KR101280546B1 - Carbon/Silicon Nano-Particle Complex and Method for Preparing Same - Google Patents

Abstract

Silicon nanoparticle core layers;
A porous buffer layer formed on an outer surface of the silicon nanoparticle core layer and including pores having a volume of 1.2 × 10 ⁻¹ to 4.0 × 10 ⁻¹ cc / g; And
A carbon-based material coating layer formed on an outer surface of the porous buffer layer;
Provided is a carbon / silicon composite nanoparticle comprising a.

Description

Carbon / Silicon Nano-Particle Complex and Method for Preparing Same}

It relates to a carbon / silicon composite nanoparticles and a method of manufacturing the same.

Among the nanomaterials that are the foundation for nanotechnology development, nanoparticles with core-shell structure that have desired characteristics by selectively controlling the composition, shape, and structure of core and shell are made by magnetic. It is possible to provide a multifunctional nanoparticle having both of two or more of the following characteristics: separation, fluorescence emission using a semiconductor material, biocompatibility using a natural polymer material, and a large specific surface area using a ceramic material. Has the advantage. Core-shell nanoparticles can provide composite functional nanomaterials that exhibit at least two or more properties such that magnetic, fluorescence properties, and properties can be varied by various combinations, including metal-metal, metal-ceramic, metal-inorganic, and organic-organic structures. Due to the combined function of acid resistance and abrasion resistance, it has been shown to be highly applicable to various fields.

Core-shell nanoparticle manufacturing methods include imprinting, associative phase separation of polymer materials, self-assembly using aerosols, and coaxial electrospraying methods. In this case, microencapsulation, spray-drying, coacervation by in situ polymerization, such as dispersion polymerization or interfacial polycondensation. Methods such as miniemulsion polymerization have been used. First, a method of preparing a mold and then polymerizing a polymer on the surface of the mold has been used in various ways, and recently, a method of alternately stacking positively or negatively charged materials by using electrostatic attraction. This is also used. However, when using these methods, there is a disadvantage in that various kinds of polymer materials are used in combination due to the interaction between the two polymers.

One aspect of the present invention to provide a core-shell structured carbon / silicon composite nanoparticles having a uniform thickness.

Another aspect of the present invention is to provide a carbon-silicon composite nanoparticles having a core-shell structure having various thicknesses.

Yet another aspect of the present invention is to provide a method of manufacturing the carbon / silicon composite nanoparticles.

One aspect of the invention the silicon nanoparticle core layer; A porous buffer layer formed on an outer surface of the silicon nanoparticle core layer and including pores having a volume of 1.2 × 10 ⁻¹ to 4.0 × 10 ⁻¹ cc / g; And it provides a carbon / silicon composite nanoparticles comprising a carbon-based material coating layer formed on the outer surface of the porous buffer layer.

The porous buffer layer in which the pores are formed may be a metal oxide layer.

The metal oxide included in the metal oxide layer may be silicon oxide or TiO ₂ represented by SiO x (1 ≦ x ≦ ₂ ).

The porosity of the porous buffer layer may be 10% or more and less than 100%. The porous buffer layer may be an empty space having a porosity of 100%.

The thickness of the porous buffer layer may be 10nm to 50nm.

The particle diameter of the silicon nanoparticle core layer may be 50nm to 200nm.

The carbonaceous material coating layer may include at least one selected from artificial graphite, natural graphite, graphitized carbon fibers, or amorphous carbon.

The carbon-based material coating layer may have a thickness of about 10 nm to about 100 nm.

According to another aspect of the present invention, after preparing a dispersion in which silicon particles are added to a mixed solution of an organic solvent and water, adding a catalyst and a metal precursor compound to the dispersion to prepare silicon oxide coated silicon particles by a sol-gel reaction. ; Coating the silicon particles coated with the metal oxide with a carbon-based material, and then forming a carbon-based material coating layer at the outermost part by carbonization; And etching a part or all of the metal oxide inside the carbon-based material coating layer by an etching process to form a porous buffer layer including pores.

The content of water in the dispersion may be 10 to 40 parts by weight based on 100 parts by weight of the organic solvent.

Specific examples of the organic solvent may be methanol, ethanol, or the like, or a combination thereof.

The metal precursor compound may be, for example, a monomer having a silanol group, tetraethylorthosilicate (TEOS), 3- (trimethoxysilyl) propyl methacrylate (TMSPM), titanium titanium isopropoxide, or titanium Butoxide, and the like.

The metal oxide may be silicon oxide or TiO ₂ represented by SiO x (1 ≦ x ≦ ₂ ).

In order to coat the silicon particles coated with the metal oxide with a carbon-based material, a mixed solution including the silicon particles coated with the metal oxide, a carbon precursor compound, and an organic solvent is heated to 50 to 80 ° C., a surfactant, an initiator, And coating the silicon particles coated with the metal oxide with a carbon-based material by polymerizing while being added dropwise into a mixed solution of water to disperse the carbon / silicon composite nanoparticles.

The carbon precursor compound may be an acrylonitrile monomer.

The carbonaceous material is polyacrylonitrile, and carbonized particles coated with such carbonaceous material may form a carbonaceous material coating layer on the outermost surface.

The heating temperature may be 700 to 1000 ℃.

The etching process may be a wet etching process using hydrofluoric acid, hydrochloric acid, nitric acid or ammonia as the etching solution.

The etching process may be performed by using a concentration of the etching solution within the range of 0.1M to 0.5M, and during the etching, the metal core is coated on the silicon core, and a carbon-based material coating layer is formed. After stirring for a minute, the centrifugation speed may be adjusted to a sinking speed, and centrifugation may be performed for 2 to 7 minutes.

The carbon / silicon composite nanoparticles may be useful in various fields as a layer having a uniform thickness is formed.

1 and 2 are SEM images of the carbon / silicon composite nanoparticles prepared according to the embodiment of the present invention.
Figure 3 is a graph showing the measurement of the BET and pore volume (pore volume) data for the carbon coated silicon nanoparticles prepared in Comparative Example 1.
Figure 4 is a graph showing the measurement of the BET and pore volume (pore volume) data for the carbon coated silicon nanoparticles prepared in Example 1.
FIG. 5 is a graph showing measurement of BET and pore volume data for carbon coated silicon nanoparticles prepared in Example 2. FIG.

Hereinafter, the present invention will be described in more detail.

One embodiment of the invention the silicon nanoparticle core layer; A porous buffer layer formed on an outer surface of the silicon nanoparticle core layer and including pores having a volume of 1.2 × 10 ⁻¹ to 4.0 × 10 ⁻¹ cc / g; And it provides a carbon / silicon composite nanoparticles comprising a carbon-based material coating layer formed on the outer surface of the porous buffer layer.

The carbon / silicon composite nanoparticles form a structure including a porous buffer layer having voids formed between the silicon nanoparticles of the inner core and the carbon-based material of the coating layer formed on the outer surface thereof.

The porous buffer layer in which the pores are formed may be a metal oxide layer.

The metal oxide included in the metal oxide layer may be silicon oxide or TiO ₂ represented by SiO x (1 ≦ x ≦ ₂ ).

The silicon oxide or TiO ₂ of SiO _x (1 ≦ _x ≦ ₂₎ is an amorphous material that forms pores, and has a porosity of 10% or more and less than 100%.

In addition, the porosity may be 100%, that is, the buffer layer may be formed as a void space.

The thickness of the porous buffer layer is preferably 10 nm to 50 nm.

The core layer is formed of silicon nanoparticles. Preferably, the particle diameter of the silicon nanoparticle core layer is 50 to 200 nm.

Specific examples of the carbonaceous material include carbonaceous materials such as artificial graphite, natural graphite, graphitized carbon fibers, and amorphous carbon. These carbonaceous materials may be used alone or in any combination.

More specific carbonaceous materials include coke, pyrolytic carbon, natural graphite, artificial graphite, meso carbon micro beads, graphitized meso face spheres (MCMB), vapor grown carbon, glassy carbon, poly One kind selected from the group consisting of carbon fiber-based, pitch-based, cellulose-based, vapor-grown carbon-based, amorphous carbon, organic-fired carbon, and mixtures thereof, including acrylonitrile-based polyacrylonitrile Can be used in combination arbitrarily.

For example, the carbon-based material coating layer has a thickness of 10 nm to 100 nm.

The carbon / silicon composite nanoparticles may be prepared by the manufacturing method described below, and the porous buffer layer and the carbon-based material coating layer are formed to have a uniform thickness, and may be usefully used in various fields.

For example, the present invention can be applied to the fields of catalysts, sensors, biotechnology, photovoltaic devices, energy storage materials for lithium ion batteries, or target drug delivery materials, modules for secondary battery systems for small mobiles and electric vehicles. In addition, it can be applied to energy storage systems such as biotechnology, photovoltaic devices, renewable energy storage, and large-capacity power magnetic field systems.

Hereinafter, a method of manufacturing the carbon / silicon composite nanoparticles will be described.

In another embodiment of the present invention, after preparing a dispersion in which the silicon particles are put in a mixed solution of an organic solvent and water, by adding a catalyst and a metal precursor compound to the dispersion to form a silicon oxide coated silicon particles by a sol-gel reaction Manufacturing; Coating the silicon particles coated with the metal oxide with a carbon-based material, and then forming a carbon-based material coating layer at the outermost part by carbonization; And etching a part or all of the metal oxide in the carbon-based material coating layer by an etching process to form a porous buffer layer in which pores are formed.

First, after preparing a dispersion in which silicon particles are added to a mixed solution of an organic solvent and water, a catalyst and a metal precursor compound are added to the dispersion to perform a sol-gel reaction, whereby a metal oxide is coated on the surface of the silicon particles.

The dispersion is a mixture of water and an organic solvent. In this case, the water content is 10 to 40 parts by weight based on 100 parts by weight of the organic solvent.

Specific examples of the organic solvent may be methanol, ethanol, or the like, and may be used in combination.

Specific examples of the metal precursor compound include monomers having a silanol group, tetraethylorthosilicate (TEOS), 3- (trimethoxysilyl) propyl methacrylate (TMSPM), titanium titanium isopropoxide and titanium titanium butoxide Side, etc., and can be used in combination.

Such precursor compounds form a metal oxide layer of silicon oxide or TiO ₂ represented by SiO x (1 ≦ x ≦ 2) on the surface of silicon (Si) particles by a sol-gel reaction.

Subsequently, the silicon oxide coated with the metal oxide is coated with a carbon-based material, and then a carbon-based material coating layer is formed at the outermost part by carbonization.

There is no restriction | limiting in particular in the method of coating the said carbon-based material, The method of crimping | bonding, the method of dissolving a solvent after apply | coating disperse | distributing a coating material in a solvent, the method of vapor-deposition, etc. can be used. In addition, for example, the carbon-based material coating layer may be formed through carbonization after coating the polymer which may be carbon through heat treatment.

The carbonization process may be performed at 700 to 1000 ° C.

In another embodiment of the present invention, in order to coat the silicon particles coated with the metal oxide with a carbon-based material, 50 to 80 ℃ a methanol mixed solution in which the silicon oxide coated with the metal oxide and the carbon precursor compound is well dispersed It is polymerized while being added dropwise to the mixed solution of the surfactant, the initiator, and the water being heated at a temperature of to, and the silicon particles coated with the metal oxide are coated with a carbon-based material.

The carbon precursor compound may be an acrylonitrile monomer, and the carbonaceous material formed from the carbon precursor compound may be polyacrylonitrile.

Subsequently, some or all of the metal oxide inside the carbon-based material coating layer may be etched by etching to form voids. As the etchant, a material capable of corroding the internal metal oxide without affecting the carbon-based material coating layer may be used. For example, hydrofluoric acid, hydrochloric acid, nitric acid, ammonia, or the like may be used as the etchant during wet etching. At this time, it is possible to control the size of the pore, the porosity, etc. by adjusting the generation degree of the pore according to the degree of etching. When the internal metal oxide layer is completely etched, the buffer layer is formed into an empty space.

For example, in the case of using hydrofluoric acid as an etching solution, the amount of hydrofluoric acid is used within the range of 0.1M to 0.5M by adjusting the amount of hydrofluoric acid when producing hydrofluoric acid solution, and the etching time is 1 depending on the concentration of each aqueous solution. It can be adjusted relatively from minutes to 15 minutes. After performing the etching, the stirring speed was stirred at about 100 rpm and centrifuged at a speed that allowed the nanoparticles of 50 nm to 350 nm to sink. For example, the concentration of aqueous hydrofluoric acid solution is stirred at 100 rpm for 1 to 3 minutes at 0.125 M, followed by etching at 12000 rpm for 2 to 7 minutes. Under the above conditions, a porosity of 10 to 100% of the metal oxide buffer layer can be obtained.

Hereinafter, the present invention will be described in detail by examples. However, the following examples are illustrative of the present invention, and the content of the present invention is not limited by the examples.

Example

Example  One

An average 50 nm silicon nanoparticle powder of LS Cable was put in a solution mixed with methanol and water, and the dispersion was prepared by treating the ultrasonic wave for about 30 minutes. Phosphoric acid (H ₂ PO ₄ ) was added to the dispersion as a catalyst, and then slowly added a monomer having a silanol group using a dropping funnel, followed by stirring at 200 rpm for 12 hours to obtain a sol-gel reaction. Was performed. After confirming the presence of the silicon oxide layer on the surface of the silicon nanoparticle powder was purified using water and ethanol. The silicon nanoparticles coated with silicon oxide were settled by repetitive purification five times using a centrifuge at 17000 rpm. The sunken composite nanoparticles were dried in a heat dryer for 12 hours, and then placed in methanol, and treated with ultrasonic waves for about 30 minutes to prepare a raw material dispersion. After the dispersion was added to the reactor, the carbon shell precursor acrylonitrile was added to disperse evenly and sonicated again. In another reactor equipped with a reflux condenser, water and a surfactant, CTAB (Cetyl trimethylammonium bromide), were added and stirred for about 30 minutes to prepare a surfactant solution. An initiator solution made by dissolving KPS (Potassium persulfate) in water was added to the surfactant solution. The surfactant solution to which the initiator solution was added was heated at a temperature of 70 ° C. The acrylonitrile-added silicon nanoparticle dispersion was slowly added to the surfactant containing the initiator using a dropping funnel. After all of the silicon nanoparticle dispersion to which acrylonitrile was added was added, the mixture was stirred and stirred at a speed of 200 rpm for 12 hours, and then the particles were separated from the solvent using a centrifuge, followed by heat drying to polyacrylonitrile. Enclosed silicon core-shell nanoparticles were obtained. The polyacrylonitrile-coated silicon nanoparticles were obtained as carbon-coated silicon nanoparticles having a metal oxide buffer layer through carbonization at 700 ° C.

The carbon-coated silicon nanoparticles having the metal oxide layer thus prepared were etched using the aqueous HF (Hydrofluoric acid) solution to etch the metal oxide layer portion inside the carbon coating layer. Specifically, the porosity of the inner space of the particles obtained through centrifugation and heat drying was adjusted by adjusting the concentration of the hydrofluoric acid solution to 0.125M and the etching time to 3 minutes, and finally, the carbon / silicon composite nanoparticles having the inner space were Prepared.

Example  2

Except having made the etching time of Example 1 into 10 minutes, the carbon / silicon composite nanoparticle which has a space | gap similarly was manufactured.

Comparative example  One

An average 50 nm silicon nanoparticle powder of LS Cable was put in a solution mixed with methanol and water, and the dispersion was prepared by treating the ultrasonic wave for about 30 minutes. Phosphoric acid (H ₂ PO ₄ ) was added to the dispersion as a catalyst, and then slowly added a monomer having a silanol group using a dropping funnel, followed by stirring at 200 rpm for 12 hours to obtain a sol-gel reaction. Was performed. After confirming the presence of the silicon oxide layer on the surface of the silicon nanoparticle powder was purified using water and ethanol. The silicon nanoparticles coated with silicon oxide were settled by repetitive purification five times using a centrifuge at 17000 rpm. The sunken composite nanoparticles were dried in a heat dryer for 12 hours, and then placed in methanol, followed by ultrasonic treatment for about 30 minutes to prepare a raw material dispersion. After the dispersion was added to the reactor, the carbon shell precursor acrylonitrile was added to disperse evenly and sonicated again. In another reactor equipped with a reflux condenser, water and a surfactant, CTAB (Cetyl trimethylammonium bromide), were added and stirred for about 30 minutes to prepare a surfactant solution. An initiator solution made by dissolving KPS (Potassium persulfate) in water was added to the surfactant solution. The surfactant solution to which the initiator solution was added was heated at a temperature of 70 ° C. The acrylonitrile-added silicon nanoparticle dispersion was slowly added to the surfactant containing the initiator using a dropping funnel. After all of the silicon nanoparticle dispersion to which acrylonitrile was added was added, the mixture was stirred and stirred at a speed of 200 rpm for 12 hours, and then the particles were separated from the solvent using a centrifuge, followed by heat drying to polyacrylonitrile. Enclosed silicon core-shell nanoparticles were obtained. The polyacrylonitrile-coated silicon nanoparticles were obtained as carbon-coated silicon nanoparticles with a silicon oxide layer through carbonization at 700 ° C.

FIG. 1 is an SEM photograph showing the carbon / silicone external form prepared in Example 1. FIG. The left photograph of FIG. 2 is for Example 1, the right photograph is for Example 2, and a cross section showing the surface and the inner space of each sample for the carbon / silicon composite nanoparticles prepared in Examples 1 and 2, respectively. SEM picture.

Figure 3 is a graph showing the measurement of the BET and pore volume (pore volume) data for the carbon coated silicon nanoparticles prepared in Comparative Example 1.

Figure 4 is a graph showing the measurement of the BET and pore volume (pore volume) data for the carbon coated silicon nanoparticles prepared in Example 1.

FIG. 5 is a graph showing measurement of BET and pore volume data for carbon coated silicon nanoparticles prepared in Example 2. FIG.

Claims (21)

Silicon nanoparticle core layers;
A porous buffer layer formed on an outer surface of the silicon nanoparticle core layer and including pores having a volume of 1.2 × 10 ⁻¹ to 4.0 × 10 ⁻¹ cc / g; And
A carbon-based material coating layer formed on an outer surface of the porous buffer layer;
Carbon / silicon composite nanoparticles comprising a. The method of claim 1,
Carbon / silicon composite nanoparticles in which the pore-formed porous buffer layer is a metal oxide layer. The method of claim 2,
The metal oxide included in the metal oxide layer is a silicon oxide or TiO ₂ represented by SiO x (1 ≦ x ≦ 2). The method of claim 1,
The porosity of the porous buffer layer is more than 10%, less than 100% carbon / silicon composite nanoparticles. The method of claim 1,
The porous buffer layer is a carbon / silicon composite nanoparticles of empty space having a porosity of 100%. The method of claim 1,
Carbon nano-silicon composite nanoparticles having a thickness of the porous buffer layer 10nm to 50nm. The method of claim 1,
Carbon / silicon composite nanoparticles having a particle diameter of 50 nm to 200 nm of the silicon nanoparticle core layer. The method of claim 1,
The carbon-based material coating layer may include at least one selected from artificial graphite, natural graphite, graphitized carbon fiber, and amorphous carbon. The method of claim 1,
The carbon-silicon composite nanoparticles having a thickness of the carbon-based material coating layer is 10nm to 100nm. 10. The method according to any one of claims 1 to 9,
Carbon / silicon composite nanoparticles for catalysts, sensors, biotechnology, photovoltaic devices, target drug delivery materials, small mobiles, biotechnology, photovoltaic devices, renewable energy storage or high-capacity power magnetic field systems. Preparing a dispersion in which silicon particles are added to a mixed solution of an organic solvent and water, and then adding a catalyst and a metal precursor compound to the dispersion to prepare silicon particles coated with a metal oxide by a sol-gel reaction;
Coating the silicon particles coated with the metal oxide with a carbon-based material, and then forming a carbon-based material coating layer at the outermost part by carbonization; And
Etching a part or all of the metal oxide inside the carbon-based material coating layer by an etching process to form a porous buffer layer having pores including pores
Carbon / silicon composite nanoparticles manufacturing method comprising a. The method of claim 11,
The content of the water in the dispersion is 10 to 40 parts by weight based on 100 parts by weight of the organic solvent of the carbon / silicon composite nanoparticles manufacturing method. The method of claim 11,
Specific examples of the organic solvent is a method for producing carbon / silicon composite nanoparticles, which is at least one member selected from the group consisting of methanol and ethanol. The method of claim 11,
The metal precursor compound is a group consisting of a monomer having a silanol group, tetraethylorthosilicate (TEOS), 3- (trimethoxysilyl) propyl methacrylate (TMSPM), titanium titanium isopropoxide and titanium titanium butoxide At least one selected from carbon / silicon composite nanoparticles. The method of claim 11,
The metal oxide is a silicon oxide or TiO ₂ represented by SiO x (1 ≦ x ≦ 2). The method of claim 11,
The mixed solution containing the silicon oxide coated with the metal oxide, the carbon precursor compound and the organic solvent is added dropwise to the mixed solution of the surfactant, initiator, and water heated to 50 to 80 ℃ dispersed and polymerized to be coated with the metal oxide A method of manufacturing carbon / silicon composite nanoparticles, the step of coating the silicon particles with a carbon-based material. 17. The method of claim 16,
The carbon precursor compound is a method for producing carbon / silicon composite nanoparticles that are acrylonitrile monomers. 17. The method of claim 16,
The carbonaceous material is polyacrylonitrile, and carbonized particles of carbon / silicon composite nanoparticles having a carbonaceous material coating layer formed on the outermost surface by carbonizing the particles coated with the carbonaceous material. The method of claim 11,
In the step of coating the silicon oxide coated with the metal oxide with a carbon-based material, and forming a carbon-based material coating layer on the outermost surface by the carbonization process,
The carbonization process is a method for producing carbon / silicon composite nanoparticles comprising the step of heating at 700 to 1000 ℃. The method of claim 11,
The etching process is a wet etching process using hydrofluoric acid, hydrochloric acid, nitric acid or ammonia as the etching solution. The method of claim 11,
The etching process may be performed by using a concentration of the etching solution within the range of 0.1M to 0.5M, and coating the metal oxide on the silicon core after the etching to form a carbon-based material coating layer for 1 to 3 minutes. After stirring for a while, the centrifugation rate is adjusted to a sinking rate, and the method for producing carbon / silicon composite nanoparticles is performed for 2 to 7 minutes.

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