A nanofiber for an air filter and a method for manufacturing the same are proposed. The nanofiber may include a styrene-(meth)acrylate-acrylonitrile random copolymer having a zwitterionic functional group in a side chain. The nanofiber can greatly enhance the bonding of particulate matter (PM) particles with the surface of a polymer by having a high dipole moment derived from the zwitterionic functional group, thereby providing high efficiency of filtration (>99.9%) of the PM particles. Furthermore, the nanofiber can be very usefully used as a core material for air purifier filters and vehicle air purification filters by having low airflow resistance and excellent antibacterial properties.

The present invention generally relates to a dual density air filtration media that comprises a plurality of nanofibers layers formed from nanofibers having different fiber diameters. Due to the presence of these multiple nanofiber layers with different nanofiber diameters, the resulting filtration media of the present invention comprises a gradient density. In particular, the present invention uses a novel combination of two or more layers of nanofibers made via an electrospinning process, wherein the nanofiber layers made up from different fiber sizes are strategically applied to a cellulose or synthetic base material or substrate, to thereby maximize the filtration efficiency and dust holding capacity of the resulting filtration media.

Provided are a sub-micron fibrous membrane in which sub-micron fibers aligned along one axis and sub-micron fibers in a random pattern form a network, and a method for producing the sub-micron fibrous membrane.

A bacterial cellulose-based air filter mesh and use thereof are disclosed. The bacterial cellulose-based air filter mesh comprises a three-layer structure, in which a layer of a bacterial cellulose-based filter mesh is sandwiched by two layers of polymer fiber filter meshes; wherein the polymer fiber filter mesh is a mesh having a uniform grid size formed from polymer fibers by blended-yarn weaving; and the bacterial cellulose-based filter mesh is formed by in-situ synthesis of bacterial cellulose on a non-woven fabric through fermentation by bacteria. The bacterial cellulose-based air filter mesh has better particle filtering effect, better formaldehyde adsorption capacity, better antibacterial performance and good electrostatic capacity; and it can be used for producing gauze windows, air conditioning filters, air purification filters and the like, and has a wide range of applications.

A filter may remove PM.sub.2.5 and/or other airborne pollutants, which filter has fibers of an average diameter of no more than 500 nm, the fibers of at least 90 wt. % polyacrylonitrile, relative to all fibers in the filter; and a catalyst of at least 90 wt. % TiO.sub.2, relative to all catalytic metals in the filter, dispersed onto the fibers. The fibers need not be charged. The TiO.sub.2 may be condensed or precipitated onto the fibers out of a liquid containing the TiO.sub.2 and the fibers by simple methods. The catalyst may be activated by UV irradiation to decompose particulate matter having an average particle size of 2.5 μm or less, i.e., PM.sub.2.5, and/or other airborne pollutants from air. Such filters may be implemented around areas of vehicle traffic, e.g., as elements of traffic lights, and may be used to controllably purify polluted air.

An air filtration system is disclosed. The system comprises an air conduit having an inlet and an outlet, a self-contained electric power source, an electrically powered fan, an air filter located transversely across said air conduit, and an air boundary containment nozzle at the outlet of the air conduit. The nozzle has an outlet diameter of between about 0.5 centimeters and about 4 centimeters. The nozzle minimizes the mixing of the unfiltered ambient air with the filtered air directed to the wearer.

A gas filtering medium is composed of hydrophobic polyester fiber as from 20-80% by total weight of textile fibers and 80-20% by total weight of hydrophilic textile fibers and a microfibrillated cellulose fiber in a weight/weight ratio of 1.5-8.5/100 parts by weight of total textile fiber.

Articles and methods involving filter media are generally provided. In certain embodiments, the filter media includes at least a first layer, a second layer, and an adhesive resin positioned between the first layer and the second layer. In some embodiments, the first layer may be a pre-filter layer or a support layer. The second layer may, for example, comprise fibers formed by a solution spinning process and/or may comprise fine fibers. In some embodiments, the adhesive resin may be present in a relatively low amount and/or may have a low glass transition temperature. The filter media as a whole may have one or more advantageous properties, including one or more of a high stiffness, a high bond strength between the first layer and the second layer, a high gamma, and/or a low increase in air resistance after being subjected to an IPA vapor discharge. The filter media may be, for example, a HEPA filter and/or an ULPA filter.

A filter media construct includes a plurality of flexible laminas joined in a stack, each lamina including an array of nanofibers extending from a surface thereof. Each lamina is configured to be permeable to a fluid such that the fluid can flow through each lamina normal to the surface thereof and in any direction along at least a portion of said surface when the fluid is flowed through the construct. The laminas can include a plurality of perforations extending therethrough such that the fluid flows through at least some of the perforations of the laminas when the fluid is flowed through the construct. A contaminant contained in the fluid is at least partially filtered from the fluid by the nanofibers when the fluid is flowed along the surface of any lamina or into or through the perforations.

A mask with at least one filtering layer that includes a fabric made of non-conductive polymer fibers embedded with nanoparticles of two different metals is provided. The population density of the nanoparticles of the two metals on the surface of non-conductive polymer fibers is configured such that the adjacent nanoparticles of the two metals have an average distance of two micrometers or less. The two different metals are selected such that the electric field intensity generated between the nanoparticles of the two different metal through the aerosol particle inactivates the microorganisms that may be inside the aerosol particle. When an aerosol particle comes into contact with the nanoparticles of the two metals, the aerosol acts as an electrolyte between the two metal types and a potential difference and an electric field is generated, through the aerosol particle, between the nanoparticles of the two metals.