Abstract: A method of making a fluorinated fibrous web, which method includes providing a nonwoven web 22 that contains polymeric fibers, creating a plasma that contains fluorine atoms at a first location 14, and contacting the nonwoven web with products from the plasma at a second location 26 remote from the first location 14. The method avoids exposure of the web to the plasma and hence expands the manufacturing processing window. Webs so fluorinated have a different C3F4H+ to C2F5+ ratio when compared to locally fluorinated webs having similar levels of surface fluorination. The remote fluorinated webs can be subsequently charged electrically to provide a good performing electret filter 40 suitable for use in an air purifying respirator 30. Webs fluorinated in accordance with this invention also may exhibit good performance even after being “aged” at high temperatures.

Abstract: Disclosed are apparatus, system, and method for enhancing air purification efficiency regarding a gaseous medium passing through an opening. Included is a high voltage source that creates an effective voltage field across the opening; and at least one charge bleeding element constructed and arranged to maintain an effective voltage field across the opening.

Abstract: Highly active, low pressure drop catalyst systems. Catalytically active material is provided on at least a portion of the channel sidewalls of a body comprising one or more flow-through channels. The channel sidewalls preferably bear a charge, e.g., an electrostatic or electret charge, to help adhere the catalytically active material to the sidewall. The catalytically active material preferably includes gold provided on a particulate support, and PVD techniques are used to deposit catalytically active gold onto the support. Optionally, the gold-bearing particulates may be charged as well in a manner to facilitate attraction between the particulates and the sidewalls.

Abstract: Use of physical vapor deposition methodologies to deposit nanoscale gold on activating support media makes the use of catalytically active gold dramatically easier and opens the door to significant improvements associated with developing, making, and using gold-based, catalytic systems. The present invention, therefore, relates to novel features, ingredients, and formulations of gold-based, heterogeneous catalyst systems generally comprising nanoscale gold deposited onto a nanoporous support.

Abstract: A method of making an electret article, from a polymeric article that has a zeta potential of greater than or less than ?7.5 millivolts. The article is charged by contacting it with an aqueous liquid that has a pH and conductivity as follows: (i) if the article has a zeta potential of ?7.5 mV or less, then the contacting liquid has pH greater than 7 and a conductivity of 5 to 9,000 microSiemens per centimeter; and (ii) if the article has a zeta potential of greater than ?7.5 mV, then the contacting liquid has a pH of 7 or less and a conductivity of 5 to 5,500 microSiemens per centimeter. An electret article made in this manner can provide improved electret performance, particularly in electret filtration articles.

Abstract: Use of physical vapor deposition methodologies to deposit nanoscale gold on activating support media makes the use of catalytically active gold dramatically easier and opens the door to significant improvements associated with developing, making, and using gold-based, catalytic systems. The present invention, therefore, relates to novel features, ingredients, and formulations of gold-based, heterogeneous catalyst systems generally comprising nanoscale gold deposited onto a nanoporous support.

Abstract: A charged multilayer filter includes a hydrocharged filtration layer containing a plurality of intertwined nanofibers that have a finite length of about 12 to about 300 mm, atop a porous roll-to-roll processable support layer.

Abstract: A charged multilayer filter includes a hydrocharged filtration layer containing a plurality of intertwined nanofibers that have a finite length of about 12 to about 300 mm, atop a porous roll-to-roll processable support layer.

Abstract: Disclosed are apparatus, system, and method for enhancing air purification efficiency regarding a gaseous medium passing through an opening. Included is a high voltage source that creates an effective voltage field across the opening; and at least one charge bleeding element constructed and arranged to maintain an effective voltage field across the opening.

Abstract: Shaped filtration articles are made from a monocomponent nonwoven web formed by flowing first and second fiber-forming materials of the same polymeric composition through first and second die cavities in respective fluid communication with first and second sets of orifices in a meltblowing die tip. The first fiber-forming material flows at a lesser flow rate or viscosity through the first die cavity and first set of orifices to form a set of smaller size filaments and the second fiber-forming material flows at a greater flow rate or viscosity through the second die cavity and second set of orifices to form a set of larger size filaments. The collected nonwoven web contains a meltblown bimodal mass fraction/fiber size mixture of intermingled continuous microfibers and larger size fibers of the same polymeric composition.

Abstract: A method of making an electret article, from a polymeric article that has a zeta potential of greater than or less than ?7.5 millivolts. The article is charged by contacting it with an aqueous liquid that has a pH and conductivity as follows: (i) if the article has a zeta potential of ?7.5 mV or less, then the contacting liquid has pH greater than 7 and a conductivity of 5 to 9,000 microSiemens per centimeter; and (ii) if the article has a zeta potential of greater than ?7.5 mV, then the contacting liquid has a pH of 7 or less and a conductivity of 5 to 5,500 microSiemens per centimeter. An electret article made in this manner can provide improved electret performance, particularly in electret filtration articles.

Abstract: A porous sheet article comprising a self-supporting nonwoven web of polymeric fibers and at least 80 weight percent sorbent particles enmeshed in the web, the fibers having sufficiently greater elasticity or sufficiently greater crystallization shrinkage than similar caliper polypropylene fibers and the sorbent particles being sufficiently evenly distributed in the web so that the web has an Adsorption Factor A of at least 1.6×104/mm water. The articles have low pressure drop and can provide filter elements having long service life and an Adsorption Factor approaching and in some instances exceeding that of a packed carbon bed.

Abstract: The present invention provides technology for controlling, or tuning, the catalytic activity of gold provided upon nanoporous supports such as those derived from nanoparticulate, crystalline titania. In some aspects of practice, the surface of nanoparticulate media incorporated into a catalyst system of the present invention is provided with chemical modifications of the surface that dramatically suppress the ability of the resultant catalyst system to oxidize hydrogen. Yet, the system still readily oxidizes CO. In other words, by selecting and/or altering the nanoparticulate surface via the principles of the present invention, PROX catalysts are readily made from materials including catalytically active gold and nanoparticulate media. Additionally, the nanoparticulate support also may be optionally thermally treated to further enhance selectivity for CO oxidation with respect to hydrogen.

Abstract: A flat-fold respirator is made from a stiff filtration panel joined to the remainder of the respirator through at least one line of demarcation. The panel contains a porous monocomponent monolayer nonwoven web that contains charged intermingled continuous monocomponent polymeric fibers of the same polymeric composition and that has sufficient basis weight or inter-fiber bonding so that the web exhibits a Gurley Stiffness greater than 200 mg and the respirator exhibits less than 20 mm H2O pressure drop. The respirator may be formed without requiring additional stiffening layers, bicomponent fibers, or other reinforcement and can be flat-folded for storage. Scrap from the manufacturing process may be recycled to make additional stiff filtration panel web.

Abstract: An electret article that includes a polymeric material that has electric charge imparted thereto, that has a CF3:CF2 ratio of at least 0.15 and that has a fluorosaturation ratio greater than about 200. The electret article may be in the form of a porous web of polymeric fibers suitable for use as a filter. The inventive electret article is resistant to charge degradation upon exposure to high temperatures for prolonged time periods.

Abstract: An electret article that includes a polymeric material that has electric charge imparted thereto, that has one or more heteroatoms, that has a fluorosaturation ratio of less than 200, and that has an atomic percent fluorine of greater than about 40%. The inventive electret article is resistant to charge degradation upon exposure to high temperatures for prolonged time periods.

Abstract: A portable walk through metal detector with interchangeable sensor panels and other structural members that can be quickly assembled, or disassembled and transported. The device includes two structural base members to anchor the archway, multiple sensor panels with which the sides of the archway are constructed, and a top cross-member to join and support the walls of the archway. In addition, the top cross-member provides a vehicle platform for moving a disassembled unit with built-in wheels, a handle, and stacking structures to support the other members.

Abstract: A method of making a respirator, which method includes placing an electret in a respirator body that is adapted to fit over the nose and mouth of a wearer. The electret is disposed in the respirator body such that air passes through it before being inhaled by a respirator wearer. The electret includes a nonwoven web that has fluorinated polymeric microfibers and that has at least about 25% atomic fluorine as detected by ESCA and a CF3:CF2 ratio of at least about 0.45.

Abstract: A portable walk through metal detector with interchangeable sensor panels and other structural members that can be quickly assembled, or disassembled and transported. The device includes two structural base members to anchor the archway, multiple sensor panels with which the sides of the archway are constructed, and a top cross-member to join and support the walls of the archway. In addition, the top cross-member provides a vehicle platform for moving a disassembled unit with built-in wheels, a handle, and stacking structures to support the other members.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.