CN110240171B

CN110240171B - Layered strontium disilicate and preparation method and application thereof

Info

Publication number: CN110240171B
Application number: CN201910614754.9A
Authority: CN
Inventors: 汪印; 李智伟; 张骏; 邢贞娇
Original assignee: Institute of Urban Environment of CAS
Current assignee: Institute of Urban Environment of CAS
Priority date: 2019-07-09
Filing date: 2019-07-09
Publication date: 2021-01-15
Anticipated expiration: 2039-07-09
Also published as: WO2021003787A1; CN110240171A

Abstract

The invention belongs to the field of inorganic silicon-strontium composite layered materials, and discloses layered strontium disilicate and a preparation method and application thereof. The preparation method of the layered strontium disilicate comprises the following steps: s1, uniformly mixing sodium silicate and soluble strontium salt in a solvent, and then carrying out hydrothermal reaction on the obtained mixed solution at the temperature of 200-300 ℃ to obtain a hydrothermal reaction product; s2, cooling the hydrothermal reaction product to below 50 ℃, filtering, and washing, drying and grinding the obtained solid product in sequence. The method provided by the invention takes sodium silicate and soluble strontium salt as raw materials, and synthesizes the strontium disilicate material which has an obvious crystal structure, can reach a purity of more than 95 percent and has a layered distribution structure by utilizing a hydrothermal reaction. In addition, the preparation process provided by the invention is simple, the raw material source is wide, the cost is low, and the current industrial-grade requirements on environmental protection, simplicity, convenience, low cost, no toxicity and no harm are met.

Description

Layered strontium disilicate and preparation method and application thereof

Technical Field

The invention belongs to the field of inorganic silicon-strontium composite layered materials, and particularly relates to layered strontium disilicate and a preparation method and application thereof.

Background

The inorganic silicon-strontium composite material is a silicate material formed by compounding silicon and strontium. At present, inorganic silicon-strontium composite materials are mainly prepared by solid-solid high-temperature reaction, and specifically, inorganic silicon and strontium-containing compounds are placed at the temperature of 900-1200 ℃ for reaction. However, the synthesis process has high energy consumption, and the obtained inorganic silicon-strontium composite material has high impurity content and low purity, thereby influencing the use effect.

Disclosure of Invention

The invention aims to overcome the defects of high impurity content and low purity of the inorganic silicon-strontium composite material prepared by the existing method, and provides layered strontium disilicate, a preparation method and application thereof.

Specifically, the invention provides a preparation method of layered strontium disilicate, wherein the method comprises the following steps:

s1, uniformly mixing sodium silicate and soluble strontium salt in a solvent, and then carrying out hydrothermal reaction on the obtained mixed solution at the temperature of 200-300 ℃ to obtain a hydrothermal reaction product;

s2, cooling the hydrothermal reaction product to below 50 ℃, filtering, and washing, drying and grinding the obtained solid product in sequence to obtain the layered strontium disilicate.

Further, the soluble strontium salt is selected from at least one of strontium chloride, strontium nitrate and strontium bromide.

Further, the sodium silicate and the soluble strontium salt are uniformly mixed in the solvent, such that a sodium silicate solution and a soluble strontium salt solution are respectively prepared, and then the two solutions are uniformly mixed; or adding sodium silicate and soluble strontium salt into the same solution and mixing uniformly. Preferably, the sodium silicate is used in the form of a sodium silicate solution and the soluble strontium salt is used in the form of a soluble strontium salt solution, and the concentration of the sodium silicate solution and the concentration of the soluble strontium salt solution are 0.01-0.5 mol/L respectively and independently. Wherein, the solvents contained in the sodium silicate solution and the soluble strontium salt solution can be the same or different, and are preferably water. In addition, the volume ratio of the sodium silicate solution to the soluble strontium salt solution is preferably 1 (1.2-4).

Further, in step S1, the hydrothermal reaction conditions include a temperature rise rate of 5 to 15 ℃/min for raising the temperature from room temperature to the reaction temperature, a reaction temperature of 200 to 300 ℃, preferably 210 to 260 ℃, and a reaction time of 2 to 4 hours.

Further, in step S2, the hydrothermal reaction product is cooled to 15 to 50 ℃.

Further, in step S2, the solid product is washed to be neutral by using deionized water.

Further, in the step S2, the drying conditions include a drying temperature of 100 to 110 ℃ and a drying time of 2 to 4 hours.

Further, in step S2, the grinding conditions are set to reduce the particle size D of the product₉₀The thickness is controlled to be 0.1-0.4 mm.

The invention also provides the layered strontium disilicate prepared by the method.

In addition, the invention also provides application of the layered strontium disilicate as an electrical insulating material, a heat insulating material or a luminescent material.

Compared with the prior art, the invention has the following beneficial effects:

the method provided by the invention does not need high-temperature calcination, saves energy, and obtains the strontium disilicate material (SrSi)₂O₅) The silicate compound with a layered structure has the purity of more than 95 percent, and has important potential application value in the fields of electric insulating materials, heat insulating materials, luminescent materials and the like due to the special layered structure and higher purity. In addition, the preparation process provided by the invention is simple, the raw material source is wide, the cost is low, and the current industrial-grade requirements on environmental protection, simplicity, convenience, low cost, no toxicity and no harm are met.

Drawings

FIG. 1 is a Scanning Electron Micrograph (SEM) of the layered strontium disilicate obtained in example 1.

Detailed Description

The following detailed description of embodiments of the invention is intended to be illustrative of the invention and is not to be construed as limiting the invention. The examples do not specify particular techniques or conditions, and are performed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

In the following examples and comparative examples, the purity of layered strontium disilicate was measured by XRD spectrum comparison and chemical composition analysis.

Example 1

S1, preparing a sodium silicate aqueous solution with the concentration of 0.01mol/L and a strontium chloride aqueous solution with the concentration of 0.01mol/L respectively. Uniformly stirring and mixing the sodium silicate aqueous solution and the strontium chloride aqueous solution according to the volume ratio of 1:1.2, then placing the obtained mixed solution into a hydrothermal reaction kettle, heating to 260 ℃ at the speed of 10 ℃/min, and stirring for 2 hours to obtain a hydrothermal reaction product;

s2, cooling the hydrothermal reaction product to 50 ℃, filtering, washing the obtained solid product to be neutral by using deionized water, drying at the temperature of 100 ℃ for 4 hours, and grinding the dried product to the particle size D₉₀0.4mm, yieldLayered strontium disilicate. The purity of the layered strontium disilicate is detected to be 95%. The SEM photograph of the layered strontium disilicate is shown in FIG. 1, and it can be seen from FIG. 1 that it has a distinct layered structure.

Example 2

S1, preparing a sodium silicate aqueous solution with the concentration of 0.5mol/L and a strontium nitrate aqueous solution with the concentration of 0.5mol/L respectively. Uniformly stirring and mixing the sodium silicate aqueous solution and the strontium nitrate aqueous solution according to the volume ratio of 1:4, then placing the obtained mixed solution into a hydrothermal reaction kettle, heating to 240 ℃ at the speed of 5 ℃/min, and stirring for reaction for 3 hours to obtain a hydrothermal reaction product;

s2, cooling the hydrothermal reaction product to 15 ℃, filtering, washing the obtained solid product to be neutral by using deionized water, drying at 100 ℃ for 3h, and grinding the dried product to a particle size D₉₀0.125mm, to obtain layered strontium disilicate. The purity of the layered strontium disilicate is 98 percent through detection. As can be seen from the scanning electron micrograph, the layered strontium disilicate has a layered structure.

Example 3

S1, preparing a sodium silicate aqueous solution with the concentration of 0.3mol/L and a strontium bromide aqueous solution with the concentration of 0.3mol/L respectively. Uniformly stirring and mixing the sodium silicate aqueous solution and the strontium bromide aqueous solution according to the volume ratio of 1:2.5, then placing the obtained mixed solution into a hydrothermal reaction kettle, heating to 210 ℃ at the speed of 15 ℃/min, and stirring for reaction for 4 hours to obtain a hydrothermal reaction product;

s2, cooling the hydrothermal reaction product to 30 ℃, filtering, washing the obtained solid product to be neutral by using deionized water, drying at 100 ℃ for 2h, and grinding the dried product to a particle size D₉₀0.1mm, to obtain layered strontium disilicate. The purity of the layered strontium disilicate is detected to be 97.6%. As can be seen from the scanning electron micrograph, the layered strontium disilicate has a layered structure.

Comparative example 1

Layered strontium disilicate was prepared according to the method of example 1, except that, in step S1, the hydrothermal reaction temperature was 400 ℃ to obtain reference layered strontium disilicate. The purity of the reference layered strontium disilicate was determined to be 90%. As can be seen from the scanning electron micrograph, the reference layered strontium disilicate has a layered and lamellar structure.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.

Claims

1. A preparation method of layered strontium disilicate is characterized by comprising the following steps:

s1, uniformly mixing sodium silicate and soluble strontium salt in a solvent, and then carrying out hydrothermal reaction on the obtained mixed solution to obtain a hydrothermal reaction product; the hydrothermal reaction conditions comprise that the temperature rising rate of raising the temperature from room temperature to the reaction temperature is 5-15 ℃/min, the reaction temperature is 240-260 ℃, and the reaction time is 2-4 h; the solvent is water;

2. The method of claim 1, wherein the soluble strontium salt is at least one selected from the group consisting of strontium chloride, strontium nitrate, and strontium bromide.

3. The method for preparing layered strontium disilicate according to claim 1, wherein the sodium silicate is used in the form of a sodium silicate solution, the soluble strontium salt is used in the form of a soluble strontium salt solution, and the concentrations of the sodium silicate solution and the soluble strontium salt solution are each independently 0.01 to 0.5 mol/L; the volume ratio of the sodium silicate solution to the soluble strontium salt solution is 1 (1.2-4).

4. The method for producing layered strontium disilicate according to any one of claims 1 to 3, wherein in step S2, the hydrothermal reaction product is cooled to 15 to 50 ℃.

5. The method for preparing layered strontium disilicate according to any one of claims 1 to 3, wherein in step S2, the solid product is washed to be neutral by deionized water.

6. The method for preparing layered strontium disilicate according to any one of claims 1 to 3, wherein in step S2, the drying conditions include a drying temperature of 100 to 110 ℃ and a drying time of 2 to 4 hours.

7. The method for producing layered strontium disilicate according to any one of claims 1 to 3, wherein in step S2, the milling is performed under conditions to give a product particle diameter D₉₀The thickness is controlled to be 0.1-0.4 mm.

8. Layered strontium disilicate obtainable by a process according to any one of claims 1 to 7.

9. Use of the layered strontium disilicate according to claim 8 as an electrical insulating material, a heat insulating material or a luminescent material.