Method for manufacturing a honeycomb body having an inorganic filtration deposit - Patents.com

Abstract

A method of surface treating a plugged honeycomb body including porous walls includes spraying particles of an inorganic material into liquid-particulate-binder droplets comprising an aqueous vehicle, a binder material, and the particles, evaporating substantially all of the aqueous vehicle from the droplets to form agglomerates comprising the particles and the binder material, and depositing the agglomerates on the porous walls of the plugged honeycomb body, wherein the agglomerates are disposed on, within, or both on and within the porous walls. Also disclosed is a plugged honeycomb body including porous walls and an inorganic material deposited thereon.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 62 / 726,192, filed August 31, 2018, and International Application No. PCT / CN2018 / 103807, filed September 3, 2018, which are hereby incorporated by reference in their entireties. [Technical field]

[0002] The present disclosure relates to a method for producing a porous body, such as a porous ceramic honeycomb body, that includes an inorganic deposit, the deposit being comprised of an inorganic filtration material. [Background technology]

[0003] Wall-flow filters are used to remove particulates from fluid exhaust streams, such as the exhaust of a combustion engine. Examples include diesel particulate filters, which are used to remove particulates from diesel engine exhaust, and gasoline particulate filters (GPFs), which are used to remove particulates from gasoline engine exhaust. Exhaust gas to be filtered enters the inlet cells, passes through the cell walls, and exits the filter via the outlet channels. Particulates are trapped on or within the walls of the inlet cells as the gas traverses and exits the filter. Summary of the Invention

[0004] Aspects of the present disclosure relate to porous bodies and methods for making and using them.

[0005] In one aspect, disclosed herein is a method for applying an inorganic deposit to a honeycomb filter body, such as a plugged honeycomb filter body, the filter body comprising porous walls, the method comprising the steps of: atomizing a feed mixture into liquid-particulate-binder droplets, the feed mixture comprising an aqueous vehicle, a binder material, and particles of inorganic material; aerosolizing the liquid-particulate-binder droplets, e.g., with a gaseous carrier stream; removing, e.g., evaporating, substantially all of the aqueous vehicle from the droplets to form aerosolized particulate-binder agglomerates comprising the particles and the binder material; directing the aerosolized agglomerates toward the porous walls of the honeycomb filter body, thereby depositing the agglomerates on, or within, the porous walls, or both on and within the porous walls. In certain embodiments, the method further comprises heating the honeycomb filter body comprising the agglomerates for a time and temperature sufficient for the binder to bond the agglomerates to the porous walls, or for a time and temperature sufficient for at least some of the agglomerates to bond to each other, or both. In some embodiments, the method further comprises heating the honeycomb filter body including the aggregates for a time and temperature sufficient to decompose the binder. In some embodiments, the binder material includes silicon, and the method further comprises heating the honeycomb filter body including the aggregates for a time and temperature sufficient to form silica from the binder material. In one or more embodiments, the binder material is a silicon-containing compound. In one or more embodiments, the silicon-containing compound comprises a siloxane or polysiloxane, a silicone, a silicate, or a combination thereof. In one or more embodiments, the silicon-containing compound comprises a silicone compound, a polysiloxane, a silicone resin, a siloxane, an alkoxysiloxane, or a combination thereof. In one or more embodiments, the silicon-containing compound comprises a silicate, an alkali silicate, a sodium silicate, or a combination thereof.

[0006] In another aspect, a method for manufacturing a honeycomb filter body is disclosed herein, the method includes the steps of: mixing particles of an inorganic material together with an aqueous vehicle and a binder material to form a liquid-particulate-binder mixture, such as a suspension or colloid; atomizing the liquid-particulate-binder mixture with an atomizing gas to form liquid-particulate-binder droplets consisting of the aqueous vehicle, the binder material, and the particles, for example, by directing the liquid-particulate-binder mixture into a spray nozzle and atomizing with a forced atomizing gas; aerosolizing the droplets with a gaseous carrier stream and carrying the droplets toward the honeycomb body with a carrier gas stream through a duct closely connected to the honeycomb filter body, the carrier gas stream comprising a gaseous carrier stream. In one or more embodiments, the duct has an outlet end adjacent to the honeycomb filter body, and an inner surface of the duct defines a chamber. In one or more embodiments, the carrier gas stream further comprises an atomizing gas. The method further includes evaporating substantially all of the aqueous vehicle from the aerosolized droplets to form aerosolized particulate-binder aggregates of the particles and binder material, and depositing the aggregates on the porous walls of the honeycomb filter body. In one or more embodiments, the deposited aggregates are disposed on, or within, the porous walls, or both on and within the porous walls. In one or more embodiments, the carrier gas stream further includes a gas phase of the aqueous vehicle. In one or more embodiments, the carrier gas stream passes through the walls of the honeycomb filter body while the aggregates are being deposited on the porous walls of the honeycomb filter body by the atomizing gas.

[0007] In one or more embodiments, the carrier gas stream is delivered to the chamber of the duct in an annular flow surrounding the spray nozzle in co-flow around the droplets exiting the nozzle. In one or more embodiments, substantially all of the aqueous vehicle evaporates from the droplets to form aerosolized particulate-binder aggregates of particles and binder material; aerosolized conglomerates of particulate-binder aggregates are created; and the aggregates and individual, e.g., unconsolidated, aggregates are deposited on the porous walls of the honeycomb filter body. In one or more embodiments, the deposited aggregates and aggregates are disposed on, or within, the porous walls, or both on and within the porous walls. In one or more embodiments, the duct is in sealed fluid communication with the honeycomb filter body during deposition.

[0008] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter.

[0009] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. [Brief description of the drawings]

[0010] [Figure 1] 1 is a flow chart illustrating an exemplary embodiment of a process for forming a material according to embodiments disclosed herein. [Diagram 2] FIG. 1 is a schematic diagram of an apparatus for depositing inorganic materials according to embodiments disclosed herein. [Diagram 3] FIG. 1 is a schematic diagram of an apparatus for depositing inorganic materials according to embodiments disclosed herein. [Figure 4] FIG. 1 is a schematic diagram of an apparatus for depositing inorganic materials according to embodiments disclosed herein. [Diagram 5] FIG. 1 is a schematic diagram of an apparatus for depositing inorganic materials according to embodiments disclosed herein. [Figure 6] FIG. 1 is a schematic diagram of an apparatus for depositing inorganic materials according to embodiments disclosed herein. [Figure 7] Schematic diagram of an unblocked honeycomb body [Figure 8] FIG. 1 is a schematic diagram of a wall-flow particulate filter according to embodiments disclosed and described herein. [Figure 9] FIG. 9 is a cross-sectional longitudinal section of the particulate filter shown in FIG. [Figure 10] Schematic diagram of a honeycomb wall loaded with fine particles [Figure 11] 1 is a flow chart illustrating an exemplary embodiment of an aqueous-based process for forming a material according to embodiments disclosed herein. [Figure 12] FIG. 1 is a graph showing the filtration efficiency of various samples prepared according to embodiments disclosed herein before and after curing. [Figure 13] Graph showing pressure drop before and after curing for various samples prepared according to embodiments disclosed herein. [Figure 14A] SEM image showing alumina aggregates formed from an ethanol-based suspension (DK-2405-5%) [Figure 14B] SEM image showing alumina aggregates formed from an aqueous-based suspension (Allied-880-20%) [Figure 14C] SEM image showing alumina aggregates formed from an aqueous-based suspension (DK-880-20%) [Figure 14D] SEM image showing alumina aggregates formed from an aqueous-based suspension (DK-880-50%) [Figure 14E] SEM image showing alumina aggregates formed from an aqueous-based suspension (DK-9950-50%) [Figure 14F]SEM image showing alumina aggregates formed from an aqueous-based suspension (DK-2404-20%) [Figure 15A] Graph showing FE / dP performance for aqueous and ethanol-based processes for various samples prepared according to embodiments disclosed herein. [Figure 15B] FIG. 1 is a graph showing the FE versus sediment loading for aqueous and ethanol-based processes for various samples prepared according to embodiments disclosed herein. [Figure 16A] SEM images showing alumina aggregates formed from an ethanol-based suspension. [Figure 16B] SEM image showing alumina aggregates formed from an aqueous-based suspension and deposited on a porous ceramic wall. [Figure 16C] Graph showing aggregate particle size for aggregates produced by ethanol-based and aqueous-based processes. [Figure 16D] Graph showing cumulative aggregate size distribution produced by ethanol-based and aqueous-based processes. [Figure 17A] Graph showing the effect of different heat treatment temperatures on the durability of filtration efficiency with respect to water resistance of samples prepared according to embodiments disclosed herein. [Figure 17B] 1 is a graph showing the effect of different heat treatment temperatures on pressure drop on the water resistance of samples prepared according to embodiments disclosed herein. [Figure 18A] Graph showing the effect of heat treatment on filtration efficiency at different heat treatment temperatures on the water resistance of samples prepared according to embodiments disclosed herein. [Figure 18B] Graph showing the effect of heat treatment on pressure drop at different heat treatment temperatures for samples prepared according to embodiments disclosed herein. [Figure 19] Graph showing filtration efficiency after various durability tests including high flow rate test, low temperature vibration test, vehicle test, and two-stage water resistance test [Figure 20]FIG. 1 is a SEM photograph of a top view of the inlet region of an inlet channel of a plugged honeycomb body prepared according to embodiments disclosed herein. [Figure 21] FIG. 1 is a SEM photograph of a cutaway side view of the inlet region of an inlet channel of a plugged honeycomb body prepared according to embodiments disclosed herein. [Figure 22] FIG. 1 is a SEM photograph of a top view of the central region of an inlet channel of a plugged honeycomb body prepared according to embodiments disclosed herein. [Diagram 23] FIG. 1 is a SEM photograph of a cutaway side view of a central region of an inlet channel of a plugged honeycomb body prepared according to embodiments disclosed herein. [Figure 24] FIG. 1 is a SEM photograph of a top view of the outlet area of ​​an inlet channel of a plugged honeycomb body prepared according to embodiments disclosed herein. [Diagram 25] FIG. 1 is a SEM photograph of a cutaway side view of the outlet area of ​​an inlet channel of a plugged honeycomb body prepared according to embodiments disclosed herein. [Figure 26] FIG. 1 is a SEM photograph of a close-up cutaway side view of the outlet area of ​​an inlet channel of a plugged honeycomb body prepared according to embodiments disclosed herein. [Figure 27] SEM photo of Figure 26 with color inversion [Figure 28A] A portion of the SEM photograph of FIG. 27, with aggregate 1500 surrounded by a dashed line. [Figure 28B] A schematic diagram of an aggregate 1502 that forms the region of the assembly 1500 outlined in dashed lines in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Reference will now be made in detail to embodiments of methods for forming honeycomb bodies, including porous honeycomb bodies including inorganic deposits (or "filtration deposits") on, or within, or both on and within the porous ceramic walls of a honeycomb body matrix, embodiments of which are illustrated in the accompanying drawings. The filtration deposits include materials deposited on the honeycomb body as well as compounds that may be formed, for example, by heating, from one or more materials originally deposited. For example, a binder material may be converted by heating to an organic component that will eventually combust or volatilize, while the inorganic components (such as silica) remain contained within the honeycomb filter body. Whenever possible, the same reference numbers are used throughout the drawings to refer to the same or similar parts.

[0012] definition As used in this specification and the appended claims, the singular forms "a," "an," and "the" include embodiments having plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in its sense including "and / or" unless the content clearly dictates otherwise.

[0013] As used in this specification, the words "have," "having," "include," "including," "comprises," "including," and the like are used in the open-ended sense and generally mean "including but not limited to."

[0014] A "honeycomb body" as referred to herein includes a ceramic honeycomb structure of a matrix of intersecting walls forming cells that define channels. The ceramic honeycomb structure may be formed, extruded, or molded from a plasticized ceramic or ceramic forming batch mixture, or paste. The honeycomb body may include a peripheral wall or skin, extruded with the matrix of walls or applied after extrusion of the matrix. For example, the honeycomb body may be a plugged ceramic honeycomb structure that forms a filtering body made of cordierite or other suitable ceramic material. A plugged honeycomb body has one or more channels plugged at one or both ends of the body.

[0015] The honeycomb body disclosed herein includes a ceramic honeycomb structure with at least one wall carrying one or more filtration material deposits configured to filter particulate matter from a gas stream. The filtration material deposits may be present in discrete regions or may form one or more layers of filtration material in some portions or in some embodiments at given locations on the walls of the honeycomb body. The filtration material deposits according to some embodiments include inorganic materials, in some embodiments include organic materials, and in some embodiments include both inorganic and organic materials. For example, the honeycomb body, in one or more embodiments, may be formed from cordierite or other porous ceramic materials and further includes inorganic material deposits disposed on or under the walls of the cordierite honeycomb structure.

[0016] In some embodiments, the filtration material includes one or more inorganic materials, such as one or more ceramic or refractory materials.

[0017] As used herein, "unfired" or "unfired ceramic" are used interchangeably and refer to unsintered or unfired materials, unless otherwise specified.

[0018] method Aspects of the present disclosure relate to methods of forming porous bodies, such as porous ceramic honeycomb bodies, that include a filtration material, such as an inorganic material, for example a ceramic or refractory material, or even a material such as a porous ceramic or refractory material. In certain embodiments, the filtration material is an aerosol-deposited filtration material. In some preferred embodiments, the filtration material includes a plurality of inorganic particle agglomerates, the agglomerates being composed of an inorganic material, such as a ceramic or refractory material. In some embodiments, the agglomerates are porous, which may allow gas to flow through the agglomerates.

[0019] Aerosol deposition allows for the deposition of filtration material onto the porous ceramic walls, which may be as small as a single agglomerate or as large as multiple agglomerates in discrete areas, and in some embodiments, present on or within, or both on and within, at least some of the surfaces of the walls of the ceramic honeycomb body, in the form of a porous layer of filtration material. In certain embodiments, an advantage of the aerosol deposition method according to one or more embodiments is that ceramic honeycomb bodies with improved filtration performance may be economically and / or more efficiently produced.

[0020] In certain embodiments, the aerosol deposition process disclosed herein includes preparing a mixture (e.g., inorganic material, liquid vehicle, and binder), spraying the mixture with an atomizing gas using a nozzle to form aggregates and / or conglomerates of the inorganic material, aqueous vehicle, and binder, if any, drying the aggregates and / or conglomerates in the presence of a carrier gas or gaseous carrier stream, depositing the aggregates and / or conglomerates on a honeycomb body, and optionally curing the material. In some embodiments, the walls of the apparatus can be heated to aid in drying the aggregates and / or conglomerates.

[0021] In various embodiments, in addition to or instead of heating the walls of the apparatus, the carrier gas can be heated so that the liquid vehicle can evaporate from the aggregates faster, which can produce the aggregates more efficiently. The heated gaseous carrier stream carries both the atomized droplets and the aggregates formed through the apparatus into the honeycomb body. In some embodiments, the atomizing gas is heated alone or in combination with heating the carrier gas. In some embodiments, co-flow of the aerosolized droplets and / or aggregates with the gaseous carrier stream in substantially the same direction into the chamber of the apparatus can help reduce material loss or overspray on the walls of the apparatus. Furthermore, a converging section can be added to the apparatus before the aggregates enter the ceramic honeycomb body to help the gas flow and particle tracking be more uniform throughout the apparatus. The inner diameter of the end of the converging section can be slightly larger than the outer diameter of the ceramic honeycomb body to reduce or eliminate boundary effects of non-uniform particle deposition.

[0022] Atomizing nozzles or atomizers can use high pressure and / or high velocity atomizing gas to break up a suspension containing a mixture of liquid vehicle, binder, and solid particles into small droplets, for example, with an average droplet size of 4-6 micrometers. Heating of these droplets and rapid evaporation of the aqueous vehicle produces porous inorganic aggregates before depositing on the walls of the honeycomb body as porous inorganic features or structures. In some embodiments, the use of multiple nozzles can reduce the flow of liquid through each nozzle, resulting in smaller droplet sizes, even under the same operating conditions.

[0023] According to one or more embodiments, a process is disclosed herein that includes forming an aerosol with a binder, which is deposited on a honeycomb body to provide a high filtration efficiency material, which may be present in discrete areas and / or in some portions or in some embodiments in an inorganic layer on the honeycomb body to provide a particulate filter. According to one or more embodiments, the performance is greater than 90% filtration efficiency and less than 10% pressure drop penalty compared to a bare filter. According to one or more embodiments, as shown in FIG. 1, a process 400 includes preparing a mixture 405, spraying to form droplets 410, mixing the droplets with a gaseous carrier stream 415, evaporating the liquid vehicle to form aggregates 420, depositing the material, e.g., aggregates, on the wall of a wall-flow filter 425, and an optional post-treatment step 430, for example, to bind the material on, or in, or both on and in the porous walls of a honeycomb body. Aerosol deposition of the binder-containing aggregates can provide high mechanical integrity even without a high temperature curing step (e.g., heating to temperatures above 1000° C.), and in some embodiments can provide even higher mechanical integrity after a curing step, such as a high temperature (e.g., heating to temperatures above 1000° C.) curing step. In the process of FIG. 1, the aerosol deposition forms an inorganic material deposit, which in some specific embodiments is a porous material deposit. In some embodiments, the material deposit is in the form of discrete regions of filtration material. In some embodiments, at least some portions of the material deposit can be in the form of a porous inorganic layer.

[0024] In various embodiments, the process further includes switching between components such that deposition of the aggregates on the porous walls of the plugged honeycomb body occurs semi-continuously or continuously, thereby reducing idling time of the device. In one or more embodiments, the switching between components is timed such that deposition is substantially continuous within and / or on the plurality of ceramic honeycomb bodies. Continuous means that the operating device is maintained under operating temperature and pressure, as well as feed streams of raw material, and that the gaseous carrier stream and aggregate streams to components such as wall-flow filters are interrupted only to switch from a loaded component to an unloaded component. Semi-continuous also allows for minor interruptions in the feed streams of raw material and adjustments of operating temperature and pressure. In one or more embodiments, semi-continuous flow means that the flows are interrupted for 0.1% to 5% of the operating time, including 0.5% or more, 1% or more, 1.5% or more, 2% or more, 2.5% or more, and / or 4.5% or less, 4% or less, 3.5% or less, 3% or less. In one or more embodiments, flow continues for greater than or equal to 95% to less than or equal to 100% of the operating time, including greater than or equal to 96%, greater than or equal to 97%, greater than or equal to 98%, greater than or equal to 99%, greater than or equal to 99.5%, and / or less than or equal to 99.9%, less than or equal to 99%, less than or equal to 98%, less than or equal to 97%.

[0025] Mixture preparation 405. Commercially available inorganic particles can be used as a mixture source in forming the inorganic material for deposition. According to one or more embodiments, the particles can be Al 2 O 3 , SiO 2 , TiO 2 , CEO 2 , ZrO 2 , SiC, MgO, and combinations thereof. In one or more embodiments, the mixture is a suspension. The particles may be provided as a feedstock suspended in an aqueous vehicle to which an additional liquid vehicle is optionally added.

[0026] Thus, in some embodiments, the mixture is aqueous-based; for example, the aqueous vehicle of the suspension may be water. In one or more embodiments, the aqueous vehicle consists essentially of water.

[0027] In some embodiments, the suspension comprises 5-20% by weight particles and 80-95% by weight liquid, and all values ​​and subranges therebetween, In one embodiment, the suspension comprises 11 weight percent ±1% alumina and 89 weight percent ±1% water.

[0028] In one or more embodiments, the particles have an average primary particle size ranging from about 10 nm to about 4 micrometers, from about 20 nm to about 3 micrometers, or from about 50 nm to about 2 micrometers, or from about 50 nm to about 900 nm, or from about 50 nm to about 600 nm. In certain embodiments, the average primary particle size is in the range of about 100 nm to about 200 nm, e.g., 150 nm. The average primary particle size is currently in the range of 10 nm to about 4 micrometers, from about 20 nm to about 3 micrometers, or from about 50 nm to about 900 nm, or from about 50 nm to about 600 nm. 2 The aerosol particle surface area can be determined as the calculated value from the BET surface area of ​​the aerosol particles, which is 1 / g.

[0029] In one or more embodiments, the primary particles are ceramic particles, such as oxide particles, e.g., Al 2 O 3 , SiO 2 , MgO, CeO 2 , ZrO 2 , CaO, TiO 2 , cordierite, mullite, SiC, aluminum titanate, and mixtures thereof.

[0030] The mixture is formed with a solvent added to dilute the suspension as needed. If the droplets produced by spraying have a similar size, reducing the solids content in the mixture will reduce the size of the aggregates proportionately. The solvent must be miscible with the suspension and be a solvent for the binder and other ingredients.

[0031] Binders are optionally added to strengthen the aggregate and provide cohesion or adhesion, and may include inorganic binders to provide mechanical integrity to the deposited material. The binders can provide interparticle bond strength at high temperatures (>500°C). The starting material may be organic. After exposure to high temperatures above about 150°C, the organic starting material decomposes or reacts with moisture and oxygen in the air, resulting in a final deposited material composition that is Al. 2 O 3 , SiO 2 , MgO, CeO 2 , ZrO 2 , CaO, TiO 2 , cordierite, mullite, SiC, aluminum titanate, and mixtures thereof. An example of a suitable binder is Dowsil™ US-CF-2405 and Dowsil™ US-CF-2403, both available from The Dow Chemical Company. Exemplary binder contents range from 5% to 25% by weight of the particle content. In one embodiment, the binder content is 15-20% by weight ±1%.

[0032] A catalyst can be added to accelerate the curing reaction of the binder. An exemplary catalyst used to accelerate the curing reaction of Dowsil™ US-CF-2405 is titanium butoxide. An exemplary catalyst content is 1% by weight of the binder.

[0033] Agitation of the mixture or suspension during storage and / or while awaiting delivery to a nozzle can be accomplished by using any desired agitation technique. In one or more embodiments, the agitation is accomplished by a mechanical agitator. In one embodiment, the use of a mechanical agitator helps reduce and / or eliminate potential contamination from plastic coated mixing rods in contact with the holding vessel used in magnetic stirring systems.

[0034] Form droplets by atomization, step 410. The mixture is atomized into fine droplets by high pressure gas through a nozzle. An example nozzle is 1 / 4J-SS+SU11-SS from Spraying Systems Co. The setup consists of the nozzle body, fluid cap 2050 and air cap 67147. The atomizing gas can help break up the liquid-particulate-binder stream into droplets.

[0035] In one or more embodiments, the nozzles herein are nozzles that utilize internal mixing, such as the internal mixing nozzles whose part numbers are given above. In one or more embodiments, the nozzles herein are nozzles that utilize external mixing, such as the Spraying Systems external mixing nozzle setup: 1 / 4J-SS+SU1A consisting of a 64 air cap and a 1650 fluid cap. Another useful setup is configured with a 64 air cap and a 1250 fluid cap. External mixing nozzles can be advantageous to allow for smaller particle sizes and narrower particle size distributions that improve material utilization and filtration efficiency. External mixing nozzles tend to be less clogged compared to internal mixing nozzles. In one or more embodiments, the nozzles herein are converging nozzles. As used herein, converging nozzles refer to nozzles that have a fluid flow path that decreases in cross-sectional area from the inlet to the outlet, thereby accelerating the flow of the fluid. Converging nozzles can be internally mixed or externally mixed.

[0036] In one or more embodiments, the liquid-particulate-binder droplets are directed into the chamber by a nozzle.

[0037] In one or more embodiments, the liquid-particulate-binder droplets are directed into the chamber by a plurality of nozzles. In one or more embodiments, the step of spraying the plurality of liquid-particulate-binder streams is performed using a plurality of spray nozzles. The plurality of nozzles can include 2 or more nozzles, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, etc. The plurality of nozzles can be equally spaced within the chamber. In one or more embodiments, each of the plurality of nozzles is angled toward the center of the device. The nozzle angle can be acute and can range from less than 90° to more than 10° relative to the sidewall of the device, including all values ​​and subranges therebetween.

[0038] The pressure of the atomizing gas can range from 20 psi (about 138 kPa) to 150 psi (about 1034 kPa). The pressure of the liquid can range from 1 to 100 psi (about 6.9 to 689 kPa). The average droplet size according to one or more embodiments can range from 1 micrometer to 40 micrometers, including, for example, from 1 micrometer to 15 micrometers; from 2 micrometers to 8 micrometers; from 4 micrometers to 8 micrometers; and from 4 micrometers to 6 micrometers; and all values ​​and subranges therebetween. The droplet size can be adjusted by adjusting the surface tension of the mixture, the viscosity of the mixture, the density of the mixture, the gas flow rate, the gas pressure, the liquid flow rate, the liquid pressure, and the nozzle design. In one or more embodiments, the atomizing gas includes nitrogen. In one or more embodiments, the atomizing gas can consist essentially of an inert gas. In one or more embodiments, the atomizing gas can be predominantly one or more inert gases. In one or more embodiments, the atomizing gas can be predominantly nitrogen gas. In one or more embodiments, the nebulizing gas can be primarily air. In one or more embodiments, the nebulizing gas can consist essentially of nitrogen or air. In one or more embodiments, the nebulizing gas can be dry. In one or more embodiments, the nebulizing gas can be substantially free of liquid vehicle upon entering the chamber.

[0039] In some embodiments, the suspension flow rate is in the range of 10 to 25 g / min, including all values ​​and subranges therebetween, including 18 g / min.

[0040] In some embodiments, the atomizing gas flow rate, nitrogen flow rate, is 5 to 6 Nm 3 2 to 10 Nm / hr, including all values ​​and subranges therebetween 3 / hour range.

[0041] The flow of the suspension and the corresponding aggregate size can be controlled by a pressure control system or a flow control system, as appropriate for the device. In a pressure control system, a pressure controller communicates with a supply conduit, such as a tube or piping, into which a suspension of primary particles in a liquid is introduced, which then flows to a nozzle. The flow control system includes an injector pump that delivers the suspension of primary particles in a liquid to the nozzle. Atomizing gas is typically supplied separately to the nozzle. In a preferred embodiment, the pump directs the liquid-particulate-binder mixture at a substantially constant flow rate to the spray nozzle. A constant flow rate can be advantageous, as opposed to maintaining a constant pressure, as it can help reduce particle size variations and thus improve material utilization.

[0042] In one or more embodiments, the suspension includes an inorganic material, an aqueous vehicle, and in some embodiments, a binder, which is delivered to the nozzle as a liquid-particulate-binder stream. That is, particles of the inorganic material may be mixed with the aqueous vehicle and binder material to form the liquid-particulate-binder stream. The liquid-particulate-binder stream is atomized by the nozzle with an atomizing gas to form liquid-particulate-binder droplets. In one or more embodiments, the liquid-particulate-binder stream is mixed with the atomizing gas. In one or more embodiments, the liquid-particulate-binder stream is directed to an atomizing nozzle, thereby atomizing the particles and forming liquid-particulate-binder droplets. The liquid-particulate-binder droplets are comprised of the aqueous vehicle, the binder material, and the particles.

[0043] In one or more embodiments, the liquid-particulate-binder stream is mixed with the atomizing gas through a spray nozzle. In one or more embodiments, the liquid-particulate-binder stream enters the spray nozzle. In one or more embodiments, the mixing of the liquid-particulate-binder stream with the atomizing gas occurs inside the spray nozzle. In one or more embodiments, the mixing of the liquid-particulate-binder stream with the atomizing gas occurs outside the spray nozzle.

[0044] Mixing 415 the droplets and the gaseous carrier stream. The droplets are carried by the gaseous carrier stream towards the honeycomb body. In one or more embodiments, the gaseous carrier stream includes a carrier gas and an atomizing gas. In one or more embodiments, at least a portion of the carrier gas contacts the atomizing nozzle. In one or more embodiments, substantially all of the aqueous vehicle evaporates from the droplets to form agglomerates of particles and binder material.

[0045] In one or more embodiments, the gaseous carrier stream is heated before being mixed with the droplets. In one or more embodiments, the gaseous carrier stream is at a temperature in the range of 50°C to 500°C, including all values ​​and subranges between 80°C to 300°C, 50°C to 150°C, and all values ​​and subranges therebetween. Without being bound by theory, it is believed that the advantage of a higher temperature is that the droplets evaporate faster and are less likely to stick when they collide if most of the liquid evaporates. In certain embodiments, smaller aggregates contribute to the formation of a better filtration material deposit. Furthermore, it is believed that if the droplets collide but contain only a small amount of liquid (such as only the interior), the droplets may not coalesce into a spherical morphology. In some embodiments, non-spherical aggregates may provide desirable filtration performance.

[0046] In one or more embodiments, the atomizing gas is heated to form a heated atomizing gas that then flows through and / or contacts the nozzle. In one or more embodiments, the heated atomizing gas is at a temperature in the range of from 50° C. to 500° C., including all values ​​from 80° C. to 300° C., from 50° C. to 150° C., and all values ​​and subranges therebetween.

[0047] In one or more embodiments, both the carrier gas and the atomizing gas are heated independently and contacted with the nozzle. In one or more embodiments, the gaseous vapor is heated, but the atomizing gas and nozzle are maintained at a low temperature (approximately equal to room temperature, e.g., 25-40° C.). In one or more embodiments, the atomizing nozzle is cooled during atomization. In one or more embodiments, the temperature of the atomizing nozzle is maintained below the boiling point of the aqueous vehicle.

[0048] A carrier gas is provided to the apparatus to facilitate drying and transport of the liquid-particulate-binder droplets, and the resulting aggregates pass through the apparatus and into the honeycomb body. In one or more embodiments, the carrier gas is primarily an inert gas, such as nitrogen. In one or more embodiments, the carrier gas consists essentially of an inert gas. In one or more embodiments, the carrier gas is primarily one or more inert gases. In one or more embodiments, the carrier gas is primarily nitrogen gas. In one or more embodiments, the carrier gas is primarily air. In one or more embodiments, the carrier gas consists essentially of nitrogen or air. In one or more embodiments, the carrier gas is dry. In one or more embodiments, the carrier gas is free of liquid vehicle upon entering the chamber. In one or more embodiments, the carrier gas includes less than 5 weight percent water vapor. In one or more embodiments, the carrier gas is heated before being mixed with the droplets. In one or more embodiments, the carrier gas is at a temperature in the range of from 50° C. to 500° C., including all values ​​from 80° C. to 300° C., from 50° C. to 150° C., and all values ​​and subranges therebetween.

[0049] In one or more embodiments, the nebulizer gas and carrier gas are independently delivered to the device at a pressure of 90 psi (about 621 kPa) or greater, including 95 psi (about 655 kPa) or greater, 100 psi (about 689 kPa) or greater, 105 psi (about 724 kPa) or greater, 100 psi (about 689 kPa) or greater, 115 psi (about 793 kPa) or greater, or 120 psi (about 827 kPa) or greater. In one or more embodiments, a booster provides the nebulizer gas and carrier gas at the desired pressure.

[0050] The apparatus may include a diffusion zone downstream of the nozzle, where at least a portion of the mixing of the gaseous carrier stream with the liquid-particulate-binder droplets occurs in the diffusion zone.

[0051] When the gaseous carrier stream mixes with the liquid-particulate-binder droplets in the chamber, a gas-liquid-particulate-binder mixture is formed. The gas-liquid-particulate-binder mixture is heated in the mixing zone. In one or more embodiments, droplets of liquid containing particles and binder are present during mixing. In one or more embodiments, the gaseous carrier stream is heated prior to mixing with the liquid-particulate-binder droplets.

[0052] In one embodiment, the carrier gas is delivered to the chamber in an annular co-flow around the nozzle.In one embodiment, the carrier gas is delivered to the chamber of the duct in an annular flow around the nozzle in co-flow around the droplet at the end of the nozzle.

[0053] Evaporation 420 to form aggregates. To avoid the impact of liquid capillary forces that can form a non-uniform material that can result in a high pressure drop penalty, the droplets are dried in the evaporation section of the device to form dry solid aggregates that can be called secondary particles or "microparticles" composed of primary nanoparticles and binder type material. The aqueous vehicle or solvent evaporates and passes through the honeycomb body in a gas or vapor phase, minimizing residual or condensation of liquid solvent during deposition of the material. When the aggregates are carried to the honeycomb body by the gas flow, there should be less than 10% residual liquid in the inorganic material by weight. In some embodiments, the drying results in all liquid being evaporated and converted to a gas or vapor phase. Residual liquid in some embodiments includes solvent in the mixture, such as water condensed from the vapor phase. The binder is not considered a liquid residue, even though some or all of the binder may be in a liquid or other non-solid state prior to curing. In one or more embodiments, the total volumetric flow rate through the chamber is less than 5 Nm 3 / hour and / or 200Nm 3 / hr or less; 20Nm 3 / hour and / or 100Nm 3 / hr or less; and all values ​​and subranges therebetween. Higher flow rates can deposit more material than lower flow rates. Higher flow rates can be useful in producing larger cross-sectional area filters. Larger cross-sectional area filters may be applied in building filtration systems or outdoor filtration systems.

[0054] In one or more embodiments, substantially all of the aqueous vehicle is evaporated from the droplets to form agglomerates of particles and binder material that are interspersed in the gaseous carrier stream. In one or more embodiments, the apparatus has an evaporation section having an axial length sufficient to allow evaporation of at least a portion of the aqueous vehicle, including a substantial portion and / or all of the aqueous vehicle from the agglomerates.

[0055] With respect to flow, in one embodiment, the path of the droplets and the path of the gaseous carrier stream are substantially perpendicular before entering the evaporation section. In one or more embodiments, the carrier gas contacts the spray nozzle via a first path, and the path of the droplets and the second path of the carrier gas are substantially perpendicular to each other before entering the evaporation section of the duct.

[0056] In another embodiment, the path of the droplets and the path of the gaseous carrier stream are substantially parallel as they enter the evaporation section. In one or more embodiments, the path of the droplets and the path of the gaseous carrier stream are substantially parallel to one another as they enter the evaporation section of the duct. In one or more embodiments, the path of the droplets and the path of the carrier gas are substantially parallel to one another as they enter the evaporation section of the duct.

[0057] In one embodiment, the gaseous carrier flow exits the chamber in a direction substantially parallel to gravity. In one embodiment, the gaseous carrier flow exits the chamber substantially downward. In one embodiment, the gaseous carrier flow exits the chamber substantially upward.

[0058] Deposition on honeycomb body 425. The secondary particles, or agglomerates of primary particles, are carried in the gas flow, and the secondary particles or agglomerates, and / or aggregates thereof, are deposited on the inlet wall of the honeycomb body as the gas passes through the honeycomb body. In one or more embodiments, the aggregates and / or aggregates thereof are deposited on the porous walls of the plugged honeycomb body. The deposited aggregates may be located on, or within, the porous walls, or both on and within the porous walls. In one or more embodiments, the plugged honeycomb body includes an inlet channel that is plugged at a distal end of the honeycomb body and an outlet channel that is plugged at a proximal end of the honeycomb body. In one or more embodiments, the aggregates and / or aggregates thereof are deposited on, or within, or both on and within the walls that define the inlet channels.

[0059] The flow can be driven by a fan, blower, or vacuum pump. Additional air can be drawn into the system to achieve the desired flow rate. Desired flow rates range from 5 to 200 m 3 / hour range.

[0060] One exemplary honeycomb body is suitable for use as a gasoline particulate filter (GPF) and has the following non-limiting characteristics: diameter 4.055 inches (10.3 cm), length 5.47 inches (13.9 cm), cells per square inch (CPSI) 200 (approximately 31.0 cells / cm 2 ), wall thickness of 8 mils (203 micrometers), and average pore size of 14 μm.

[0061] In one or more embodiments, the average diameter of the secondary particles or aggregates ranges from 300 nm to 10 micrometers, 300 nm to 8 micrometers, 300 nm to 7 micrometers, 300 nm to 6 micrometers, 300 nm to 5 micrometers, 300 nm to 4 micrometers, or 300 nm to 3 micrometers. In certain embodiments, the average diameter of the secondary particles or aggregates ranges from 1.5 micrometers to 3 micrometers, including about 2 micrometers. The average diameter of the secondary particles or aggregates can be measured by scanning electron microscopy.

[0062] In one or more embodiments, the average diameter of the secondary particles or aggregates is in the range of 300 nm to 10 micrometers, 300 nm to 8 micrometers, 300 nm to 7 micrometers, 300 nm to 6 micrometers, 300 nm to 5 micrometers, 300 nm to 4 micrometers, or 300 nm to 3 micrometers, including 1.5 micrometers to 3 micrometers, including about 2 micrometers, and there is a ratio of the average diameter of the secondary particles or aggregates to the average diameter of the primary particles that is in the range of about 2:1 to about 67:1; :1 to about 9:1; about 2:1 to about 8:1; about 2:1 to about 7:1; about 2:1 to about 6:1; about 2:1 to about 5:1; about 3:1 to about 10:1; about 3:1 to about 9:1; about 3:1 to about 8:1; about 3:1 to about 7:1; about 3:1 to about 6:1; about 3:1 to about 5:1; about 4:1 to about 10:1; about 4:1 to about 9:1; about 4:1 to about 8:1; about 4:1 to about 7:1; about 4:1 to about 6:1; about 4:1 to about 5:1; about 5:1 to about 10:1; about 5:1 to about 9:1; about 5:1 to about 8:1; about 5:1 to about 7:1; or about 5:1 to about 6:1, including about 10:1 to about 20:1.

[0063] In one or more embodiments, depositing the aggregates on the porous walls further comprises passing a gaseous carrier stream through the porous walls of the honeycomb body, the walls of the honeycomb body filtering out at least some of the aggregates by trapping the filtered aggregates on or within the walls of the honeycomb body. In one or more embodiments, depositing the aggregates on the porous walls comprises filtering the aggregates from the gaseous carrier stream using the porous walls of the plugged honeycomb body.

[0064] Post-treatment 430. Post-treatment can optionally be used to adhere the aggregates to the honeycomb body and / or to each other. That is, in one or more embodiments, at least some of the aggregates adhere to the porous walls. In one or more embodiments, post-treatment includes heating and / or curing a binder, if present, according to one or more embodiments. In one or more embodiments, the binder material adheres or bonds the aggregates to the walls of the honeycomb body. In one or more embodiments, the binder material increases the cohesiveness of the aggregates.

[0065] Depending on the binder composition, the curing conditions vary. According to some embodiments, a low temperature curing reaction is used, for example, a temperature of 100° C. or less. In some embodiments, the curing can be completed in vehicle exhaust gases at a temperature of 950° C. or less. A bake treatment is optional and can be performed at a temperature of 650° C. or less. Exemplary curing conditions are temperatures ranging from 40° C. to 200° C. for 10 minutes to 48 hours.

[0066] In one or more embodiments, the aggregates and / or their aggregates are heated after being deposited on the honeycomb body. In one or more embodiments, heating the aggregates causes the organic components of the binder material to be removed from the deposited aggregates. In one or more embodiments, heating the aggregates causes the inorganic components of the binder material to physically bond the aggregates to the walls of the honeycomb body. In one or more embodiments, heating the aggregates causes the inorganic components of the binder to form a porous inorganic structure on the porous walls of the honeycomb body. In one or more embodiments, heating the deposited aggregates burns or volatilizes the organic components of the binder material from the deposited aggregates.

[0067] In one aspect, a method of surface treating a plugged honeycomb body including porous walls includes the steps of: mixing particles of an inorganic material with an aqueous vehicle and a binder material to form a liquid-particulate-binder stream; mixing the liquid-particulate-binder stream with an atomizing gas and directing the liquid-particulate-binder stream into a spray nozzle, thereby atomizing the particles into liquid-particulate-binder droplets comprised of the aqueous vehicle, the binder material, and the particles; conveying the droplets toward the plugged honeycomb body with a gaseous carrier stream, the gaseous carrier stream comprising a carrier gas and an atomizing gas; evaporating substantially all of the aqueous vehicle from the droplets to form aggregates comprised of the particles and the binder material; depositing the aggregates on the porous walls of the plugged honeycomb body, the deposited aggregates being disposed on, or within, the porous walls, or both on and within the porous walls.

[0068] In another aspect, a method of forming a honeycomb body includes the steps of: supplying a suspension to a nozzle in fluid communication with a duct having an evaporation section, the suspension including an inorganic material, a binder material, and an aqueous vehicle; supplying a carrier gas to the duct; contacting the nozzle with the carrier gas; evaporating at least a portion of the aqueous vehicle in the evaporation section, thereby forming aggregates of the inorganic material; depositing the aggregates on a wall of the honeycomb body; and bonding the inorganic material to the honeycomb body to form a porous inorganic material. The porous inorganic material may include primary particles and aggregates of these primary particles.

[0069] A further aspect is a method of applying an inorganic material to a blocked honeycomb body comprising a porous wall, the method comprising the steps of: supplying a suspension comprising particles of the inorganic material and an aqueous vehicle to a nozzle in fluid communication with a duct comprising an evaporation section; atomizing the suspension with an atomizing gas to form droplets; supplying a heated carrier gas; mixing a gaseous carrier stream comprising the heated carrier gas with the droplets in a chamber of the duct to form a gas-liquid-particulate-binder mixture; evaporating at least a portion of the aqueous vehicle from the droplets to form agglomerates of the particles, the agglomerates being interspersed in the gaseous carrier stream; passing the agglomerates and the gaseous carrier stream through a blocked honeycomb body in fluid communication with the duct, whereby the gaseous carrier stream passes through the porous walls of the blocked honeycomb body and the walls of the blocked honeycomb body capture the agglomerates, and the agglomerates and / or their aggregates are deposited on or in the walls of the honeycomb body.

[0070] Device Examples of apparatus that can be used in the process for depositing inorganic materials with a binder on a ceramic honeycomb body are shown in Figures 2-6. Generally, an apparatus suitable for the methods described herein includes a duct defining a chamber. The duct can have several sections that define different spaces and chambers. In one or more embodiments, the liquid droplets and the gaseous carrier stream are conveyed through a duct having an outlet end proximate to the plugged honeycomb body. The duct can include a converging section for engaging the proximal end of the honeycomb body. The converging section is advantageous in that convection of the fluid is enhanced. The duct can be in closed fluid communication with the plugged honeycomb body during the deposition process. In one or more embodiments, the duct is adiabatic or substantially adiabatic. In some embodiments, the nozzle temperature is adjusted to achieve a preferred atomization.

[0071] In some embodiments, a chamber with a round cross-section can facilitate keeping the aggregates entrained in the gaseous carrier flow. In various embodiments, a duct with a round cross-section reduces and / or prevents recirculation regions or "dead zones," which can be the result of, for example, the presence of corners.

[0072] In one or more embodiments, the average temperature of the duct walls is lower than the temperature of the gaseous carrier stream.In one or more embodiments, the average temperature of the duct walls is higher than the temperature of the gaseous carrier stream.

[0073] In the following, devices A-D (Figures 2-3 and 5-6) show schematic co-flow, where the paths of the droplets and the gaseous carrier stream are substantially parallel as they enter the evaporation section. Device "T" (Figure 4) shows the carrier gas contacting the spray nozzle via a first path, where the paths of the droplets and the second path of the carrier gas are substantially perpendicular to each other before entering the evaporation section of the duct.

[0074] FIG. 2 shows an apparatus 500 (apparatus “A”) for forming a honeycomb body, the apparatus 500 including a duct 551 , a deposition zone 531 , an exit zone 536 , an exit conduit 540 , and a flow driver 545 .

[0075] The duct 551 extends from a first end 550 to a second end 555 and defines a duct chamber including a plenum volume 503 at the first end 550 and an evaporation chamber 523 downstream of the plenum volume 503. In one or more embodiments, the duct 551 is substantially adiabatic. That is, the duct 551 may not have an external heat source. The evaporation chamber 523 is defined by an evaporation section 553 of the duct 551, which in this embodiment includes a first section 527 of non-uniform diameter and a second section 529 of substantially uniform diameter. The evaporation section 553 includes an inlet end 521 and an outlet end 525. The first section 527 of non-uniform diameter has an increasing diameter from the inlet end 521 to the uniform diameter section 529, which creates a divergence space for the flow to occupy.

[0076] Carrier gas is supplied by conduit 501 to duct 551, which may have a heat source for generating heated carrier gas 505. Atomizing gas 515 and suspension 510 are separately supplied by separate supply conduits, such as tubes or piping, to nozzle 520, which is at an inlet end 521 of evaporation section 553 and in fluid communication with duct 551 (specifically evaporation chamber 523 in this embodiment). Suspension 510 is sprayed into nozzle 520 with atomizing gas 515. In one or more embodiments, suspension 510 includes inorganic material, aqueous vehicle, and binder, as defined herein, and is a liquid-particulate-binder stream when supplied to the nozzle. The liquid-particulate-binder stream is atomized by nozzle 520 with atomizing gas 515 into liquid-particulate-binder droplets.

[0077] In one or more embodiments, the heated carrier gas 505 flows through a nozzle 520. The nebulizer gas 515 can be heated to form a heated nebulizer gas. The temperature of the nozzle can be adjusted as needed.

[0078] The outlet flow from the nozzle 520 and the flow of heated carrier gas 505 are both in the "Z" direction, as shown in Figure 2. Downstream of the nozzle there may be a diffusion region 522 where at least some mixing occurs. In this embodiment, the diffusion region 522 is located in the evaporation chamber 523, but in other embodiments the diffusion region 522 may be located in the plenum volume 503 depending on the location of the nozzle.

[0079] The outlet flow from the nozzle is mixed with a heated carrier gas 505, thereby forming a gas-liquid-particulate-binder mixture that flows through the chamber of duct 551. Specifically, the gas-liquid-particulate-binder mixture flows through an evaporation chamber 523 of evaporation section 553 and into a deposition zone 531 at an outlet end 525 of evaporation section 553. Upon mixing, the gas-liquid-particulate-binder mixture is heated within the chamber by the heated carrier gas.

[0080] In this embodiment, the nozzle exit flow and the heated carrier gas enter the evaporation chamber 523 of the evaporation section 553 from substantially the same direction. In the evaporation chamber 523, substantially all of the aqueous vehicle is evaporated from the droplets, thereby forming agglomerates of particles and binder material that are interspersed within a gaseous carrier flow of carrier gas and atomizing gas.

[0081] A deposition zone 531 in fluid communication with duct 551 contains a plugged ceramic honeycomb body 530, e.g. a wall-flow particulate filter. The deposition zone 531 has an inner diameter larger than the outer diameter of the ceramic honeycomb body 530. To avoid leakage of the gas carrying the ceramic powder, the ceramic honeycomb body 530 is sealed to the inner diameter of the deposition zone 531, a suitable seal being, e.g., an expandable "inner tube". A pressure gauge labeled "PG" measures the pressure difference upstream and downstream of the particulate filter.

[0082] The gas-liquid-particulate-binder mixture flows into the ceramic honeycomb body 530, thereby depositing the inorganic material in suspension onto the ceramic honeycomb body. Specifically, the aggregates and gaseous carrier stream enter the honeycomb body such that the gaseous carrier stream passes through the porous walls of the honeycomb body, the walls of the honeycomb body capture the aggregates, and the aggregates and / or their aggregates are deposited on or within the walls of the honeycomb body. The inorganic material bonds to the ceramic honeycomb body upon post-processing thereto. In one embodiment, the binder material adheres or bonds the aggregates to the walls of the honeycomb body.

[0083] Downstream of the ceramic honeycomb body 530 is an exit zone 536 that defines an exit chamber 535. A flow driver 545 is downstream of the ceramic honeycomb body 530 and is in fluid communication with the deposition zone 531 and the exit zone 536 via an exit conduit 540. Non-limiting examples of flow drivers are fans, blowers, and vacuum pumps. The aerosolized suspension is dried and deposited on one or more walls of the particulate filter as agglomerates of filtration material present as discrete regions of filtration material, or as portions or layers in some embodiments, or both, where the agglomerates are comprised of primary particles of inorganic material.

[0084] Flow-through embodiments, such as device 500, are considered to be directed downward, e.g., substantially parallel to the direction of gravity. In other embodiments, the device is configured such that the flow is directed substantially upward or vertically.

[0085] In FIG. 3, an apparatus 600 (apparatus “B”) for forming a honeycomb body is shown that includes a duct 651 , a deposition zone 631 , an exit zone 636 , an exit conduit 640 , and a flow driver 645 .

[0086] The duct 651 extends from a first end 650 to a second end 655 and defines a duct chamber including a plenum space 603 at the first end 650 and an evaporation chamber 623 downstream of the plenum space 603. In one or more embodiments, the diameter of the duct 651 that defines the plenum space 603 can be equal to the diameter of an evaporation section 653 of the duct 651 that defines the evaporation chamber 623. In one or more embodiments, the duct 651 is substantially adiabatic. That is, the duct 651 may not have an external heat source. The evaporation chamber 623 includes a single section of substantially uniform diameter 629 in this embodiment. The evaporation section 653 includes an inlet end 621 and an outlet end 625.

[0087] Carrier gas is supplied by conduit 601 to duct 651, which may have a heat source for generating heated carrier gas 605. Atomizing gas 615 and suspension 610 are separately supplied by separate supply conduits, such as tubes or piping, to nozzle 620, which is at the inlet end 621 of evaporation section 653 and in fluid communication with duct 651 (specifically evaporation chamber 623 in this embodiment). Suspension 610 is sprayed into nozzle 620 with atomizing gas 615. In one or more embodiments, suspension 610 includes inorganic material, aqueous vehicle, and binder, as defined herein, and is a liquid-particulate-binder stream when supplied to the nozzle. The liquid-particulate-binder stream is atomized by nozzle 620 with atomizing gas 615 into liquid-particulate-binder droplets.

[0088] In one or more embodiments, the heated carrier gas 605 flows through a nozzle 620. The atomizing gas 615 can be heated to form a heated atomizing gas. The temperature of the nozzle can be adjusted as needed.

[0089] The outlet flow from the nozzle 620 and the flow of heated carrier gas 605 are both in the "Z" direction, as shown in Figure 3. In certain embodiments, downstream of the nozzle there is a diffusion region 622 where at least some mixing occurs. In this embodiment, the diffusion region 622 is located in the evaporation chamber 623, although in other embodiments the diffusion region may be located in the plenum volume 603 depending on the location of the nozzle.

[0090] The exit flow from the nozzle is mixed with a heated carrier gas 605, thereby forming a gas-liquid-particulate-binder mixture that flows through the chamber of duct 651. Specifically, the gas-liquid-particulate-binder mixture flows through evaporation chamber 623 of evaporation section 653 and into deposition zone 631 at the exit end 625 of evaporation section 653. Upon mixing, the gas-liquid-particulate-binder mixture is heated within the chamber by the heated carrier gas.

[0091] In this embodiment, the nozzle exit flow and the carrier gas enter the evaporation chamber 623 of the evaporation section 653 from substantially the same direction. In the evaporation chamber 623, substantially all of the aqueous vehicle is evaporated from the droplets, thereby forming agglomerates of particle and binder material that are interspersed within a gaseous carrier flow of carrier gas and atomizing gas.

[0092] The deposition zone 631, in fluid communication with the duct 651, contains a plugged ceramic honeycomb body 630, such as a wall-flow particulate filter. The deposition zone 631 has an inner diameter larger than the outer diameter of the ceramic honeycomb body 630. To avoid leakage of the gas carrying the ceramic powder, the ceramic honeycomb body 630 is sealed to the inner diameter of the deposition zone 631, a suitable seal being, for example, an expandable "inner tube". A pressure gauge labeled "PG" measures the pressure difference upstream and downstream of the particulate filter. The gas-liquid-particulate-binder mixture flows into the ceramic honeycomb body 630, thereby depositing the inorganic material in suspension on the ceramic honeycomb body. Specifically, the aggregates and the gaseous carrier stream enter the honeycomb body such that the gaseous carrier stream passes through the porous walls of the honeycomb body, which capture the aggregates, which are deposited on or within the walls of the honeycomb body. The inorganic material bonds to the ceramic honeycomb body upon post processing of the ceramic honeycomb body, hi one embodiment, the binder material adheres or bonds the aggregates to the walls of the honeycomb body.

[0093] Downstream of the ceramic honeycomb body 630 is an exit zone 636 that defines an exit chamber 635. A flow driver 645 is downstream of the ceramic honeycomb body 630 and is in fluid communication with the deposition zone 631 and the exit zone 636 via an exit conduit 640. Non-limiting examples of flow drivers are fans, blowers, and vacuum pumps. The aerosolized suspension is dried and deposited on one or more walls of the particulate filter as agglomerates of filtration material present as discrete regions of filtration material, or as portions or layers in some embodiments, or both, where the agglomerates are comprised of primary particles of inorganic material.

[0094] Flow-through embodiments, such as device 600, are considered to be directed downward, e.g., substantially parallel to the direction of gravity. In other embodiments, the device is configured such that the flow is directed substantially upward or vertically.

[0095] In FIG. 4, an apparatus 900 (apparatus “T”) for forming a honeycomb body is shown including a duct 951 , a deposition zone 931 , an exit zone 936 , an exit conduit 940 , and a flow driver 945 .

[0096] The duct 951 includes a right cylindrical section 928 from a first end 950 to a second end 955, all defining a chamber of the duct including a first plenum volume 903 at the first end 950, an evaporation chamber 923 downstream of the first plenum volume 903, and a second plenum volume 929 defined by the right cylindrical section 928. In one or more embodiments, the diameter of the duct 951 defining the plenum volume 903 can be equal to the diameter of the first inlet location 921 of the evaporation section 953 of the duct 951. In one or more embodiments, the duct 951 is substantially adiabatic. That is, the duct 951 may not have an external heat source. The evaporation chamber 923 is defined by the evaporation section 953 of the duct 951. The evaporation section 953 includes a first inlet location 921 from the first plenum volume 903, a second inlet location 924 from the second plenum volume 929, and an outlet end 925. In some embodiments, some evaporation may occur in at least a portion of the second plenum volume 929 defined by the right cylindrical section 928.

[0097] A carrier gas is supplied by a conduit 901 in a first path to a duct 951, which may have a heat source 906a to generate a primary heated carrier gas 905a that enters a first plenum space 903, and optionally another secondary heated carrier gas 905b in a second path to a second plenum space 929. The atomizing gas 915 and the suspension 910 are separately supplied by separate supply conduits, such as tubes or piping, to a nozzle 920, which is in a second plenum space 929 of a right cylindrical section 928 and in fluid communication with an evaporation chamber 923 of an evaporation section 953. The suspension 910 is sprayed into the nozzle 920 with the atomizing gas 915. In one or more embodiments, the suspension 910 includes an inorganic material, an aqueous vehicle, and a binder, as defined herein, which is a liquid-particulate-binder stream as it is supplied to the nozzle. The liquid-particulate-binder stream is atomized by nozzle 920 with atomizing gas 915 into liquid-particulate-binder droplets.

[0098] In one or more embodiments, the secondary heated carrier gas 905b flows through a nozzle 920, and the temperature of the nozzle can be adjusted as needed.

[0099] The exit flow from the nozzle 920 and, if present, the flow of secondary heated carrier gas 905b are both in the "X" direction as shown in Figure 4. The flow of primary heated carrier gas 905a is in the "Z" direction as shown in Figure 4. Downstream of the nozzle, there may be a diffusion region 922 where at least some mixing occurs. In this embodiment, the diffusion region 922 is located at least partially within the second plenum volume 929, although in other embodiments the diffusion region 922 may be located in the evaporation chamber 923 depending on the location of the nozzle.

[0100] The outlet flow from the nozzles is mixed with heated carrier gas 905a and 905b, thereby forming a gas-liquid-particulate-binder mixture that flows through the chamber of duct 951. Specifically, the gas-liquid-particulate-binder mixture flows through evaporation chamber 923 of evaporation section 953 and into deposition zone 931 at the outlet end 925 of evaporation section 953. Upon mixing, the gas-liquid-particulate-binder mixture is heated within the chamber by the heated carrier gas.

[0101] In this embodiment, the nozzle exit flow and primary carrier gas 905a enters the evaporation chamber 923 of the evaporation section 953 from a substantially vertical direction. In the evaporation chamber 923, substantially all of the aqueous vehicle is evaporated from the droplets, thereby forming agglomerates of particle and binder material that are interspersed in a gaseous carrier flow comprised of the carrier gas and atomizing gas.

[0102] The deposition zone 931, in fluid communication with the duct 951, contains a plugged ceramic honeycomb body 930, such as a wall-flow particulate filter. The deposition zone 931 has an inner diameter larger than the outer diameter of the ceramic honeycomb body 930. To avoid leakage of the gas carrying the ceramic powder, the ceramic honeycomb body 930 is sealed to the inner diameter of the deposition zone 931, a suitable seal being, for example, an expandable "inner tube". A pressure gauge labeled "PG" measures the pressure difference upstream and downstream of the particulate filter. The gas-liquid-particulate-binder mixture flows into the ceramic honeycomb body 930, thereby depositing the inorganic material in suspension on the ceramic honeycomb body. Specifically, the aggregates and the gaseous carrier stream enter the honeycomb body such that the gaseous carrier stream passes through the porous walls of the honeycomb body, which capture the aggregates, which are deposited on or within the walls of the honeycomb body. The inorganic material bonds to the ceramic honeycomb body upon post processing of the ceramic honeycomb body, hi one embodiment, the binder material adheres or bonds the aggregates to the walls of the honeycomb body.

[0103] Downstream of the ceramic honeycomb body 930 is an exit zone 936 that defines an exit chamber 935. A flow driver 945 is downstream of the ceramic honeycomb body 930 and is in fluid communication with the deposition zone 931 and the exit zone 936 via an exit conduit 940. Non-limiting examples of flow drivers are fans, blowers, and vacuum pumps. The aerosolized suspension is dried and deposited on one or more walls of the particulate filter as agglomerates of filtration material present as discrete regions of filtration material, or as portions or layers in some embodiments, or both, where the agglomerates are comprised of primary particles of inorganic material.

[0104] Generally, flow-through embodiments, such as device 900, are considered to be directed downward, e.g., substantially parallel to the direction of gravity. In other embodiments, the device is configured such that the flow is directed substantially upward or vertically.

[0105] FIG. 5 illustrates an apparatus 700 (apparatus “C”) for forming a honeycomb body, the apparatus 700 including a duct 751 , a deposition zone 731 , an exit zone 736 , an exit conduit 740 , and a flow driver 745 .

[0106] The duct 751 extends from a first end 750 to a second end 755 and defines a duct chamber including a plenum space 703 at the first end 750 and an evaporation chamber 723 downstream of the plenum space 703. In one or more embodiments, the diameter of the duct 751 defining the plenum space 703 can be equal to the diameter of the evaporation section 753 at the inlet end 721. In one or more embodiments, the duct 751 is substantially adiabatic. That is, the duct 751 may not have an external heat source. The evaporation chamber 723 is defined by the evaporation section 753 of the duct 751, which in this embodiment includes a first section 727 of non-uniform diameter and a second section 729 of substantially uniform diameter. The evaporation section 753 includes an inlet end 721 and an outlet end 725. The non-uniform diameter first section 727 has a diameter that decreases from the exit end 725 to the uniform diameter section 729 , which creates a converging space for the flow as it enters the deposition zone 731 .

[0107] Carrier gas is supplied by conduit 701 to duct 751, which may have a heat source for generating heated carrier gas 705. Atomizing gas 715 and suspension 710 are separately supplied by separate supply conduits, such as tubes or piping, to nozzle 720, which is at the inlet end 721 of evaporation section 753 and in fluid communication with duct 751 (specifically evaporation chamber 723 in this embodiment). Suspension 710 is sprayed into nozzle 720 with atomizing gas 715. In one or more embodiments, suspension 710 includes inorganic material, aqueous vehicle, and binder, as defined herein, and is a liquid-particulate-binder stream when supplied to the nozzle. The liquid-particulate-binder stream is atomized by nozzle 720 with atomizing gas 715 into liquid-particulate-binder droplets.

[0108] In one or more embodiments, the heated carrier gas 705 flows through a nozzle 720. The atomizing gas 715 can be heated to form a heated atomizing gas. The temperature of the nozzle can be adjusted as needed.

[0109] The outlet flow from the nozzle 720 and the flow of heated carrier gas 705 are both in the "Z" direction, as shown in Figure 5. Downstream of the nozzle there may be a diffusion region 722 where at least some mixing occurs. In this embodiment, the diffusion region 722 is located in the evaporation chamber 723, but in other embodiments the diffusion region may be located in the plenum volume 703 depending on the location of the nozzle.

[0110] The exit flow from the nozzle is mixed with a heated carrier gas 705, thereby forming a gas-liquid-particulate-binder mixture that flows through the chamber of duct 751. Specifically, the gas-liquid-particulate-binder mixture flows through an evaporation chamber 723 of the evaporation section 753 and into a deposition zone 731 at the exit end 725 of the evaporation section 753. Upon mixing, the gas-liquid-particulate-binder mixture is heated within the chamber by the heated carrier gas.

[0111] In this embodiment, the nozzle exit flow and the heated carrier gas enter the evaporation chamber 723 of the evaporation section 753 from substantially the same direction. In the evaporation chamber 723, substantially all of the aqueous vehicle is evaporated from the droplets, thereby forming agglomerates of particles and binder material that are interspersed within a gaseous carrier flow of carrier gas and atomizing gas.

[0112] The deposition zone 731, in fluid communication with the duct 751, contains a plugged ceramic honeycomb body 730, such as a wall-flow particulate filter. The deposition zone 731 has an inner diameter larger than the outer diameter of the ceramic honeycomb body 730. To avoid leakage of the gas carrying the ceramic powder, the ceramic honeycomb body 730 is sealed to the inner diameter of the deposition zone 731, a suitable seal being, for example, an expandable "inner tube". A pressure gauge labeled "PG" measures the pressure difference upstream and downstream of the particulate filter. The gas-liquid-particulate-binder mixture flows into the ceramic honeycomb body 730, thereby depositing the inorganic material in suspension on the ceramic honeycomb body. Specifically, the aggregates and the gaseous carrier stream enter the honeycomb body such that the gaseous carrier stream passes through the porous walls of the honeycomb body, the walls of the honeycomb body capture the aggregates, and the aggregates and / or their aggregates are deposited on or within the walls of the honeycomb body. The inorganic material bonds to the ceramic honeycomb body upon post processing of the ceramic honeycomb body, hi one embodiment, the binder material adheres or bonds the aggregates to the walls of the honeycomb body.

[0113] Downstream of the ceramic honeycomb body 730 is an exit zone 736 that defines an exit chamber 735. A flow driver 745 is downstream of the ceramic honeycomb body 730 and is in fluid communication with the deposition zone 731 and the exit zone 736 via an exit conduit 740. Non-limiting examples of flow drivers are fans, blowers, and vacuum pumps. The atomized suspension droplets are aerosolized, dried, and deposited on one or more walls of the particulate filter as agglomerates of filtration material present as discrete regions of filtration material, or as portions or layers in some embodiments, or both, where the agglomerates are comprised of primary particles of inorganic material.

[0114] Flow-through embodiments, such as device 700, are considered to be directed downward, e.g., substantially parallel to the direction of gravity. In other embodiments, the device is configured such that the flow is directed substantially upward or vertically.

[0115] FIG. 6 illustrates an apparatus 800 for forming a honeycomb body (apparatus “D”) that includes a duct 851 , a deposition zone 831 , an exit zone 836 , an exit conduit 840 , and a flow driver 845 .

[0116] The duct 851 extends from a first end 850 to a second end 855 and defines a chamber of the duct including a plenum space 803 at the first end 850 and an evaporation chamber 823 downstream of the plenum space 803. In one or more embodiments, the duct 851 is substantially adiabatic. That is, the duct 851 may not have an external heat source. The evaporation chamber 823 is defined by an evaporation section 853 of the duct 851, which in this embodiment includes a first section 827 of non-uniform diameter and a second section 829 of substantially uniform diameter. The evaporation section 853 includes an inlet end 821 and an outlet end 825. The first section 827 of non-uniform diameter has a diameter that decreases from the outlet end 825 toward the uniform diameter section 829, which creates a convergence space for the flow as it enters the deposition zone 831. In some embodiments, evaporation section 853 is configured to have a single section of substantially uniform diameter, similar to device "B." Alternatively, evaporation section 853 has a non-uniform diameter section that increases from inlet end 821 to the uniform diameter section, similar to device "A."

[0117] Carrier gas is supplied by conduit 801 to duct 851, which may have a heat source for generating heated carrier gas 805. Atomizing gas 815 and suspension 810 are separately supplied to a number of nozzles 820a, 820b, and 820c in fluid communication with plenum volume 803 via separate supply conduits, such as tubes or piping. Each nozzle has an input of atomizing gas, e.g., 815a supplies nozzle 820a and 815b supplies nozzle 820b. Each nozzle has an input of suspension, e.g., 810a supplies nozzle 820a and 810b supplies nozzle 820b. Optionally, each nozzle has a supply of heated carrier gas, e.g., 802a supplies nozzle 820a and 802b supplies nozzle 820b. Although the embodiment of FIG. 6 shows three nozzles, in other embodiments, any number of multiple nozzles are used. The suspension 810 is atomized into the nozzle 820 along with the atomizing gas 815. In one or more embodiments, the suspension 810 includes an inorganic material, an aqueous vehicle, and a binder, as defined herein, and is a liquid-particulate-binder stream as it is delivered to the nozzle. The liquid-particulate-binder stream is atomized by the nozzle 820 along with the atomizing gas 815 into liquid-particulate-binder droplets.

[0118] In one or more embodiments, heated carrier gas 805 and optionally 802a and 802b flow through the nozzles. Atomizing gases 815a and 815b can be heated to form heated atomizing gases. The temperature of the nozzles can be adjusted individually or collectively as needed.

[0119] The flow of heated carrier gas 805 is in the "Z" direction as shown in Figure 6. The exit flows from nozzles 820a, 820b, and 820c may be angled toward the center of duct 851, but upon mixing with heated carrier gas 805, the exit flows of the nozzles are generally in the "Z" direction. Downstream of the nozzles there may be a diffusion region 822 where at least some mixing occurs. In this embodiment, diffusion region 822 is located in plenum volume 803, but in other embodiments the diffusion region may be located in evaporation chamber 823 depending on the location of the nozzle.

[0120] The exit flow from the nozzle is mixed with a heated carrier gas 805, thereby forming a gas-liquid-particulate-binder mixture that flows through the chamber of duct 851. Specifically, the gas-liquid-particulate-binder mixture flows through an evaporation chamber 823 of evaporation section 853 and into a deposition zone 831 at an exit end 825 of evaporation section 853. Upon mixing, the gas-liquid-particulate-binder mixture is heated within the chamber by the heated carrier gas.

[0121] In this embodiment, the nozzle exit flow and the heated gas enter the evaporation chamber 823 of the evaporation section 853 from substantially the same direction. In the evaporation chamber 823, substantially all of the aqueous vehicle is evaporated from the droplets, thereby forming agglomerates of particle and binder material that are interspersed within a gaseous carrier flow comprised of the carrier gas and the atomizing gas.

[0122] The deposition zone 831, in fluid communication with the duct 851, contains a plugged ceramic honeycomb body 830, such as a wall-flow particulate filter or "wall-flow filter". The deposition zone 831 has an inner diameter larger than the outer diameter of the ceramic honeycomb body 830. To avoid leakage of the gas carrying the ceramic powder, the ceramic honeycomb body 830 is sealed to the inner diameter of the deposition zone 831, a suitable seal being, for example, an expandable "inner tube". A pressure gauge labeled "PG" measures the pressure difference upstream and downstream of the particulate filter. The gas-liquid-particulate-binder mixture flows into the ceramic honeycomb body 830, thereby depositing the inorganic material in suspension on the ceramic honeycomb body. Specifically, the aggregates and the gaseous carrier stream enter the honeycomb body such that the gaseous carrier stream passes through the porous walls of the honeycomb body, the walls of the honeycomb body capture the aggregates, and the aggregates and / or their aggregates are deposited on or in the walls of the honeycomb body. The inorganic material bonds to the ceramic honeycomb body upon post processing of the ceramic honeycomb body, hi one embodiment, the binder material adheres or bonds the aggregates to the walls of the honeycomb body.

[0123] Downstream of the ceramic honeycomb body 830 is an exit zone 836 that defines an exit chamber 835. A flow driver 845 is downstream of the ceramic honeycomb body 830 and is in fluid communication with the deposition zone 831 and the exit zone 836 via an exit conduit 840. Non-limiting examples of flow drivers are fans, blowers, and vacuum pumps. The atomized suspension droplets are aerosolized, dried, and deposited on one or more walls of the particulate filter as agglomerates of filtration material present as discrete regions of filtration material, or as portions or layers in some embodiments, or both, where the agglomerates are comprised of primary particles of inorganic material.

[0124] Flow-through embodiments, such as device 800, are considered to be directed downward, e.g., substantially parallel to the direction of gravity. In other embodiments, the device may be configured such that the flow is directed substantially upward or vertically.

[0125] Honeycomb Body Overview The ceramic articles described herein include honeycomb bodies comprising a porous ceramic honeycomb structure with porous walls having walls defining a plurality of internal channels.

[0126] In some embodiments, the porous ceramic walls include a material such as a filtration material, which may include a porous inorganic layer disposed on some portions or, in some embodiments, one or more wall surfaces of the walls. In some embodiments, the filtration material includes one or more inorganic materials, such as one or more ceramic or refractory materials. In some embodiments, the filtration material is disposed on the walls to enhance filtration efficiency, both through and locally on the walls, and generally through the honeycomb body, at least during initial use of the honeycomb body as a filter after a clean or regenerated state of the honeycomb body, such as after an extended period of use of the honeycomb body as a filter and before substantial accumulation of ash and / or soot occurs on the inside of the honeycomb body.

[0127] In one aspect, the filtration material is present in some parts or embodiments as a layer disposed on the surface of one or more walls of the honeycomb structure. The layer in some embodiments is porous to allow gas to flow through the walls. In some embodiments, the layer is present as a continuous coating over at least a portion, or the entire surface, of one or more walls. In some embodiments of this aspect, the filtration material is a flame-deposited filtration material.

[0128] In another aspect, the filtration material is present as a plurality of discrete regions of filtration material disposed on the surface of one or more walls of the honeycomb structure. The filtration material may partially block some of the pores of the porous walls while allowing gas flow through the walls. In some embodiments of this aspect, the filtration material is an aerosol-deposited filtration material. In some preferred embodiments, the filtration material comprises a plurality of inorganic particle aggregates, the aggregates being made of an inorganic or ceramic or refractory material. In some embodiments, the aggregates are porous, thereby allowing gas flow through the aggregates.

[0129] In some embodiments, the honeycomb body comprises a porous ceramic honeycomb body having a first end, a second end, and a plurality of walls having walls defining a plurality of interior channels. Some portions or deposited materials, such as a filtration material, which in some embodiments may be a porous inorganic layer, are disposed on one or more walls of the honeycomb body.The deposited material, such as a filtration material, which may be a porous inorganic layer, has a porousness of about 20% to about 95%, or about 25% to about 95%, or about 30% to about 95%, or about 40% to about 95%, or about 45% to about 95%, or about 50% to about 95%, or about 55% to about 95%, or about 60% to about 95%, or about 65% to about 95%, or about 70% to about 95%, or about 75% to about 95%, or about 80% to about 95%, or about 85% to about 95%, or about 30% to about 95%, or about 40% to about 95%, or about 45% to about 95%, as measured by mercury intrusion porosimetry, SEM, or X-ray tomography. %, or about 50% to about 95%, or about 55% to about 95%, or about 60% to about 95%, or about 65% to about 95%, or about 70% to about 95%, or about 75% to about 95%, or about 80% to about 95%, or about 85% to about 95%, or about 20% to about 90%, or about 25% to about 90%, or about 30% to about 90%, or about 40% to about 90%, or about 45% to about 90%, or about 50% to about 90%, or about 55% to about 90%, or about 60% to about 90%, or about 65% to about 90%, or about 70% to about 90%, or about 75% to about 90%, or about 80% to about 90%, or about 85% to about 90%, or about 20% to about 85%, or about 25% to about 85%, or about 30% to about 85%, or about 40% to about 85%, or about 45% to about 85%, or about 50% to about 85%, or about 55% to about 85%, or about 60% to about 85%, or about 65% to about 85%, or about 70% to about 85%, or about 75% to about 85%, or about 80% to about 85%, or about 20% to about 80%, or about 25% to about 80%, or about 30% to about 80%, or about 40% to about 80%, or about 45% to about 80%, or about 50% to about 80%, or about 55% to about 80%, or about 60% to about The porous inorganic layer has a porosity in the range of 80%, or about 65% to about 80%, or about 70% to about 80%, or about 75% to about 80%, and the deposited material, such as a filtration material, which may be the porous inorganic layer, has an average thickness of 0.5 μm to 50 μm, or 0.5 μm to 45 μm, or 0.5 μm to 40 μm, or 0.5 μm to 35 μm, or 0.5 μm to 30 μm, or 0.5 μm to 25 μm, or 0.5 μm to 20 μm, or 0.5 μm to 15 μm, or 0.5 μm to 10 μm.Various embodiments of honeycomb bodies and methods of forming such honeycomb bodies are described herein with particular reference to the accompanying drawings.

[0130] The material in some embodiments comprises a filtration material, and in some embodiments, an inorganic filtration material. According to one or more embodiments, the inorganic filtration material provided herein comprises discrete regions and / or discontinuous layers formed from the inlet end to the outlet end, comprising discrete, unconnected patches of material or filtration material and binder, consisting of primary particles in secondary particles or aggregates that are substantially spherical. In one or more embodiments, the primary particles are non-spherical. In one or more embodiments, "substantially spherical" refers to aggregates having a cross-sectional area with a circularity in the range of about 0.8 to about 1, or about 0.9 to about 1, where 1 represents a perfect circle. In one or more embodiments, 75% of the primary particles deposited on the honeycomb body have a circularity of less than 0.8. In one or more embodiments, the secondary particles or aggregates deposited on the honeycomb body have an average circularity of greater than 0.9, greater than 0.95, greater than 0.96, greater than 0.97, greater than 0.98, or greater than 0.99.

[0131] Circularity can be measured using a Scanning Electron Microscope (SEM). The term "cross-sectional circularity (or simply circularity)" is a value that is expressed using the formula shown below. A circle with a circularity of 1 is a perfect circle: Circularity = (4π × cross-sectional area) / (circumference of cross section) 2 .

[0132] A honeycomb body of one or more embodiments may include a honeycomb structure and a deposited material, such as a filtration material, disposed on one or more walls of the honeycomb structure. In some embodiments, the deposited material, such as a filtration material, is applied to a surface of a wall present within the honeycomb structure, the wall having a surface that defines a plurality of internal channels.

[0133] The internal channels, if present, can have a variety of cross-sectional shapes, such as, for example, circles, ellipses, triangles, squares, pentagons, hexagons, or tessellated combinations of any of these, and can be arranged in any suitable geometric configuration. The internal channels, if present, can be discrete or intersecting and can extend through the honeycomb body from a first end thereof to a second end opposite the first end.

[0134] Referring now to FIG. 7, a honeycomb body 100 is shown according to one or more embodiments shown and described herein. The honeycomb body 100, in an embodiment, can include a plurality of walls 115 that define a plurality of internal channels 110. The plurality of internal channels 110 and intersecting channel walls 115 extend between a first end 105, which can be an inlet end or an outlet end, and a second end 135, which can be an outlet end, of the honeycomb body. The honeycomb body can have one or more channels blocked at one or both of the first end 105 and the second end 135. The pattern of blocked channels in the honeycomb body is not limited. In some embodiments, the pattern of blocked and unblocked channels at one end of the honeycomb body can be a checkerboard pattern with alternating channels at one end of the honeycomb body being blocked. In some embodiments, a blocked channel at one end of the honeycomb body has a corresponding unblocked channel at the other end, and an unblocked channel at one end of the honeycomb body has a corresponding blocked channel at the other end.

[0135] In one or more embodiments, the honeycomb body may be formed from cordierite, aluminum titanate, enstatite, mullite, forsterite, corundum (SiC), spinel, sapphirine, and periclase. Generally, cordierite can be represented by the formula Mg 2 Al 4 S 5 O 18In some embodiments, the pore size of the ceramic material, the porosity of the ceramic material, and the pore size distribution of the ceramic material are controlled, for example, by varying the particle size of the ceramic raw materials. Additionally, pore formers can be included in the ceramic batch used to form the honeycomb body.

[0136] In some embodiments, the walls of the honeycomb body can have an average thickness of 25 μm to 250 μm, e.g., 45 μm to 230 μm, 65 μm to 210 μm, 65 μm to 190 μm, or 85 μm to 170 μm. The walls of the honeycomb body can be described as having a base portion consisting of a bulk portion (also referred to herein as bulk) and a surface portion (also referred to herein as surface). The surface portion of the wall extends from the surface of the honeycomb body wall into the wall toward the bulk portion of the honeycomb body. The surface portion can extend to a depth of 0 to about 10 μm into the base portion of the wall of the honeycomb body. In some embodiments, the surface portion can extend about 5 μm, about 7 μm, or about 9 μm (i.e., a depth of 0 (zero)) into the base portion of the wall. The bulk portion of the honeycomb body constitutes the thickness of the wall minus the surface portion. Therefore, the bulk fraction of the honeycomb body can be determined by the following formula: T 全体 -2t 表面 Here, t 全体 is the total thickness of the wall, and t 表面 is the thickness of the wall surface.

[0137] In one or more embodiments, the bulk of the honeycomb body (before any filtration material is applied) has a bulk average pore size of 7 μm to 25 μm, such as 12 μm to 22 μm, or 12 μm to 18 μm. For example, in some embodiments, the bulk of the honeycomb body can have a bulk average pore size of about 10 μm, about 11 μm, about 12 μm, about 13 μm, about 14 μm, about 15 μm, about 16 μm, about 17 μm, about 18 μm, about 19 μm, or about 20 μm. Generally, the pore sizes of a given material exist in a statistical distribution. Thus, the term "average pore size" or "d50" (before any filtration material is applied) refers to the measurement of the length above which 50% of the pores have a pore size and below which the remaining 50% of the pores have a pore size, based on the statistical distribution of all pores. The pores in the ceramic body can be produced by at least one of the following: (1) the particle size and size distribution of the inorganic batch materials; (2) the firing time and temperature schedule of the furnace / heat treatment; (3) the furnace atmosphere (e.g., low or high oxygen and / or moisture content), and (4) pore formers such as, for example, polymers and polymer particles, starch, wood flour, hollow inorganic particles, and / or graphite / carbon particles.

[0138] In a particular embodiment, the average pore size (d50) of the bulk of the honeycomb body (before the application of the filtration material) ranges from 10 μm to about 16 μm, for example 13-14 μm, where d10 refers to the length measurement above which 90% of the pores are sized and below which the remaining 10% of the pores are sized, based on a statistical distribution of all pores, and is about 7 μm. In a particular embodiment, d90 refers to the length measurement above which 10% of the pores of the bulk of the honeycomb body (before the application of the filtration material) are sized and below which the remaining 90% of the pores are sized, based on a statistical distribution of all pores, and is about 30 μm. In a particular embodiment, the average diameter (D50) of the secondary particles or aggregates is about 2 micrometers. In certain embodiments, it has been determined that excellent filtration efficiency results and low pressure drop results are achieved when the average aggregate size D50 and the average wall pore diameter d50 of the bulk honeycomb body are such that the ratio of the average aggregate size D50 to the average wall pore diameter d50 of the bulk honeycomb body is in the range of 5:1 to 16:1. In more specific embodiments, the ratio of the average aggregate size D50 to the average wall pore diameter d50 of the bulk honeycomb body (before application of the filtration material) is in the range of 6:1 to 16:1, 7:1 to 16:1, 8:1 to 16:1, 9:1 to 16:1, 10:1 to 16:1, 11:1 to 16:1, or 12:1 to 6:1, resulting in excellent filtration efficiency results and low pressure drop results.

[0139] In some embodiments, the bulk of the honeycomb body can have a bulk porosity, excluding coating, of 50% or more to 75% or less, as measured by mercury intrusion porosimetry. Other methods for measuring porosity include scanning electron microscopy (SEM) and x-ray tomography, two methods that are particularly useful for measuring surface and bulk porosity independent of one another. In one or more embodiments, the bulk porosity of the honeycomb body can be, for example, in the range of about 50% to about 75%, in the range of about 50% to about 70%, in the range of about 50% to about 65%, in the range of about 50% to about 60%, in the range of about 50% to about 58%, in the range of about 50% to about 56%, or in the range of about 50% to about 54%.

[0140] In one or more embodiments, the surface portion of the honeycomb body has a surface average pore size of 7 μm to 20 μm, such as 8 μm to 15 μm, or 10 μm to 14 μm. For example, in some embodiments, the surface of the honeycomb body can have a surface average pore size of about 8 μm, about 9 μm, about 10 μm, about 11 μm, about 12 μm, about 13 μm, about 14 μm, or about 15 μm.

[0141] In some embodiments, the surface of the honeycomb body may have a surface porosity of 35% or more and 75% or less, prior to application of the filtration material deposition, as measured by mercury intrusion porosimetry, SEM, or X-ray tomography. In one or more embodiments, the surface porosity of the honeycomb body may be less than 65%, e.g., less than 60%, less than 55%, less than 50%, less than 48%, less than 46%, less than 44%, less than 42%, less than 40%, less than 48%, or less than 36%.

[0142] 8 and 9, a honeycomb body in the form of a particulate filter 200 is shown generally. The particulate filter 200 may be used as a wall-flow filter for filtering particulate matter from an exhaust gas stream 250, such as an exhaust gas stream emitted from a gasoline engine, in which case the particulate filter 200 is a gasoline particulate filter. The particulate filter 200 generally includes a honeycomb body having a plurality of channels 201 or cells extending between an inlet end 202 and an outlet end 204 and defining an overall length La (shown in FIG. 9). The channels 201 of the particulate filter 200 are formed by, and at least partially defined by, a plurality of intersecting channel walls 206 that extend from the inlet end 202 to the outlet end 204. The particulate filter 200 may also include an outer skin layer 205 surrounding the plurality of channels 201. This skin layer 205 may be extruded during formation of the channel walls 206, or may be formed in a later process as a subsequently applied skin layer, such as by applying a skin cement to the perimeter of the channel.

[0143] An axial cross section of the particulate filter 200 of FIG. 8 is shown in FIG. 9. In some embodiments, certain channels are designated as inlet channels 208 and certain other channels are designated as outlet channels 210. In some embodiments of the particulate filter 200, at least a first set of channels may be occluded with plugs 212. Generally, the plugs 212 are placed proximate to the ends of the channels 201 (i.e., the inlet or outlet ends). The plugs are generally placed in a predefined pattern, such as the checkerboard pattern shown in FIG. 8, where every other channel is occluded at an end. The inlet channels 208 may be occluded at or near the outlet end 204, and the outlet channels 210 may be occluded at or near the inlet end 202 of the channels that do not correspond to the inlet channels, as shown in FIG. 9. Thus, each cell may be occluded only at or near one end of the particulate filter.

[0144] While FIG. 8 generally illustrates a checkerboard plugging pattern, it should be understood that other plugging patterns may be used in the porous ceramic honeycomb article. In embodiments disclosed herein, the particulate filter 200 may be formed with a channel density of up to about 600 channels per square inch (cpsi). For example, in some embodiments, the particulate filter 100 may be formed with a channel density of up to about 100 cpsi (about 15.5 cells / cm). 2 ) ~ approx. 600cpsi (approx. 93.0 cells / cm 2 In some other embodiments, the particulate filter 100 may have a channel density in the range of about 100 cpsi (about 15.5 cells / cm). 2 ) ~ approx. 400cpsi (approx. 62.0 cells / cm 2 ), or even about 200 cpsi (about 31.0 cells / cm 2 ) ~ approx. 300cpsi (approx. 46.5 cells / cm 2 ) may have a channel density in the range of

[0145] In embodiments disclosed herein, the channel walls 206 of the particulate filter 200 can have a thickness greater than about 4 mils (101.6 micrometers). For example, in some embodiments, the thickness of the channel walls 206 can range from about 4 mils up to about 30 mils (762 micrometers). In some other embodiments, the thickness of the channel walls 206 can range from about 7 mils (177.8 micrometers) to about 20 mils (508 micrometers).

[0146] In some embodiments of the particulate filter 200 described herein, the channel walls 206 of the particulate filter 200 may have an exposed open porosity (i.e., the porosity before the coating is applied to the honeycomb body) %P≧35% prior to application of a coating to the particulate filter 200. In some embodiments, the exposed open porosity of the channel walls 206 may be such that 40%≦%P≦75%. In other embodiments, the exposed open porosity of the channel walls 206 may be such that 45%≦%P≦75%, 50%≦%P≦75%, 55%≦%P≦75%, 60%≦%P≦75%, 45%≦%P≦70%, 50%≦%P≦70%, 55%≦%P≦70%, or 60%≦%P≦70%.

[0147] Moreover, in some embodiments, the channel walls 206 of the particulate filter 200 are formed such that the pore distribution within the channel walls 206 has an average pore size of ≦30 micrometers prior to the application of any coatings (i.e., bare). For example, in some embodiments, the average pore size may be 8 micrometers or more and less than or equal to 30 micrometers. In other embodiments, the average pore size may be 10 micrometers or more and less than or equal to 30 micrometers. In other embodiments, the average pore size may be 10 micrometers or more and less than or equal to 25 micrometers. In some embodiments, particulate filters having an average pore size greater than about 30 micrometers have reduced filtration efficiency, while particulate filters manufactured with an average pore size less than about 8 micrometers may have difficulty infiltrating the pores with a washcoat containing a catalyst. Thus, in some embodiments, it is desirable to maintain the average pore size of the channel walls in the range of about 8 micrometers to about 30 micrometers, such as in the range of 10 micrometers to about 20 micrometers.

[0148] In one or more embodiments described herein, the honeycomb body of the particulate filter 200 is formed from a metal or ceramic material, such as, for example, cordierite, silicon carbide, aluminum oxide, aluminum titanate, or any other ceramic material suitable for use in high temperature particulate filtration applications. For example, the particulate filter 200 can be formed from cordierite by mixing a batch of ceramic precursor materials, which may include building materials suitable for producing ceramic articles containing a predominantly cordierite crystalline phase. Generally, building materials suitable for forming cordierite include a combination of inorganic components including talc, a silica-forming source, and an alumina-forming source. The batch composition may further include a clay, such as, for example, kaolin clay. The cordierite precursor batch composition may also include organic components, such as organic pore formers, which are added to the batch mixture to achieve the desired pore size distribution. For example, the batch composition may include starch suitable for use as a pore former and / or other processing aid. Alternatively, the build materials may include one or more cordierite powders suitable for forming a sintered cordierite honeycomb structure upon firing, as well as an organic pore former material.

[0149] The batch composition may further include one or more processing aids, such as, for example, a binder, and an aqueous vehicle, such as water or a suitable solvent. Processing aids are added to the batch mixture to plasticize the batch mixture and generally improve processing, reduce drying time, reduce cracking during firing, and / or help produce desired properties in the honeycomb body. For example, the binder may include an organic binder. Suitable organic binders include water-soluble cellulose ether binders, such as, for example, methylcellulose, hydroxypropylmethylcellulose, methylcellulose derivatives, hydroxyethyl acrylate, polyvinyl alcohol, and / or any combination thereof. Incorporating an organic binder into the plasticized batch composition allows the plasticized batch composition to be easily extruded. In some embodiments, the batch composition may include one or more optional forming or processing aids, such as, for example, a lubricant to aid in the extrusion of the plasticized batch mixture. Exemplary lubricants may include tall oil, sodium stearate, or other suitable lubricants.

[0150] After the batch of ceramic precursor material is mixed with appropriate processing aids, the batch of ceramic precursor material is extruded and dried to form a green honeycomb body including an inlet end and an outlet end with a plurality of channel walls extending between the inlet end and the outlet end. The green honeycomb body is then fired according to a firing schedule suitable for producing a fired honeycomb body. At least a first set of channels of the fired honeycomb body are then plugged in a predefined plugging pattern with a ceramic plugging composition, and the fired honeycomb body is fired again to ceramify the plugging and secure the plugging to the channel.

[0151] In various embodiments, the honeycomb body is configured to filter particulate matter from a gas stream, such as, for example, an exhaust gas stream from a gasoline engine. Thus, the average pore size, porosity, shape, and other design aspects of both the bulk and surface of the honeycomb body are selected with these filtration requirements of the honeycomb body in mind. As an example, as shown in the embodiment of FIG. 10, the wall 310 of a honeycomb body 300, which may be in the form of a particulate filter as shown in FIGS. 8 and 9, has a filtration material deposit 320 disposed thereon, which in some embodiments is sintered or otherwise bonded by a heat treatment. The filtration material deposit 320 is deposited on the wall 310 of the honeycomb body 300 and includes particles 325 that help prevent particulate matter, such as soot and / or ash, from exiting the honeycomb body with the gas stream 330 and from clogging the base portion of the wall 310 of the honeycomb body 300. Thus, according to an embodiment, the filtration material deposit 320 can function as a primary filtration component, while a base portion of the honeycomb body can be configured to minimize pressure drop, for example, as compared to a honeycomb body without such a filtration material deposit. The filtration material deposit is delivered by an aerosol deposition method as disclosed herein.

[0152] As mentioned above, the material on the wall of the honeycomb body, which may be an inorganic layer in some parts or in some embodiments, is very thin compared to the thickness of the base part of the wall of the honeycomb body. As will be explained in more detail below, the material on the wall of the honeycomb body, which may be an inorganic layer, may be formed by a method that allows the deposited material to be applied to the surface of the wall of the honeycomb body in a very thin coating or in some parts in a layer. In an embodiment, the average thickness of the material, which may be a deposited area or an inorganic layer, on the base part of the wall of the honeycomb body is 0.5 μm to 50 μm, or 0.5 μm to 45 μm, 0.5 μm to 40 μm, or 0.5 μm to 35 μm, or 0.5 μm to 30 μm, 0.5 μm to 25 μm, or 0.5 μm to 20 μm, or 0.5 μm to 15 μm, 0.5 μm to 10 μm.

[0153] As discussed above, some portions or deposited materials, which may be inorganic layers in some embodiments, may be applied to the walls of the honeycomb body by methods that allow the inorganic material, which may be an inorganic layer, to have a small average pore size. This small average pore size allows the material, which may be an inorganic layer, to filter a high percentage of fine particles and prevents the fine particles from penetrating the honeycomb and settling in the pores of the honeycomb. The small average pore size of the material, which may be an inorganic layer, according to embodiments, increases the filtration efficiency of the honeycomb body. In one or more embodiments, the material, which may be an inorganic layer, on the walls of the honeycomb body has an average pore size of 0.1 μm to 5 μm, for example, 0.5 μm to 4 μm, or 0.6 μm to 3 μm. For example, in some embodiments, the material, which may be an inorganic layer, on the walls of the honeycomb body may have an average pore size of about 0.5 μm, about 0.6 μm, about 0.7 μm, about 0.8 μm, about 0.9 μm, about 1 μm, about 2 μm, about 3 μm, or about 4 μm.

[0154] The material that may be an inorganic layer on the walls of the deposited honeycomb body may in some embodiments cover substantially 100% of the wall surfaces that define the internal channels of the honeycomb body, while in other embodiments the material that may be an inorganic layer on the walls of the honeycomb body covers substantially less than 100% of the wall surfaces that define the internal channels of the honeycomb body. For example, in one or more embodiments, the material that may be an inorganic layer on the walls of the deposited honeycomb body covers at least 70% of the wall surfaces that define the internal channels of the honeycomb body, covers at least 75% of the wall surfaces that define the internal channels of the honeycomb body, covers at least 80% of the wall surfaces that define the internal channels of the honeycomb body, covers at least 85% of the wall surfaces that define the internal channels of the honeycomb body, covers at least 90% of the wall surfaces that define the internal channels of the honeycomb body, or covers at least 85% of the wall surfaces that define the internal channels of the honeycomb body.

[0155] As described above with respect to Figures 8 and 9, the honeycomb body may have a first end and a second end. The first end and the second end are separated by an axial length. In some embodiments, the filtration material deposit on the wall of the honeycomb body may extend along the entire axial length of the honeycomb body (i.e., extend along 100% of the axial length). However, in other embodiments, the material, which may be an inorganic layer, on the wall of the honeycomb body may extend along at least 60% of the axial length, e.g., extend along at least 65% of the axial length, extend along at least 70% of the axial length, extend along at least 75% of the axial length, extend along at least 80% of the axial length, extend along at least 85% of the axial length, extend along at least 90% of the axial length, or extend along at least 95% of the axial length.

[0156] In embodiments, the material on the walls of the honeycomb body (which may be some portions or, in some embodiments, an inorganic layer) extends from a first end of the honeycomb body to a second end of the honeycomb body. In some embodiments, the material on the walls of the honeycomb body, which may be an inorganic layer, extends the entire distance from the first surface of the honeycomb body to the second surface of the honeycomb body (i.e., extends along 100% of the distance from the first surface of the honeycomb body to the second surface of the honeycomb body). However, in one or more embodiments, the layer or material, which may be an inorganic layer, on the wall of the honeycomb body extends along 60% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body, e.g., extends along 65% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body, extends along 70% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body, extends along 75% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body, extends along 80% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body, extends along 85% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body, extends along 90% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body, or extends along 95% of the distance between the first surface of the honeycomb body and the second surface of the honeycomb body.

[0157] Selecting a honeycomb body having a low pressure drop in combination with a low thickness and porosity of the filtration material on the honeycomb body according to the embodiment allows the honeycomb body of the embodiment to have a low initial pressure drop when compared to other honeycomb bodies. In an embodiment, the bed loading is in the range of 0.3-30 g / L on the honeycomb body, such as in the range of 1-30 g / L on the honeycomb body, or in the range of 3-30 g / L on the honeycomb body. In other embodiments, the bed loading is in the range of 1-20 g / L on the honeycomb body, such as in the range of 1-10 g / L on the honeycomb body, or 0.1-10 g / L, or 0.1-5 g / L on the honeycomb body. In certain embodiments, the layer loading ranges from 1-9 g / L, 1-8 g / L, 1-7 g / L, 1-8 g / L, 1-5 g / L, 1-4 g / L, 1-3 g / L, 2-10 g / L, 2-9 g / L, 2-8 g / L, 2-7 g / L, 2-6 g / L, 2-5 g / L, 2-4 g / L, 3-10 g / L, 3-9 g / L, 3-8 g / L, 3-7 g / L, 3-6 g / L, 3-5 g / L, 4-10 g / L, 4-9 g / L, 4-8 g / L, 4-7 g / L, or 4-6 g / L on the honeycomb body. In some embodiments, the increase in pressure drop across the honeycomb by applying a porous layer over it is less than 20% of that of an uncoated honeycomb. In other embodiments, the increase can be 9% or less, or 8% or less. In other embodiments, the increase in pressure drop across the honeycomb body is 7% or less, such as 6% or less. In yet other embodiments, the increase in pressure drop across the honeycomb body is 5% or less, such as 4% or less, or 3% or less.

[0158] Without being bound by any particular theory, it is believed that the small pore size of the filtration material deposit on the wall of the honeycomb body allows the honeycomb body to have good filtration efficiency even before the honeycomb body experiences ash or soot accumulation. The filtration efficiency of the honeycomb body is measured herein using the protocol outlined in Tandon et al., 65 Chemical Engineering Science 4751-60 (2010). As used herein, the initial filtration efficiency of the honeycomb body refers to a new or regenerated honeycomb body that does not contain any measurable soot or ash load. In an embodiment, the initial filtration efficiency (i.e., clean filtration efficiency) of the honeycomb body is 70% or more, such as 80% or more, or 85% or more. In yet another embodiment, the initial filtration efficiency of the honeycomb body is greater than 90%, such as 93% or more, or 95% or more, or 98% or more.

[0159] The material, which in some embodiments is an inorganic filtration material, on the walls of the honeycomb body according to the embodiment is thin and porous, and in some embodiments also has good chemical durability and physical stability. The chemical durability and physical stability of the filtration material deposit on the honeycomb body can be determined in embodiments by subjecting the honeycomb body to a test cycle including a burnout cycle and an aging test, and measuring the initial filtration efficiency before and after the test cycle. For example, one exemplary method for measuring the chemical durability and physical stability of the honeycomb body includes the steps of measuring the initial filtration efficiency of the honeycomb body; loading the honeycomb body with soot under simulated operating conditions; burning out the accumulated soot at about 650°C; subjecting it to an aging test at 1050°C and 10% humidity for 12 hours; and measuring the filtration efficiency of the honeycomb body. The soot accumulation and burnout cycle can be performed multiple times. A small change in filtration efficiency (ΔFE) from before the test cycle to after the test cycle indicates a better chemical durability and physical stability of the filtration material deposit on the honeycomb body. In some embodiments, ΔFE is 5% or less, such as 4% or less, or 3% or less, hi other embodiments, ΔFE is 2% or less, or 1% or less.

[0160] In some embodiments, the filtration material deposit on the walls of the honeycomb body is, for example, SiO 2 , Al 2 O 3 , MgO, ZrO 2 , CaO, TiO 2 , CEO 2 , Na 2 The filtration material deposit on the honeycomb body wall may be composed of one or a mixture of ceramic components, such as ceramic components selected from the group consisting of O, Pt, Pd, Ag, Cu, Fe, Ni, and mixtures thereof. Thus, the filtration material deposit on the honeycomb body wall may include oxide ceramics. As discussed in more detail below, the method of forming the filtration material deposit on the honeycomb body according to the embodiment may allow customization of the filtration material composition for a given application. This may be beneficial, for example, because the ceramic components may be combined to match the physical properties of the honeycomb body (e.g., coefficient of thermal expansion (CTE) and Young's modulus, etc.), which may improve the physical stability of the honeycomb body. In some embodiments, the filtration material deposit on the honeycomb body wall may include cordierite, aluminum titanate, enstatite, mullite, forsterite, corundum (SiC), spinel, sapphirine, and periclase.

[0161] In some embodiments, the composition of the filtration material deposit on the walls of the honeycomb body is the same as the composition of the honeycomb body, however, in other embodiments, the composition of the filtration material is different from the composition of the walls of the honeycomb body matrix.

[0162] The properties of the filtration material deposit, as well as the properties of the honeycomb body as a whole, result from the ability to apply a sparse or thin porous filtration material having a small median pore size compared to the host honeycomb body.

[0163] In some embodiments, a method of forming a honeycomb body includes forming or obtaining a mixture or suspension including a ceramic precursor material and a solvent. The ceramic precursor material of the filtration material precursor can be, for example, SiO. 2 , Al 2 O3 , TiO 2 , MgO, ZrO 2 , CaO, CeO 2 , Na 2 Includes ceramic materials that act as sources of O, Pt, Pd, Ag, Cu, Fe, Ni, etc.

[0164] In one or more embodiments, the suspension is atomized with an atomizing gas to form liquid-particulate-binder droplets consisting of an aqueous vehicle, binder material, and particles, which are directed toward the honeycomb body, and then the aggregates formed upon removal or evaporation of the aqueous vehicle are deposited on the honeycomb body. In some embodiments, the honeycomb body may have one or more channels that are blocked at one end, such as the first end of the honeycomb body, during deposition of the aerosol on the honeycomb body. The blocked channels may be removed after deposition of the aerosol in some embodiments. However, in other embodiments, the channels may remain blocked even after deposition of the aerosol. The pattern of blocked channels in the honeycomb body is not limited, and in some embodiments, all of the channels in the honeycomb body may be blocked at one end. In other embodiments, only a portion of the channels in the honeycomb body may be blocked at one end. In such embodiments, the pattern of blocked and unblocked channels at one end of the honeycomb body is not limited, and may be, for example, a checkerboard pattern in which alternating channels at one end of the honeycomb body are blocked. The aerosol can be distributed evenly within the channels of the honeycomb body by blocking all or a portion of the channels at one end of the honeycomb body during deposition of the aerosol.

[0165] According to one or more embodiments, a binder having high temperature (e.g., greater than 400°C) resistance is included in the aggregates and filtration material deposits to enhance the integrity of the aggregates and deposits even at the high temperatures encountered in exhaust gas emission treatment systems. In certain embodiments, the filtration material may include about 5-25 wt.% Dowsil™ US-CF-2405, an alkoxy-siloxane resin. The microstructure of the filtration material deposits was similar to the as-deposited morphology after various tests described below. Inorganic binders Aremco Ceramabind™ 644A and 830 may also be used in one or more embodiments. The filtration efficiency of both samples was 850 Nm 3 The results showed that the solubility of the binders was greater than 60% after a high flow blow test, a high flow test at 10000 / hr. The tests demonstrated that the binders, including organic and inorganic binders, bind primary particles to form secondary particles (also called agglomerates) that bind to the filter walls, even when exposed to high temperatures encountered in the engine exhaust stream. According to one or more embodiments, silicates (e.g., Na 2 SiO 3 ), phosphates (e.g. AlPO 4 , AlH 2 (PO 4 ) 3 ), hydraulic cements (e.g., calcium aluminate), sols (e.g., mSiO 2 nH 2 O, Al(OH) x ·(H 2 O) 6-x ), and other inorganic and organic binders such as metal alkoxides may also be utilized to enhance mechanical strength, for example, by an appropriate curing process.

[0166] Aqueous-based methods According to one or more embodiments, a method is disclosed for depositing an aqueous aerosol of inorganic material onto the porous walls of a plugged honeycomb body. The porous walls of the plugged honeycomb body form a plurality of channels in the honeycomb body. In certain embodiments, an aqueous-based suspension of inorganic material and binder passes through a nozzle, which, after contact with a gas flow, provides a stream of aerosol particles before being forced into the open channels of the honeycomb body. A layer of inorganic material is then deposited on the porous walls, with some aggregates or inorganic material entering the pores. An offline heat treatment process may be applied for curing the layer, which in some embodiments forms a membrane. According to one or more embodiments, both before and after curing, the honeycomb bodies manufactured and described herein exhibit significantly higher filtration efficiency and / or better FE / dP tradeoff than bare honeycomb body substrate parts.

[0167] 11, according to one or more embodiments, a process 1400 includes preparing an aqueous-based suspension 1405, spraying to form droplets 1410, mixing the droplets with a gaseous carrier stream 1415, evaporating the liquid vehicle to form aggregates 1420, depositing the material, e.g., aggregates, on the walls of a wall-flow filter 1425, and an optional post-processing step 1430 to bond the material, e.g., offline curing, to the porous walls of the honeycomb body, or both on and in the porous walls. Aerosol deposition of the aggregates with binder can provide high mechanical integrity without a high temperature curing step (e.g., heating to temperatures above 1000° C.), and in some embodiments can provide even higher mechanical integrity after an optional offline curing step, such as a high temperature (e.g., heating to temperatures above 1000° C.) curing step. In one or more embodiments, "off-line" refers to a curing process that is carried out separately from the aerosol deposition device, such as in a separate device.

[0168] In one or more embodiments, a stable aqueous inorganic material suspension or slurry is made by mixing a powder of an inorganic material (e.g., alumina) with deionized water and an aqueous binder. In some embodiments, such a suspension is made by diluting a commercially available aqueous-based organic suspension (e.g., an aqueous-based alumina suspension with deionized water) and then adding an aqueous-based binder. In some embodiments, it may be desirable to add a dispersing agent. The inorganic material is in the form of spherical, rod-like, flat, or irregular particles with a primary particle size between 30 nm and 500 nm. The concentration of the inorganic material, according to one or more embodiments, varies in the range of 1% to 20% by weight of the suspension. Exemplary ranges of inorganic materials by weight are 1-2%, 1-3%, 1-4%, 1-5%, 1-6%, 1-8%, 1-9%, 1-10%, 1-15%, 1-20%, 2-3%, 2-4%, 2-5%, 2-6%, 2-8%, 2-9%, 2-10%, 2-15%, 2-20%, 3-4%, 3-5%, 3-6%, 3-8%, 3-9%, 3-10%, 3-15%, 3-20%, 4-5%, 4-6%, 4-8%, 4-9%, 4-10%, 4-15%, 4-20%, 5-6%, 5-8%, 5-9%, 5-10%, 5-15%, 5-20%, 10-15%, 10-16%, 10-17%, 10-18%, 10-19%, 10-20%, 15-18%, 15-19%, and 15-20%. In one or more embodiments, the binder comprises an inorganic material or an organic material. Non-limiting examples of inorganic binders include silica, titania, silicates, aluminates, phosphates, or hydraulic cements. Non-limiting examples of organic binders include silicone resins, polyvinyl alcohol (PVA), or polyethylene glycol (PEG). The concentration of the binder can range from 5% to 100% by weight of the alumina.Exemplary ranges of binder by weight of inorganic material in mass % are 5-100%, 10-100%, 15-100%, 20-100%, 25-100%, 30-100%, 35-100%, 40-100%, 45-100%, 50-100%, 55-100%, 60-100%, 5-90%, 10-90%, 15-90%, 20-90%, 25-90%, 30-90%, 35-90%, 40-90%, 45-90%, 50-90%, 55-90%, 60~90%, 5~80%, 10~80%, 15~80%, 20~80%, 25~80%, 30~80%, 35~80%, 40~80%, 45~80%, 50~80%, 55~80%, 60~80%, 5~70%, 10~70%, 15~70%, 20~70%, 25~70%, 30~70%, 35~70%, 40~70%, 45~70%, 50~70%, 55~70%, 60~70%, 5~60%, 10~60%, 15~60%, 20~60 %, 25~60%, 30~60%, 35~60%, 40~60%, 45~60%, 50~60%, 55~60%, 5~50%, 10~50%, 15~50%, 20~50%, 25~50%, 30~50%, 35~50%, 40~50%, 45~50%, 5~40%, 10~40%, 15~40%, 20~40%, 25~40%, 30~40%, 35~40%, 5~30%, 10~30%, 15~30%, 20~30%, 25~30%, 5~2 5%, 10-25%, 15-25%, 20-25%, 1-20%, 2-20%, 3-20%, 4-20%, 5-20%, 6-20%, 7-20%, 8-20%, 9-20%, 10-20%, 1-15%, 2-15%, 3-15%, 4-15%, 5-15%, 6-15%, 7-15%, 8-15%, 9-15%, 10-15%, 1-10%, 2-10%, 3-10%, 4-10%, 5-10%, 6-10%, 7-10%, and 8-10%. In one or more embodiments, the mixing is performed mechanically or acoustically. The as-prepared suspension according to some embodiments is stable for at least 1 hour without any appreciable settling.

[0169] In some embodiments, the tape test can be used to roughly evaluate the effectiveness of different binders and to determine the amount of binder to be added to the suspension. A layer of wet coating of the sample suspension is prepared according to the embodiments described herein and then coated on one microscope slide using the as-prepared inorganic material suspension. After drying, the coated slide is placed in an oven and heated to the curing temperature for a time ranging from 10 minutes up to 2 hours. The curing temperature and profile vary depending on the binder used. After curing, a piece of regular tape, such as Highland™ transparent tape, is pressed onto the cured coating and then lifted off the coating. According to some embodiments, if particles of inorganic material are observed on the tape, the cohesive strength of the cured suspension is unacceptable. More binder or a different binder can be used and the test can be repeated.

[0170] FIG. 4, discussed above, shows a schematic diagram of a deposition system in which an aqueous-based suspension containing inorganic materials can be used for aerosol deposition, according to one or more embodiments. In FIG. 4, the suspension is contained in a suspension container 902, and hydraulic pressure is applied and controlled by a gas supply 904, which in some embodiments is in the form of a cylinder. In one or more embodiments, the pressure is controlled by a digital automatic pressure regulator or a piezo actuator valve. The atomizing gas according to one or more embodiments includes nitrogen or air. A first heat source 906a heats the carrier gas 905a entering the first plenum space 903. A second heat source 906b is positioned downstream of the nozzle 920 to heat the suspension 910 atomized in the nozzle 920. A third heat source 906c is positioned in the evaporation chamber 923, and the nozzle outlet flow and the primary carrier gas 905a enter the evaporation chamber 923 in the evaporation section 953.

[0171] In one or more embodiments, an aqueous-based aerosol deposition process and products made therewith are provided that provide closed honeycomb bodies including porous walls and inorganic material deposited thereon that exhibit significantly higher filtration efficiency and minimal backpressure penalty than those prepared by other methods. Such honeycomb bodies in some embodiments exhibit greater durability in certain tests, including vibration tests, vehicle tests, and water resistance tests, as further described below.

[0172] In certain embodiments, a process is provided that includes flowing an aqueous-based suspension of inorganic material (e.g., alumina nanoparticles) in suspension with a binder (e.g., a water-soluble silicate binder) through a spray nozzle to provide a stream of aerosol particles that form aggregates after contact with a dry gas stream. In certain embodiments, the aggregates are forced into the open channels of the plugged honeycomb body and onto and / or into the surfaces of the porous walls that form the channels. In some embodiments, the aggregates first contact the surface pores. In one or more embodiments, an offline heat treatment process is utilized to harden the binder and strengthen the deposit. After deposition and heat treatment, the filter components show improved filtration efficiency or FE / dP tradeoff performance compared to bare plugged honeycomb bodies. The plugged honeycomb bodies made according to the methods made herein pass various durability tests, including water resistance tests with heat treatment. According to one or more embodiments, a water-soluble or aqueous compatible binder is used. The aqueous process according to one or more embodiments forms a deposit with a microstructure of densely packed aggregates.

[0173] According to one or more embodiments, the aqueous-based process provides a less complicated and cheaper process than the ethanol-based process. In some embodiments, the lower deposit loading with the aqueous-based process results in similar FE / dP performance compared to the ethanol-based process, resulting in lower material costs, shorter deposition times, and higher production rates. In some embodiments, a higher FE can be achieved at the same loading compared to the ethanol-based process. In some embodiments, the morphology of the deposited inorganic material can be tailored to be similar for the ethanol-based and aqueous-based processes.

[0174] Closed honeycomb body containing inorganic material An embodiment of the present disclosure relates to a closed honeycomb body including porous walls and inorganic material deposited on or within the porous walls, or both on and within the porous walls, resulting in a filtration article configured to filter particulates from an exhaust gas stream. In a particular embodiment, the filtration article includes a gasoline particulate filter (GPF) used to remove particulates from a gasoline engine exhaust gas. Exhaust gas to be filtered enters the inlet cells, passes through the cell walls, and exits the filter via the outlet channels. As the gas traverses and exits the filter, particulates are trapped on or within the walls of the inlet cells. According to one or more embodiments, the porous walls of the filtration article with inorganic material deposited on or within the porous walls, or both on and within the porous walls, provide improved filtration efficiency and superior durability, including durability when exposed to water.

[0175] In one or more embodiments, the inorganic material includes fine particles or primary particles of inorganic material (e.g., alumina), fine particle-binder aggregates (referred to as "aggregates") consisting of particles and binder material, and aggregates of fine particle-binder aggregates. In one or more embodiments, "fine particles" or "primary particles" refer to the smallest discrete masses of inorganic material. In one or more embodiments, "aggregates" refer to masses of primary particles or fine particles and binder, where the primary particles or fine particles are held together by the binder. In one or more embodiments, "aggregates of fine particle-binder aggregates" or "aggregates of primary particle-binder aggregates" (referred to as "aggregates") refer to clustered masses of fine particle-binder aggregates or primary particle-binder aggregates, where they are held together by the binder. In one or more embodiments, some of the aggregates and individual, e.g., non-aggregated, aggregates are deposited on the porous walls of the honeycomb filter body. In one or more embodiments, at least a portion of the primary particles or fine particles are present in, on, or both in and on the porous walls as discrete masses that are not part of an aggregate or conglomerate. In one or more embodiments, at least a portion of the fine particle-binder aggregates or primary particle-binder aggregates are present in, on, or both in and on the porous walls as discrete masses that are not part of an aggregate.

[0176] In one or more embodiments, the inorganic material in or on the porous walls of a filtration article in the form of a plugged honeycomb body is present as "clusters" or "chains" of aggregates and / or aggregates. In some embodiments, the clusters or chains provide an inorganic material morphology that is one or more of finger-like, fibrillar, or spongy, e.g., resembling a sea sponge.

[0177] As discussed herein, according to embodiments, the inorganic material is formed from a suspension of nanoparticles (e.g., inorganic particles, ceramic particles, refractory particles, alumina particles, etc.), a binder (e.g., a silicon-containing binder and / or an aqueous binder), and a liquid vehicle (e.g., alcohol or water). The suspension is delivered to a nozzle, which atomizes droplets of the suspension with the assistance of a gas flow. The liquid vehicle evaporates from the droplets to form spherical agglomerates of the nanoparticles. The binder acts as one or more of an aggregation promoter, an assembly promoter, a chain promoter, and a cluster promoter. Some of the spherical agglomerates are carried to the porous ceramic wall and remain either on the surface of the porous ceramic wall (on, in, or throughout the surface pores present in the wall) or within the pores within the porous ceramic wall (below the surface of the porous ceramic wall), or come into contact with other previously deposited agglomerates located in or on the porous ceramic wall to form a collection of spherical agglomerates therein or thereon. The other spherical agglomerates contact further other spherical agglomerates as they are transported towards the honeycomb filter body to form agglomerates of spherical agglomerates, which are then transported towards the porous ceramic wall, where the agglomerates either remain on the surface of the porous ceramic wall (on, in, or throughout the surface pores present in the wall), or in the pores within the porous ceramic wall (below the surface of the porous ceramic wall), or come into contact with other previously deposited agglomerates or agglomerates that have been deposited either in or on the porous ceramic wall, forming agglomerates of spherical agglomerates in or on it.

[0178] Thus, according to one or more embodiments, the inorganic deposits consist of individual agglomerates of nanoparticles (e.g., spherical agglomerates of nanoparticles), aggregates of aggregates, and / or porous clusters or chains of aggregates of spherical agglomerates, where some clusters or chains are disposed within pores in or under the surface of the porous ceramic wall, and / or some clusters are disposed on the surface of the porous ceramic wall. In some embodiments, some of the porous clusters are porous clusters or cluster islands that include exposed aggregates of aggregates (e.g., spherical agglomerates). In some embodiments, the porous clusters or cluster islands include one or more chains of two or more aggregates, each chain extending substantially outwardly from the porous ceramic wall. In some embodiments, the multiple outwardly extending chains collectively provide a morphology that resembles a member of the group consisting of fingers, tufts, sponges (e.g., sea sponges), and fans. In some embodiments, at least one chain includes a free end of the chain that protrudes above the surface of the porous ceramic wall. In some embodiments, the inorganic material on the honeycomb body is present as an inorganic deposit that comprises a network of aggregated spherical agglomerates of inorganic material particles.

[0179] In an embodiment, the loading of inorganic material is present on the honeycomb body in a range of 0.3-30 g / L on the honeycomb body, such as in a range of 1-30 g / L on the honeycomb body, or in a range of 3-30 g / L on the honeycomb body, hi other embodiments, the loading of inorganic material is in a range of 1-20 g / L on the honeycomb body, such as in a range of 1-10 g / L on the honeycomb body. In certain embodiments, the loading of inorganic material is in the range of 1-9 g / L, 1-8 g / L, 1-7 g / L, 1-8 g / L, 1-5 g / L, 1-4 g / L, 1-3 g / L, 2-10 g / L, 2-9 g / L, 2-8 g / L, 2-7 g / L, 2-6 g / L, 2-5 g / L, 2-4 g / L, 3-10 g / L, 3-9 g / L, 3-8 g / L, 3-7 g / L, 3-6 g / L, 3-5 g / L, 4-10 g / L, 4-9 g / L, 4-8 g / L, 4-7 g / L, or 4-6 g / L on the honeycomb body. The loading of inorganic material is the weight of the material to be added in grams divided by the volume of the geometric part in liters. The volume of the geometric portion is based on the outer dimensions of the honeycomb filter body (or plugged honeycomb body).

[0180] In one or more embodiments, the particles of inorganic material are 5 μm or less. 2 / g~15m 2 / g, 5m 2 / g~14m 2 / g, 5m 2 / g~13m 2 / g, 5m 2 / g~12m 2 / g, 5m 2 / g~12m 2 / g, or 5m 2 / g~10m 2 / g range of surface area.

[0181] In one or more embodiments, the inorganic material deposit on the honeycomb body does not include rare earth oxides such as ceria, lanthana, and yttria. In one or more embodiments, the inorganic material does not include a catalyst, for example, an oxidation catalyst such as a platinum group metal (e.g., platinum, palladium, and rhodium) or a selective catalytic reduction catalyst such as a molecular sieve (e.g., zeolite) promoted with copper, nickel, or iron.

[0182] In one or more embodiments, prior to heat treatment of the honeycomb body including inorganic material on or in, or on and in, the honeycomb body further includes a water soluble binder, such as a water soluble silicon-containing binder, a water soluble silicate binder (e.g., a metal silicate binder such as sodium silicate), a water soluble aluminate binder (e.g., a metal aluminate binder such as sodium aluminate). In one or more embodiments, the binder is present in a range of 5% to 40%, 5% to 35%, 5% to 30%, 5% to 25%, 5% to 20%, 5% to 15%, or 5% to 10% by weight based on the weight of the organic material on the honeycomb body. In one or more embodiments, the binder or binder material is provided by a precursor binder or precursor binder material. In one or more embodiments, the precursor binder or precursor binder material is silicon-containing. In one or more embodiments, the silicon-containing precursor binder is a silicone resin, or a siloxane, or an alkali siloxane, or an alkoxy siloxane, or a silicate, such as an alkali silicate or sodium silicate. In one or more embodiments, the silicon-containing precursor binder is composed of an inorganic component and an organic component. In one or more embodiments, the silicon-containing precursor binder is transformed into silica when heat is applied. In one or more embodiments, the silicon-containing precursor binder is composed of an inorganic component and an organic component, and when heat is applied, the organic component is driven off and the inorganic component is transformed into silica. EXAMPLES

[0183] The embodiments will be further understood by the following non-limiting examples.

[0184] Wall-flow filter. The diameter and length of the wall-flow filter substrate used in the examples were 4.055 inches (about 10.3 cm) and 5.47 inches (about 13.9 cm). The CPSI was 200 (about 31.0 cells / cm 2 ) and had a wall thickness of 8 mils (203 micrometers). The pore size was 14 micrometers.

[0185] Raw Materials. Unless otherwise specified in the examples, the following raw materials were used: the inorganic material being deposited was alumina, the atomizing gas was nitrogen, and a binder was present. The carrier gas was either air or nitrogen.

[0186] Raw Material Utilization. Raw material utilization was determined by measuring the weight gain of the honeycomb and comparing it to the calculated amount of ceramic put into the process. For example, if the weight gain was equal to the amount of ceramic put into the process, the utilization was calculated to be 100%; alternatively, if the weight gain was only half of the ceramic put into the process, the utilization was calculated to be 50%.

[0187] In accordance with one or more embodiments, a honeycomb filter body including an inorganic deposit disposed within the honeycomb filter body to produce a filtration article is characterized according to the following test.

[0188] Smoke Filtration Efficiency (FE) A smoke filtration test was used to evaluate the smoke filtration efficiency performance of deposited inorganic materials disposed within a honeycomb filter body.

[0189] Filtration efficiency (in percent) is calculated as follows:

[0190]

number

[0191] where C is the smoke concentration at the exit and entrance sides of the part, respectively.

[0192] Two particle counter units (Lighthouse 2016, USA) are used simultaneously at upstream and downstream positions to objects located under the floor of the dilution chamber. A cigarette is lit in the smoke generator to provide a desired amount of soot particles in the dilution chamber and to reduce the concentration to a certain level (500,000 particles / cm) before the smoke moves to the entrance side of the tunnel. 3The flow is driven by a blower which carries the soot particles through a tunnel and ultimately to the wall-flow filter element. When the concentration upstream of the GPF reached a steady state, the two particle counters were reset to begin counting for 60 seconds and the filtration efficiency (FE) was calculated based on the difference in the total particle counts ≥0.3 μm. The pressure drop (dP) measured by pressure gauges located upstream and downstream of the article was also 51 Nm 3 Record at a fixed flow rate per hour.

[0193] Pre-test Canning During pre-test canning, the article is wrapped in a ceramic fiber mat material and then placed in a metal can. The article, mat, and can assembly is heated in an oven to 650°C and held at 650°C for a pre-determined period of time. The mat expands to help hold the article in place within the can. This process is called mat popping, as the mat expands and "pops" inside the can to hold the article in place. The duration of pre-test canning is selected based on the subsequent tests to be performed.

[0194] Post-test cleaning After the test has been performed, the following procedure is completed to accomplish post-test cleaning of the article: The article, mat, and can assembly are placed in a 650° C. oven and held at 650° C. for a predetermined time (usually about 6 hours) to burn off the soot loaded into the article from the article.

[0195] Clean Filtration Efficiency As used herein, the "clean filtration efficiency" of a honeycomb body or filtration article refers to a new or refurbished honeycomb body that does not contain a measurable soot load. In embodiments, the clean filtration efficiency of the honeycomb body or filtration article is 70% or greater, such as 80% or greater, or 85% or greater. In yet other embodiments, the initial filtration efficiency of the honeycomb body or filtration article is greater than 90%, such as 93% or greater, or 95% or greater, or 98% or greater.

[0196] As used herein, the "Clean Filtration Efficiency Test" refers to testing an article as follows.

[0197] After 6 hours of canning prior to testing, a blower provides airflow at a rapid rate upstream of the article and the clean pressure drop across the filter is measured using a differential pressure sensor / gauge at room temperature (approximately 25°C). The airflow rate is increased in 10 increments over a 25.5m 3 / 356.8m from time 3 / h and the flow rate was maintained for 1 minute after each new increment. Each increment ranged from approximately 8 to 68 m 3 / h. Next, the concentration was 8 mg / m 3 and flow rate of 22.5m 3 An airflow containing 10000 / hr soot particles is introduced upstream of the filter for 45 minutes. The soot is produced from a commercial propane burner with a particle size of approximately 110 nm. The clean filtration efficiency at 30°C is determined by measuring the difference between the number of particles introduced into the article and the number of particles exiting the article before and after exposure to flow conditions. After measuring the clean filtration efficiency, a post-test cleaning is performed for 6 hours.

[0198] Water Exposure Test Several evaluation protocols were utilized to understand the durability of the filtration articles disclosed herein. Analysis of the effect of various intensities of water exposure on honeycomb filter bodies having aerosol-deposited inorganic materials is indicative of the durability of the filtration articles.

[0199] Water immersion test As used herein, "Water Immersion Test" refers to testing an article as follows.

[0200] Water immersion tests were conducted to simulate the detection of an incoming water source when the vehicle's exhaust pipeline is underfloor.

[0201] First, the article is measured by the Clean Filtration Efficiency Test for a baseline FE / dP measurement.

[0202] The article is then weighed at 75°C to determine the initial weight. The article is then placed horizontally, skin side up, in a Petri dish to simulate the underfloor position of a filter in a vehicle's exhaust system, and immersed in a large amount of deionized water for 2 hours. After the part is saturated with water to the target amount, it is dried at 75°C until completely dry (weight returns to as deposited). The target amount of water can be measured in advance. For example, a nominal 300 grams of water can be used. In one or more embodiments, there is a water absorption level (e.g., 1 / 2 to 3 / 4 of the filter diameter), which can be described as a percentage of the distance along the diameter of the article facing the absorbed water. The article is then dried in a heating oven at 100°C for 5-6 hours until the initial weight is reached. The clean filtration efficiency is then measured. To evaluate the clean filtration efficiency, a concentration of 8 mg / m 3 and flow rate of 22.5m 3 An airflow containing 100 g / L soot particles is introduced upstream of the filter for 45 minutes. The soot is generated from a commercial propane burner with a particle size of about 110 nm. The clean filtration efficiency at 30°C is determined by measuring the difference between the number of particles introduced to the article and the number of particles exiting the article. After measuring the filtration efficiency, a post-test cleaning is performed for 6 hours. The filtration efficiency at 0 g / L soot is compared before and after exposing the article to a water immersion test.

[0203] Water Immersion Test Another method for evaluating the durability of filtration articles is a water immersion test, in which the parts are completely submerged in water to mimic the worst case scenario of submerging an exhaust pipeline in water.

[0204] As used herein, "water immersion test" refers to testing an article as follows.

[0205] First, the article is measured by the Clean Filtration Efficiency Test for a baseline FE / dP measurement.

[0206] The article is then weighed at 75°C to determine the initial weight. The article, with the inlet end facing down, is slowly immersed in a container of water for a predefined period of time. The amount of water depends on the size of the article in order to completely immerse the article. The sample is allowed to remain in the water for 1 minute and then slowly removed from the water and left for 2 hours. The article is weighed. The filter is then dried in an oven at 100°C for 5-6 hours until the initial weight is reached. Another clean filtration efficiency measurement is performed to evaluate the change in filtration efficiency after exposure to water.

[0207] Water nebulizer test As used herein, "water nebulizer testing" refers to testing an article as follows: The article is placed in a can containing a bladder. The bladder is inflated with air to hold the filter in place. The clean pressure drop across the filter is then measured using a differential pressure sensor / gauge at room temperature (approximately 25°C). The flow rate of exhaust gas upstream of the assembly is increased to 25.5 Nm in 10 increments. 3 356.8Nm / hour 3 / hr and the flow rate was maintained for 1 minute after each new step increment. Each step increment ranged from approximately 8 to 68 Nm 3 The filtration efficiency was then measured at 30°C and an exhaust flow rate of 21 Nm 3 / h, and 8.5 mg / m of soot particles with a median particle size of 120 nm. 3 A concentration of 10 ...

[0208] The article is weighed at room temperature. The article is exposed to a fine mist or spray of water using a nebulizer or atomizer as described in U.S. Pat. No. 7,520,918 until the part is exposed to 15 g / L of water. The article is then dried in an oven using 250° C. for 3 hours. The article and can assembly are then dried at 30° C. and 8.5 mg / m 3 And 21Nm 3 The filter is then tested for filtration efficiency at 1000 nm / hour and compared to the filtration efficiency at 0 g / L soot measured before the 650° C. heat treatment and nebulizer water exposure. The article is then subjected to a cleaning procedure in an oven at 650° C. for 12 hours. The filter is then removed from the can and exposed to a fine mist or spray of water using a nebulizer or sprayer as described in U.S. Pat. No. 7,520,918 until the part is exposed to 15 g / L water. The article is then dried in an oven using 650° C. for 9 hours. The article and can assembly is then dried at 30° C. and 8.5 mg / m 3 And 21Nm 3 The filtration efficiency at 0 g / L soot measured after the second nebulizer water exposure is compared to the baseline filtration efficiency at 0 g / L soot before the initial 650° C. heat treatment and nebulizer water exposure.

[0209] High Flow Test As used herein, "High Flow Test" refers to testing an article as follows.

[0210] First, the article is measured by the Clean Filtration Efficiency Test for a baseline FE / dP measurement.

[0211] The high flow rate is then introduced into the article. The flow rate of the exhaust gas upstream of the assembly is increased over 10 steps at about 25° C. for 85 m 3 / 850.8m from time 3 / hr and maintained the flow rate for 1 minute after each new increment. Each increment ranged from approximately 85 to 170 m 3 / h. Next, the concentration was 8 mg / m 3 and flow rate of 22.5m 3An airflow containing 100 g / L soot particles is introduced upstream of the filter for 45 minutes. The soot is generated from a commercial propane burner with a particle size of approximately 110 nm. The clean filtration efficiency at 30°C is determined by measuring the difference between the number of particles introduced to the article and the number of particles exiting the article before and after exposure to flow conditions. After measuring the filtration efficiency, a post-test cleaning is performed for 6 hours. The filtration efficiency at 0 g / L soot is compared before and after exposing the article to the high flow test.

[0212] Soot Loading Pressure Drop Test After 6 hours of canning prior to testing, the article was loaded with soot and the flow rate of the exhaust gas upstream of the assembly was increased over 10 steps at approximately 25°C for 25.5 m 3 / 356.8m from time 3 / h and the flow rate was maintained for 1 minute after each new increment. Each increment ranged from approximately 8 to 68 m 3 / hr. Soot loading was increased from 0g / L to 3g / L. After the filter was loaded with soot, the soot-loaded pressure drop across the filter was measured using a differential pressure sensor / gauge at room temperature (approximately 25°C). After the soot-loaded pressure drop was measured, a post-test cleaning was performed for 6 hours.

[0213] Low temperature vibration test The article is subjected to two-dimensional vibration at 706 m / s along the longitudinal and transverse axes. 2 , and place on a shaking table vibrating at 200 Hz for 2 hours.

[0214] Vehicle Testing The canned article is attached to a vehicle traveling on a highway simulating acceleration followed by a "fuel cut" or reduction in speed. The article is then driven for 1000m 3 / hr for a minimum of 30 seconds, experience five short pulses of high temperature and flow.

[0215] Example 1 A water-based suspension was prepared using Ceramabind™ 880 binder and Allied 0.3 μm alumina suspension as the inorganic material of the suspension. Ceramabind™ 880, purchased from Aremco, is a high temperature water-dispersible silicone resin. It is cured at 232° C. for 1 hour or at 249° C. for 45 minutes. It has a pH=6.5 and a solids content of 50% by weight. Allied 0.3 μm alumina suspension, purchased from Allied High Tech, has a median particle size of 0.3 μm or 300 nm. It contains 18.2% alumina and 81.8% distilled water by weight. It has a pH=9 and is completely miscible with water. In this example, four diluted alumina suspensions were prepared by diluting the as-received Allied 0.3 μm alumina suspension with deionized (DI) water and then adding various amounts of Ceramabind™ 880. All four samples had the same alumina concentration of 3%, but different concentrations of binder: 10%, 30%, 50%, and 100% by weight of alumina, respectively. The pH value of each sample was measured, as shown in Table 1. The stability of the suspension with 10% binder was acceptable, with the sample showing no clear separation for 1-2 hours. The other suspension samples with more binder had good stability, with the sample showing no clear separation for over 4 hours. The tape test showed that samples with up to 50% binder addition did not pass the test, while the sample with 100% binder passed the test. However, the tape test is not considered a conclusive test of whether the suspension will work in the production of honeycomb filter bodies.

[0216] [Table 1]

[0217] Example 2 An aqueous-based suspension was prepared containing a suspension of BINDZIL 9950 colloidal silica and Sky Spring alumina powder. The binder, BINDZIL 9950 colloidal silica, was purchased from AkzoNoble. It contains 50% silica in water with colloidal particles in the size range of 10-20 nm. It was diluted at pH=9 and 80 mM NaCl. 2 SkySpring α-alumina powder purchased from SkySpring Nanomaterials, Inc. has an average alumina particle size of 150 nm and a specific surface area of ​​10 m 2 / g. In this example, five diluted alumina suspensions were prepared by mixing SkySpring alumina powder with DI water, followed by the addition of various amounts of BINDZIL 9950 colloidal silica. As shown in Table 2, all four samples had the same alumina concentration of 10%, but different concentrations of binder, 20%, 30%, 50%, and 100% by weight of alumina, respectively. The stability of the suspension was good, and the samples did not maintain clear separation for more than four hours. Tape tests showed that samples with up to 50% binder addition did not pass the test, and the sample with 100% binder barely passed the test.

[0218] [Table 2]

[0219] Example 3 Ethanol-based aerosol deposition experiments were carried out on the same type of wall-flow filter substrate used in Examples 1 and 2.

[0220] 150nm Al 2 O 3An ethanol suspension of the above (solid content 30% by mass, manufactured by Beijing Dk Nano technology Co.LTD, http: / / www.nanoinglobal.com / en / ProductShow.asp?ID=189) was diluted to 11% by mass with ethanol (AR, manufactured by Sinopharm Group Co.LTD). Dowsil 2405 was added as a binder.

[0221] The solution was sprayed using a two-phase fluid nozzle (1 / 4J-SS+SU11-SS, Spraying Systems Co.) The atomizing gas was nitrogen at 91.5 psi (approximately 631 kPa), and the liquid spray rate was 18 ml / min.

[0222] The droplets were dried in a deposition chamber, as shown in Figure 4. The gas flow and droplets were heated by heaters placed around the chamber. The set temperatures were 350°C, 350°C, and 120°C for heat sources 906a, 906b, and 906c, as shown in Figure 4.

[0223] The flow was driven by a 2518RPM fan (TBR R11Q CL.HP from Twin city fan (Shanghai) Co. Ltd.). The total flow rate was 21.5Nm 3 / hr. Additional air was drawn into the system to make up the total flow required. The final Al 2 O 3 The loading was 4.4 g / part. After deposition, the parts were cured at 200° C. for 1 hour.

[0224] Filtration efficiency was then measured using tobacco smoke particulates with a median diameter of 300 nm. The upstream concentration was 500,000 particles in 30 seconds, which is approximately 353 particles / cm at a flow rate of 0.1 cfm (approximately 2.83 L / min) into a Lighthouse Handheld 3016 particle counter. 3 Particle counts were collected for 30 seconds upstream and 30 seconds downstream. The entire test took approximately 1-2 minutes to complete. Air velocity was 51 m 3 / h. Filtration efficiency was calculated based on the reduction in particle number concentration downstream. Pressure drop was measured with a differential pressure gauge at the same flow rate. Filtration efficiency was 80% and pressure drop was 195 Pa.

[0225] Example 4 Aqueous aerosol deposition experiments on a wall-flow filter.

[0226] Two types of Al 2 O 3 Aqueous-based suspensions were used. One suspension was Allied 0.3 μm alumina suspension, and the other was 0.15 μm alumina suspension (30% solids by weight, Beijing DK Nano technology Co.LTD, http: / / www.nanoinglobal.com / en / ProductShow.asp?ID=189). The suspensions were diluted with DI water and mixed with a binder to form the solution compositions shown in Table 3.

[0227] The solution was sprayed using a two-phase fluid nozzle (1 / 4J-SS+SU11-SS, Spraying Systems Co.). The atomizing gas was nitrogen, and the liquid pressure was adjusted to achieve a liquid flow rate of about 10 ml / min, as listed in Table 3. The droplets were dried in a deposition chamber, as shown in Figure 1. The gas flow and droplets were heated by heaters placed around the chamber. The set temperatures of the heat sources 906a, 906b, and 906c shown in Figure 4 were 350°C, 350°C, and 300°C. The flow was driven by a 2518 RPM fan (TBR R11Q CL.HP, Twin city fan (Shanghai) Co. Ltd.). The total flow rate was 21.5 Nm 3 / hr. Additional air was drawn into the system to make up the total flow required.

[0228] After deposition, the parts were cured for 1 hour at the temperatures listed in Table 3. Filtration efficiency was measured using cigarette smoke particulates with a median particle size of 300 nm. The procedure is described above and a comparison of FE and dP is shown in Figures 12 and 13. All samples had higher filtration efficiency compared to the uncoated honeycomb body. There was little difference before and after curing.

[0229] [Table 3]

[0230] Figures 14A-D show SEM images of the morphology of alumina aggregates formed from ethanol-based and aqueous-based suspensions. The aqueous-based process produced aggregates smaller than 10 micrometers similar to the ethanol-based process (e.g., DK-2405-5%). For the aqueous-based samples made with the DK binder, especially those made with the DK suspension, aggregate size was controlled through adjustments to the batch formulation (e.g., lowering the alumina concentration) and spray conditions (e.g., lowering the liquid flow rate).

[0231] Example 5 Sodium silicate solution was purchased from Sigma-Aldrich and was reagent grade, containing approximately 10.6% Na 2 O and about 26.5% SiO 2Its density is 1.39g / mL at 25°C and its pH value is 12.9. The alumina suspension ("DK suspension") purchased from Beijing DK Nano technology Co.LTD has a solid concentration of 21.7% and a pH of about 9, and the size of the alumina nanoparticles is about 150nm. Seven samples were prepared by mixing 5 grams of DK suspension with various amounts of sodium silicate solution, followed by vortex mixing at a speed of 3000 rpm for 10 seconds. The resulting suspension was applied to a glass slide to form a thin layer coating, followed by a heat drying process. The tape test showed that the samples with or without 5.1% binder did not pass the test, while the samples with 7.7% or more binder passed the test.

[0232] [Table 4]

[0233] Example 6 A series of aqueous-based aerosol deposition experiments were performed on a wall-flow filter with a diameter of 4.055 in. (10.3 cm), length of 5.47 in. (13.9 cm), and a cell count per square inch (CPSI) of 200 (approximately 31.0 cells / cm). 2 ), wall thickness of 8 mil (203 micrometers), and average pore size of 14 μm. The same 0.15 μm alumina suspension (21.7% solids by weight, Beijing DK Nano technology Co.LTD, http: / / www.nanoinglobal.com / en / ProductShow.asp?ID=189) was used for each sample shown in Table 5. The suspension was diluted with DI water and mixed with a binder to form the solution composition shown in Table 5.

[0234] The suspension was sprayed using a two-phase fluid nozzle (2050 / 70, 1 / 4J-SS+SU11-SS, Spraying Systems Co.). The atomizing gas was nitrogen. The suspension was delivered to the nozzle by a syringe pump at a flow rate of 10 ml / min, as described in Table 5.

[0235] Droplets were formed and dried into alumina aggregates in the deposition chamber, as shown in FIG. 3. A heat source 606 in the form of an electrical resistance heating tape was located in the evaporation section 653 before the exit end 625. The drying gas was heated to 220° C. with a heat transfer device, and the chamber surface heating tape was set at 130° C. while the chamber mixture temperature was maintained at 120° C. to evaporate the water. The gas flow was driven by a 2518 RPM fan (TBR R11Q CL.HP from Twin city fan (Shanghai) Co. Ltd.). The total flow rate was 40 Nm 3 / hr. Additional air was drawn into the system to make up the total flow required. After deposition, the parts were heat treated at different temperatures ranging from 250 °C to 1100 °C for 1 h.

[0236] [Table 5]

[0237] Filtration efficiency was tested using cigarette smoke particulates with a median particle size of 300 nm. The procedure is described above, and FE vs. dP and FE vs. loading are shown in Figures 15A and 15B. All samples had higher filtration efficiency compared to the uncoated flow-type filter. There was a difference between samples before and after curing. The pressure drop penalty was comparable to the ethanol-based process with similar filtration efficiency levels.

[0238] A two-stage water spray test was used to perform two-stage water resistance tests to measure the fully submerged FE / dP performance before and after mist immersion or full submersion and after complete drying. The water spray test was performed such that the deposited channels faced the mist flow, so that the deposited aggregates directly contacted and sucked in the water droplets (mist) and held the water droplets within the pores by the capillary forces of the pores. The two-stage water spray test included a first stage with 15-20g water absorption and a second stage with 60-70g water absorption if the first stage test was passed. The full submersion test was performed by completely immersing the filter in a water tank for several minutes, and the water absorption of the substrate was at least 300g.

[0239] Figures 15A and 15B show the performance of parts containing sediment from the aqueous-based and ethanol-based processes in terms of FE / dP performance and FE as a dependency of sediment loading. The suspensions and treatment conditions are shown in Table 5. Figure 15A shows similar FE-dP trends for the two processes. Figure 15B shows that at the same sediment loading, the aqueous-based process gave higher FE values. As an example, at a sediment loading of 3 g / L, the aqueous-based process produced 90% FE and the ethanol-based process produced 84% FE.

[0240] 16A and 16B show the morphology and size of the alumina aggregates formed on the surface of the wall-flow filter for the aqueous-based process deposit and the ethanol-based process. It can be seen that the aqueous-based process forms a deposit microstructure of packed spherical aggregates that partially penetrate the pores of the honeycomb wall.

[0241] Another difference observed for these particular examples and these particular process conditions is that the aqueous process resulted in larger aggregates than the ethanol-based process. As shown in Figure 16B, the aggregate sizes were 1.72 μm and 1.78 μm for the ethanol-based and aqueous processes, respectively. However, further experiments with fluid flow (gas and suspension) and nozzle design modifications showed that similar aggregate sizes could be achieved between the two processes.

[0242] Table 6 shows the FE / dP performance of filters made with different amounts of sodium silicate binder, 10%, 20%, and 30% by weight, respectively.

[0243] [Table 6]

[0244] FIG. 16C is a graph showing aggregate size distribution for aqueous-based and ethanol-based examples. Aggregate size was measured using scanning electron microscopy. FIG. 16D is a graph showing cumulative aggregate size distribution between two process embodiments. Data for the ethanol-based process is shown as a dotted line, and data for the aqueous-based process is shown as a solid line. Table 7 shows the particle size details for both processes. The d10, d50 and d90 values ​​refer to the diameter at which 10%, 50% and 90% of the deposited mass of the sample are composed of particles with a diameter smaller than the provided value.

[0245] [Table 7]

[0246] Figures 17A and 17B show the effect of heat treatment temperature on water resistance. The samples were made using the same 5 wt% alumina suspension with 20 wt% sodium silicate binder, except for one sample, L-0411-02, as shown in Table 8. Heat treatment at temperatures above 600°C, preferably above 650°C, was found to significantly improve the water resistance of FE performance, preferably resulting in less than 6% FE drop after exposure to one of the water resistance tests (Neb-1, Neb-2, submersion). Higher temperature heat treatments resulted in less loss of FE after exposure to water tests. For example, after completion of the two-stage spray test and full submersion test, the 1100°C treated filters had no loss of FE and the 650°C treated samples had a net overall loss of 5.9%. The 425°C treated filters lost 36% in net FE after exposure to water. In some embodiments, a porous ceramic honeycomb body comprising an aggregate of 1-15 wt. % alumina nanoparticles and 5-25 wt. % binder is heat treated by increasing the temperature of the alumina nanoparticle-containing honeycomb body to a maximum temperature of 600-1200° C., e.g., 650-1100° C., for 1-24 hours.

[0247] [Table 8]

[0248] It was found that post-deposition heat treatment can reduce FE, dP, or both FE and dP, as shown in Figures 18A and 18B. As shown in Figure 18A, the lower treatment temperatures of the examples in Table 8 result in less loss of filtration efficiency (less loss of FE) due to heat treatment; for example, 1100°C treatment reduced the FE value of the filter by 6.3%, and after 650°C treatment, the FE of a similarly alumina-loaded filter decreased by about 2% (the two examples in Figure 18A show a net loss of FE of 2.2% to 2.5%). As shown in FIG. 18B, the lower treatment temperatures of the examples in Table 8 showed an increase in pressure drop across the filter for lower heat treatment temperatures (below 600° C., or in the range of 400-600° C.; FIG. 18B shows two examples at a heat treatment temperature of 425° C.), whereas the higher heat treatment temperatures resulted in a decrease in pressure drop compared to the as-deposited state (examples in FIG. 18B show a pressure drop decrease of 10 Pa or more for heat treatment temperatures above 600° C., and examples in FIG. 18B correspond to 650, 910, and 1100° C.). Thus, the highest heat treatment temperatures of 600-700° C., preferably 625-675° C., showed a slight decrease in FE along with an advantageous decrease in pressure drop after heat treatment.

[0249] Figure 19 shows the smoke FE data measured after heat treatment and each durability (e.g. water resistance) test. The water resistance test includes three stages: 1) a first nebulizer test with a water load of 15-20g; 2) a second water nebulizer test with a water load of 60-70g; and 3) a water immersion test with a water load of >300g. The net loss of total FE during the test was 1.66% for the 250°C treated filters and 8.74% for the 650°C treated filters. It should be noted that the 250°C treated samples were exposed to 650°C for 10 hours during hot canning prior to the vehicle test and water test, which improved the strength and water resistance of the deposit.

[0250] Example 7 - Morphology of inorganic deposits This example demonstrates the morphology of a filtration article, such as a plugged honeycomb body having inorganic material deposited on or within the porous walls of the plugged honeycomb body, or on and within the walls of the honeycomb body, which is achieved by an aerosol deposition process of the inorganic material.

[0251] 200CPSI (approx. 31.0 cells / cm 2 Ethanol-based aerosol deposition experiments were conducted on a 4.252 inch diameter and 4.724 inch long wall-flow filter substrate with a wall thickness of 8 mil (203 micrometers) and an average pore size of 13.5 μm and an average porosity of 55%. The inorganic material was deposited at a loading of 6.95 g / L. A co-flow chamber similar to that shown in FIG. 5 was used with 11% solid alumina (DK-2405), 15% Dow 2405 binder, atomizing nozzle, and external mixing nozzle (SU1A, 2050 / 7). The liquid flow rate was 24 g / min (8 g / min from three nozzles). The atomizing gas flow rate was 30 Nm 3 / hour (10Nm from each of the three nozzles) 3 / h). The carrier gas flow rate was 70Nm 3 / hr. A heat transfer device 706a was used to increase the inlet temperature above the nozzle 720. The set point of the heat transfer device 706a was 230°C to provide a measured temperature of approximately 150°C. The first heater 706b was set at 270°C (actually 150°C), the second heater 706c was set at 300°C (actually 155°C), and the third heater 706d was set at 300°C (actually 120°C).

[0252] SEM pictures of the wall-flow filter with the resulting aerosol-deposited alumina on the wall-flow filter were obtained as follows.

[0253] FIG. 20 is an SEM photograph of a top view of the inlet region of the inlet channel; FIG. 21 is an SEM photograph of a cutaway side view of the inlet region of the inlet channel; FIG. 22 is an SEM photograph of a top view of the central region of the inlet channel; FIG. 23 is an SEM photograph of a cutaway side view of the central region of the inlet channel; FIG. 24 is an SEM photograph of a top view of the outlet region of the inlet channel; FIG. 25 is an SEM photograph of a cutaway side view of the outlet region of the inlet channel; FIG. 26 is an SEM photograph of a close-up cutaway side view of the exit region of the inlet channel; FIG. 27 is a SEM photograph of FIG. 26 with the colors inverted; FIG. 28A is a portion of the SEM photograph of FIG. 27 with the aggregate 1500 surrounded by a dashed line; FIG. 28B is a schematic diagram of an aggregate 1502 that forms the region of assembly 1500 outlined in dashed lines in FIG. 28A.

[0254] As best shown in Figures 26, 27, and 28A-B, the inorganic material on the porous walls includes fine particles or primary particles of inorganic material (in this particular example, alumina), fine particle-binder aggregates of particles and binder material, and aggregates of fine particle-binder aggregates. The inorganic material in or on the porous walls of a filtration article in the form of a closed honeycomb body is present as "clusters" or "chains" of aggregates and / or aggregates. In some embodiments, the clusters or chains provide an inorganic material morphology that is one or more of finger-like, fibril-like, or spongy, e.g., resembling a sea sponge.

[0255] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Accordingly, it is intended that the present specification cover modifications and variations of the various embodiments described herein, provided that such modifications and variations come within the scope of the appended claims and their equivalents.

[0256] Preferred embodiments of the present invention will be described below in detail.

[0257] EMBODIMENT 1 1. A method of providing a surface treatment to a blocked honeycomb body including porous walls, the method comprising: atomizing particles of inorganic material into liquid-particulate-binder droplets consisting of an aqueous vehicle, a binder material, and said particles; evaporating substantially all of the aqueous vehicle from the droplets to form agglomerates of the particles and the binder material; depositing the aggregates on the porous walls of the plugged honeycomb body. Including, the deposited aggregates are disposed on the porous walls, or within the porous walls, or both on and within the porous walls; method.

[0258] EMBODIMENT 2 2. The method of embodiment 1, wherein the step of spraying further comprises providing a suspension of the particles, the aqueous vehicle, and the binder material.

[0259] EMBODIMENT 3 3. The method of claim 1 or 2, wherein at least some of the aggregates adhere to the porous walls.

[0260] EMBODIMENT 4 4. The method of any one of the preceding claims, wherein the binder material enhances the cohesiveness of the agglomerate.

[0261] EMBODIMENT 5 5. The method of any of the preceding claims, wherein the particles are mixed with the aqueous vehicle and the binder material to form a liquid-particulate-binder stream, and the liquid-particulate-binder stream is directed towards a spray nozzle.

[0262] EMBODIMENT 6 6. The method of any one of the preceding claims, further comprising aerosolizing the liquid-microparticle-binder droplets.

[0263] EMBODIMENT 7 7. The method of any of the preceding claims, wherein the liquid-particulate-binder stream is mixed with an atomizing gas through the atomizing nozzle.

[0264] EMBODIMENT 8 8. The method of any one of the preceding claims, wherein the liquid-particulate-binder stream enters the spray nozzle.

[0265] EMBODIMENT 9 9. The method of any of claims 6 to 8, wherein mixing the liquid-particulate-binder stream with the atomizing gas occurs inside the atomizing nozzle.

[0266] EMBODIMENT 10 9. The method of any of claims 6 to 8, wherein mixing the liquid-particulate-binder stream with the atomizing gas occurs outside the atomizing nozzle.

[0267] EMBODIMENT 11 11. The method of any one of the preceding claims, wherein the spray nozzle is cooled during the aerosolization.

[0268] EMBODIMENT 12 12. The method of any one of the preceding claims, wherein the temperature of the spray nozzle is maintained below the boiling point of the aqueous vehicle.

[0269] EMBODIMENT 13 13. The method of any of the preceding claims, wherein the droplets are aerosolized and carried towards the blocked honeycomb body by a gaseous carrier stream.

[0270] EMBODIMENT 14 14. The method of any one of the preceding claims, wherein the gaseous carrier stream consists of the atomizing gas and a carrier gas.

[0271] EMBODIMENT 15 15. The method of any one of the preceding claims, wherein the gaseous carrier stream is heated before being mixed with the droplets.

[0272] EMBODIMENT 16 16. The method of any of the preceding claims, wherein the gaseous carrier stream is heated to a temperature in the range of from 50°C or more to 500°C or less.

[0273] EMBODIMENT 17 17. The method of any of the preceding claims, wherein the gaseous carrier stream is heated to a temperature in the range of from 80°C or more to 300°C or less.

[0274] EMBODIMENT 18 18. The method of any of the preceding claims, wherein the gaseous carrier stream is heated to a temperature in the range of from 80°C or more to 150°C or less.

[0275] EMBODIMENT 19 19. The method of any of claims 13 to 18, wherein the liquid droplets and the gaseous carrier stream are conveyed through a duct having an outlet end proximate to the plugged honeycomb body.

[0276] EMBODIMENT 20 20. The method of any one of the preceding claims, wherein the duct is in sealed fluid communication with the plugged honeycomb body during the depositing step.

[0277] EMBODIMENT 21 The total volumetric flow rate through said duct is 5 Nm 3 / hour and / or 200Nm 3 21. The method of embodiment 19 or 20, wherein the treatment is at least one day / hour or less.

[0278] EMBODIMENT 22 The total volumetric flow rate is 20 Nm 3 / hour and / or 100Nm 3 22. The method of any preceding embodiment, wherein the sedative dose is 1 / hour or less.

[0279] EMBODIMENT 23 23. The method of any one of claims 19 to 22, wherein the duct is substantially insulating.

[0280] EMBODIMENT 24 24. The method of any one of claims 19 to 23, wherein the average temperature of the walls of the duct is lower than the temperature of the gaseous carrier stream.

[0281] EMBODIMENT 25 25. The method of any one of claims 19 to 24, wherein the average temperature of the walls of the duct is higher than the temperature of the gaseous carrier stream.

[0282] EMBODIMENT 26 26. The method of any one of the preceding claims, further comprising spraying multiple liquid-particulate-binder streams with multiple spray nozzles.

[0283] EMBODIMENT 27 27. The method of any one of claims 19 to 26, wherein the plurality of spray nozzles are equally spaced within the chamber of the duct.

[0284] EMBODIMENT 28 27. The method of embodiment 26, wherein each of the plurality of spray nozzles is angled toward a center of the duct.

[0285] EMBODIMENT 29 29. The method of any of claims 26 to 28, wherein the atomizing gas contributes to breaking up the liquid-particulate-binder stream into droplets.

[0286] EMBODIMENT 30 30. The method of any of claims 13 to 29, wherein the step of depositing the agglomerates on the porous walls further comprises passing the gaseous carrier stream through the porous walls of the honeycomb body, wherein the walls of the honeycomb body filter out at least some of the agglomerates by trapping the filtered agglomerates on or within the walls of the honeycomb body.

[0287] EMBODIMENT 31 31. The method of any one of claims 13 to 30, wherein depositing the agglomerates on the porous walls comprises filtering the agglomerates from the gaseous carrier stream using the porous walls of the plugged honeycomb body.

[0288] EMBODIMENT 32 32. The method of any of the preceding claims, wherein an organic component of the binder material is removed from the deposited agglomerates.

[0289] EMBODIMENT 33 33. The method of any preceding claim, further comprising heating the deposited aggregates.

[0290] EMBODIMENT 34 34. The method of any of the preceding claims, wherein the deposited agglomerates are heated to combust or volatilize organic components of the binder material from the deposited agglomerates.

[0291] EMBODIMENT 35 35. The method of any one of the preceding claims, wherein the aggregates are heated to physically bond inorganic components of the binder material in the deposited aggregates to the porous walls of the honeycomb body.

[0292] EMBODIMENT 36 36. The method of claim 34 or 35, wherein heating the aggregates causes inorganic components of the binder material in the deposited aggregates to form a porous inorganic structure on the porous walls of the honeycomb body.

[0293] EMBODIMENT 37 15. The method of embodiment 14, wherein the carrier gas is nitrogen.

[0294] EMBODIMENT 38 15. The method of embodiment 14, wherein the carrier gas consists essentially of an inert gas.

[0295] EMBODIMENT 39 15. The method of embodiment 14, wherein the carrier gas is predominantly one or more inert gases.

[0296] EMBODIMENT 40 15. The method of embodiment 14, wherein the carrier gas is primarily nitrogen gas.

[0297] EMBODIMENT 41 15. The method of embodiment 14, wherein the carrier gas is primarily air.

[0298] EMBODIMENT 42 15. The method of embodiment 14, wherein the carrier gas consists essentially of nitrogen or air.

[0299] EMBODIMENT 43 15. The method of embodiment 14, wherein the carrier gas is dry.

[0300] EMBODIMENT 44 15. The method of embodiment 14, wherein the carrier gas comprises less than 5 weight percent water vapor.

[0301] EMBODIMENT 45 45. The method of any one of embodiments 19 to 44, wherein the carrier gas is substantially free of liquid vehicle upon entering the chamber of the duct.

[0302] EMBODIMENT 46 46. ​​The method of any one of claims 19 to 45, wherein the duct comprises an evaporation section having an axial length configured to allow evaporation of a substantial portion or all of the aqueous vehicle from the aggregate.

[0303] EMBODIMENT 47 47. The method of any one of embodiments 19 to 46, wherein the path of the droplets and the path of the gaseous carrier stream are substantially perpendicular to each other before entering the evaporation section of the duct.

[0304] EMBODIMENT 48 47. The method of any one of claims 19 to 46, wherein the path of the droplets and the path of the gas stream are substantially parallel to each other as they enter the evaporation section of the duct.

[0305] EMBODIMENT 49 49. The method of any of embodiments 19 to 48, wherein the carrier gas is delivered to the chamber of the duct in an annular flow surrounding the nozzle in co-flow around the droplet at the end of the nozzle.

[0306] EMBODIMENT 50 47. The method of any one of embodiments 19 to 46, wherein the path of the droplets and the path of the carrier gas are substantially perpendicular to each other before entering the evaporation section of the duct.

[0307] EMBODIMENT 51 47. The method of any one of embodiments 19 to 46, wherein the path of the droplets and the path of the carrier gas are substantially parallel to each other before entering the evaporation section of the duct.

[0308] EMBODIMENT 52 20. The method of claim 19, wherein the duct includes a diverging region downstream of the nozzle.

[0309] EMBODIMENT 53 20. The method of claim 19, wherein the duct includes a converging section for engaging a proximal end of the honeycomb body.

[0310] EMBODIMENT 54 54. The method of any one of the preceding claims, wherein the plugged honeycomb body comprises an inlet channel that is plugged at a distal end of the honeycomb body and an outlet channel that is plugged at a proximal end of the honeycomb body.

[0311] EMBODIMENT 55 55. The method of any preceding claim, wherein the aggregates are deposited on the walls defining the inlet channel.

[0312] EMBODIMENT 56 56. The method of any one of the preceding claims, wherein the aqueous vehicle has a vapor pressure greater than the vapor pressure of water at the temperature of the gaseous carrier stream.

[0313] EMBODIMENT 57 57. The method of any of the preceding claims, wherein the aqueous vehicle consists essentially of materials having a boiling point lower than the boiling point of water at the temperature of the gaseous carrier stream.

[0314] EMBODIMENT 58 58. The method of any preceding embodiment, wherein the agglomerates comprise a particle size having a d50 greater than 1.5 micrometers and less than 5 micrometers, a d90 greater than 2 micrometers and less than 5 micrometers, and a d10 greater than 1 micrometer and less than 2 micrometers.

[0315] EMBODIMENT 59 59. The method of any one of the preceding claims, wherein the agglomerates form a deposit microstructure of packed spherical agglomerates.

[0316] EMBODIMENT 60 60. The method of any preceding embodiment, wherein the aggregates are densely packed.

[0317] EMBODIMENT 61 61. The method of any preceding embodiment, wherein the aqueous vehicle consists essentially of water.

[0318] EMBODIMENT 62 62. The method of any one of embodiments 13 to 61, wherein the gaseous carrier flow exits the chamber in a direction substantially parallel to gravity.

[0319] EMBODIMENT 63 62. The method of any one of embodiments 13 to 61, wherein the gaseous carrier flow exits the chamber in a substantially downward direction.

[0320] EMBODIMENT 64 62. The method of any one of embodiments 13 to 61, wherein the gaseous carrier flow exits the chamber in a substantially upward direction.

[0321] EMBODIMENT 65 65. The method of any preceding claim, wherein the liquid-microparticle-binder droplets are directed into the chamber by a plurality of nozzles.

[0322] EMBODIMENT 66 66. The method of any preceding embodiment, wherein the average size of the liquid-microparticle-droplets is 1 μm or more and 15 μm or less.

[0323] EMBODIMENT 67 67. The method of any one of the preceding claims, wherein the average size of the liquid-microparticle-droplets is 2 μm or more and 8 μm or less.

[0324] EMBODIMENT 68 68. The method of any one of the preceding claims, wherein the average size of the liquid-microparticle-droplets is 4 μm or more and 8 μm or less.

[0325] EMBODIMENT 69 69. The method of any one of the preceding claims, wherein the average size of the liquid-microparticle-droplets is 4 μm or more and 6 μm or less.

[0326] EMBODIMENT 70 1. A method of providing a surface treatment to a blocked honeycomb body including porous walls, the method comprising: mixing particles of inorganic material with an aqueous vehicle and binder material to form a liquid-particulate-binder stream; mixing said liquid-particulate-binder stream with an atomizing gas; directing the liquid-particulate-binder stream into a spray nozzle, thereby aerosolizing the particles into liquid-particulate-binder droplets comprised of the aqueous vehicle, the binder material, and the particles; conveying the droplets toward the blocked honeycomb body by a gaseous carrier flow through a duct having an exit end proximate to the blocked honeycomb body, the gaseous carrier flow comprising a carrier gas and the atomizing gas; evaporating substantially all of the aqueous vehicle from the droplets to form agglomerates of the particles and the binder material; and depositing the aggregates on the porous walls of the plugged honeycomb body. Including, the deposited aggregates are disposed on the porous walls, or within the porous walls, or both on and within the porous walls; method.

[0327] EMBODIMENT 71 71. The method of embodiment 70, wherein the duct is in sealed fluid communication with the plugged honeycomb body during the depositing step.

[0328] EMBODIMENT 72 72. The method of embodiment 70 or 71, wherein the carrier gas is delivered to the chamber of the duct in an annular manner surrounding the nozzle in co-flow around the droplet at the end of the nozzle.

[0329] EMBODIMENT 73 73. The method of any of claims 70 to 72, wherein the duct includes a converging section for engaging a proximal end of the honeycomb body.

[0330] EMBODIMENT 74 74. The method of any one of embodiments 70 to 73, wherein the duct comprises a round cross-sectional shape.

[0331] EMBODIMENT 75 75. The method of any one of embodiments 70 to 74, wherein mixing the liquid-particulate-binder stream with the atomizing gas occurs outside the atomizing nozzle.

[0332] EMBODIMENT 76 76. The method of any one of embodiments 70 to 75, wherein the spray nozzle is a convergent nozzle.

[0333] EMBODIMENT 77 77. The method of any one of embodiments 70 to 76, wherein the step of aerosolizing the particles into liquid-microparticle-binder droplets comprises aerosolizing a plurality of liquid-microparticle-binder streams using a plurality of spray nozzles.

[0334] EMBODIMENT 78 78. The method of any one of the preceding claims, wherein the plurality of spray nozzles are equally spaced within the chamber of the duct.

[0335] EMBODIMENT 79 79. The method of any one of the preceding claims, wherein each of the plurality of spray nozzles is angled toward a center of the duct.

[0336] Embodiment 80 80. The method of any one of embodiments 70 to 79, wherein the step of depositing the aggregates on the porous walls of the plugged honeycomb body is performed semi-continuously for a plurality of plugged honeycomb bodies.

[0337] Embodiment 81 81. The method of any of the preceding claims, further comprising releasing a sealed fluid communication between a first plugged honeycomb body having an agglomerate and the duct, and engaging a second plugged honeycomb body in sealed fluid communication with the duct.

[0338] EMBODIMENT 82 82. The method of embodiment 81, wherein the second plugged honeycomb body is engaged 30 seconds or less after unsealing the first plugged honeycomb body.

[0339] EMBODIMENT 83 83. The method of any one of the preceding claims, wherein the second plugged honeycomb body is engaged 15 seconds or less after unsealing the first plugged honeycomb body.

[0340] EMBODIMENT 84 84. The method of any one of the preceding claims, wherein the second plugged honeycomb body is engaged less than 5 seconds after unsealing the first plugged honeycomb body.

[0341] EMBODIMENT 85 85. The method of any one of the preceding claims, wherein the second plugged honeycomb body is engaged less than 2 seconds after unsealing the first plugged honeycomb body.

[0342] EMBODIMENT 86 86. The method of any one of embodiments 70 to 85, wherein the step of directing the liquid-particulate-binder stream towards the spray nozzle is performed at a substantially constant flow rate.

[0343] EMBODIMENT 87 87. The method of any one of embodiments 70 to 86, wherein mixing the particles of the inorganic material with the aqueous vehicle and the binder material is performed by mechanical agitation.

[0344] EMBODIMENT 88 88. The method of any one of embodiments 70 to 87, wherein the atomizing gas and the carrier gas are supplied independently at a pressure of 90 psi or greater.

[0345] EMBODIMENT 89 89. The method of any one of embodiments 70 to 88, wherein the atomizing gas and the carrier gas are each independently supplied at a pressure of 125 psi or less.

[0346] EMBODIMENT 90 90. The method of any one of embodiments 70 to 89, wherein the temperature of the spray nozzle is maintained below the boiling point of the aqueous vehicle.

[0347] EMBODIMENT 91 91. The method of any one of embodiments 70 to 90, wherein the gaseous carrier stream is heated before being mixed with the droplets.

[0348] EMBODIMENT 92 1. A method of providing a surface treatment to a blocked honeycomb body including porous walls, the method comprising: mixing an atomizing gas with a liquid-particulate-binder stream, said liquid-particulate-binder stream comprising particles of inorganic material, an aqueous vehicle, and binder material; directing the liquid-particulate-binder stream into a spray nozzle, thereby aerosolizing the particles into liquid-particulate-binder droplets comprised of the aqueous vehicle, the binder material, and the particles; conveying the droplets toward the blocked honeycomb body by a gaseous carrier flow through a duct having an exit end proximate to the blocked honeycomb body, the gaseous carrier flow comprising a carrier gas and the atomizing gas; delivering the carrier gas to a chamber of the duct in an annular flow surrounding the nozzle in co-flow around the droplet at the end of the nozzle; evaporating substantially all of the aqueous vehicle from the droplets to form agglomerates of the particles and the binder material; and depositing the aggregates on the porous walls of the plugged honeycomb body. Including, the deposited aggregates are disposed on, or within, the porous walls, or both on and within the porous walls; During the deposition process, the duct is in sealed fluid communication with a deposition zone containing the plugged honeycomb body. method.

[0349] EMBODIMENT 93 93. The method of any one of the preceding claims, wherein the step of depositing the aggregates on the porous walls of the plugged honeycomb body is performed semi-continuously for a plurality of plugged honeycomb bodies.

[0350] EMBODIMENT 94 94. The method of any of the preceding claims, further comprising the steps of releasing the sealed fluid communication between the duct and the deposition zone, moving a first plugged honeycomb body having deposited agglomerates to a position away from the duct, and engaging a second plugged honeycomb body in sealed fluid communication with the duct.

[0351] EMBODIMENT 95 The following features: the duct including a converging section for engaging a proximal end of the honeycomb body; the duct comprises a round cross-sectional shape; the spray nozzle is a convergent nozzle; the spray nozzle is an external mix nozzle; a plurality of atomizing nozzles that aerosolize a plurality of liquid-particulate-binder streams; a mechanical agitator for mixing the particles of the inorganic material with the aqueous vehicle and the binder material to form the liquid-particulate-binder stream; a pump for directing said liquid-particulate-binder stream at a substantially constant flow rate to said spray nozzle; a booster for independently supplying the atomizing gas and the carrier gas at a pressure of 90 psi (about 621 kPa) or more; an expandable seal between the outer diameter of the plugged honeycomb body and the inner diameter of the deposition zone; and a valve covering an open end of the duct when fluid communication between the first blocked honeycomb body having accumulated agglomerates and the duct is unsealed. 95. The method of any one of embodiments 92 to 94, further comprising one or a combination of:

[0352] EMBODIMENT 96 1. An apparatus for providing a surface treatment to a closed honeycomb body including a porous wall, the apparatus comprising: a duct having a round cross-sectional shape from the first end to the second end; a deposition zone for receiving the plugged honeycomb body in fluid communication with the duct at the second end of the duct; and a spray nozzle in fluid communication with the chamber of said duct; 13. An apparatus comprising:

[0353] EMBODIMENT 97 The following features: the duct including a converging section for engaging the deposition zone; the spray nozzle is a convergent nozzle; the spray nozzle is an external mix nozzle; Multiple spray nozzles; providing a liquid-particulate-binder stream at or near the first end of the duct in fluid communication with the spray nozzle, the liquid-particulate-binder stream including a mechanical agitator for mixing the particles of inorganic material with an aqueous vehicle and binder material, and / or a pump for directing the liquid-particulate-binder stream at a substantially constant flow rate to the spray nozzle; a booster for supplying atomizing gas to said nozzle at a pressure of at least 90 psi (approximately 621 kPa); an expandable seal between the outer diameter of the plugged honeycomb body and the inner diameter of the deposition zone; and a valve that covers an open end of said duct when fluid communication between said duct and a blocked honeycomb body having accumulated agglomerates is unsealed. 97. The device of embodiment 96, further comprising one or a combination of:

[0354] EMBODIMENT 98 1. A filtration article comprising: A honeycomb filter body having a porous wall having pores; and an inorganic deposit comprising inorganic material nanoparticles and a binder disposed within the honeycomb filter body; Including, the inorganic deposit comprises a network of assembled aggregates of the inorganic material nanoparticles and the binder, the binder comprising a water-soluble binder; Filtration articles.

[0355] EMBODIMENT 99 99. The filtration article of embodiment 98, wherein the aggregates are comprised of nanoparticles of an inorganic material, and the network of aggregates comprises a collection of aggregates.

[0356] EMBODIMENT 100 100. The filtration article of embodiment 99, wherein the network of aggregates comprises clusters or chains of the aggregates.

[0357] EMBODIMENT 101 101. The filtration article of embodiment 100, wherein at least a portion of the clusters or chains are disposed within the pores within or below the surface of the porous wall, and at least a portion of the clusters or chains are disposed on the surface of the porous wall.

[0358] EMBODIMENT 102 102. The filtration article of embodiment 100 or 101, wherein some of the clusters are porous clusters comprising exposed collections of aggregates.

[0359] EMBODIMENT 103 103. The filtration article of embodiment 102, wherein the porous cluster comprises one or more chains of two or more aggregates, each chain extending outwardly from the porous wall.

[0360] EMBODIMENT 104 103. The filtration article of embodiment 102, wherein the porous cluster comprises a plurality of the outwardly extending chains that collectively provide a morphology resembling a member of the group consisting of fingers, tufts, and sponges.

[0361] EMBODIMENT 105 105. The filtration article of any of embodiments 98-104, wherein the inorganic material comprises one or more of ceramic particles, metal oxide particles, and refractory metal oxide particles.

[0362] EMBODIMENT 106 106. The filtration article of any of embodiments 98-105, wherein the inorganic material comprises alumina.

[0363] EMBODIMENT 107 107. The filtration article of any of embodiments 98-106, wherein the inorganic material is present on the honeycomb filter body at a loading of 0.1-20 g / L to 0.1-5 g / L.

[0364] EMBODIMENT 108 108. The filtration article of any of embodiments 98-107, wherein the inorganic material is present on the honeycomb filter body at a loading of 0.1-5 g / L to 0.1-2 g / L.

[0365] EMBODIMENT 109 109. The filtration article of any of embodiments 98 to 108, wherein the water-soluble binder comprises a silicon-containing binder.

[0366] Embodiment 110 110. The filtration article of any of embodiments 98-109, wherein the binder comprises a silicate or an aluminate.

[0367] EMBODIMENT 111 111. The filtration article of any of embodiments 98-110, wherein the binder comprises sodium silicate.

[0368] EMBODIMENT 112 112. The filtration article of any of embodiments 98-111, wherein the binder is present on the honeycomb filter body in an amount ranging from 5% to about 30% by weight of the inorganic material.

[0369] EMBODIMENT 113 113. The filtration article of any of embodiments 98-112, wherein the inorganic deposit does not include rare earth oxides, platinum group metals, and molecular sieves. [Explanation of symbols]

[0370] 100 Honeycomb body 105 First end 110 Internal Channel 115 Wall 135 Second End 200 Particulate Filter 201 Channel 202 Inlet end 204 Outlet end 205 Outer skin layer 206 Channel Wall 208 Entrance Channel 210 Exit Channel 250 Exhaust gas flow 300 Honeycomb body 310 Wall 320 Filtration material deposit 325 particles 330 Gas Flow 500,600,700,800,900 equipment 501,601,701,801,901 Conduit 503,603,703,803,903 Plenum Space 505,605,705,805 Carrier gas 510,610,710,810 Suspension 515,615,715,815a,815b,915 Atomizing gas 520,620,720,820a,820b,820c,920 nozzles 521,621,721,821 Inlet end 522,622,722,822,922 Diffusion Area 523,623,723,823,923 Evaporation chamber 525,625,725,825,925 Outlet end 527,727,827 First Section 529,729,829 Second Section 531,631,731,831,931 Sedimentation Zone 536,636,736,836,936 Exit Zone 540,640,740,840,940 Outlet conduit 545,645,745,845,945 Flow Driver 550,650,750,850,950 First end 551,651,751,851,951 Duct 553,653,753,953 Evaporation Section 555,655,755,855,955 Second end 905a Primary heating carrier gas 905b Secondary heating carrier gas 921 First entrance location 924 Second Entrance Location 928 Right Cylindrical Section 929 Second Plenum Space

Claims

1. 1. A method of providing a surface treatment to a blocked honeycomb body including porous walls, the method comprising: atomizing particles of inorganic material into liquid-particulate-binder droplets comprising an aqueous vehicle, a binder material comprising silicon, and said particles; evaporating substantially all of the aqueous vehicle from the droplets to form agglomerates of the particles and the binder material; depositing the aggregates on the porous walls of the plugged honeycomb body. Including, the deposited aggregates are disposed on the porous walls, or within the porous walls, or both on and within the porous walls; method.

2. The method of claim 1 , wherein an organic component of the binder material is removed from the deposited aggregates.

3. The method of claim 2 , further comprising heating the aggregates to physically bond inorganic components of the binder material in the deposited aggregates to the porous walls of the honeycomb body.

4. 1. A filtration article comprising: A honeycomb filter body having a porous wall having pores, and An inorganic deposit comprising inorganic material nanoparticles and silicon disposed within the honeycomb filter body. Including, the inorganic deposit comprises a network of aggregates of the inorganic nanoparticles; Filtration articles.

5. The filtration article of claim 4, wherein the network of aggregates comprises a collection of aggregates.

6. 6. The filtration article of claim 4 or 5, wherein the inorganic deposits are present on the honeycomb filter body at a loading of 0.3 to 30 g / L.

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