A DDR-type zeolite seed crystal has an average particle diameter of less than or equal to 0.2 μm, and an average aspect ratio of less than or equal to 1.3.

A DDR-type zeolite seed crystal has an average particle diameter of less than or equal to 0.2 μm, and an average aspect ratio of less than or equal to 1.3.

Provided are an all-silica zeolite separation membrane for separating carbon dioxide, etc., and not causing a decrease in the processing amount due to adsorption of water molecules, and a production method therefor. One aspect of the present invention is a zeolite separation membrane, in which the framework of a zeolite crystal structure formed on a porous support is all silica, characterized in that the zeolite crystal structure formed on the porous support is fluorine free. Another aspect of the present invention is a method for producing a zeolite separation membrane having a zeolite crystal structure on a porous support, characterized in that the method includes a step of producing a seed crystal, a step of applying the seed crystal onto the porous support, a step of producing a membrane synthesis raw material composition, and a step of immersing the porous support having the seed crystal applied thereon in the membrane synthesis raw material composition and performing hydrothermal synthesis, and the membrane synthesis raw material composition contains a silica source and an organic template and does not contain a fluorine compound.

Provided are an all-silica zeolite separation membrane for separating carbon dioxide, etc., and not causing a decrease in the processing amount due to adsorption of water molecules, and a production method therefor. One aspect of the present invention is a zeolite separation membrane, in which the framework of a zeolite crystal structure formed on a porous support is all silica, characterized in that the zeolite crystal structure formed on the porous support is fluorine free. Another aspect of the present invention is a method for producing a zeolite separation membrane having a zeolite crystal structure on a porous support, characterized in that the method includes a step of producing a seed crystal, a step of applying the seed crystal onto the porous support, a step of producing a membrane synthesis raw material composition, and a step of immersing the porous support having the seed crystal applied thereon in the membrane synthesis raw material composition and performing hydrothermal synthesis, and the membrane synthesis raw material composition contains a silica source and an organic template and does not contain a fluorine compound.

The invention relates to a process for preparing an IZM-2 zeolite, comprising at least: i) mixing, in aqueous medium, of at least one source of at least one tetravalent element X (XO.sub.2), at least one source of at least one trivalent element (Y.sub.2O.sub.3), 1,6-bis(methylpiperidinium)hexane dihydroxide, at least one source of at least one alkali metal M of valency n chosen from alkali metal chlorides, n being an integer greater than or equal to 1, M being chosen from lithium, potassium, sodium and caesium, and the mixture of at least two of these metals, and optionally in the presence of a source of at least one fluoride anion, BF, the mixture having a specific molar composition to obtain a homogeneous precursor gel; ii) hydrothermal treatment of said precursor gel.

The invention relates to a process for preparing a synthetic IZM-2 zeolite, which consists in performing a hydrothermal treatment of an aqueous gel containing a source of silicon and a source of amorphous aluminium, two nitrogenous or structuring organic compounds including two quaternary ammonium functions, 1,6-bis(methylpiperidinium)hexane dihydroxide and 1,6-bis(methylpiperidinium)hexane dibromide, used as a mixture, in combination with a source of a specific alkali metal chloride M (preferably NaCl), the aqueous gel not comprising any source of at least one fluoride anion.

The present invention relates in one aspect to the discovery of novel mesoporous silica nanoparticles (MSNs) templated around and comprising benzalkonium chloride (BAC). In certain embodiments, the BAC-SiO.sub.2 mesoporous nanoparticles are capable of sustained release of BAC under acidic conditions, thereby acting as a long release antimicrobial agent. In other embodiments, the BAC-SiO.sub.2 mesoporous nanoparticles can be incorporated into a variety of consumer products as an antimicrobial agent additive, including for example, but not limited to, surgical dressings, bandages, deodorants, soaps, facial cleansers and industrial cleaners.

The present disclosure provides a method for transforming an arsenic sulfide slag and curing and stabilizing the resulting compound by means of microencapsulation, comprising the following steps: (1) preparing arsenic trioxide from the arsenic sulfide slag as a raw material; (2) preparing 4-hydroxy-3-nitrophenylarsonic acid from the arsenic trioxide as a raw material; (3) preparing an iron-manganese dinuclear cluster metal arsenate compound having a porous structure; (4) subjecting the iron-manganese dinuclear cluster metal arsenate compound having a porous structure to surface coating with silicon; (5) synthesizing an Fe(0)/Al-SBA-15 mesoporous composite stabilizer by a hydrothermal reaction; and (6) subjecting the silicon coated iron-manganese dinuclear cluster metal arsenate compound to curing and stabilizing treatment by means of microencapsulation. The present disclosure involves transforming the arsenic sulfide slag into 4-hydroxy-3-nitrophenylarsonic acid and finally into a metal arsenate compound having a porous structure, which has the characteristics of good stability and low toxicity in comparison to conventional arsenic compounds. Thus, the toxicity associated with arsenic compounds can be greatly reduced.

The present disclosure provides a method for transforming an arsenic sulfide slag and curing and stabilizing the resulting compound by means of microencapsulation, comprising the following steps: (1) preparing arsenic trioxide from the arsenic sulfide slag as a raw material; (2) preparing 4-hydroxy-3-nitrophenylarsonic acid from the arsenic trioxide as a raw material; (3) preparing an iron-manganese dinuclear cluster metal arsenate compound having a porous structure; (4) subjecting the iron-manganese dinuclear cluster metal arsenate compound having a porous structure to surface coating with silicon; (5) synthesizing an Fe(0)/Al-SBA-15 mesoporous composite stabilizer by a hydrothermal reaction; and (6) subjecting the silicon coated iron-manganese dinuclear cluster metal arsenate compound to curing and stabilizing treatment by means of microencapsulation. The present disclosure involves transforming the arsenic sulfide slag into 4-hydroxy-3-nitrophenylarsonic acid and finally into a metal arsenate compound having a porous structure, which has the characteristics of good stability and low toxicity in comparison to conventional arsenic compounds. Thus, the toxicity associated with arsenic compounds can be greatly reduced.

The invention relates to a process for preparing an IZM-2 zeolite, comprising at least: i) mixing, in aqueous medium, of at least one source of at least one tetravalent element X (XO.sub.2), at least one source of at least one trivalent element (Y.sub.2O.sub.3), 1,6-bis(methylpiperidinium)hexane dihydroxide, at least one source of at least one alkali metal M of valency n chosen from alkali metal chlorides, n being an integer greater than or equal to 1, M being chosen from lithium, potassium, sodium and caesium, and the mixture of at least two of these metals, and optionally in the presence of a source of at least one fluoride anion, BF, the mixture having a specific molar composition to obtain a homogeneous precursor gel; ii) hydrothermal treatment of said precursor gel.