阅读说明：本技术 一种陶瓷粉体改性方法 (Ceramic powder modifying method ) 是由 邓延生 周江山 方仁德 赵文兴 于 2021-10-14 设计创作，主要内容包括：本发明提供了一种陶瓷粉体改性方法,涉及陶瓷材料处理技术领域,包括以下步骤：配制硅烷偶联剂溶液；将陶瓷粉体置于煅烧设备中以一定转速氧化,得到表面氧化的陶瓷粉体；将表面氧化的陶瓷粉体加入至硅烷偶联剂溶液中混合得到粉体浆料,再将粉体浆料置于煅烧设备中以一定转速硅烷化处理2～72h；其中,煅烧设备为可以转动的煅烧设备。本发明的方法,采用可以转动的煅烧设备,可以使陶瓷粉体表面氧化更均匀、更充分,且氧化层与粉体的结合力强,同时氧化后的粉体表面存在大量的羟基基团,再通过煅烧设备对氧化后的陶瓷粉体进行动态的硅烷化处理,可以大大提高粉体与硅烷偶联剂发生偶联作用,进而提高其硅烷化效率和速率。(The invention provides a ceramic powder modification method, which relates to the technical field of ceramic material treatment and comprises the following steps: preparing a silane coupling agent solution; placing the ceramic powder in a calcining device to oxidize at a certain rotating speed to obtain ceramic powder with oxidized surface; adding the surface-oxidized ceramic powder into a silane coupling agent solution, mixing to obtain powder slurry, and placing the powder slurry into calcining equipment to perform silanization treatment for 2-72 hours at a certain rotating speed; wherein, the calcining equipment is rotatable calcining equipment. The method of the invention adopts the rotary calcining equipment, can ensure that the surface of the ceramic powder is oxidized more uniformly and fully, the bonding force between an oxide layer and the powder is strong, meanwhile, a large amount of hydroxyl groups exist on the surface of the oxidized powder, and the oxidized ceramic powder is subjected to dynamic silanization treatment by the calcining equipment, so that the coupling effect between the powder and the silane coupling agent can be greatly improved, and the silanization efficiency and speed are further improved.)

1. A ceramic powder modification method is characterized by comprising the following steps:

preparing a silane coupling agent solution for later use;

placing the ceramic powder in a calcining device to oxidize at a certain rotating speed to obtain ceramic powder with oxidized surface;

adding the surface-oxidized ceramic powder into the silane coupling agent solution to be mixed to obtain powder slurry, and then placing the powder slurry into calcining equipment to perform silanization treatment at a certain rotating speed for 2-72 hours at a temperature of 20-200 ℃, so as to complete modification of the ceramic powder;

or spraying the silane coupling agent solution onto the surface of the ceramic powder with the oxidized surface to obtain powder slurry, and then placing the powder slurry into calcining equipment to perform silanization treatment at a certain rotating speed for 2-72 hours at 20-200 ℃, so as to complete the modification of the ceramic powder;

wherein the calcining equipment is rotatable calcining equipment.

2. The method for modifying ceramic powder according to claim 1, wherein the calcining apparatus is a rotary kiln.

3. The method for modifying ceramic powder according to claim 1, wherein the step of oxidizing the ceramic powder in a calcining device at a rotational speed of 5r/min to 100 r/min.

4. The method for modifying ceramic powder according to claim 1, wherein in the step of performing silanization at a constant rotation speed for 2 to 72 hours, the rotation speed is 5 to 100 r/min.

5. The method for modifying ceramic powder according to claim 1, wherein the preparation of the silane coupling agent solution specifically comprises: adding a silane coupling agent into a solvent, adjusting the pH to 3-6, and preparing a silane coupling agent solution with the mass fraction of 0.1-30%;

wherein the solvent is one or more of water, ethanol, methanol and acetone.

6. The method for modifying ceramic powder according to claim 5, wherein the silane coupling agent comprises one or more of γ -aminopropyltriethoxysilane, γ - (2, 3-glycidoxy) propyltrimethoxysilane, N- (β -aminoethyl) - γ -aminopropyltrimethoxysilane, N- (β -aminoethyl) - γ -aminopropyltriethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, 3-aminopropyltriethoxysilane, and γ - (methacryloyloxy) propyltrimethoxysilane.

7. The method for modifying ceramic powder according to claim 1, wherein in the step of oxidizing the ceramic powder in a calcining device at a certain rotation speed, the oxidizing temperature is 200 to 800 ℃ and the oxidizing time is 2 to 48 hours.

8. The method for modifying ceramic powder according to claim 1, wherein the ceramic powder with oxidized surface is added into the silane coupling agent solution and mixed to obtain powder slurry, wherein the solid content of the powder slurry is 5-40%, and the pH of the powder slurry is 8-11.

9. The method for modifying ceramic powder according to claim 5, wherein a silane coupling agent is added to a solvent, and the pH is adjusted to 3 to 6 using an acid, wherein the acid comprises oxalic acid or acetic acid.

10. The method for modifying ceramic powder according to claim 8, wherein the pH of the powder slurry is adjusted to 8 to 11 using an alkali, and the alkali includes ammonia water or tetramethylammonium hydroxide.

Technical Field

The invention relates to the technical field of ceramic material treatment, in particular to a ceramic powder modification method.

Background

The superfine ceramic powder is usually used in the field of inorganic non-metallic ceramic preparation, and generally comprises micron-sized (1-100 mu m), submicron-sized (0.1-1 mu m) and nanoscale (1-100 nm) particles, and because the particle size of the superfine ceramic powder is very small, the surface energy is high, agglomeration is easy to occur, secondary particles are formed, and excellent surface effect, volume effect, quantum size effect and the like cannot be presented. The most effective method is to modify the surface of the powder, and modify the surface of the ultrafine powder to improve the dispersibility of the powder particles and the compatibility between the powder particles and other substances.

At present, the ceramic powder is modified mainly by a liquid phase oxidation method, a high temperature oxidation method and a powder silanization method. For the liquid phase method, the bonding force between an oxidation layer and powder is not strong during oxidation, the oxidation layer of the powder is easy to fall off during the oxidation process or later mechanical stirring treatment, and particularly, an oxidation layer protective film cannot be formed on the surface of the powder in the oxidation reaction stage, so that the powder can react indefinitely, and the performance of the powder is influenced; for a high-temperature oxidation method, a muffle furnace static calcining method is generally adopted at present, and the powder oxidized by the method generally has the defect of nonuniform and insufficient oxidation; the silanization treatment of the powder is to directly carry out surface modification treatment by using a silane coupling agent or some surfactants under certain conditions, and the powder is not particularly subjected to pretreatment such as oxidation, so that the silanization efficiency of the powder is low, the silanization operation is complicated, and a large amount of waste liquid needs to be treated in the later stage.

Based on the various defects of the existing ceramic powder modification treatment, improvement on the defects is needed.

Disclosure of Invention

In view of the above, the present invention provides a method for modifying ceramic powder, which solves or at least partially solves the technical defects in the prior art.

In a first aspect, the present invention provides a method for modifying ceramic powder, comprising the following steps:

preparing a silane coupling agent solution for later use;

placing the ceramic powder in a calcining device to oxidize at a certain rotating speed to obtain ceramic powder with oxidized surface;

adding the surface-oxidized ceramic powder into the silane coupling agent solution to be mixed to obtain powder slurry, and then placing the powder slurry into calcining equipment to perform silanization treatment at a certain rotating speed for 2-72 hours at a temperature of 20-200 ℃, so as to complete modification of the ceramic powder;

or spraying the silane coupling agent solution onto the surface of the ceramic powder with the oxidized surface to obtain powder slurry, and then placing the powder slurry into calcining equipment to perform silanization treatment at a certain rotating speed for 2-72 hours at 20-200 ℃, so as to complete the modification of the ceramic powder;

wherein the calcining equipment is rotatable calcining equipment.

On the basis of the above technical solution, preferably, in the ceramic powder modification method, the calcining apparatus is a rotary kiln.

On the basis of the above technical solution, preferably, in the ceramic powder modification method, the ceramic powder is placed in a calcining device and oxidized at a certain rotation speed, where the rotation speed is: 5 r/min-100 r/min.

On the basis of the technical scheme, preferably, in the step of silanization at a certain rotation speed for 2-72 hours, the rotation speed is as follows: 5 r/min-100 r/min.

On the basis of the above technical scheme, preferably, the method for modifying ceramic powder comprises the following steps: adding a silane coupling agent into a solvent, adjusting the pH to 3-6, and preparing a silane coupling agent solution with the mass fraction of 0.1-30%.

Preferably, the silane coupling agent comprises one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane, N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane, N- (beta-aminoethyl) -gamma-aminopropyltriethoxysilane methyl triethoxysilane, vinyl triethoxysilane, 3-aminopropyltriethoxysilane, and gamma- (methacryloyloxy) propyltrimethoxysilane;

the solvent is one or more of water, ethanol, methanol and acetone.

On the basis of the technical scheme, preferably, in the ceramic powder modification method, in the step of oxidizing the ceramic powder in the calcining equipment at a certain rotating speed, the oxidizing temperature is 200-800 ℃, and the oxidizing time is 2-48 h.

On the basis of the technical scheme, preferably, in the ceramic powder modification method, the ceramic powder with oxidized surface is added into the silane coupling agent solution and mixed to obtain powder slurry, wherein the solid content of the powder slurry is 5-40%, and the pH value of the powder slurry is 8-11.

Preferably, the ceramic powder modification method includes adding a silane coupling agent into a solvent, and adjusting the pH to 3-6 by using an acid, wherein the acid includes oxalic acid or acetic acid.

Preferably, in the method for modifying ceramic powder, the pH of the powder slurry is adjusted to 8 to 11 by using alkali, wherein the alkali comprises ammonia water or tetramethylammonium hydroxide.

Compared with the prior art, the ceramic powder modification method has the following beneficial effects:

(1) according to the ceramic powder modification method, the rotary calcining equipment is adopted to carry out high-temperature oxidation treatment on the ceramic powder, so that the surface of the ceramic powder can be oxidized more uniformly and more sufficiently, the bonding force between an oxide layer and the powder is strong, a large number of hydroxyl groups exist on the surface of the oxidized powder, and the oxidized ceramic powder is dynamically silanized by the calcining equipment, so that the coupling effect between the powder and a silane coupling agent can be greatly improved, and the silanization efficiency and speed are improved;

according to the ceramic powder modification method, the oxidation of the ceramic powder is realized by dynamic high-temperature oxidation of the calcining equipment instead of static high-temperature oxidation of a common muffle furnace, so that the uniformity and the sufficiency of the oxidation of the powder can be improved; the oxidation of the ceramic powder is carried out through high-temperature oxidation instead of liquid-phase oxidation, and compared with the liquid-phase oxidation, the bonding force between an oxidation layer subjected to high-temperature oxidation and the powder is stronger and the powder is not easy to fall off; the ceramic powder is silanized after being oxidized, the silanization on the surface of the powder is mainly realized by the action of a silane coupling agent and hydroxyl groups on the surface of the powder, more hydroxyl groups exist on the surface of the powder after the powder is oxidized, and the bonding force between the hydroxyl groups and the powder is very firm; the ceramic powder modification method can simultaneously realize the oxidation and silanization of the surface of the ceramic powder, and has the advantages of simple method, easy operation, easy realization of industrialization and no waste liquid generation.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a scanning electron micrograph of a silicon nitride oxide fine powder prepared in example 1 of the present invention;

FIG. 2 is a scanning electron micrograph of the fine silica powder prepared in example 2 of the present invention;

FIG. 3 is a scanning electron microscope image of the fine silica powder prepared in the comparative example;

FIG. 4 is an EDS chart of the fine silicon nitride oxide powder produced in example 1 of the present invention;

FIG. 5 is an EDS chart of the fine silica powder produced in example 2 of the present invention;

fig. 6 is an EDS diagram of the fine silica powder prepared in the comparative example.

Detailed Description

In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The embodiment of the application provides a ceramic powder modification method, which comprises the following steps:

s1, preparing a silane coupling agent solution for later use;

s2, placing the ceramic powder in a calcining device to be oxidized at a certain rotating speed to obtain ceramic powder with oxidized surface;

s3, adding the ceramic powder with the oxidized surface into a silane coupling agent solution to be mixed to obtain powder slurry, and then placing the powder slurry into a calcining device to be silanized for 2-72 hours at a certain rotating speed at the temperature of 20-200 ℃ to finish the modification of the ceramic powder;

or spraying the silane coupling agent solution on the surface of the ceramic powder with oxidized surface to obtain powder slurry, and then placing the powder slurry in calcining equipment for silanization treatment at a certain rotating speed for 2-72 hours at 20-200 ℃, thus finishing the modification of the ceramic powder;

wherein, the calcining equipment is rotatable calcining equipment.

It should be noted that the ceramic powder used in the embodiments of the present application includes micron-sized (1 to 100 μm), submicron-sized (0.1 to 1 μm), and nanoscale (1 to 100nm), and specifically may include inorganic silicide micro powder, silicon micro powder, and the like, where the inorganic silicide may be silicon nitride micro powder, silicon carbide micro powder, and the like, and in practice, besides modifying one ceramic powder, a plurality of ceramic powders may also be modified; the calcining equipment is rotatable, namely, the ceramic powder is oxidized in the calcining equipment at a certain rotating speed at a certain temperature, so that the uniformity and the sufficiency of the oxidation of the ceramic powder can be improved, the bonding force between an oxidation layer and the ceramic powder is strong, meanwhile, the oxidized ceramic powder forms a layer of oxidation layer film such as a silicon oxide film on the surface, the surface of a newly generated silicon oxide film has more coordination defects, a silicon dangling bond has the tendency of capturing negative charges, so that the charge balance is kept, the charge transfer is generated between the silicon dangling bond and water molecules, the water molecules are promoted to be dissociated at the tail ends of the silicon dangling bond, so that Si-OH is formed on the surface of the silicon oxide film, and a large number of hydroxyl groups exist on the surface of the oxidized ceramic powder; when the ceramic powder is oxidized in the calcining equipment, the oxidizing atmosphere can be air or oxygen; further, when the ceramic powder with the oxidized surface is subjected to silanization treatment, the ceramic powder with the oxidized surface can be added into a silane coupling agent solution to be mixed to obtain powder slurry, then the powder slurry is placed in a calcining device to be subjected to silanization treatment, or the silane coupling agent solution can be sprayed onto the surface of the ceramic powder with the oxidized surface to obtain powder slurry, then the powder slurry is placed in the calcining device to be subjected to silanization treatment, and specifically, silanization treatment is performed at a certain temperature and a certain rotating speed, so that the silanization rate and efficiency of the ceramic powder can be improved; the ceramic powder modification method adopts the rotary calcining equipment to carry out high-temperature oxidation treatment on the ceramic powder, so that the surface oxidation of the ceramic powder is more uniform and sufficient, the bonding force of an oxidation layer and the powder is strong, a large amount of hydroxyl groups exist on the surface of the oxidized powder, dynamic silanization treatment is carried out on the oxidized ceramic powder through the calcining equipment, the coupling effect between the powder and a silane coupling agent can be greatly improved, and the silanization efficiency and the silanization speed are further improved. According to the ceramic powder modification method, the oxidation of the ceramic powder is realized by dynamic high-temperature oxidation of calcining equipment instead of static high-temperature oxidation of a common muffle furnace, so that the uniformity and the sufficiency of the oxidation of the powder can be improved; the oxidation of the ceramic powder is carried out through high-temperature oxidation instead of liquid-phase oxidation, and compared with the liquid-phase oxidation, the bonding force between an oxidation layer subjected to high-temperature oxidation and the powder is stronger and the powder is not easy to fall off; the ceramic powder is silanized after being oxidized, the silanization on the surface of the powder is mainly realized by the action of a silane coupling agent and hydroxyl groups on the surface of the powder, more hydroxyl groups exist on the surface of the powder after the powder is oxidized, and the bonding force between the hydroxyl groups and the powder is very firm; the ceramic powder modification method can simultaneously realize the oxidation and silanization of the surface of the ceramic powder, and has the advantages of simple method, easy operation, easy realization of industrialization and no waste liquid generation.

In some embodiments, the calcining apparatus is a rotary kiln. In the embodiment of the application, the rotary furnace can rotate forwards and backwards, and is provided with a quick and slow driving device, so that the equipment which can drive the ceramic powder to rotate in the calcining process is obviously feasible in practice. In the embodiment of the application, the same rotary furnace is adopted for the oxidation and the silanization of the ceramic powder, and the oxidation and the silanization processes can be sequentially completed through a simple rotary furnace device, so that the method is suitable for industrial production.

In some embodiments, the ceramic powder is placed in a calcining device for oxidation at a rotation speed of: 5r/min to 10 r/min.

In some embodiments, the step of silylation is performed at a rotation speed of 5r/min to 10r/min for 2 to 72 hours.

In some embodiments, the silane coupling agent solution is specifically formulated as: adding a silane coupling agent into a solvent, adjusting the pH to 3-6, and preparing a silane coupling agent solution with the mass fraction of 0.1-30%.

In some embodiments, the silane coupling agent comprises one or more of gamma-aminopropyltriethoxysilane, gamma- (2, 3-glycidoxy) propyltrimethoxysilane, N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane, N- (beta-aminoethyl) -gamma-aminopropyltriethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, 3-aminopropyltriethoxysilane, gamma- (methacryloyloxy) propyltrimethoxysilane;

and/or the solvent is one of water, ethanol, methanol and acetone.

In some embodiments, the ceramic powder is placed in a calcining device to be oxidized at a certain rotation speed, the temperature of the oxidation is 200-800 ℃, and the time of the oxidation is 2-48 h.

In some embodiments, the ceramic powder with oxidized surface is added into a silane coupling agent solution and mixed to obtain a powder slurry, wherein the solid content of the powder slurry is 5-40%, and the pH of the powder slurry is 8-11.

In some embodiments, a silane coupling agent is added to a solvent and the pH is adjusted to 3-6 using an acid, including oxalic acid or acetic acid, preferably oxalic acid.

In some embodiments, the pH of the powder slurry is adjusted to 8-11 using a base, wherein the base comprises ammonia water or tetramethylammonium hydroxide, preferably tetramethylammonium hydroxide.

In some embodiments, the silanization treatment further comprises drying the silanized ceramic powder at 40-100 ℃.

The method for modifying a ceramic powder according to the present invention will be described below with reference to specific examples.

Example 1

The embodiment of the application provides a ceramic powder modification method, which comprises the following steps:

s1, adding the gamma-aminopropyl triethoxysilane coupling agent into water to prepare a mixed solution with the mass fraction of 10%, uniformly stirring, and adjusting the pH value of the mixed solution to 5 by using oxalic acid to obtain a silane coupling agent solution for later use;

s2, placing 10kg of silicon nitride micro powder in a rotary furnace at the rotating speed of 5r/min, introducing oxygen, heating to 600 ℃ at the heating rate of 50 ℃/h, preserving the heat at 600 ℃ for 5 hours, and cooling to room temperature along with the furnace to obtain silicon nitride micro powder with oxidized surface;

s3, adding the silicon nitride micro powder with the oxidized surface into the silane coupling agent solution in the S1, preparing silicon nitride slurry with the solid content of 20%, adjusting the pH value to 10 by using tetramethylammonium hydroxide, adding the prepared silicon nitride slurry into a rotary furnace with the rotation speed of 5r/min, rotating for 10 hours at 25 ℃ for silanization treatment, and then drying at 40 ℃ to finish the modification of the silicon nitride micro powder.

Example 2

The embodiment of the application provides a ceramic powder modification method, which comprises the following steps:

s1, adding the gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane coupling agent into an ethanol solution with the mass fraction of 50% to prepare a mixed solution with the mass fraction of 10%, uniformly stirring, and adjusting the pH value of the mixed solution to 4 by using oxalic acid to obtain a silane coupling agent solution for later use;

s2, placing 10kg of silicon micro powder in a rotary furnace at the rotating speed of 5r/min, introducing oxygen, heating to 600 ℃ at the heating rate of 50 ℃/h, preserving the heat at 600 ℃ for 5 hours, and cooling to room temperature along with the furnace to obtain silicon micro powder with oxidized surface;

s3, adding the surface oxidized silicon powder into the silane coupling agent solution in the S1, preparing silicon powder slurry with the solid content of 30%, adjusting the pH value to 10 by using tetramethylammonium hydroxide, adding the prepared silicon powder slurry into a rotary furnace with the rotation speed of 5r/min, rotating for 10 hours at 25 ℃ for silanization treatment, and drying at 80 ℃ to finish the modification of the silicon powder.

Comparative example

The comparative example provides a silica powder modification method, which comprises the following steps:

s1, adding the gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane coupling agent into an ethanol solution with the mass fraction of 50% to prepare a mixed solution with the mass fraction of 10%, uniformly stirring, and adjusting the pH value of the mixed solution to 4 by using oxalic acid to obtain a silane coupling agent solution for later use;

s2, placing 10kg of silicon micro powder in a muffle furnace, heating to 600 ℃ at a heating rate of 50 ℃/h, preserving heat at 600 ℃ for 5 hours, and cooling to room temperature along with the furnace to obtain silicon micro powder with oxidized surface;

s3, adding the surface oxidized silicon powder into the silane coupling agent solution in the S1, preparing silicon powder slurry with the solid content of 30%, adjusting the pH value to 10 by using tetramethylammonium hydroxide, standing the prepared silicon powder slurry for 10 hours, and drying at 40 ℃ to finish the modification of the silicon powder.

Performance testing

FIG. 1 is a scanning electron micrograph of the silicon nitride oxide fine powder prepared in example 1 of the present invention; FIG. 4 is an EDS image and the mass percentages of the respective elements of silicon nitride oxide prepared in the above example 1 of the present invention; the distribution image of N, O, Si three elements, in which the mass percentage of N element was 54.04%, the mass percentage of O element was 7.68%, and the mass percentage of Si element was 38.29%, is shown in fig. 4.

FIG. 2 is a scanning electron micrograph of the fine silica powder prepared in example 2 of the present invention; fig. 5 is an EDS image and the mass percentages of the respective elements of the fine silica powder produced in the above example 2 of the present invention, and fig. 5 shows a distribution image of C, O, Si three elements in which the mass percentage of C element is 19.08%, the mass percentage of O element is 25.04%, and the mass percentage of Si element is 55.88%.

FIG. 3 is a scanning electron micrograph of the fine silica powder prepared according to the above comparative example of the present invention; fig. 6 is an EDS image of the differential of the silicon oxide prepared by the above comparative example and distribution images of C, O, Si three elements, in which the mass percentage of C element is 18.89%, the mass percentage of O element is 20.54%, and the mass percentage of Si element is 60.57%, are shown in fig. 6.

As can be seen from the comparison of FIGS. 5 to 6, the EDS image and the mass percentage of each element of the silica powder prepared in example 2 are improved by 25% compared with the comparative example, the oxidation of the silica powder is obviously more sufficient, and the distribution of the oxygen element is relatively uniform.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.