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Methods and apparatus for hydrodischarging and hydrocharging substrates and articles to produce enhanced ability to avoid attraction of contaminants or improved capability of removing contaminants from fluids are disclosed. In another form the method involves removal of electric charges or neutraliz

Methods and apparatus for hydrodischarging and hydrocharging substrates and articles to produce enhanced ability to avoid attraction of contaminants or improved capability of removing contaminants from fluids are disclosed. In another form the method involves removal of electric charges or neutralization of charge on or within substrates. Also disclosed are methods of making using electret substrates and articles for removing particulates and mists from fluid streams.

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What is claimed is: 1. A method of making an electret, comprising the steps of: a. providing a substrate; b. removing a first gas from the substrate with a functional, second, gas; c. adding at least one functional liquid to the substrate; and d. removing the functional liquid from the substrate.

What is claimed is: 1. A method of making an electret, comprising the steps of: a. providing a substrate; b. removing a first gas from the substrate with a functional, second, gas; c. adding at least one functional liquid to the substrate; and d. removing the functional liquid from the substrate. 2. The method of making an electret of claim 1, whereby the step of removing the first gas involves the functional gas displacing substantially all of the first gas from the substrate. 3. The method of making an electret of claim 1, whereby the step of adding a functional liquid replaces substantially all of the functional gas from the substrate and creates a substantially continuous, covering layer of functional liquid on the substrate. 4. The method of making an electret of claim 1, whereby the step of removing the functional liquid breaks down the functional liquid into a distribution of drops and subsequently completely removes the drops. 5. The method of making an electret of claim 1, wherein the substrate is an element selected from the group of elements consisting of a sheet, a piece part, an article, a web, free particles, and free fibers. 6. The method of making an electret of claim 1, wherein the substrate is selected from the group consisting of polymeric porous and non porous materials. 7. The method of making and electret of claim 1, wherein the first gas is air. 8. The method of making an electret of claim 1, wherein the step of removing the first gas involves flushing by the functional gas. 9. The method of making an electret of claim 1, wherein the step of removing the first gas includes applying a functional gas to the substrate via a contactor. 10. The method of making an electret of claim 1, further comprising the step of heating the functional gas. 11. The method of making an electret of claim 1, wherein the functional gas is steam. 12. The method of making an electret of claim 1, wherein the functional gas is condensed to a liquid. 13. The method of making an electret of claim 1, wherein the step of adding a functional liquid involves immersing the substrate in the functional liquid. 14. The method of making an electret of claim 1, wherein the step of adding a functional liquid involves applying the functional liquid to the substrate via a contactor. 15. The method of making an electret of claim 1, wherein the step of adding a functional liquid involves condensing a heated functional gas on to the substrate. 16. The method of making an electret of claim 1, wherein the functional liquid has a conductivity of equal to or greater than 500 pico-Siemens per meter. 17. The method of making an electret of claim 16, wherein the functional liquid is a degassed liquid. 18. The method of making an electret of claim 16, wherein the functional liquid is water. 19. The method of making an electret of claim 1, further comprising the step of heating the functional liquid. 20. The method of making an electret of claim 1, wherein the step of removing the functional liquid is at least one mechanical step selected from the group consisting of blowing, centrifuging, sucking, vacuuming, gravity draining, vibrating, scraping, and squeezing. 21. The method of making an electret of claim 1, wherein the step of removing the functional liquid is at least one phase change step. 22. The method of making an electret of claim 1, wherein the step of removing functional liquid involves first mechanically removing a portion of the functional liquid from the substrate, and secondly removing any remaining portion of the functional liquid from the substrate via a phase change. 23. The method of making an electret of claim 1, wherein the steps of removing the first gas and adding a functional liquid are combined into one step involving exposing the substrate to a 2-phase functional gas and functional liquid mixture. 24. The method of making an electret of claim 23, wherein the exposing step is repeated. 25. The method of making an electret of claim 23, comprising a step of adding an additional functional liquid to the substrate after the exposing step. 26. The method of making an electret of claim 23, wherein the 2-phase functional gas and functional liquid mixture is boiling water. 27. The method of making an electret of claim 1, at least one of the adding and removing steps are repeated. 28. The method of making an electret of claim 1, further comprising the step of cleaning the provided substrate. 29. The method of making an electret of claim 28, wherein the cleaning step is accomplished before the step of removing the first gas. 30. The method of making an electret of claim 28, wherein the cleaning step is accomplished during the step of removing the first gas. 31. The method of making an electret of claim 28, wherein the cleaning step is accomplished after the step of removing the first gas. 32. The method of making an electret of claim 1, wherein the cleaning step involves washing the substrate with a wetting liquid. 33. The method of making an electret of claim 28, wherein the cleaning step is accomplished by heating the functional gas or functional liquid. 34. The method of making an electret of claim 1, further comprising the step of cleaning the functional gas or functional liquid. 35. The method of making an electret of claim 1, further comprising the step of absorbing, adsorbing, reacting, dissolving, or condensing the functional gas after the step of removing the first gas and prior to the step of adding a functional liquid. 36. The method of making an electret of claim 1, further comprising the step of absorbing, adsorbing, reacting, dissolving, or condensing the functional gas after the step of removing the first gas and simultaneous with the step of adding a functional liquid. 37. The method of making an electret of claim 1, further comprising the step of adding at least one charge additive to the functional liquid. 38. The method of making an electret of claim 37, wherein the charge additive is at least one compound selected from the group consisting of fluorinated oxazolidinones, fluorinated piperazines, and perfluorinated alkanes. 39. The method of making an electret of claim 1, further comprising the step of applying an electrical charge to the functional liquid. 40. The method of making an electret of claim 1, further comprising the step of appending additional elements to the substrate, the elements being selected from the group consisting of particles, molecules, colloids, and aggregations. 41. The method of making an electret of claim 40, wherein the step of appending elements to the substrate is accomplished after the functional liquid removal step. 42. The method of making an electret of claim 39, wherein the substrate is a polymer selected from the group consisting of polyolefin, polyester, polycarbonate, polystyrene, polyphenylenesulfate, fluorine-based resin, parylene and mixtures thereof. 43. The method of making an electret of claim 1, wherein the electret surface properties are targeted to a predetermined filtration challenge. 44. The method of making an electret of claim 43, wherein the filtration challenge is a liquid mist in a gas or a liquid drop in an immiscible liquid. 45. The method of making an electret of claim 44, wherein the targeting involves adjusting the combination of substrate surface and the gas properties to prevent wetting of the substrate by the mist. 46. The method of making an electret of claim 44, wherein the targeting involves adjusting the combination of substrate surface properties and the gas conditions to prevent wetting of the substrate by the mist. 47. The method of making an electret of claim 44, wherein the adjusting involves adjusting the contact angle of the liquid of the mist to greater than 45 degrees by lowering the surface energy of the substrate in the gas. 48. The method of making an electret of claim 45, wherein the adjusting involves adjusting the contact angle to greater than 45 degrees by increasing the surface tension of a contaminant mist in the gas. 49. A method of making an electret, comprising the steps of: a. providing a polymeric substrate selected from the group consisting of a sheet, a piece part, an article, free fibers, and webs; and b. hydrocharging the substrate by: i. removing air from the substrate with a functional gas, whereby the gas displaces substantially all of the air from the substrate; ii. adding at least one functional liquid to the substrate, whereby the functional liquid replaces substantially all of the functional gas from the substrate and creates a substantially continuous, covering layer of functional liquid on the substrate; and iii. removing the functional liquid from the substrate, whereby the functional liquid breaks down into a distribution of drops on the substrate and subsequently are removed. 50. A method of making an electret, comprising the steps of: a. providing a substrate selected from the group consisting of a sheet, a piece part, an article, free particles, free fibers, and webs; and b. hydrocharging the substrate by: i. removing air from the substrate by immersing the substrate in boiling water; ii. removing the substrate from the boiling water; and iii. removing at least some portion water from the substrate by drying. 51. A method of making an electret comprising the steps of providing a substrate in a noncondensible gas; replacing the noncondensible gas with a functional liquid; selecting the functional liquid or the operating conditions so that the noncondensible gas is functional with respect to the functional liquid; and removing the functional liquid. 52. A method of controlling charge on a substrate, comprising the steps of: a. moving a substrate; b. applying at least one grounded liquid to at least one side of the moving substrate; c. removing the liquid from the substrate; and d. maintaining an electrically conductive path between the substrate and the liquid until it is removed. 53. The method of controlling charge on a substrate of claim 52, wherein some portion of the charge is neutralized. 54. The method of controlling charge on a substrate of claim 52, wherein the substrate is an element selected from the group of elements consisting of a sheet, a piece part, an article, a web, free particles, and free fibers. 55. The method of controlling charge on a substrate of claim 52, wherein the substrate is selected from the group consisting of porous and non porous substrates. 56. The method of controlling charge on a substrate of claim 52, wherein the liquid is non-wetting and forms a three phase contact line with respect to the substrate. 57. The method of controlling charge on a substrate of claim 56, wherein the substrate moves through a 3-phase contact line. 58. The method of controlling charge on a substrate of claim 52, wherein the removing step takes place at a zone of removal, and wherein the electrically conductive path is maintained from this zone to a liquid grounding electrode. 59. The method of controlling charge on a substrate of claim 58, wherein the liquid is wetting and the zone of removal is a drying zone. 60. The method of controlling charge on a substrate of claim 52, wherein the applying step includes dipping. 61. The method of controlling charge on a substrate of claim 52, wherein the applying step is implemented by moving the substrate past at least one contactor applicator. 62. The method of controlling charge on a substrate of claim 52, wherein the step of adding a liquid to a first side of the moving substrate is implemented by adding a liquid at a first segment, moving the substrate and adding a liquid at a second segment. 63. The method of controlling charge on a substrate of claim 52, further comprising the step of adding at least one liquid to a second side of the substrate by a second grounded contactor applicator. 64. The method of controlling charge on a substrate of claim 63, wherein the step of adding a liquid to the second side of the substrate is implemented substantially simultaneously with the step of adding a liquid to the first side of the web substrate. 65. The method of controlling charge on a substrate of claim 52, wherein the step of removing includes wiping. 66. The method of controlling charge on a substrate of claim 52, wherein the step of removing includes evaporation. 67. The method of controlling charge on a substrate of claim 52, wherein the step of removing includes blowing. 68. The method of controlling charge on a substrate of claim 52, wherein the step of removing includes at least one mechanical step selected from the group consisting of blowing, centrifuging, sucking, vacuuming, gravity draining, vibrating, scraping, and squeezing.