A method for producing a honeycomb-shaped ceramic structure by extrusion-molding a moldable material including a cordierite-forming material and a pore-forming material, wherein the cordierite-forming material contains 15-25% by mass of silica having an average particle size of 20-30 μm, with 5% or less by mass of particles having particle sizes of 10 μm or less and 5% or less by mass of particles having particle sizes of 100 μm or more, a particle size distribution deviation SD of 0.5 or less, and sphericity of 0.5 or more, and wherein the pore-forming material is present in an amount of 5-40% by mass based on the cordierite-forming material and has an average particle size of 15-50 μm, with 10% or less by mass of particles having particle sizes of 5 μm or less and 5% or less by mass of particles having particle sizes of 80 μm or more.

Disclosed are porous elements that include sintered polymeric particles. The polymeric particles can be formed of a thermoplastic composition that includes a polyarylene sulfide. The polymeric particles sintered to form the porous elements have a very narrow size distribution. The porous elements can maintain their functionality and morphology even when utilized in high temperature applications.

A filter material composing a ceramic clay having an interconnected network of pores formed from cellulose fiber combustion is useful for removing chemical and biological contaminants from a water supply. Coating the ceramic clay with lanthanum enhances the removal of anionic species of As(V), As(III), Cr(VI), microbes and virus.

A nonwoven fabric is formed of fibers of 0.10 μm or more and 5.00 μm or less. The nonwoven fabric includes a coarse layer portion and a dense layer portion. In the coarse layer portion, a void volume Pc is at least 90% and an average pore diameter Dc is in a range of 0.5 μm or more and 50 μm or less. In the dense layer portion, a void volume Pd is at least 70% and a relative standard deviation of pore diameter distribution is 20% or less.

Producing a filtration body formed of a layered double hydroxide having a crystallite size of 20 nm or less carried on a carrier including a thermally fusible fiber is described. The carrier is prepared that has a first mesh carrier having a first mesh size and a second mesh carrier provided above the first mesh carrier. The second mesh carrier has a second mesh size larger than the first mesh size. A layered double hydroxide in the form of granules is supplied toward the second mesh carrier. The first mesh carrier carries the layered double hydroxide that has passed through the second mesh carrier. The carrier is shaken so that a portion of the layered double hydroxide (e.g., at least one granule) passes through the first and second mesh carriers. Thereafter, the layered double hydroxide carried on the first mesh carrier is adhered by thermally fusing the thermally fusible fiber.

Filter media comprising polyethersulfone, related components, and related methods are generally described.

Filter media and filters, such as air filters, face masks, gas turbine and compressor air intake filters, panel filters and the like, are provided that include nanoparticles dispersed throughout at least a portion of the filter media. A filter media comprises a fiber substrate with a first surface and an opposing second surface. The filter media includes nanoparticles disposed within the fiber substrate at least between the first and second surfaces such that an area density of the nanoparticles decreases from the first surface towards the second surface. This density gradient formed by the nanoparticles through at least a portion of the substrate improves the performance characteristics of the filter. The nanoparticles increase the overall surface area within the fiber substrate, which may increase its filtration efficiency and allows for the capture of submicron contaminants without significantly compromising other factors, such as pressure drop or air flow through the filter.

An object of the present invention is to provide a method for producing a propionic acid derivative with high productivity. The object can be achieved by a method for producing a compound represented by formula (1):

##STR00001##

wherein R.sup.1 is a halogen atom or the like, R.sup.2 and R.sup.3 are each independently a hydrogen atom, a halogen atom, or an organic group, X is an oxygen atom or a sulfur atom, R.sup.4 and R.sup.5 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group optionally having one or more substituents, R.sup.E is a hydrocarbon group optionally having one or more substituents; the method comprising step A of reacting a compound represented by formula (2):

##STR00002##

with a compound represented by formula (3):
M(R.sup.1).sub.n, wherein M is a cation, n is an integer corresponding to the valence of M, and a compound represented by formula (4):
R.sup.6—X—H; and
step B of separating, by filtration, the compound represented by formula (5): MF.sub.n from the mixture obtained by the above reaction.

Disclosed are a honeycomb structure body, a honeycomb structure filter and an extrusion molding die for a honeycomb structure body, which belong to the field of vehicle exhaust purification materials. The honeycomb structure body includes a honeycomb body and a skin layer around the honeycomb body, the honeycomb body including axially-extending channels defined by a porous wall, wherein a radial path of a radial section of the honeycomb body from a central axis to the skin layer consists of a porous wall inner section and a porous wall outer section in sequence, an average wall thickness of inner porous walls provided in the porous wall inner section is smaller than an average wall thickness of outer porous walls provided in the porous wall outer section, and a length of the porous wall inner section in the radial path accounts for 71%-95%. The arrangement of the specific structure of the honeycomb structure body of the present application not only increases the strength of the honeycomb structure body, but also ensures good thermal shock resistance and small back pressure of the honeycomb structure body; and the honeycomb structure body of the present application is prepared by integral molding, thereby achieving high production efficiency and low preparation cost.

Water impermeable, air permeable membrane assemblies are described herein. In some embodiments, the assemblies include a polymer membrane and at least one support structure. Certain assemblies are configured to provide an acoustic impedance having phase angle of +45 degrees to −45 over a frequency range of 50 to 20,000 Hz.