KR20110074115A - Fabrication of silica-titania mixed hollow nanostructured nanoparticles using sonication-induced etching and redeposition method - Google Patents

Abstract

PURPOSE: A manufacturing method of silica-titania dioxide hollow structure nanoparticle is provided to manufacture simple and economic silica - titanium dioxide hollow structure nanoparticle by an ultrasonic wave induced etching-redeposition method without using a surfactant. CONSTITUTION: The manufacturing method of silica-titania dioxide hollow structure nanoparticle includes following steps.(i) A silica / titania dioxide core-shell nanoparticle is dispersed into an aqueous solution.(ii) A base is introduced to the core-shell nanoparticle aqueous solution. A basic solution is created.(iii) The ultrasonic wave is added to the basic core-shell nanoparticle aqueous solution. The hollow structure is induced.(iv) A centrifuge is used to collect the silica - titania dioxide hollow structure nanoparticle in the solution treated with the ultrasonic wave. An additive quantity of the silica - titania dioxide hollow structure nanoparticle and the base is 0.01-10 parts by weight compared to the aqueous solution 100.0. The ultrasonic wave treatment is carried out with an intensity of 10-500W for 30 second -300 minutes.

Description

Fabrication of silica-titanium mixed hollow nanostructured nanoparticles using sonication-induced etching and redeposition method

The present invention relates to a method for producing silica-titanium dioxide hollow structured nanoparticles using an ultrasonic induced corrosion-deposition method, wherein a part of silica when ultrasonically induced in a basic aqueous solution in which silica car / titanium dioxide core-cell nanoparticles are dispersed Hollow silica-titanium dioxide by inducing hollow structure using ultrasonic induced corrosion-re-deposition method through reversible and repeated etching and redeposition of silica and titanium dioxide that appear after partial etching A method of preparing structural nanoparticles is provided.

In general, a material having a size of 1 to several tens of nanometers is referred to as a nanomaterial, and due to the large surface area derived from the nano-size, it has excellent physical properties compared to existing bulk materials. In particular, hollow hollow nanoparticles of nanomaterials are nanoparticles having hollow inner parts, which have a large pore volume and a large surface area compared to general nanoparticles. It is becoming. The hollow structured nanoparticles having a large surface area and a hollow inner portion are used as a drug delivery carrier by carrying a drug, or applied as a catalyst support carrying a catalyst material. Filler components that are introduced into nanocomposites to change the refractive index have been studied.

In manufacturing hollow structured nanoparticles having such characteristics, generally, hollow structured nanoparticles are prepared using a method of using polymeric particles as a hard template and a soft template using a surfactant. Manufacturing is the most widely used manufacturing method.

In addition, silica and titanium dioxide nanomaterials are known to have physical, chemical, and mechanical stability and biochemical stability (biocompatibility) in solutions excluding strong acids and strong bases. Hollow structured nanoparticles composed of silica and titanium dioxide have low cytotoxicity due to the components of the material in biochemical applications and excellent drug delivery performance due to the hollow part of the hollow structure. It is expected.

In the case of manufacturing hollow structured nanoparticles using the polymer particles as a hard mold, since the size of the polymer mold is generally 100 nanometers or more, it is difficult to produce particles of 100 nanometers or less. . Considering the biochemical application of hollow nanoparticles and the introduction of nanoparticles into the cell with 50 nanometer sized nanoparticles, cellular uptake is highly efficient. It is important to have a size. In other applications, such as catalysts, materials with a size of less than 100 nanometers have a larger surface area, which increases the catalytic activity, thereby requiring hollow structured nanomaterials with sizes of less than 100 nanometers. . As a method for improving this, many methods for producing hollow structured nanoparticles using a soft mold through a surfactant have been studied.

In the case of manufacturing hollow structured nanoparticles using a soft mold through a surfactant, a high concentration of a surfactant is required to control the nanostructure, and considering the high price of the surfactant, in terms of fairness and economics, Indicates a disadvantage. In addition, since the soft mold through the surfactant is changed in various ways to achieve thermodynamic stability depending on the temperature, concentration, and dispersion state of the introduced material, it is unstable according to the chemical environment, and thus the shape of the finally obtained material There is a great difficulty in controlling the size easily.

Therefore, in order to produce hollow nanoparticles for biochemical applications, the hollow nanoparticles are composed of silica and titanium dioxide, and have a size of less than 100 nanometers, and a new manufacturing method having a simple, affordable and easy method is strongly recommended. It is required.

The object of the present invention is to remedy and re-deposit the reversible and repetitive corrosion of silica and titanium dioxide, which occurs after partial corrosion of silica in a basic aqueous solution in which silica / titanium dioxide core-cell nanoparticles are dispersed. By inducing a hollow structure through, to prepare a silica-titanium dioxide hollow structure nanoparticles.

An object of the present invention is to provide a hollow structure silica-titanium dioxide nanoparticles prepared by the above method.

After numerous experiments and in-depth studies, the inventors have repeatedly and reversibly performed after partial corrosion of silica in a basic aqueous solution in which silica / titanium dioxide core-cell nanoparticles are dispersed. Phosphorus corrosion and redeposition process was induced in both silica and titanium dioxide to induce a hollow structure, thereby confirming that it is possible to produce silica-titanium dioxide hollow structure nanoparticles and to the present invention.

The present invention is directed to the production of silica-titanium dioxide hollow structure nanoparticles by inducing a hollow structure by using an ultrasonic guided corrosion-deposition method in a basic aqueous solution in which silica / titanium dioxide core-cell nanoparticles are dispersed.

Method for producing silica-titanium dioxide hollow structure nanoparticles according to the present invention

(A) dispersing silica / titanium dioxide core-cell nanoparticles in an aqueous solution;

(B) introducing a base into the aqueous core-cell nanoparticles to make a basic aqueous solution; And,

(C) inducing a hollow structure by applying ultrasonic waves to the aqueous solution of basic core-cell nanoparticles; And,

(D) recovering the silica-titanium dioxide hollow structure nanoparticles from the ultrasonically applied solution using a centrifuge.

Silica-titanium dioxide hollow structure nanoparticles by the ultrasonic induced corrosion-deposition method according to the present invention is a completely new method that has not been reported so far, the limitation on the size of less than 100 nanometers, which was a problem in the conventional method This problem is significantly reduced, and hollow structured nanoparticles can be easily produced. In addition, it has the advantage of mass production of silica-titanium dioxide hollow structure nanoparticles through a simple manufacturing method. The silica-titanium dioxide hollow structured nanoparticles prepared in this way can be produced without limitation in terms of size in size smaller than the particles prepared through the existing polymer template, in particular, less than 100 nanometers in size, hollow structured nanoparticles The thickness of the outer wall of the can be controlled for the nanometer size, and because it does not use an organic solvent that dissolves the surfactant and the polymer template, unlike the previous approach, a very inexpensive method to prepare hollow structure nanoparticles. The silica-titanium dioxide hollow structured nanoparticles thus obtained can be used as filler materials for biochemical applications, drug carriers, catalyst carriers, and polymer composites.

In the case of the silica / titanium dioxide core-cell nanoparticles used in step (A), silica / titanium dioxide core-cell nanoparticles in which titanium dioxide cells are introduced on the surface of the silica nanoparticles using a commonly known sol-gel reaction. Although the shape is not limited to a specific shape, but spherical particles are preferable, and silica / titanium oxide core-cell nanoparticles prepared by using an interfacial sol-gel reaction (see -2009-0033953, South Korea).

The size of the silica / titanium dioxide core-cell nanoparticles is preferably from 5 nanometers to 5 micrometers, and the cell thickness of titanium dioxide introduced from the silica / titanium dioxide core-cell nanoparticles is not particularly limited, but at 1 nanometer It is preferable that it is 1 micrometer.

The silica / titanium dioxide core-cell nanoparticles may be added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the aqueous solution, but are not limited to these ranges and may be more or less than the above ranges.

The kind of base to be introduced in step (B) is not limited to a specific base, and ammonium hydroxide (ammonium hydroxide, NH ₄ OH), tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (tetraethylammonium) hydroxide, TEAH), tetrabutylammonim hydroxide (TBAH) may be used as the base.

The addition amount of the base may be added in 0.01 to 10 parts by weight relative to 100 parts by weight of the aqueous solution, but is not limited to these ranges may be more or less than the above range. If the amount of the base is less than 0.01 parts by weight, when the ultrasonic induction, the corrosion of silica and titanium dioxide due to the base does not occur completely to obtain a partially corroded nanoparticles rather than a hollow structure, if more than 10 parts by weight, The amount of base or more required for the reaction is present, which is undesirable in terms of process costs.

In the ultrasonic waves applied in step (C), the intensity of the ultrasonic waves is preferably 10 to 500 W. If the intensity of the ultrasonic wave is less than 10 W, the ultrasonic intensity is insufficient to generate ultrasonic induced corrosion-deposition, and partially corroded nanoparticles are produced. Not desirable in The time for which the ultrasonic wave is applied is not particularly limited but is preferably 30 seconds to 300 minutes, and in less than 30 seconds, the reaction time is short, so that partially corroded nanoparticles are produced, and in 300 minutes or more, the reaction is completed in 300 minutes. It is not desirable at the cost of the process.

In general, silica nanomaterials are partially etched due to the hydroxide ions of the base present on the surface. When the silica / titanium dioxide core-cell nanoparticles are subjected to ultrasonic waves in a basic aqueous solution, preferentially, the outside of the silica (interface of the core-cell nanoparticles) of the core portion is corroded by the above reaction. At the time of ultrasonic induction, strong energy from ultrasonic waves is applied to the boundary of the core-cell nanoparticles induced by corrosion, and titanium dioxide, which was not corroded by strong energy, also corrodes with silica. This will proceed. In addition, the portions of silica and titanium dioxide corroded by hydroxide ions are repeatedly redeposited to the outside of the nanoparticles which are partially corroded through the reversible sol-gel reaction, whereby silica and titanium dioxide are mixed. Silica-titanium dioxide hollow structured nanoparticles having outer walls are prepared. In addition, the thickness of the outer wall of the hollow structured nanoparticles according to the silica-titanium dioxide core-cell nanoparticles having different thicknesses of titanium dioxide through the difference in the corrosion rate of the silica and titanium dioxide and the ultrasonic induced corrosion-deposition reaction, the nano-thickness Can be adjusted with.

In the centrifuge in step (D), the settling speed of the centrifuge is preferably 100 to 10,000 rpm, and the settling time of the centrifuge is preferably 5 to 120 minutes.

The base used in the ultrasonic induced corrosion-deposition method can be removed through a centrifuge, and the precipitated silica-titanium dioxide hollow structured nanoparticles are dispersed again in an aqueous solution, so that the silica present in a neutral solution that is not acidic or basic. An aqueous solution in which the titanium dioxide hollow structured nanoparticles are dispersed may be prepared, and the prepared aqueous dispersion solution may be used for biochemical applications.

[Example]

Although specific examples of the present invention will be described with reference to the following Examples, the scope of the present invention is not limited thereto.

Example 1

10 g of silica / titanium dioxide core-cell nanoparticles having a size of 45 nanometers and a titanium dioxide cell thickness of 100 mL of distilled water were added and stirred for 1 hour to disperse the core-cell nanoparticles. Add 10 g and stir for 1 hour. Ultrasound of 500 W is applied to the reaction solution into which the base and the core-cell nanoparticles are introduced for 30 seconds to cause the ultrasonic induced corrosion-deposition. Ultrasonically reacted reaction solution was recovered by using a centrifuge at 10,000 rpm for 5 minutes to recover silica-titanium dioxide hollow structured nanoparticles.

As a result of analyzing the prepared silica-titanium dioxide hollow structure nanoparticles using a transmission electron microscope, it was confirmed that the hollow structure nanoparticles having a size of 50 nanometers having an outer wall of about 7 nanometers were prepared. (Fig. 1) In addition, through the results of elemental analysis (mapping) through electron energy loss spectroscopy (EELS), silica and silicon dioxide (silicon, Si), titanium (titanium, Ti) is mixed on the outer wall It was confirmed that there exists, and through this it was confirmed that the hollow structure nanoparticles made of silica-titanium dioxide was prepared. (Figure 2)

[Example 2]

Using the same method as Example 1, 0.01 g of silica / titanium dioxide core-cell nanoparticles having a size of 20 nanometers and a titanium dioxide cell thickness of 3 nanometers was added to 100 mL of distilled water, followed by 0.01 g of ammonium hydroxide. After the introduction of 10 W ultrasonic wave for 300 minutes, ultrasonic induced corrosion-deposition occurred, and the silica-titanium dioxide hollow structure nanoparticles were recovered through a centrifuge at 100 rpm and 120 minutes. As a result of analysis using a transmission electron microscope, it was confirmed that the silica-titanium dioxide hollow structure nanoparticles having a size of 25 nanometers having an outer wall of 5 nanometers were prepared.

Example 3

Using the same method as in Example 1, 10 g of silica / titanium dioxide core-cell nanoparticles having a size of 5 nanometers and a titanium dioxide cell thickness of 1 nanometer were added to 100 mL of distilled water, followed by tetramethylammonium hydride. After introducing 10 g of the hydroxide, 500 W of ultrasonic waves were applied for 30 seconds to cause ultrasonic induced corrosion-deposition. The silica-titanium hollow structure nanoparticles were recovered through a centrifuge at 10,000 rpm for 120 minutes. . As a result of analysis using a transmission electron microscope, it was confirmed that 7 nanometer-sized silica-titanium hollow structure nanoparticles having an outer wall of 2 nanometers were prepared.

Example 4

Using a method similar to Example 1, 0.01 g of silica / titanium dioxide core-cell nanoparticles having a size of 5 micrometers and a titanium dioxide cell thickness of 1 micrometer were added to 100 mL of distilled water, followed by tetraethylammonium hydride. After introducing 10 g of the hydroxide, 500 W of ultrasonic waves were applied for 300 minutes to cause ultrasonic induced corrosion-deposition, and silica-titanium dioxide hollow structure nanoparticles were recovered through a centrifuge at 100 rpm and 120 minutes. . As a result of analysis using a transmission electron microscope, it was confirmed that 5 micrometer-sized silica-titanium hollow structure nanoparticles having an outer wall of 1 micrometer were prepared.

Example 5

Using the same method as in Example 1, 10 g of silica / titanium dioxide core-cell nanoparticles having a size of 90 nanometers and a titanium dioxide cell thickness of 15 nanometers were added to 100 mL of distilled water, followed by tetraethylammonium hydride. After introducing 5 g of the hydroxide, 250 W of ultrasonic waves were applied for 300 minutes to cause ultrasonic induced corrosion-deposition. The silica-titanium hollow structure nanoparticles were recovered through a centrifuge at 10,000 rpm for 60 minutes. . As a result of analysis using the transmission electron microscope, it was confirmed that the silica-titanium dioxide hollow structure nanoparticles having a size of 100 nanometers having an outer wall of 20 nanometers were prepared.

Example 6

Using the same method as Example 1, 10 g of silica / titanium dioxide core-cell nanoparticles having a size of 95 nanometers and a titanium dioxide cell thickness of about 3 nanometers were added to 100 mL of distilled water, followed by tetrabutylammonium. After introducing 7 g of hydroxide, 500 W ultrasonic wave was applied for 100 minutes to cause ultrasonic induced corrosion-deposition, and the silica-titanium dioxide hollow structure nanoparticles were recovered through a centrifuge at 10,000 rpm for 90 minutes. It was. As a result of analysis using the transmission electron microscope, it was confirmed that the silica-titanium dioxide hollow structure nanoparticles having a size of 100 nanometers having an outer wall of 5 nanometers were prepared.

1 is a transmission electron micrograph of the silica-titanium dioxide hollow structure nanoparticles prepared in Example 1 of the present invention;

Figure 2 is a photograph of the element analysis distribution results by electron energy loss spectroscopy of the silica-titanium dioxide hollow structure nanoparticles prepared in Example 1 of the present invention.

Claims (10)

Dispersing silica / titanium dioxide core-cell nanoparticles in an aqueous solution; Introducing a base into the aqueous solution of core-cell nanoparticles to form a basic aqueous solution; And, Inducing a hollow structure by applying ultrasonic waves to the basic core-cell nanoparticle solution; And, A method for producing silica-titanium dioxide hollow structured nanoparticles, comprising recovering the silica-titanium dioxide hollow structured nanoparticles from the ultrasonically applied solution using a centrifuge. The method of claim 1, wherein the silica / titanium dioxide core-cell nanoparticles have a size of 5 nanometers to 5 micrometers. The method of claim 1, wherein the cell thickness of the titanium dioxide in the silica / titanium dioxide core-cell nanoparticles is 1 nanometer to 1 micrometer. The method of claim 1, wherein the silica / titanium dioxide core-cell nanoparticles are added in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the aqueous solution. The method of claim 1, wherein the base is one of ammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, characterized in that the silica-titanium dioxide hollow structure nanoparticles Manufacturing method. The method of claim 1, wherein the addition amount of the base is 0.01 to 10 parts by weight based on 100 parts by weight of the aqueous solution. The method of manufacturing silica-titanium dioxide hollow structured nanoparticles according to claim 1, wherein the intensity of the ultrasonic wave is 10 to 500 W. The method for producing silica-titanium dioxide hollow structured nanoparticles according to claim 1, wherein the applied time in the ultrasonic waves is from 30 seconds to 300 minutes. The method of claim 1, wherein the centrifuge has a speed of 100 to 10,000 rpm. The method of claim 1, wherein the centrifuge has a time of 5 to 120 minutes.

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