A cement composition for application to a ceramic substrate, such as a cement skin composition for application to a ceramic honeycomb body is provided. The cement composition includes a first source of inorganic particles having a mean particle diameter <50 nm, wherein the first source of inorganic particles is present at about <15% (by dry weight), a second source of inorganic particles having a mean particle diameter of from about 50 nm to about 700 nm, wherein the second source of inorganic particles is present at from about 5% to about 15% (by dry weight), and a water-soluble organic binder. An inorganic fibrous material can be present at about <15% (based on dry weight). The amount of at least one of the first source of inorganic particles or the inorganic fibrous material is greater than 0% (by dry weight).

A cement composition for application to a ceramic substrate, such as a cement skin composition for application to a ceramic honeycomb body is provided. The cement composition includes a first source of inorganic particles having a mean particle diameter <50 nm, wherein the first source of inorganic particles is present at about <15% (by dry weight), a second source of inorganic particles having a mean particle diameter of from about 50 nm to about 700 nm, wherein the second source of inorganic particles is present at from about 5% to about 15% (by dry weight), and a water-soluble organic binder. An inorganic fibrous material can be present at about <15% (based on dry weight). The amount of at least one of the first source of inorganic particles or the inorganic fibrous material is greater than 0% (by dry weight).

A method of applying a NOx degrading composition on a concrete element, including providing a concrete element having a surface, and applying a composition including photocatalytic titanium dioxide particles dispersed in a continuous phase on the surface of said concrete element. Also, a concrete element having NOx degrading properties. Also, a concrete element having photocatalytic titanium dioxide particles dispersed thereon.

A method of applying a NOx degrading composition on a concrete element, including providing a concrete element having a surface, and applying a composition including photocatalytic titanium dioxide particles dispersed in a continuous phase on the surface of said concrete element. Also, a concrete element having NOx degrading properties. Also, a concrete element having photocatalytic titanium dioxide particles dispersed thereon.

A concrete curing agent, a curing coating layer and a preparation method thereof, the concrete curing agent comprises a hardening agent and a hydrophobic agent, the raw materials of the hardening agent comprises the following raw materials in parts by weight: 0.1-10 parts of fluorosilicate salt and 100 parts of water, and the hydrophobic agent comprises the following raw materials in parts by weight: 0.1-10 parts of a base catalyst, 1-10 parts of a silane coupling agent, 0.1-10 parts of hydrogen-containing silicone oil, 5-10 parts of a cross-linking agent, 10-100 parts of silica sol and 100-1000 parts of water. The present invention can significantly improve the strength, hardness and hydrophobicity, impermeability and freeze-thaw resistance of surface of concrete before and after hardening, and effectively improves the service life of concrete structures.

A concrete curing agent, a curing coating layer and a preparation method thereof, the concrete curing agent comprises a hardening agent and a hydrophobic agent, the raw materials of the hardening agent comprises the following raw materials in parts by weight: 0.1-10 parts of fluorosilicate salt and 100 parts of water, and the hydrophobic agent comprises the following raw materials in parts by weight: 0.1-10 parts of a base catalyst, 1-10 parts of a silane coupling agent, 0.1-10 parts of hydrogen-containing silicone oil, 5-10 parts of a cross-linking agent, 10-100 parts of silica sol and 100-1000 parts of water. The present invention can significantly improve the strength, hardness and hydrophobicity, impermeability and freeze-thaw resistance of surface of concrete before and after hardening, and effectively improves the service life of concrete structures.

A method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having large numbers of longitudinal cells partitioned by porous cell walls having porosity of 50% or more, and a peripheral wall formed on a peripheral surface of the ceramic honeycomb body, comprising the steps of extruding moldable ceramic material to form a honeycomb-structured ceramic green body; machining a peripheral portion of the green body or a sintered body obtained from the green body to remove part of cell walls in the peripheral portion to obtain a ceramic honeycomb body having longitudinal grooves on a peripheral surface; applying colloidal metal oxide to a peripheral surface of the ceramic honeycomb body and drying it, and then applying a coating material comprising ceramic aggregate having an average particle size of 1 μm or more to form the peripheral wall.

A method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having large numbers of longitudinal cells partitioned by porous cell walls having porosity of 50% or more, and a peripheral wall formed on a peripheral surface of the ceramic honeycomb body, comprising the steps of extruding moldable ceramic material to form a honeycomb-structured ceramic green body; machining a peripheral portion of the green body or a sintered body obtained from the green body to remove part of cell walls in the peripheral portion to obtain a ceramic honeycomb body having longitudinal grooves on a peripheral surface; applying colloidal metal oxide to a peripheral surface of the ceramic honeycomb body and drying it, and then applying a coating material comprising ceramic aggregate having an average particle size of 1 μm or more to form the peripheral wall.

The honeycomb filter of the present invention comprises a ceramic honeycomb substrate formed from a porous body of sintered ceramic particles, and a filter layer formed on the surface of the cell walls, wherein a portion of the filter layer penetrates from the surface of the cell walls into pores formed by the ceramic particles to form inter-particle filtration bodies, these inter-particle filtration bodies are formed from a plurality of spherical ceramic particles and crosslinking bodies which bind the spherical ceramic particles to each other, and the spherical ceramic particles and the crosslinking bodies form a three-dimensional network structure.

The honeycomb filter of the present invention comprises a ceramic honeycomb substrate formed from a porous body of sintered ceramic particles, and a filter layer formed on the surface of the cell walls, wherein a portion of the filter layer penetrates from the surface of the cell walls into pores formed by the ceramic particles to form inter-particle filtration bodies, these inter-particle filtration bodies are formed from a plurality of spherical ceramic particles and crosslinking bodies which bind the spherical ceramic particles to each other, and the spherical ceramic particles and the crosslinking bodies form a three-dimensional network structure.