A nanofiber based multi-layer filtration material suitable for use in providing air filtration to a user's respiratory system may be provided. as an air filtration garment and/or other air filterina devices such as a face mask, mask and garments or the like. The laminate includes a one or more fabric layer adjacent to one or more nanofiber layers.

Various embodiments disclosed relate to a fire-resistant filter and methods of making and using the same. A filter includes a fibrous web or sheet comprising fire-resistant fibers, the fire-resistant fibers comprising oxidized polyacrylonitrile (OPAN), flame-retardant (FR) rayon, or a combination thereof.

Provided is a fiber structure in which an extra-fine fiber layer and a substrate layer are integrated deeply. The fiber structure includes an extra-fine fiber layer 10 spreading in a plane direction, and a substrate layer 20 adjoining the extra-fine fiber layer, wherein the extra-fine fiber layer 10 includes extra-fine fibers having a number average single fiber diameter of 5 μm or less; the substrate layer 20 includes non-extra-fine fibers having a number average single fiber diameter of 7 μm or more; and in a cross section along a thickness direction of the fiber structure, the substrate layer 20 contains mixture portions 12 in each of which some of the extra-fine fibers pushed between the non-extra-fine fibers are widened in a crosswise direction.

Filter media including out-of-plane solid elements are generally described. Inventive methods of forming them and uses thereof are also described.

A thermally bonded filtration media that can be used in high temperature conditions in the absence of any loss of fiber through thermal effects or mechanical impact on the fiber components is disclosed. The filter media can be manufactured and used in a filter unit or structure, can be placed in a stream of removable fluid, and can remove a particulate load from the mobile stream at an increased temperature range. The combination of bi-component fiber, other filter media fiber, and other filtration additives provides an improved filtration media having unique properties in high temperature, high performance applications.

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.

An improved stretchable filtration fabric laminate is provided. The laminate includes a first fabric layer and a nanofiber layer. The laminate may be stretched without damaging the laminate. The laminate is thus suitable for incorporation into wearable protective garments, such as protective hoods, balaclavas, scarves, etc. that provide both protection and air filtration to the wearer.

Novel methods and means for convergent nanofabrication and nanoassembly are disclosed, and systems produced by and performing same are targeted at a broad range of applications. Molecules and/or nanostructures are bound to supported binding means and manipulated to translate such precursors or intermediates to bond together in precisely desired locations and orientations to yield desired precise structures. Methods and means suitable for precise fabrication of a range of materials including diamond, Beta-Silicon-Carbide and related materials, and precise modifications thereof such as color centers in predetermined configuration for quantum computation and information processing and storage applications, and for precise fabrication of halite structured materials including MgO, MgS, TiC, VN, ScN, precisely Mn doped ScN, NbN, HfC, TaC, HfxTayC, AbOS, SrO, BaO, Zr02, ZrC, ZrN, HfN, and also metals including refractory metals such as W are disclosed, yielding an extremely broad range of materials and materials properties which may be availed or utilized.

A flame-retardant antibacterial composite polypropylene filter material and a preparation method thereof are disclosed. The filter material includes the following components in weight percent: 70-90 wt % of isotactic polypropylene, 3-10 wt % of a functional negative ion-releasing material, 3-10 wt % of a nano-antibacterial agent, 2-5 wt % of graphene oxide, 0.5-5 wt % of a flame retardant and 1-3 wt % of a dispersant. The filter material of the present invention can be prepared into network, fabric and other forms by the melt-blending extrusion, which can be applied for air pollutant removal in different environments. The functional negative ion-releasing material is a piezoelectric material, which can spontaneously produce negative oxygen ions, without consumption of energy or producing secondary pollution such as ozone. The released negative oxygen ions interact with positively charged particles in the air for settling, so as to quickly remove the particles.

A personal air filtering device comprising a rigid component comprising a transparent face shield, a fabric component, wherein the face shield and fabric combine to cover an entire head of a user and form a seal around the user's neck, an intake port with an inlet filter, an exhaust port with an exhaust filter, an air mover causing filtered air to enter the intake port from outside the device and exhaust air to exit the exhaust port, and a controller configured to adjust the rate at which the air mover moves air.