200 μm, between 250 and 300 μm, between 300 and 350 μm, between 350 and 400 μm, between 400 and 450 μm, or between 450 and 500 μm.

In some embodiments of the invention, the anti-microbial agent is selected from the group consisting of a surfactant, aBiological substances (MgO and/or Mg (OH)₂) In the form of a mixture and/or combination of nanoparticles and microparticles. In some embodiments, the mixture and/or combination includes nanoparticles (nanoparticles) having a size selected from one or more of the embodiments listed above and microparticles (microparticles) having a size selected from one or more of the embodiments listed above.

In some embodiments, the antimicrobial substance comprises a mixture of at least one particle or material population (material). As non-limiting illustrative examples, the antimicrobial substance may include a mixture of particles of different sizes, MgO particles and Mg (OH) ₂Mixture of particles, MgO particles and Mg (OH)₂MgO particles and Mg (OH) having different particle sizes and/or size distributions₂Mixtures of particles, and the like.

It is another object of the present invention to disclose a method for producing an antimicrobial article, comprising or consisting of the steps of: (a) dispersing a first suspension on the substrate, the first suspension comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH)₂A mixture thereof and a combination thereof or a mixture of nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH)₂A mixture thereof, and a combination thereof, thereby producing an antimicrobial layer comprising an upper surface and a lower surface, wherein the antimicrobial material is at least partially embedded within the antimicrobial layer; and drying the antimicrobial layer. In a preferred embodiment of the invention, the method does not comprise any step involving crosslinking or the use of a crosslinking agent. In a preferred embodiment of the invention, the first suspension does not comprise any OH-rich material. In a preferred embodiment of the invention, the first suspension does not comprise any non-toxic components.

It is another object of the present invention to disclose a method for producing an antimicrobial article, wherein said first suspension comprises at least one additive. In some preferred embodiments of the present invention, the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

It is another object of this invention to disclose such a method for producing an antimicrobial article, which method further comprises: (a) dispersing on the substrate a nano-crystalline cellulose (NCC) containing but not MgO or Mg (OH)₂Thereby producing a layer of NCC; and, (b) drying the NCC layer; wherein the step of dispersing the first suspension comprises dispersing the first suspension onto the NCC layer. In some preferred embodiments of the invention, at least one of the first suspension and the second suspension comprises at least one additive. In some preferred embodiments of the present invention, the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers. In some embodiments of the invention, the step of dispersing the first suspension is performed after the step of drying the NCC layer. In some preferred embodiments of the invention, at least one of the first suspension and the second suspension comprises between 0.1% and 3% NCC (weight/volume (w/v)). In some preferred embodiments of the invention, each of the first suspension and the second suspension comprises between 0.1% and 15% NCC (w/v). In some preferred embodiments of the invention, each of the first suspension and the second suspension comprises between 0.1% and 6% NCC (w/v). In some preferred embodiments of the invention wherein the method comprises the use of a second suspension, the method comprises pretreating the substrate prior to the step of dispersing the second suspension. In some preferred embodiments, the second suspension does not include any non-toxic substances. In some preferred embodiments, the second suspension does not include any OH-rich material.

It is another object of the present invention to disclose a method for manufacturing an antimicrobial article as defined in any of the above, comprising dispersing a thin upper NCC layer on said upper surface, said thin upper NCC layer comprising NCC but not MgO or mg (oh)₂。

It is another object of the invention to disclose a method for producing an antimicrobial article as defined in any of the above, wherein said substrate is not cationic.

It is a further object of the invention to disclose a method for producing an antimicrobial article as defined in any of the above, wherein said antimicrobial substance is in the form of nanoparticles.

It is a further object of the present invention to disclose a method for producing an antimicrobial article as defined in any of the above, wherein said antimicrobial substance is in the form of microparticles.

It is a further object of the invention to disclose a method for producing an antimicrobial article as defined in any of the above, wherein said antimicrobial substance is in the form of a mixture or combination of nanoparticles and microparticles.

It is a further object of this invention to disclose a method of producing an antimicrobial article as defined in any of the above, wherein said antimicrobial substance is in powder form. In some preferred embodiments of the invention, the antimicrobial substance is in the form of a powder comprising particles selected from the group consisting of nanoparticles, microparticles, mixtures thereof, and combinations thereof.

It is another object of the present invention to disclose a method for producing an antimicrobial article as defined in any of the above, wherein said antimicrobial article is selected from the group consisting of MgO and Mg (OH)₂The material of the group consisting comprises particles having a median diameter of from 1 μm to 10 μm.

It is another object of the invention to disclose a method for producing an antimicrobial article as defined in any of the above, wherein said first suspension comprises between 0.1% and 15% NCC (w/v).

It is another object of the present invention to disclose a method of producing an antimicrobial article as defined in any of the above, wherein said first suspension comprises a mixture of water and an organic solvent in a ratio of 1: 100 to 50: between 100 (weight/weight (w/w)) of the antimicrobial substance and NCC. In some preferred embodiments of the invention, the first suspension comprises a mixture of two or more of the following components in a ratio of 10: 100 to 40: between 100(w/w) of said antimicrobial substance and NCC. In some preferred embodiments of the invention, the first suspension comprises a mixture of two or more of the following components in a ratio of 10: 100 to 20: between 100(w/w) of said antimicrobial substance and NCC. In some preferred embodiments of the invention, the first suspension comprises a mixture of two or more of the following components in a ratio of 20: 100 to 40: between 100(w/w) of said antimicrobial substance and NCC.

It is another object of the invention to disclose a method for producing an antimicrobial article as defined in any of the above, wherein the first suspension comprises between 1% and 2% NCC (w/v), and the ratio of the antimicrobial substance and NCC is between 10: 100 to 20: 100 (w/w).

It is a further object of this invention to disclose a method of producing an antimicrobial article as defined in any of the above, comprising pre-treating said substrate prior to said step of dispersing said first suspension.

It is another object of the present invention to disclose a method of manufacturing an antimicrobial article as defined in any of the above, wherein said antimicrobial substance is not located between said antimicrobial layer and said substrate.

It is a further object of the present invention to disclose the method of manufacturing an antimicrobial article as defined in any of the above, wherein the substrate is selected from the group consisting of glass, polymers, hybrid materials, biological materials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum (plaster), wood, food surfaces, and any combination thereof.

It is another object of the current invention to disclose a method of producing an antimicrobial article as defined in any of the above, wherein said dispersing step comprises dispersing said first suspension to produce an antimicrobial layer having a thickness between 0.5 μm and 10 μm. In some preferred embodiments of the invention wherein the method comprises the use of a second suspension, said dispersing step comprises dispersing said second suspension to produce a layer of NCC having a thickness between 0.5 μm and 10 μm.

It is another object of the present invention to disclose a method of applying an antimicrobial coating to a substrate, the method comprising: (a) will be firstA suspension is dispersed on the substrate, the first suspension comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO and Mg (OH)₂A substance of the group, thereby producing an antimicrobial layer; and (b) drying the antimicrobial layer. In a preferred embodiment of the invention, the first suspension does not comprise any OH-rich material. In a preferred embodiment of the invention, the process does not comprise any crosslinking step. In some embodiments of the invention, the first suspension comprises at least one additive. In some embodiments of the invention, the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

It is another object of this invention to disclose such a method for applying an antimicrobial coating to a substrate, wherein said dispersing step is preceded by: (a) dispersing a second suspension comprising NCC on the substrate, thereby producing a NCC layer; and (b) drying the NCC layer. In some preferred embodiments of the invention, the method comprises the step of pre-treating said substrate prior to the step of dispersing said second suspension on said substrate. In some preferred embodiments of the invention, the step of dispersing the second suspension comprises dispersing the second suspension to produce a layer of NCC having a thickness between 0.5 μm and 10 μm. In some embodiments of the invention, the second suspension comprises at least one additive. In some embodiments of the invention, the at least one additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

It is another object of the present invention to disclose a method for applying an antimicrobial coating on a substrate as defined in any of the above, wherein said substrate is not cationic.

It is another object of the present invention to disclose a method for applying an antimicrobial coating on a substrate as defined in any of the above, wherein said coating is selected from the group consisting of MgO and Mg (OH)₂The materials in the group are in powder form. In some preferred embodiments of the invention, the metal is selected from the group consisting of MgO and Mg (OH)₂The substance of the group is in the form of a powder comprising particles selected from the group consisting of nanoparticles and microparticles.

It is another object of the invention to disclose a method of applying an antimicrobial coating onto a substrate as defined in any of the above, wherein said first suspension comprises between 0.1% and 3% NCC (w/v). In some preferred embodiments of those embodiments in which the method of dispersing a second suspension is included, each of the first suspension and the second suspension comprises between 0.1% and 3% NCC (w/v).

It is another object of the present invention to disclose a method of applying an antimicrobial coating on a substrate as defined in any of the above, wherein said first suspension is applied in a ratio of between 1: 100 to 50: the ratio between 100(w/w) comprises the substance and NCC. In some preferred embodiments of the method, the first suspension is suspended in a solvent at a ratio of between 10: 100 to 40: the ratio between 100(w/w) comprises the substance and NCC. In some preferred embodiments of the method, the first suspension is suspended in a solvent at a ratio of between 10: 100 to 20: the ratio between 100(w/w) comprises the substance and NCC. In some preferred embodiments of the method, the first suspension is suspended in a solvent at a ratio of between 20: 100 to 40: the ratio between 100(w/w) comprises the substance and NCC.

It is another object of the present invention to disclose a method of applying an antimicrobial coating onto a substrate as defined in any of the above, comprising pre-treating said substrate prior to said step of dispersing said first suspension.

It is another object of the present invention to disclose a method of applying an antimicrobial coating onto a substrate as defined in any of the above, wherein the substrate is selected from the group consisting of glass, polymers, hybrid materials, biomaterials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum, wood, food surfaces, and any combination thereof.

It is another object of the present invention to disclose a method of applying an antimicrobial coating onto a substrate as defined in any of the above, wherein said dispersing step comprises dispersing said first suspension to produce an antimicrobial layer having a thickness between 0.5 μm and 10 μm.

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap to a substrate, the method comprising: dispersing a first suspension on the substrate, the first suspension comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH) ₂Antimicrobial substances in the group consisting of mixtures thereof and combinations thereof or from nanocrystalline cellulose (NCC) and from MgO, Mg (OH)₂An antimicrobial substance in the group consisting of mixtures thereof and combinations thereof, thereby producing an antimicrobial chemical trap comprising an antimicrobial layer; and, drying the antimicrobial layer. In a preferred embodiment of the invention, it does not comprise any step involving crosslinking. In a preferred embodiment of the invention, the first suspension does not comprise any OH-rich material. In a preferred embodiment of the invention, the first suspension does not comprise any components that are non-toxic.

It is another object of this invention to disclose such a method of applying an antimicrobial chemical trap to a substrate, wherein said dispersing step is preceded by: will contain NCC but not MgO or Mg (OH)₂On said substrate, thereby producing a layer of NCC; and drying the NCC layer. In some preferred embodiments, at least one of the first suspension and the second suspension comprises between 0.1% and 3% NCC (w/v).

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein the form of the antimicrobial substance is selected from the group consisting of nanoparticles, microparticles, mixtures thereof, and combinations thereof. In some preferred embodiments of the invention, the antimicrobial substance comprises or consists of particles having a median diameter between 0.5 μm and 10 μm.

It is another object of the invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein the first suspension comprises at least one additive. In some preferred embodiments of the present invention, the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers. In some embodiments of the invention, wherein the method comprises using a second suspension, at least one of the first suspension and the second suspension comprises at least one additive. In some embodiments of the invention wherein the method comprises using a second suspension, at least one of said first suspension and said second suspension comprises at least one additive selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives, and inert fillers.

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein said substrate is not cationic.

It is another object of the invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein the first suspension comprises between 0.1% and 15% NCC (w/v). In some preferred embodiments of the invention, the first suspension comprises between 0.1% and 6% NCC (w/v). In some preferred embodiments of the invention, the first suspension comprises between 0.1% and 3% NCC (w/v).

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein said first suspension comprises a mixture of water and an organic solvent in a ratio of 1: 100 to 50: between 100(w/w) of said antimicrobial substance and NCC. In some preferred embodiments, the first suspension comprises a mixture of two or more of the following components in a ratio of 10: 100 to 40: between 100(w/w) of said antimicrobial substance and NCC. In some preferred embodiments, the first suspension comprises a mixture of two or more of the following components in a ratio of 10: 100 to 20: between 100(w/w) of said antimicrobial substance and NCC. In some preferred embodiments, the first suspension comprises a mixture of two or more of the following components in a ratio of 20: 100 to 40: between 100(w/w) of said antimicrobial substance and NCC. In some particularly preferred embodiments, the first suspension comprises between 1% and 2% NCC (w/v), and the ratio of the first substance and the NCC is between 10: 100 and 20: 100 (w/v).

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, said method comprising pre-treating said substrate prior to said step of dispersing said first suspension.

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein the substrate is selected from the group consisting of glass, polymers, hybrid materials, biomaterials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum, wood, food surfaces, and any combination thereof.

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein said dispersing step comprises dispersing said first suspension to produce an antimicrobial layer having a thickness between 0.5 and 10 μm.

It is another object of the present invention to disclose a method of applying an antimicrobial chemical trap onto a substrate as defined in any of the above, wherein said method does not comprise any step of dispersing said antimicrobial substance between said antimicrobial layer and said substrate.

It is another object of the present invention to disclose an article comprising an antimicrobial coating, said article comprising: (a) a substrate; and (b) an antimicrobial chemical trap, said trap comprising or consisting of an antimicrobial layer characterized by an upper surface and a lower surface, said antimicrobial chemical trap comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH) ₂An antimicrobial substance embedded in the film disposed on at least one surface of the substrate, in the group consisting of mixtures thereof and combinations thereofThe lower surface is brought into contact with the substrate. In a preferred embodiment of the invention, the antimicrobial coating does not comprise an OH-rich material. In a preferred embodiment of the invention, the antimicrobial coating does not comprise any crosslinking agent or catalyst or any substance that is a product of a crosslinking reaction. In a preferred embodiment of the invention, the antimicrobial coating does not comprise any non-toxic components.

It is another object of this invention to disclose such an article comprising an antimicrobial coating, wherein said antimicrobial coating comprises at least one additive. In a preferred embodiment of the invention, the additive is selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives and inert fillers.

It is another object of the present invention to disclose an article comprising an antimicrobial coating as defined in any of the above, wherein said antimicrobial chemical catcher comprises a coating comprising NCC but not MgO or mg (oh) disposed between said substrate and said antimicrobial layer ₂The NCC layer of (2). In some preferred embodiments of the invention, the NCC layer has a thickness between 0.5 μm and 10 μm. In some embodiments of the invention, the NCC layer comprises at least one additive. In a preferred embodiment of the invention, the NCC layer comprises at least one additive selected from the group consisting of polymers, plasticizers, colorants, antioxidants, preservatives and inert fillers.

It is another object of the present invention to disclose an article comprising an antimicrobial coating as defined in any of the above, wherein said antimicrobial substance is in a form selected from the group consisting of nanoparticles, microparticles, mixtures thereof and combinations thereof. In some preferred embodiments of the invention, the antimicrobial substance comprises or consists of particles having a median diameter between 0.5 μm and 10 μm.

It is another object of the present invention to disclose an article comprising an antimicrobial coating as defined in any of the above, wherein said film comprises between 1% and 50% by weight of said antimicrobial substance. In some preferred embodiments of the invention, the film comprises between 1% and 15% by weight of the antimicrobial substance. In some preferred embodiments of the invention, the film comprises between 10% and 40% by weight of the antimicrobial substance. In some preferred embodiments of the invention, the film comprises between 10% and 20% by weight of the antimicrobial substance. In some preferred embodiments of the invention, the film comprises between 20% and 40% by weight of the antimicrobial substance.

It is another object of the present invention to disclose an article comprising an antimicrobial coating as defined in any of the above, wherein said antimicrobial chemical trap comprises a thin upper NCC layer disposed on said upper surface, the upper NCC layer comprising NCC but not MgO or mg (oh)₂。

It is another object of the present invention to disclose an article comprising the antimicrobial coating as defined in any of the above, wherein said substrate is not cationic.

It is a further object of the present invention to disclose an article comprising the antimicrobial coating as defined in any of the above, wherein the substrate is selected from the group consisting of glass, polymers, hybrid materials, biomaterials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum, wood, food surfaces, and any combination thereof.

It is another object of the present invention to disclose an article comprising an antimicrobial coating as defined in any of the above, wherein said substrate comprises at least one surface that has been pretreated to induce, allow or accelerate the association (association) of said surface with said layer.

It is another object of the present invention to disclose an article comprising the antimicrobial coating as defined in any of the above, wherein said antimicrobial layer is characterized by a thickness between 0.5 μm and 10 μm.

It is another object of the invention to disclose an article comprising an antimicrobial coating as defined in any of the above, which article is produced according to the method of production of an article having an antimicrobial coating as defined in any of the above.

It is another object of the present invention to disclose an article comprising an antimicrobial coating as defined in any of the above, wherein said article is selected from the group consisting of a cloth, a package, a container, a product for packaging and containing food, a coating for walls, a work surface coating, a shelf coating and a table top coating.

It is another object of the present invention to disclose an article comprising a substrate coated with an antimicrobial coating, wherein said antimicrobial coating is applied on said substrate according to the method as defined in any of the above.

It is another object of the present invention to disclose a method for controlling a microbial population, wherein said method comprises: obtaining an antimicrobial chemical trap or membrane as defined in any one of the above; and, exposing a collection of microorganisms to the upper surface of the antimicrobial trap, thereby exposing the microorganisms to antimicrobial activity caused by the antimicrobial substance. In some embodiments of the invention, the method comprises controlling a population of at least one microorganism selected from the group consisting of: escherichia coli (e.coli), staphylococcus aureus (s.aureus), pseudomonas aeruginosa (p.aeruginosa), Salmonella (Salmonella), and Listeria (Listeria).

It is another object of the present invention to disclose a method for controlling a microbial population, the method comprising exposing the microbial population to said antimicrobial layer or chemical antimicrobial trap in an article as defined in any of the above. In a preferred embodiment of the invention, the method comprises exposing the population to the antimicrobial layer until the population is reduced by a predetermined amount. In some embodiments of the invention, said step of exposing said collection of microorganisms to said antimicrobial layer comprises exposing said collection of microorganisms to said antimicrobial layer until said collection is reduced by at least two orders of magnitude. In some embodiments of the invention, said step of exposing said collection of microorganisms to said antimicrobial layer comprises exposing said collection of microorganisms to said antimicrobial layer until said collection is reduced by at least three orders of magnitude. In some embodiments of the invention, said step of exposing said collection of microorganisms to said antimicrobial layer comprises exposing said collection of microorganisms to said antimicrobial layer until said collection is reduced by at least four orders of magnitude. In some embodiments of the invention, the exposing step comprises exposing a population comprising at least one microorganism selected from the group consisting of: escherichia coli (e.coli), staphylococcus aureus (s.aureus), pseudomonas aeruginosa (p.aeruginosa), Salmonella (Salmonella), and Listeria (Listeria).

It is another object of the present invention to disclose a method for controlling a microbial population, the method comprising: dispersing a first suspension on a substrate, the first suspension comprising nanocrystalline cellulose (NCC) and a material selected from the group consisting of MgO, Mg (OH)₂An antimicrobial substance, mixtures thereof, and combinations thereof, thereby producing an antimicrobial layer characterized by an upper surface and a lower surface, such that the antimicrobial substance is disposed sufficiently close to the upper surface such that microorganisms impinging on the upper surface will be exposed to antimicrobial activity from the antimicrobial substance; drying the antimicrobial layer; and, placing the antimicrobial layer in a position such that the upper surface is accessible to microorganisms. In some embodiments, the method further comprises: dispersing a second suspension on the substrate, the second suspension comprising nanocrystalline cellulose (NCC) but not MgO or Mg (OH)₂Thereby producing a NCC layer; and drying the NCC layer; wherein the step of dispersing the first suspension comprises dispersing the first suspension onto the NCC layer. In some preferred embodiments of the method, it comprises exposing a collection of microorganisms to the antimicrobial layer.

It is a further object of this invention to disclose a method for controlling a microbial population, the method comprising exposing a microbial population to said antimicrobial layer of an article as defined in any of the above, until said population is reduced by a predetermined amount.

Drawings

The invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 shows a scanning electron micrograph (SEM picture) of an unmodified NCC surface;

FIGS. 2A and 2B show SEM photographs and EDS analysis, respectively, of MgO/NCC surfaces;

FIGS. 3A and 3B show SEM photograph and EDS analysis of the surface of the nano-particle MgO/NCC, respectively; and the combination of (a) and (b),

fig. 4A, 4B and 4C show SEM photographs and EDS analysis of a MgO/NCC surface comprising MgO particles having a median diameter of 2.36 μm and SEM photographs of a control NCC surface, respectively.

Detailed Description

In the following description, various aspects of the present invention will be described. For purposes of explanation and illustration, specific details are set forth in order to provide a thorough understanding of the invention disclosed herein, and to assist those of ordinary skill in the art in making and using the same. Therefore, the specific details provided in the description and examples should not be construed as limiting the scope of the invention. It will be apparent to those skilled in the art that other embodiments of the invention may vary in detail without affecting the essence thereof; the inventors regard all such embodiments as falling within the scope of the present invention. Further, the listing of particular combinations of elements is not intended to be limiting. The inventors contemplate that any combination of the non-self-contradictory elements disclosed herein is within the scope of the invention.

Unless otherwise indicated, any numerical range recited herein should be understood to include the endpoints, including the values given as the upper and lower limits of the range.

As used herein, the abbreviations "NCC" and "CNC" are used synonymously to denote the expression "nanocrystalline cellulose".

As used herein, the abbreviation "MgO/NCC" refers to the product of the compositions disclosed herein or the methods disclosed herein, regardless of the exact chemical name (chemical identity) of the magnesium-containing component of the product. As non-limiting examples, in some non-limiting embodiments of the inventionThe composition described as "MgO/NCC" may contain Mg (OH) in addition to MgO₂Or with Mg (OH)₂Instead of MgO, it is described in detail below.

As used herein, the term "antimicrobial chemical trap" is used to describe a material that exhibits significant antimicrobial activity and comprises particles of an antimicrobial substance immobilized in or on a polymeric matrix.

As used herein, the abbreviation "BOPP" stands for the expression "biaxially oriented polypropylene".

As used herein, the term "OH-rich material" is used to refer to an organic compound having three or more-OH groups.

As used herein, the term "nanoparticle" refers to a particle having at least one dimension (dimension) of 1nm and less than 1000nm, wherein "dimension" refers to the diameter of a spherical particle and the effective diameter of a non-spherical particle.

As used herein, the term "microparticle" refers to particles having a size between 1 μm and 1000 μm, wherein "size" refers to the diameter of a spherical particle and the effective diameter of a non-spherical particle.

As used herein, when a particulate material is described as "embedded" in a matrix, the term "embedded" is used to describe particles that are sufficiently immobilized within the matrix at least partially below the surface of the matrix. According to this definition, an "embedded" particle may be entirely within the matrix, or partially within the matrix, partially above the surface of the matrix.

As used herein, the term "non-toxic" is used to refer to LD reported for ingestion or skin contact having a body weight greater than 1g/kg₅₀The substance of (1).

The invention disclosed herein provides improved methods of making antimicrobial coatings or films; an improved method of making an antimicrobial article comprising a substrate coated with an antimicrobial coating; a novel antimicrobial film useful as a coating for a variety of substrates; "chemical traps" comprising novel antimicrobial films; antimicrobial articles comprising an antimicrobial composition having applied thereto an antimicrobial composition A substrate coated with a substance; and a method of controlling a microbial population. In all cases, the antimicrobial coating comprises MgO, Mg (OH)₂Or a mixture of the two or a combination of the two as an active ingredient. In a preferred embodiment, other than MgO or Mg (OH)₂In addition, no active antimicrobial substance is used in the formulations of the present invention.

For simplicity, in the following description, embodiments of the invention are described in which the active ingredient is MgO, but it is understood that in all cases MgO may be present in equimolar amounts of Mg (OH)₂Partially or wholly replaced. Mg (OH)₂May for example be present as a product of an accidental reaction between water and MgO, as a product of a purposefully induced reaction between water and MgO, or as such a separately added component.

The MgO/NCC film of the present invention includes an antibacterial layer including an NCC film having a typical thickness of between 0.5 μm and 10 μm, and MgO particles dispersed on or in the NCC film, and MgO particles. In a preferred embodiment of the invention, the NCC is characterized by crystal sizes of 5-50nm wide and 150-500nm long. In some embodiments of the present invention, the antibacterial layer comprises nano-particulate MgO. The inventors have surprisingly found that in many cases the antibacterial activity of a film comprising MgO particles having a median diameter of 1-10 μm is at least as large or even larger than a film comprising nanoparticulate MgO. Examples of antimicrobial activity of some illustrative non-limiting embodiments of the invention are given below. Thus, in some preferred embodiments of the present invention, the antibacterial layer comprises particulate MgO. In a preferred embodiment of the invention, the membrane does not comprise any antimicrobial substance other than MgO. In a preferred embodiment of the present invention, the MgO particles are uniformly dispersed in or on the film. That is, for any given portion of the membrane, the number of MgO particles per unit membrane area will be approximately the same.

In some embodiments of the invention, the film further comprises a layer of NCC without any MgO below the antimicrobial layer. For certain substrates, the embodiments comprising the NCC layer were found to adhere to the substrate more effectively than the embodiments without the NCC layer.

In some embodiments of the invention, the film further comprises a thin upper NCC layer applied over the antimicrobial layer. In a preferred embodiment of the invention, the thin upper NCC layer has a thickness of less than 1 μm. In the most preferred embodiment of the invention, the thinner upper NCC layer has a thickness of about 100 nm. The thin upper NCC layer serves to coat the MgO particles, but bring them close enough to the surface that microorganisms can interact with them, e.g. after consumption of the cellulose, and thus come into contact with the MgO particles or with antimicrobial substances generated in the vicinity of the MgO particles.

In contrast to oxide/NCC films known in the art, in the films of the present invention, the MgO particles are not located between the NCC film and the substrate. Rather, they are located at or near the upper surface of the membrane (i.e., the surface that is not in contact with the substrate). As shown below, the surface of the MgO particles does not have to be directly exposed to the environment because the thin layer of NCC on the MgO particles does not eliminate its antimicrobial activity. Furthermore, it is reasonably expected that the preparation process of the MgO/NCC film described below will at least partially coat the MgO particles with a layer of NCC.

Surprisingly, the inventors have found that useful MgO/NCC films or coatings comprising up to 50 wt% MgO relative to the weight of NCC can be prepared, compared to similar materials known in the art. In a preferred embodiment of the invention, the film comprises from 1% to 50% by weight of MgO, relative to the weight of NCC. In a more preferred embodiment of the invention, the film comprises from 10% to 40% by weight of MgO, relative to the weight of NCC. In the most preferred embodiment of the invention, the film comprises from 10% to 20% by weight of MgO, relative to the weight of NCC.

Exemplary, non-limiting embodiments of the inventive antimicrobial films disclosed herein and of the articles coated with the antimicrobial films are now described. These methods of preparation are contemplated by the inventors to be within the scope of the invention disclosed herein.

A suspension comprising NCC and MgO was prepared. In a preferred embodiment, the MgO is in the form of a powder, preferably a powder comprising nanoparticles or microparticles. Surprisingly, the inventors found that MgO/NCC materials comprising particulate MgO are at least as effective in controlling microbial populations as MgO/NCC materials comprising nanoparticle MgO, and in many cases, materials comprising particulate are actually more effective than materials comprising nanoparticles.

Surprisingly, the inventors have found that useful MgO/NCC films or coatings comprising up to 50 wt% MgO relative to the weight of NCC can be prepared, compared to similar materials known in the art. In an exemplary embodiment of the invention, the NCC comprises crystals characterized by a width of 5-50nm and a length of 150-500 nm. In typical embodiments, the concentration of NCC in the suspension is 0.1-3% (w/v), and MgO: the ratio of NCC was 1: 100 to 50: 100 (w/w). In some preferred embodiments of the invention, the ratio of MgO: NCC ratio was 10: 100 to 40: 100 (w/w). In some particularly preferred embodiments of the invention, the ratio of MgO: the NCC ratio is 10: 100 (w/w). In other particularly preferred embodiments of the present invention, the ratio of MgO: the NCC ratio was 20: 100 (w/w).

The suspension may be prepared by any method known in the art; one non-limiting example is sonication. In these embodiments, the mixture is typically sonicated for several minutes until a homogeneous suspension is obtained.

The suspension is then dispersed on at least one surface of a substrate to form a film. The suspension may be dispersed on the substrate by any method known in the art that will produce a film of the desired thickness, typically between 0.5 μm and 10 μm. Sheets with a thickness of more than 10 μm can also be produced in this way. The exact thickness of the coating produced (e.g., a coating having a thickness <10 μm or a sheet having a thickness ≧ 10 μm) will depend on the particular use of the end product. Non-limiting examples of methods that can be used to disperse the coating on the substrate include using a rod coater (rod coater) or a commercially available paper or plastic coating apparatus, or methods for forming a film on a solid surface known in the art by wetting, brushing, dipping, rolling, R2R, S2S, or any other method.

Reaction of MgO with water to form Mg (OH)₂Are well known in the art. Depending on, for example, the preparation of the suspension and its distribution on the substrateTime between dispersions, particle size, etc., some or all of the MgO added to the suspension may react with water to form Mg (OH) before the suspension is dispersed on the substrate₂. Although in a preferred embodiment of the method of making the antimicrobial film, the suspension is made using MgO, the inventors believe that any product made by this method is within the scope of the invention, regardless of the exact name (exact identity) of the magnesium-containing component therein.

After dispersing the suspension on the substrate, the film is dried. As will be appreciated by those of ordinary skill in the art, the conditions used to dry the film will depend on the particular substrate. Drying is usually carried out at room temperature in air. In some embodiments, drying is carried out at elevated temperatures, typically between room temperature and 220 ℃; the optimum drying temperature depends on the surface.

In some embodiments, the NCC film is coated prior to coating the substrate to form the MgO/NCC film. In these embodiments, a suspension of NCC (i.e., a suspension that does not include MgO) is prepared as described above, dispersed on the surface of the substrate, and dried to form a layer of NCC, and then dried as described above. An antimicrobial MgO/NCC layer was then prepared as described above, except that the antimicrobial layer was dispersed on the NCC layer rather than directly on the substrate surface. The inventors have found that the NCC/MgO layer tends to adhere better to the NCC layer rather than to the substrate surface, thus providing a first NCC layer, on which the NCC/MgO antimicrobial layer is coated, results in a more active and more stable final product.

Any substrate on which a coating will form a stable film may be used. Non-limiting examples include glass, polymers, hybrid materials, biomaterials, dielectric materials, fibers, paper, cardboard, metal surfaces, cement, concrete, gypsum, wood, and food surfaces. Non-limiting examples of food surfaces that can be used as a substrate include freshly cut fruits and vegetables. Non-limiting examples of polymers that may be used as the substrate include Polyethylene (PE), biaxially oriented polypropylene (BOPP), and polyethylene terephthalate (PET). Can be used forNon-limiting examples of fibers to be used as substrates include cotton fibers and glass fibers. The inventors note that the present invention does not require placing a NCC/MgO coating on a positively charged surface, as opposed to similar items known in the prior art that require a cationic surface to electrostatically attach a negatively charged NCC layer. In fact, in the present invention, the surface to be coated is preferablyIs notA cation. Without being bound by theory, it appears that in the compositions of the present invention, MgO neutralizes the NCC layer, thereby eliminating any necessity for a cationic surface.

In some embodiments, the surface of the substrate is pretreated to enhance or accelerate the bonding of the film to the substrate. Any suitable pretreatment method known in the art may be used. Non-limiting examples include washing, etching, heating, plasma treatment, UV/ozone treatment, corona discharge, laser, flash lamp, or microwave radiation of the surface, coating through a protective layer or primer layer, or any combination thereof.

It is further emphasized that, in contrast to MgO impregnated fibers and sheets known in the art, the present invention produces MgO/NCC coatings and sheets in which the MgO remains exposed and available on the surface, and is thus capable of interacting with and killing microbes near or touching the surface. It is also emphasized that, in contrast to compositions known in the art comprising NCC films containing nanoparticles, in the films and coatings of the invention disclosed herein, the MgO particles are predominantly located at or near the upper surface of the film (i.e., the surface not in contact with the substrate or the surface in contact with the layer not in contact with the substrate), rather than between the NCC film and the substrate. In preferred embodiments of the invention disclosed herein, the MgO is at least partially exposed at or above the upper surface of the film or coating.

Referring now to fig. 1-3, there are provided non-limiting examples of experimental characterization of some MgO/NCC surfaces prepared according to the methods disclosed herein. Figure 1 shows SEM pictures of unmodified NCC surfaces. Fig. 2 shows SEM photographs (2A) and EDS analysis (2B) of the MgO/NCC surface of the present invention, wherein the MgO/NCC suspension was prepared by using a Special Industrial Grade (Special Industrial Grade,SIG) MgO (periclase) preparation, assigned ≥ 99.0% MgO, and is characterized by a d of 39.7 μm₉₀(ii) a D of 16.5 μm₅₀(ii) a And d of 3.8 μm₁₀. FIG. 3 shows SEM pictures (3A) and EDS analysis (3B) of an MgO/NCC surface of the present invention in which MgO/NCC suspensions are prepared by using fine-particle MgO. Table 1 shows a summary of the experimental characterization of the particulate MgO used in the MgO/NCC suspension from which the surface shown in fig. 3 was prepared.

Thus, a single inventive method disclosed herein can be used to provide antimicrobial coatings for a wide variety of different articles, such as cloths, packages, containers, products for packaging and containing food, exposed surfaces of food (e.g., freshly cut fruits and vegetables), coatings and finishes for walls, work surfaces, shelves, countertops (e.g., in food preparation areas such as kitchens), and the like, as well as methods for producing non-toxic antimicrobial surfaces for such products.

In some embodiments of the invention, the material acts as a "chemical trap" for microorganisms. The NCC functions to enhance the adhesion of microorganisms to the surface and/or to provide a material that itself (i.e., in the absence of MgO) can increase the number of microbial populations thereon. As discussed above, microorganisms are killed by contact with MgO or an antimicrobial chemical (e.g., peroxide) produced by a chemical reaction of or catalyzed by MgO. Thus, without being bound by theory, it appears that the MgO need not be fully exposed at the upper surface of the coating or film, but need only be close enough to that surface that the microbial population will at least partially consume any NCC coating that coats the MgO particles, thereby contacting the particles or antimicrobial substances generated in the vicinity of the particles. Thus, NCC and MgO provide a synergistic combination: NCC is a good medium for bacteria and thus actually facilitates contact between the bacteria and the medium used to control their population.

In addition to the synergistic effect between NCC and MgO, disclosed hereinYet another advantage of the present invention is that it is made of non-toxic materials. The inertness and low toxicity of MgO are well known in the art, LD₅₀About 1g/kg body weight. In practice, MgO is used as an excipient, for example, for pills. NCC is also considered to be non-toxic when ingested or skin-contacted (roman, m.; "Toxicity of Cellulose Nanocrystals: Review (Toxicity of Cellulose Nanocrystals: a Review)"; industrial biotechnology (ind. biotechnology)2015, 11, 25; digital object identification (doi): 10.1089/ind.2014.0024).

The following examples are put forth so as to provide those of ordinary skill in the art with a convenient understanding of the invention, and are intended to be included within the scope of the appended claims. They should not be construed as limiting in any way.