Gas-phase oleophylic modified silicon dioxide nanosphere and preparation method thereof

Abstract

The invention belongs to the field of nano material preparation, and particularly relates to a gas-phase oleophylic modified silicon dioxide nanosphere and a preparation method thereof, and the preparation method comprises the following steps: cleaning and drying metallic silicon; heating and gasifying to obtain silicon steam; oxidizing to obtain silicon dioxide liquid drops, cooling the silicon dioxide liquid drops, carrying out self-pitching to obtain silicon dioxide nanospheres, feeding the silicon dioxide nanospheres into a gas-phase modification reactor, spraying a modifier, carrying out gas-phase modification, and collecting the gas-phase oleophylic modified silicon dioxide nanospheres. The gas-phase modified high-lipophilicity silicon dioxide nanosphere and the preparation method thereof have the advantages of simple process, high yield and low pollution emission, and the obtained modified silicon dioxide nanosphere has good dispersity, flowability and lipophilicity and high surface chemical activity; the polymer can be used in materials such as adhesives, sealants, composite surfactant functional materials, functional nano material carriers, nano oil displacement agents and the like, and is expected to be widely applied to the fields of packaging, coatings, catalysis, cleaning, nano oil displacement, recovery efficiency improvement and the like.

Description

Technical Field

[0001] The invention belongs to the field of nano material preparation, and particularly relates to gas phase lipophilic modified silicon dioxide nanospheres and a preparation method thereof. Background Art

[0003] Silica powder is required to be ultrafine, high-purity, uniform in particle size distribution, and without serious agglomeration. At present, the main methods for preparing spherical silica powder are sol-gel method, spray pyrolysis method, hydrothermal method, modified Bayer method, etc. At present, the existing technology can use solution method to prepare ultrafine silica powder, the product morphology is good, the particle size is small, but there are disadvantages such as many processes, large water consumption, high emission, and high impurity ion content. Or the halosilane combustion hydrolysis method is used to prepare fumed silica. Although the process steps are relatively simple and the product appearance is smaller, there is acidic hydrogen halide gas as a by-product in the process, which has certain pollution. At the same time, the silica particles are very easy to produce dendritic structures that are difficult to separate, resulting in poor fluidity, and it is difficult to separate even after modification.

[0004] The preparation of silica nanoparticles by gas phase oxidation spheroidization-modification method is a new synthesis method. Silicon dioxide nanospheres are synthesized in one step by direct oxidation reaction of silicon vapor in an oxidizing atmosphere, and the modifier is adsorbed and bonded to the surface of silica by gas phase modification method, which can effectively overcome the above defects. Therefore, the industry needs to develop a production process for synthesizing and modifying modified silica nanospheres by silicon vapor to meet the needs of potential promotion and application in the field of nano oil recovery. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for preparing gas-phase lipophilic modified silica nanospheres, comprising:

[0006] cleaning and drying the metallic silicon;

[0007] heating and gasifying the treated metallic silicon to obtain silicon vapor;

[0008] The silicon vapor is sent into an oxidation reactor for oxidation to obtain silicon dioxide droplets;

[0009] The silica droplets are cooled and spontaneously spheronized to obtain silica nanospheres;

[0010] The silicon dioxide nanospheres are fed into a gas phase modification reactor, and a modifier is sprayed into the reactor for gas phase modification.

[0011] Collect gas-phase lipophilic modified silica nanospheres.

[0012] A further preferred technical solution is: heating and gasification, specifically, sending the treated metallic silicon into a heating electric furnace, wherein the heating electric furnace is any one of an electric arc furnace and an induction furnace.

[0013] A further preferred technical solution is: sending silicon vapor into an oxidation reactor for oxidation, using an inert carrier gas to send silicon vapor into the oxidation reactor, wherein the inert carrier gas is nitrogen, argon or a mixture of nitrogen and argon.

[0014] A further preferred technical solution is: in the oxidation reactor, the oxidizing atmosphere is a mixture of oxygen and the inert carrier gas, the oxygen concentration is 1%-20%, and the remainder is the inert carrier gas.

[0015] A further preferred technical solution is that the reaction temperature of the oxidation reactor is room temperature.

[0016] Its further preferred technical solution is: cooling, specifically a combination of circulating water cooling and air cooling, the air cooling environment temperature is 25°C, the air cooling pipeline length is 3-6m, the water cooling temperature is 15-25°C, the water cooling pipeline length is 1-3m, and the silicon dioxide droplets are cooled to spheroidize.

[0017] The further preferred technical scheme is: gas phase modification, specifically: heating the modifier to between 150-360°C, spraying the modifier into the modification reactor, and mixing with the silicon dioxide nanospheres. During the mixing process, the temperature is a constant value between 150-360°C.

[0018] A further preferred technical solution is that the modifier is selected from one or more combinations of 9-octadecenoic acid, octadecanoic acid, hexadecanoic acid, octanoic acid and decanoic acid.

[0019] A further preferred technical solution is to collect the gas-phase lipophilic modified silica nanospheres, specifically, by using a filtering micropowder collector.

[0020] The further preferred technical scheme is: gas phase lipophilic modified silica nanospheres, sphericity is above 95%, average particle size is less than 200nm, specific surface area is greater than 15m 2 / g.

[0021] The gas-phase modified highly lipophilic silica nanospheres and the preparation method thereof provided by the present invention have the advantages of simple process, high yield and low pollution emission. The obtained modified silica nanospheres have good dispersibility, fluidity, lipophilicity and high surface chemical activity, and can be used in adhesives, sealants, composite surfactant functionalities, functional nanomaterial carriers, nano oil-displacing agents and other materials, and are expected to be widely used in packaging, coatings, catalysis, cleaning, nano oil-displacing to enhance recovery and other fields.

[0022] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A process flow chart according to an embodiment of the present invention is shown;

[0025] Figure 2 The particle size distribution diagram of modified silica nanospheres according to Example 1 of the present invention is shown.

[0026] Figure 3 The nitrogen BET adsorption curve of the modified silica nanospheres obtained according to Example 1 of the present invention is shown.

[0027] Figure 4 A scanning electron microscope (SEM) image of modified silica nanospheres obtained according to Example 1 of the present invention is shown. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] like Figure 1 As shown, a method for preparing gas-phase lipophilic modified silica nanospheres comprises:

[0031] cleaning and drying the metallic silicon;

[0032] The treated metallic silicon is sent into an electric arc furnace for heating and gasification to obtain silicon vapor;

[0033] The silicon vapor is sent into an oxidation reactor for oxidation through an inert carrier gas, wherein the inert carrier gas is nitrogen, and the oxidizing atmosphere is nitrogen and oxygen, wherein the nitrogen concentration is 90% and the oxygen concentration is 10%. During the oxidation process, the reaction temperature is room temperature, thereby obtaining silicon dioxide droplets;

[0034] The silica droplets are sent to a cooling device, which consists of an air cooling pipe and a water cooling pipe; the air cooling pipe is 3m long and is cooled by the external ambient temperature, which is 25°C; the water cooling pipe is 1m long and is cooled by circulating cooling water, which is 15°C, so that the silica droplets are cooled to room temperature and spontaneously spheroidized to obtain silica nanospheres.

[0035] The silica nanospheres are sent into a gas phase modification reactor, which is composed of a heater and a gasification nozzle. The 9-octadecenoic acid is heated to 350°C by a modifier gasification device; the 9-octadecenoic acid is sprayed into the modification reactor by a gasification nozzle and mixed with the silica nanospheres to make the 9-octadecenoic acid adsorbed on the surface of the silica nanospheres. The constant temperature blast device is kept at 200°C. The particle size distribution diagram of the modified silica nanospheres is shown in the figure below: Figure 2 As shown, the BET adsorption curve of nitrogen gas of modified silica is as follows Figure 3 As shown, the scanning electron microscope (SEM) image of the modified silica nanospheres is as follows Figure 4 As shown, it can be seen that the modified silica nanospheres obtained by the present invention have good dispersibility, fluidity, lipophilicity and high surface chemical activity, and can be used in adhesives, sealants, composite surfactant functionality, functional nanomaterial carriers and other materials, and are widely used in packaging, coatings, catalysis, cleaning and other fields.

[0036] Example 2

[0037] A method for preparing gas-phase lipophilic modified silica nanospheres, comprising:

[0038] Pretreatment, cleaning and drying the metallic silicon; in a spheroidization reaction device, heating the metallic silicon with an induction furnace until it begins to gasify into silicon vapor; using nitrogen as an inert carrier gas to send the silicon vapor into an oxidation reactor, introducing a nitrogen-carried 1% oxygen oxidizing atmosphere to oxidize it, obtaining silicon dioxide droplets and spontaneously spheroidizing;

[0039] The silica droplets are sent to a cooling device, which consists of an air cooling pipe and a water cooling pipe; the air cooling pipe is 5m long and is cooled by the external ambient temperature, which is 25°C; the water cooling pipe is 2m long and is cooled by circulating cooling water, which is 25°C, so that the silica droplets are cooled to room temperature to obtain silica nanospheres.

[0040] The silica nanospheres are sent into a gas phase modification reactor, which is composed of a heater and a gasification nozzle. The octadecanoic acid is heated to 350°C by a modifier gasification device; the octadecanoic acid is sprayed into the modification reactor by a gasification nozzle and mixed with the silica nanospheres, so that the octadecanoic acid is adsorbed on the surface of the silica nanospheres. The constant temperature blowing device is kept constant at 200°C.

[0041] Example 3

[0042] A method for preparing gas-phase lipophilic modified silica nanospheres, comprising:

[0043] S1, pretreatment, cleaning and drying the metallic silicon; in a spheroidization reaction device, heating the metallic silicon with an induction furnace until it begins to gasify into silicon vapor; using argon as an inert carrier gas to send the silicon vapor into an oxidation reactor, the oxidizing atmosphere is nitrogen and oxygen, the nitrogen concentration is 70%, the oxygen concentration is 10%, and the argon concentration is 10%. During the oxidation process, the reaction temperature is room temperature, thereby obtaining silicon dioxide droplets, and spontaneous spheroidization is performed;

[0044] The silica droplets are sent to a cooling device, which consists of an air cooling pipe and a water cooling pipe; the air cooling pipe is 4m long and is cooled by the external ambient temperature, which is 25°C; the water cooling pipe is 2m long and is cooled by circulating cooling water, which is 20°C, so that the silica droplets are cooled to room temperature to obtain silica nanospheres.

[0045] The silica nanospheres are sent into a gas phase modification reactor, which is composed of a heater and a gasification nozzle. The modifier gasification device heats the hexadecanoic acid to 320°C. The hexadecanoic acid is sprayed into the modification reactor by the gasification nozzle and mixed with the silica nanospheres to make the hexadecanoic acid adsorbed on the surface of the silica nanospheres. The constant temperature blowing device is kept at 200°C to complete the gas phase modification.

[0046] The modified silica nanospheres were collected by a filter-type micropowder collector to obtain modified silica nanospheres modified with hexadecanoic acid; the sphericity was above 95%, the average particle size was 187nm, and the specific surface area was greater than 17.8m 2 / g, stable contact angle 159.1.

[0047] Example 4

[0048] S1, pretreatment, cleaning and drying the metallic silicon; in a spheroidization reaction device, heating the metallic silicon with an electric arc furnace until it begins to gasify into silicon vapor; using argon as an inert carrier gas to send the silicon vapor into an oxidation reactor, and introducing an argon-carried 10% oxygen oxidizing atmosphere to oxidize it, obtaining silicon dioxide droplets and spontaneously spheroidizing;

[0049] S2, sending the high-temperature silica droplets into an air cooling pipe, the air cooling pipe is 5m long, and the ambient temperature is 25°C; after preliminary cooling and solidification, they enter a water cooling pipe for cooling, the water cooling pipe is 2m long, and the cooling water is cooled by circulating cooling water, the cooling water temperature is 15°C, and the silica nanospheres are cooled to room temperature;

[0050] S3, using a modifier gasification device to heat hexadecanoic acid to 230°C; using a gasification nozzle to spray tetradecanoic acid into a modification reactor, and mix it with silica nanospheres to make tetradecanoic acid adsorbed on the surface of silica nanospheres, and the constant temperature blowing device is kept at 150°C.

[0051] S4. The modified silica nanospheres are collected by a filtering micropowder collector to obtain tetradecanoic acid-modified modified silica nanospheres; the sphericity is above 95%, the average particle size is 196 nm, and the specific surface area is greater than 15.3 m 2 / g, stable contact angle 164.4°.

[0052] Example 5

[0053] S1, pretreatment, cleaning and drying the metallic silicon; in a spheroidization reaction device, heating the metallic silicon with an induction furnace until it begins to gasify into silicon vapor; using nitrogen as an inert carrier gas to send the silicon vapor into an oxidation reactor, introducing an argon-carried 10% oxygen oxidizing atmosphere to oxidize it, obtaining silicon dioxide droplets and spontaneously spheroidizing;

[0054] S2, sending the high-temperature silica droplets into an air cooling pipe, the air cooling pipe is 5m long, and the ambient temperature is 25°C; after preliminary cooling and solidification, they enter a water cooling pipe for cooling, the water cooling pipe is 1m long, and the cooling water is circulated at 20°C to cool the silica nanospheres to room temperature;

[0055] S3. Heat the capric acid to 230° C. using a modifier gasification device; spray the capric acid into a modification reactor using a gasification nozzle to mix with the silica nanospheres so that the capric acid is adsorbed on the surface of the silica nanospheres, and the constant temperature blowing device is kept constant at 150° C.

[0056] S4. Collect the modified silica nanospheres through a filtering micropowder collector to obtain modified silica nanospheres modified with decanoic acid.

[0057] Example 6

[0058] S1, pretreatment, cleaning and drying the metallic silicon; in a spheroidization reaction device, heating the metallic silicon with an induction furnace until it begins to gasify into silicon vapor; using nitrogen as an inert carrier gas to send the silicon vapor into an oxidation reactor, introducing a nitrogen-carried 10% oxygen oxidizing atmosphere to oxidize, obtaining silicon dioxide droplets and spontaneously spheroidizing;

[0059] S2, sending the high-temperature silica droplets into an air cooling pipe, the air cooling pipe is 5m long, and the ambient temperature is 25°C; after preliminary cooling and solidification, they enter a water cooling pipe for cooling, the water cooling pipe is 1m long, and the cooling water is circulated at 20°C to cool the silica nanospheres to room temperature;

[0060] S3. Use a modifier gasification device to mix the modifiers tetradecanoic acid and octanoic acid in a ratio of 1:1 and heat to 230°C; use a gasification nozzle to spray the modifier into a modification reactor, mix it with the silica nanospheres, and make the modifier adsorb on the surface of the silica nanospheres. The constant temperature blowing device is kept constant at 150°C.

[0061] S4. Collect the modified silica nanospheres through a filtering micropowder collector to obtain modified silica nanospheres modified with tetradecanoic acid and octanoic acid.

[0062] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing gas-phase lipophilic modified silica nanospheres, characterized in that: include: cleaning and drying the metallic silicon; heating and gasifying the treated metallic silicon to obtain silicon vapor; The silicon vapor is sent into an oxidation reactor for oxidation to obtain silicon dioxide droplets; The silica droplets are cooled and spontaneously spheronized to obtain silica nanospheres; The silicon dioxide nanospheres are sent into a gas phase modification reactor, a modifier is sprayed into the reactor, the silicon dioxide nanospheres are modified in the gas phase, and the gas phase lipophilic modified silicon dioxide nanospheres are collected.

2. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 1, characterized in that: The heating and gasification is specifically to send the treated metallic silicon into a heating electric furnace, and the heating electric furnace is any one of an electric arc furnace and an induction furnace.

3. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 1, characterized in that: The silicon vapor is sent into the oxidation reactor for oxidation by using an inert carrier gas, wherein the inert carrier gas is nitrogen, argon or a mixed gas of nitrogen and argon.

4. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 3, characterized in that: In the oxidation reactor, the oxidizing atmosphere is a mixture of oxygen and the inert carrier gas, the oxygen concentration is 1%-20%, and the remainder is the inert carrier gas.

5. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 3, characterized in that: The reaction temperature of the oxidation reactor is room temperature.

6. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 1, characterized in that: The cooling is specifically a combination of circulating water cooling and air cooling, the air cooling environment temperature is 25°C, the air cooling pipeline length is 3-6m, the water cooling temperature is 15-25°C, the water cooling pipeline length is 1-3m, and the silicon dioxide droplets are cooled to spheroidize.

7. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 1, characterized in that: The gas phase modification is specifically as follows: the modifier is heated to a temperature between 150 and 360°C, the modifier is sprayed into a modification reactor, and mixed with the silicon dioxide nanospheres. During the mixing process, the temperature is a constant value between 150 and 360°C.

8. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 7, characterized in that: The modifier is selected from one or more combinations of 9-octadecenoic acid, octadecanoic acid, hexadecanoic acid, octanoic acid and decanoic acid.

9. The method for preparing gas-phase lipophilic modified silica nanospheres according to claim 1, characterized in that: The collecting of the gas-phase lipophilic modified silica nanospheres is specifically carried out by using a filtering micro powder collector.

10. A gas phase lipophilic modified silica nanosphere prepared by the method according to claim 9, characterized in that: The gas-phase lipophilic modified silica nanospheres have a sphericity of more than 95%, an average particle size of less than 200 nm, and a specific surface area of ​​more than 15 m 2 / g.

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