KR101833143B1 - Wire with hollow structure and Preparation Method thereof - Google Patents

Abstract

The present invention relates to a hollow wire and a manufacturing method thereof, wherein the hollow wire exhibits excellent optical characteristics by including metal particles in a silicon matrix and has a hollow structure therein, thereby having advantages of carrying a drug, DNA or a biomaterial. The hollow wire of the present invention includes: a first region being in the form of a hollow rod and having an average outer diameter of D1; and a second region formed at one end of the first region and having a hollow structure and an average longest outer diameter of D2.

Description

Technical Field [0001] The present invention relates to a hollow wire,

The present invention relates to a hollow wire having a hollow structure therein and a method of manufacturing the hollow wire.

Typical silicon wires have one-dimensional nanostructures such as nanowires, nanorods, and nanotubes. Among them, the hollow tube structure, which grows in the longitudinal direction, has been used in many supercapacitors, transistors, sensors, batteries, resonators, etc. due to the specificity of its shape. For example, many types of one-dimensional nanotubes have been prepared with zinc oxide, titanium oxide, tin oxide, silica, carbon and the like by hydrothermal, light-based deposition, electrospinning, electrodeposition, sol-gel method and the like. However, the manufacturing method for such a silicon wire is complicated, and there is no know-how on a simple manufacturing method, and a mechanism for diffusion of constituent atoms is still insufficient.

Korean Patent Publication No. 10-2009-0049307.

The present invention provides a hollow wire including a metal particle in a silicon matrix and forming a three-dimensional structure and having a hollow structure therein, and a method of manufacturing the hollow wire.

The present invention is a wire structure having an average length in the range of 50 to 500 占 퐉 and including a first region and a second region below in the longitudinal direction,

(I) a first region in the form of a hollow rod and having an outer diameter average value of D1; And

(Ii) a second region formed at one end of the first region and having a hollow structure and having a longest outer diameter average value of D2,

D2 is a number two or more times larger than D1,

The wire comprising a silicon matrix represented by the following formula (1) and metal particles dispersed in the silicon matrix:

[Chemical Formula 1]

SiO _x

In Formula 1, x is 0? X? 2.

The present invention also provides a method of manufacturing a hollow wire including heating a silicon substrate while supplying a metal.

The hollow wire of the present invention includes metal particles in a silicon matrix to exhibit excellent optical characteristics, and can morphologically carry drugs, DNA, or biomaterials.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an image obtained by scanning electron microscopy of a process of producing silicon oxide including tin forming a hollow wire according to the present invention. FIG.
2 is an image of a hollow wire according to the present invention taken by a scanning electron microscope.
3 is an image of a hollow wire according to the present invention taken by a transmission electron microscope.
4 is an energy dispersive spectroscopy (EDS) analysis graph of a hollow wire according to the present invention.
5 is an X-ray diffraction (XRD) graph of a hollow wire according to the present invention.
FIG. 6 is a graph showing the relation between the growth speed (V), supersaturated driving force (F) and mobility (M) of the hollow wire according to the present invention.
7 is a graph showing the Gibbs free energy value of a hollow wire according to the present invention.
FIG. 8 is an image of a method of manufacturing a hollow wire according to the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to a hollow wire and a method of manufacturing the same.

The hollow wire according to the present invention is formed of a silicon matrix in which silicon oxides including metal particles are gathered. Typical wires have one-dimensional nanostructures such as nanowires, nanorods, and nanotubes. On the other hand, the hollow wire according to the present invention forms a three-dimensional structure and includes a hollow structure therein. This may allow delivery of drugs, DNA, or biomaterials. In addition, the hollow wire according to the present invention is advantageous in that it can be manufactured through heating, thereby simplifying the manufacturing method.

Specifically, the present invention is a wire structure having an average length in the range of 50 to 500 占 퐉 and including a first region and a second region below the first and second regions,

(I) a first region in the form of a hollow rod and having an outer diameter average value of D1; And (ii) a second region formed at one end of the first region and having a hollow structure and having a longest outer diameter average value of D2,

Wherein D2 is a number that is at least two times greater than D1, said wire being for a hollow wire containing a silicon matrix represented by the following formula (1) and metal particles dispersed in said silicon matrix:

[Chemical Formula 1]

SiO _x

In Formula 1, x is 0? X? 2.

For example, the silicon matrix may comprise silicon (x = 0, Si), and in some cases silicon (Si) may include silicon oxides naturally or artificially oxidized .

The hollow wire according to the present invention may contain metal particles dispersed in a silicon matrix. Specifically, the metal particles may be at least one selected from the group consisting of tin, manganese, zinc, magnesium and bismuth. More specifically, the metal particles may be at least one selected from the group consisting of tin, manganese, and zinc. By incorporating such a metal into the silicon matrix, the wire can exhibit excellent optical activity.

In one example, the metal particles within the silicon matrix may comprise from 0.01 to 5 atomic percent, based on 100 atomic percent silicon (Si). Specifically, the metal particles in the silicon matrix may be contained in the range of 0.05 to 3 atomic%, 0.1 to 1 atomic%, or 0.15 to 0.5 atomic% based on 100 atomic% of silicon (Si).

In one example, the hollow wire according to the present invention may have an average length in the range of 50 to 500 mu m. Specifically, the hollow wire according to the present invention may have an average length in the range of 60 to 450 mu m, 80 to 400 mu m, or 100 to 350 mu m. The average length of the hollow wire may be a length including the first region and the second region.

The hollow wire according to the present invention can be divided into a first region and a second region. The first region is in the form of a hollow rod and may have an average outer diameter of D1. In the present invention, the term " hollow rod shape " may mean a long rod shape having a hollow hollow.

In one example, the outer diameter average value D1 of the first region of the hollow wire may range from 0.5 to 5 mu m. Specifically, the outer diameter average value D1 of the first region may be in the range of 1 to 4 占 퐉 or 1.5 to 3.5 占 퐉. Further, the thickness of the hollow rod in the first region may be 200 to 800 nm. Further, the thickness of the hollow rod may be 300 to 700 nm or 400 to 600 nm. By having the outer diameter average value D1 of the first region and the thickness of the hollow rod as described above, it is possible to have a rod shape of the hollow hollow structure.

In one example, the average length (L ₁ ) of the first region of the hollow wire may range from 30 to 500 μm. Specifically, the average length L ₁ of the first region may range from 35 to 400 μm, from 40 to 300 μm, from 45 to 200 μm, or from 50 to 150 μm.

Also, the second region may be formed at one end of the first region, and may have a hollow structure and an average value of the longest outer diameter of D2. In one example, the average value D2 of the longest outer diameter of the second region of the hollow wire may range from 1 to 20 mu m. The average value D2 of the longest outer diameter of the second region may be in the range of 2 to 18 mu m, 3 to 15 mu m, or 5 to 15 mu m.

In one example, the second region may satisfy the following general formula:

[Formula 1]

(1) D2a < D2b

(2) D2c < D2b

D2b denotes an outer diameter at a position 2/4 in the longitudinal direction from the distal end of the second region, D2c denotes an outer diameter at the end of the second region, Means the outer diameter of the point 3/4 in the longitudinal direction from the end of the region.

Specifically, the second region can realize a spherical three-dimensional shape. In the present invention, the term &quot; spherical shape &quot; means a spherical shape in which the overall shape of the cross-sectional area is an ellipse or a circular shape. Specifically, the second region may be a spherical shape having a closed sphere shape except for a portion connected to the first region, or may have a hole in addition to a portion connected to the first region. The size of the holes may be smaller than the average value D2 of the longest outer diameters of the second regions. The presence and size of the hole may vary depending on the position where the hollow wire formed on the silicon substrate is cut off.

In addition, the average value D2 of the longest outer diameters of the second regions may be two or more times larger than the average value D1 of the outer diameters of the first regions. Specifically, the average value D2 of the longest outer diameters of the second regions may be a large number two to eight times or three to six times the average value D1 of the outer diameters of the first regions.

In one example, the average length (L ₂ ) of the second region of the hollow wire may be equal to the average value of the longest outer diameter of the second region. Specifically, the average length (L ₂ ) of the second region of the hollow wire may range from 1 to 20 μm. Specifically, the average length (L ₂ ) of the second region may be in the range of 2 to 18 μm, 3 to 15 μm, or 5 to 15 μm.

The ratio (L ₁ / L ₂ ) of the length (L ₁ ) of the first region to the length (L ₂ ) of the second region may be in the range of 1 to 30. Specifically, the ratio (L ₁ / L ₂ ) of the length (L ₁ ) of the first region to the length (L ₂ ) of the second region may be in the range of 2 to 25, 3 to 20, or 5 to 15.

In one example, the thickness of the spherical shape of the second region may be between 200 and 800 nm. The thickness of the spherical shape may be 300 to 700 nm or 400 to 600 nm. At this time, the thickness means the difference between the outer diameter and the inner diameter. The hollow wire of the present invention includes a second region in the form of a closed sphere and has the longest outer diameter average value (D2) of the second region, so that the drug, DNA or biomaterial can be transported.

The present invention also relates to a method of manufacturing a hollow wire including a step of heating while supplying a metal to a silicon substrate. Specifically, a gas supply pipe formed with a metal oxide thin film is fluidly connected to the silicon substrate, and the metal can be supplied by converting the metal oxide of the gas supply pipe into metal and desorbing it.

8 (a) is a step of forming a metal oxide thin film on a gas supply pipe, and FIG. 8 (b) is a step of forming a metal oxide thin film on a silicon substrate And heating the metal while supplying the metal.

In one example, the method of manufacturing a hollow wire may be such that a silicon substrate is positioned inside a gas supply tube having a metal oxide thin film formed therein, and an inert gas is blown at a high temperature to convert and remove the metal oxide into a metal. The inert gas may include argon gas or nitrogen gas. In addition, indium oxide and graphite powder may be added to promote the conversion and desorption of the metal oxide into the metal. At this time, the indium oxide included as an additive substitutes with the metal, and the graphite powder can help to discharge carbon monoxide and carbon dioxide.

A method of manufacturing a hollow wire according to the present invention is a method of manufacturing a hollow wire in which a metal oxide of a gas supply pipe is converted into and removed from a metal and is adsorbed on a silicon substrate and adsorbed metal particles react with the silicon substrate to form metal oxide particles . The silicon component may be derived from the silicon substrate as described above. Further, since the metal particles contact the silicon substrate, the melting point of silicon is lowered, and hollow wires can be produced at a relatively low temperature.

Specifically, when a substrate, for example, a silicon substrate is brought into contact with metal particles, the melting point is rapidly lowered, and the melting point of the silicon falls from 1414 degrees Celsius to 500 degrees Celsius, and silicon can grow. At this time, how much the melting point of the silicon substrate can be lowered depends on the type of the metal particles to be contacted, but the substrate can be grown by the difference in solubility regardless of the kind of the metal particles.

In one example, the kind of the metal oxide may include at least one kind selected from the group consisting of tin oxide, magnesium oxide, zinc oxide, manganese oxide and bismuth oxide. Specifically, the metal oxide may be tin oxide, magnesium oxide, or zinc oxide.

In one example, the step of heating while supplying the metal to the silicon substrate can be carried out in a temperature range of 500 to 1500 ° C. Specifically, the heating may be performed at a temperature of 600 to 1400 ° C or 700 to 1200 ° C.

Further, the step of heating while supplying the metal to the silicon substrate may be performed at a pressure of 0.01 to 0.5 mtorr for 20 minutes to 100 minutes. Specifically, the heating step may be performed at a pressure of 0.05 to 0.3 mtorr for 30 minutes to 90 minutes.

In the case of heating for the above-mentioned time, the silicon oxide including the metal particles continues to grow to form a silicon matrix to produce a wire. Specifically, when heating is performed for the above-described time, the silicon oxide including the metal particles reaches a supersaturation state for nucleation and forms a spherical three-dimensional structure at first and then grows into a hollow rod shape at the end of the spherical shape .

In one example, the method for manufacturing a hollow wire according to the present invention may further comprise the step of forming a metal oxide thin film on a gas supply pipe. The gas supply pipe may be an alumina tube or a quartz tube.

Specifically, the step of forming the metal oxide thin film on the gas supply pipe can be produced by heating the metal powder and the gas gas at a high temperature. For example, the step of forming the metal oxide thin film may be performed at a temperature of 500 to 1100 DEG C for 2 to 6 hours. By heating at a temperature within the above range, the metal can be converted into a metal oxide to form a thin film. The gas may be nitrogen gas or oxygen gas. The metal powder may include at least one of tin powder, magnesium powder, zinc powder, manganese powder, and bismuth powder.

In addition, the method of manufacturing a hollow wire according to the present invention may include separating a hollow wire grown on a silicon substrate from a substrate. Specifically, the hollow wires grown on the silicon substrate can be separated by the method due to the difference in solubility.

Best Mode for Carrying Out the Invention Hereinafter, the present invention will be described in more detail with reference to examples and drawings based on the above description. The following examples are intended to illustrate the invention and are not intended to limit the scope of the invention.

Production Example 1

To form the tin oxide thin film, tin powder (3 g) and oxygen gas of 300 sccm and nitrogen gas of 10 sccm were used in the alumina tube. 8A, tin powder was placed in a pure alumina tube, and nitrogen gas and oxygen gas were injected for 4 hours while maintaining a temperature of 900 DEG C and a pressure of 2.5 torr. Then, the alumina tube having the tin oxide thin film was prepared by natural cooling at room temperature.

Example 1

1 g of indium oxide powder and 0.1 g of graphite powder were placed in the alumina tube having the tin oxide thin film formed in Preparation Example 1, and the silicon substrate was placed upside down on the powder and maintained at a temperature of 1100 ° C. and a pressure of 0.1 mtorr for 40 minutes . Then, the wire was naturally cooled at room temperature and cut out from the silicon substrate to prepare a hollow wire.

Experimental Example 1

In order to examine the shape of the hollow wire according to the present invention, a scanning electron microscope (SEM) and a transmission electron microscope (TEM) were used for the tin-containing silicon particles and wires produced in Example 1 The measured results are shown in FIGS. 1 to 3. FIG.

1 is an image obtained by scanning electron microscopy of the production process of silicon oxide including tin forming the hollow wire of Example 1. Fig. Referring to FIG. 1, FIG. 1 (a) is an image in which square tin particles having a size of several tens of nanometers or tens of micrometers are formed on a silicon surface. At this time, irregular and small tin particles are obtained from the deposited tin oxide thin film. Fig. 1 (b) is an image in which tin particles formed on a silicon surface are crowded to reduce the surface energy, and quadrangular tin particles are circular. FIG. 1 (c) shows an image formed on a silicon substrate where tin particles are sphere-shaped, with the embryo which can not be formed into nuclei removed. These crowded spherical tin particles are nucleated and grown with tinned silicon oxide by the employment of silicon and oxygen. At this time, the limit that the tin can be solved in the silicon is too small, and the shape of the tin is embossed. That is, according to the silicon-tin phase balance diagram, tin can be solved at only 0.1% at 1000 ° C or higher. Figure 1 (d) is an image that continues to grow spherically with silicon oxide containing tin.

Fig. 2 is an image of a hollow wire prepared in Example 1 by scanning electron microscope. Fig. 2 (a) is a second region, which is an image of a spherical shape formed on one side of the hollow rod (first region). Referring to FIG. 2 (a), the spherical shape of the second region has a diameter of about 5 탆. FIGS. 2 (b) and 2 (c) are images of the hollow wire of Example 1, in which the silicon oxide containing tin particles is initially laid on flat silicon like a terrace by a terrace-ledge-kink model, It is then gathered at the stepped ledge, and finally the atoms at the corner (kink) can be assimilated into the final spherical shape. In addition, it can be seen that there is a second region as a whole in the form of a sphere, and a first region of a hollow rod exists. Specifically, it can be confirmed that the average length of the first region is 50 to 100 占 퐉 and the average length of the second region is 5 to 15 占 퐉. 2 (d) is a cross-sectional image of the silicon hollow rod, which shows that the diameter of the rod is about 2 μm and the thickness of the hollow rod is about 500 nm.

3 is an image of a hollow wire manufactured in Example 1, taken by a transmission electron microscope. Referring to FIG. 3, the diameter of the hollow wire is 1 to 2 占 퐉. 3 (a) to 3 (c) are enlarged images of the first region of the hollow wire, and it is confirmed that silicon oxide particles including tin particles are formed by the hollow wires. This is a phenomenon where new nucleation occurs due to the need for lower energy than the growth reaction. 3 (d) to 3 (f) are photographs of silicon oxide containing tin particles at a high magnification transmission electron microscope, wherein dark black is tin particles and light gray is silicon oxide. Referring to FIG. 3 (f), it can be seen that the interplanar spacing is about 0.292 nm.

It can be seen from the results that the hollow wire according to the present invention has a wire having a hollow structure inside and a spherical second region formed at one end of the first region in the form of a hollow rod. Further, it can be seen that the hollow wire is formed of silicon oxide containing tin particles and tin particles are dispersed in silicon oxide.

Experimental Example 2

Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) of the wires prepared in Example 1 were measured to examine the content of the hollow wires according to the present invention, The measured results are shown in Fig. 4 and Fig.

Referring to FIG. 4, it can be seen that the hollow wire of Example 1 is made of silicon, oxygen, tin and indium.

Referring to FIG. 5, it can be confirmed that amorphous silicon oxide and crystalline tin are mixed together in the hollow wire of the first embodiment. It can also be seen that there are other materials besides silicon and tin. Specifically, it can be confirmed that In _0.2 Sn _0.8 , Si (silicon), Sn (tin) and In (indium) exist in the hollow wire. As shown in FIG. 5, when the 2? Values were measured at 30 ± 0.5 °, 32 ± 1 °, 44 ± 2 °, 58 ± 2 °, 66 ± 1 °, 67 ± 1 °, 72 ± 1 ° and 75 ± 1 ° In _{0 . 2} Sn _{0 .8} can be confirmed, the peak of silicon can be confirmed at 69 ± 0.5 °, tin peaks can be confirmed at 31 ± 0.5 °, 44.5 ± 0.5 ° and 64 ± 0.5 °, and 33 ± 0.5 The indium peak can be identified. This means that the indium oxide contained as a reactant reacts simultaneously with silicon and tin, meaning that the reaction is still proceeding. This is because indium can be substituted with tin. As the reaction progresses, In _{0 . 2} Sn _{0 . 8} will turn into silicon oxide. Further, silicon also shows not only the (400) plane but also the tin tetragonal planes of (200), (211) and (400).

From these results, it can be seen that the hollow wire according to the present invention is mainly composed of silicon oxide and the tin is dispersed in silicon oxide in a very small amount. In addition, indium is present in the hollow wire, but it is present in a small amount of indium, which is a reactant, and disappears when the reaction proceeds.

Experimental Example 3

In order to confirm the growth mechanism of the hollow wire according to the present invention, the relationship between the growth rate (V), the supersaturated driving force (F) and the mobility (M) was measured for the wire produced in Example 1, The results are shown in Fig.

FIG. 6 is a graph of relationship between growth rate (V), supersaturated driving force (F), and mobility (M), showing surface nucleation of tin particles on a flat interface and successive growth mechanisms on a rough surface. Referring to FIG. 6, it can be divided into (1) anisotropic nucleation, (2) two-dimensional growth, and (3) silicon oxide containing isotropic tin. Specifically, the anisotropic nucleation process, when tin particles are adsorbed onto a silicon substrate, tin particles are flattened to form a two-dimensional nucleation and growth from a ternary cluster. At this time, the reaction of the tin atoms in contact with the flat silicon leads to the overall reaction, and the interfacial reaction is dominant. This reaction takes place at low temperatures and continues to the supersaturated state where nucleation takes place, resulting in two-dimensional growth. Subsequent nucleation of the ternary system leads to rapid growth, which results in the formation of isotropic tin-containing silicon oxide, which diffuses through the diffusion of silicon on the rough surface, leading to a diffusion reaction.

From these results, it can be confirmed that the hollow wire according to the present invention has a three-dimensional structure, and silicon oxide containing tin is formed and then silicon oxide is piled up to form a hollow wire. It can also be seen that the hollow wire grows into a hollow rod structure after the silicon oxide containing tin has grown into spherical shape.

Experimental Example  4

In order to confirm the production principle of the wire according to the present invention, the Gibbs free energy was measured on the wire manufactured in Example 1, and the measured results are shown in FIG.

The Gibbs free energy associated with the generation of tin particles was determined by considering the disk type tin particles on the silicon. Where r is the radius of the disk, h is the height of the disk, and E ₁ is the energy of the ledge, which is related to the interfacial energy. And V and _V △ G corresponds to the Gibbs energy of the volume and the volume (V = πr ² h) of the disc, respectively. When the tin disk is adsorbed on a flat silicon substrate, the interfacial energy increases linearly while the volumetric energy decreases with parabolic relation. Therefore, in the arithmetic relationship of the two items, different Gibbs energies are calculated. As shown in Fig. 7, when the particle size of the tin does not reach the size at which nucleation begins, the interfacial energy increases and the resulting embryo disappears. However, since the size of the tin represents the total Gibbs energy always negative, the wire containing tin particles continues to grow.

Claims (13)

A wire structure having an average length in the range of 50 to 500 占 퐉 and comprising a first region and a second region which are divided in the longitudinal direction,
(I) a first region in the form of a hollow rod and having an outer diameter average value of D1; And
(Ii) a second region formed at one end of the first region and having a hollow structure and having an average value of the longest outer diameter of D2,
D2 is a number two or more times larger than D1,
Wherein the wire comprises a silicon matrix represented by the following formula (1) and metal particles dispersed in the silicon matrix:
[Chemical Formula 1]
SiO _x
In Formula 1, x is 0? X? 2. The method according to claim 1,
Wherein the ratio (L ₁ / L ₂ ) of the length (L ₁ ) of the first region to the length (L ₂ ) of the second region is 1 to 30. The method according to claim 1,
And the second region satisfies the following general formula (1): &quot; (1) &quot;
[Formula 1]
(1) D2a &lt; D2b
(2) D2c &lt; D2b
In this case, D2a denotes an outer diameter at a quarter point in the longitudinal direction from the distal end of the second region,
D2b denotes an outer diameter at a point 2/4 in the longitudinal direction from the distal end of the second region,
And D2c denotes an outer diameter at a point 3/4 in the longitudinal direction from the distal end of the second region. The method according to claim 1,
Wherein the metal particles are at least one selected from the group consisting of tin, manganese, zinc, magnesium and bismuth. The method according to claim 1,
Wherein the ratio of the metal particles in the silicon matrix is 0.01 to 5 atomic% based on 100 atomic% of silicon (Si). The method according to claim 1,
And the average value (D1) of the outer diameter of the first region is 0.5 to 5 占 퐉. The method according to claim 1,
And the average value (D2) of the longest outer diameter of the second region is 1 to 20 占 퐉. delete delete delete delete delete delete

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