WO2012144728A2

WO2012144728A2 - Method for manufacturing a nanoparticle array the size of which is adjustable, nanoparticle array manufactured thereby, and uses thereof

Info

Publication number: WO2012144728A2
Application number: PCT/KR2012/001216
Authority: WO
Inventors: 김상욱; 신동옥; 문정호; 박수진
Original assignee: 한국과학기술원
Priority date: 2011-04-19
Filing date: 2012-02-17
Publication date: 2012-10-26
Also published as: WO2012144728A3

Abstract

The present invention relates to a method for manufacturing a monodisperse nanoparticle array, the size of which is adjustable, to a nanoparticle array manufactured thereby, and to the uses thereof. According to the present invention, the method for manufacturing a size adjustable nanoparticle array, the size of which is adjustable, is characterized by comprising the steps of: self-assembling block copolymers; selectively binding, through electrostatic interaction, a first polymer of the self-assembled block copolymers to metal ions of the nanoparticles to be deposited; and removing the copolymers. According to the present invention, monodisperse nanoparticle arrays can be deposited through a block copolymer lithographic process. Also, since nanoparticle size can be controlled simply by means of adjusting the loading time of metal ions, the present invention can be effectively used for various applied elements such as catalysts.

Description

Method for manufacturing nanoparticle array with adjustable size, nanoparticle array manufactured by the present invention and its application

The present invention relates to a method for manufacturing a nanoparticle array which can be adjusted in size, and to a nanoparticle array prepared by the present invention and its application, and more particularly, the nanoparticle size can be easily controlled by the loading time of the metal ion, such as a catalyst and the like. The present invention relates to a method for manufacturing a scalable nanoparticle array, which can be effectively applied to various applications of the nanoparticle array and its application.

Nanoscale particles have a large surface area resulting from nanoscale quantum confinement effects and small sizes, from which they exhibit size-dependent electrical, magnetic, chemical, optical, and catalytic properties. Patterning nanoparticles into two-dimensional (2D) arrays is already under considerable research due to their potential applications in sensors, magnetic data reservoirs, flash memories, and catalysts. However, despite active research in nanoparticle synthesis, the technique of precisely positioning, aligning and immobilizing nanoparticles on a desired substrate remains a technical challenge. In addition, it is very important to arrange nanopatterned particles on a desired substrate in a controlled manner. If the accuracy of the technique of locating and arranging nanoparticles is high, a nanoparticle array with controlled size can be applied to the various applications described above. Block copolymer lithography is evolving into lithography technology to overcome the inherent resolution limitations of conventional photolithography processes. The horizontal self-assembly technique of the separated block copolymer nanodomains of the microphase allows the fabrication of nanolithography masks that repeat at a size of 30 nm or less on any large area. Furthermore, recent self-assembly and orientation techniques using external electric field application, chemical or topography prepattern methods have achieved nano-patterns arranged horizontally over large areas. However, the inherent polydispersity of self-assembled nanoregions remains a technical challenge for producing nanopatterned morphologies with monodispersity. Moreover, scaled pattern transfer techniques have not been achieved on a block copolymer lithography basis to date.

Accordingly, the problem to be solved by the present invention is to provide a method for producing a nanoparticle array having a monodisperse property and controllable in size on a substrate and a nanoparticle array produced thereby. To provide an application method using a nanoparticle array of monodisperse properties.

The present invention provides a nanoparticle array comprising contacting a metal ion solution with a charged polymer that electrostatically bonds with the metal ion in the solution, thereby binding the metal ion to the polymer. Provide a method.

According to one embodiment of the present invention, monodisperse nanoparticle arrays can be deposited by block copolymer lithography. In addition, since the nanoparticle size can be easily controlled by the loading time of the metal ion, it can be effectively applied to various applications such as a catalyst. In addition, according to another embodiment of the present invention, metals having different physical properties may be deposited on a substrate in an array of lines and dots. In particular, it is possible to freely determine the type of metal array and the type of metal through the selective electrostatic bonding of the block copolymer of self-assembly and the specific polymer of the block copolymer with the metal ion, and also there is no limitation on the substrate area. Furthermore, according to the present invention, an alloy array due to the simultaneous bonding of dissimilar metal ions can also be easily manufactured.

1 is a process schematic diagram according to an embodiment of the present invention.

2 is a process schematic diagram according to another embodiment of the present invention.

3 to 5 are PS-b-P4VP thin film SEM images (FIG. 1B) after spin on a silicon substrate, and PS-b-P4VP thin film images (FIG. 1C, 1D) after solvent-annealing.

6 to 8 are SEM images of Fe 2 O 3 nanoparticle arrays prepared by immersing a spincast-solvent annealed block copolymer template in an aqueous solution containing a metal ion complex for 1 minute.

9-11 are statistical distributions of Fe 2 O 3 nanoparticle diameters.

FIG. 12 is an SEM image showing the growth of an array of nanoparticles obtained from a solvent annealed template for 5 hours with time the template was immersed (loaded) in a metal complex ion solution.

FIG. 13 is a graph illustrating change in diameter of nanoparticles according to metal ion loading time. FIG.

14 is an XPS spectrum of the Fe 2 O 3 nanoparticle array obtained after oxygen plasma treatment.

15 is a cross-sectional SEM image of vertically grown carbon nanotubes.

FIG. 16 is an SEM image of the lower portion of the carbon nanotube at high magnification. FIG.

17 and 18 are SEM images of carbon nanotubes grown from double-walled and triple-walled nanoparticle catalysts.

FIG. 19 is a graph of statistically comparing the number of carbon walls prepared from the block copolymer template in the spin state with the block copolymer template after annealing for 5 hours.

FIG. 20 shows single-walled carbon nanotubes (SWNTs), double-walled carbon nanotubes (DWNTs), triple-walled carbon nanotubes (TWNTs), and four-walled multi-walled carbon nanotubes (MWNTs) prepared from a 5-hour annealed block copolymer template. The relative fractions of) are analyzed according to the loading time of the complex complex.

FIG. 21 is a schematic diagram of hierarchical patterning of nanoparticle arrays and corresponding carbon nanotube growth. FIG.

22-25 illustrate a method of depositing nanoparticles in various forms by a scheme in accordance with the present invention.

FIG. 26 is a photograph after formation of a Pt line (34 nm period, 10 nm wide) according to the first block copolymer lithography prepared according to the present invention.

FIG. 27 is a photograph showing that the P4VP cylinder structure protruding in a plane at the 34 nm period and the 10 nm diameter was correctly formed between Pt lines.

FIG. 28 is a photograph showing that a 10 nm diameter Pd nanopoint is formed at a position of the P4VP cylinder nanodomain of FIG. 27.

FIG. 29 shows an array of nanoparticles formed in the form of an intersection of a Pt line and a Pd line, FIG. 30 is a dot-dot form, and FIGS. 31 and 32 are EDS mapping images of the Pt line and the Pd dot array.

33 to 37 are images of Pt line-Co point, Pt line-Au point, Pd line-Fe ₂ O ₃ point, Pt point-Fe ₂ O ₃ point, and Pd line-Pd line, respectively.

38 is a step-by-step schematic diagram of the composite metal array manufacturing method according to the embodiment of the present invention.

39 to 41 are SEM images and size distribution graphs, FePt alloy nanodot arrays and size distribution graphs, TEM images and high temperature heat treatment graphs of self-assembled cylinder block copolymers, respectively.

Hereinafter, an item usage period control method and a server therefor according to an embodiment of the present invention will be described with reference to the accompanying drawings. In order to clarify the understanding of the present invention in the following description, features of the present invention will be described. Description of well-known techniques will be omitted. The following embodiments are detailed description to help understand the present invention, and it should be understood that the present invention is not intended to limit the scope of the present invention. Therefore, equivalent inventions that perform the same functions as the present invention will also fall within the scope of the present invention.

The present invention provides a method for achieving monodisperse nanoparticle arrays that can be scaled to sub-nanometer levels directly from block copolymer lithography in order to solve the above problems. The present invention produces monodisperse nanoparticle arrays on a substrate, in particular by inducing an electrostatic interaction between a polymer and a metal ion of any of the self-assembled block copolymers. The interaction of block copolymers with metal ions in the present invention has a very high specificity (because electrostatic interactions only occur for certain block polymers of limited size) and are oriented in a specific direction with metal deposition. Monodispersed nanoparticle arrays can be deposited to a desired size, depending on the uniformity of the block copolymer morphology of the structure.

The method for producing a nanoparticle array according to the present invention produces a nanoparticle array using a block copolymer comprising at least two different types of polymers, namely, a first polymer and a second polymer, as described above. The copolymer is self-assembled to prepare a block copolymer template having a specific structure, and the metal ions of the specific polymer (first polymer) in the self-assembled block copolymer template and the nanoparticles to be prepared are subjected to electrostatic interaction. Selectively bind and remove the block copolymer again. In the case of the present invention, the block copolymer is used as a template for preparing nanoparticle arrays, and in particular, the present invention specifically binds the self-assembled first polymer and precursor solution ions of nanoparticles (metal nanoparticles). To prepare a nanoparticle array. Therefore, according to one embodiment of the present invention, the selective bonding between the base metal ion and the first polymer proceeds in such a way that the self-assembled block copolymer is immersed in the solution containing the metal ion. The metal ion is in the form of an anionic metal complex and the first polymer bears a cation in the aqueous solution. In an embodiment of the present invention, a polymer having a cation-containing nitrogen-containing group (for example, pyridine) bound by protonation under weak acid conditions such as HCl is used as the first polymer, and an anion containing a metal such as Fe is used. A metal nanoparticle array obtained from metal ions, which is bound to the first polymer and is then removed, can be obtained.

1 is an overall schematic diagram of a process according to an embodiment of the present invention.

Referring to Figure 1, the amphiphilic poly (styrene-block-4-vinylpyridine) (PS-b-P4VP) on any substrate (PS block (second polymer) is 24.0 kg / mol, P4VP block ( 1 polymer) was mixed with a 9.5 kg / mol) block copolymer thin film in a toluene: tetrahydrofuran (THF) mixed solution, spin-cast and immediately self-assembled to form a P4VP nanocylinder array perpendicular to the PS matrix. , Self-assembled structure was formed. The solvent was then annealed in toluene, with the THF mixed vapor slowly ordering the cylindrical nanoregions sideways over time. With this horizontal arrangement, the size of the self-assembled cylinder region structure was fairly uniform. Thus, following an annealing of about 5 hours, a horizontally-arranged hexagonal cylinder array with a very narrow size distribution was produced. As such, the block copolymer thin film having a high order, horizontally arranged nanoarea structure, and deposited on the substrate was immersed in a 1 mM K 3 [Fe (CN) ₆ ]: 0.1% HCl aqueous solution. The anionic metal complex of Fe (CN) 6-3 binds to the quantized pyridine nitrogen (cationic) of the P4VP cylinder nanodomain, which is the first polymer. Thereafter, an oxygen plasma treatment was performed on the entire area to remove the organic block polymer template, wherein the monodispersed iron oxide (Fe 2 O 3) nanoparticle array remained at the position of the P4VP cylinder. Depending on the loading time of the iron ion complex on the aqueous solution (ie, contact time), the nanoparticle size can be controlled to be less than nanometers.

The Fe 2 O 3 nanoparticle array prepared according to the present invention may function as a catalytic functional material for carbon nanotube (CNT) growth. However, as well as K 3 [Fe (CN) ₆ ], any other ionic metal complex ion can be used to fabricate and fix various types of metal nanoparticle arrays on any substrate. Furthermore, the following examples of the present invention used one kind of metal ion complex, but when two or more ion complexes are mixed and used, heterogeneous metal nanoparticle arrays are also possible. In addition, when the self-assembly of the block copolymer on the first formed metal nanostructure again and then the second metal is deposited in the same manner, a multilayer dissimilar metal array having a point-point, line-point, and core-shell structure Can be formed.

In another embodiment of the present invention, only a specific block copolymer (P4VP in one embodiment of the present invention) that is protonated in an acidic solution is immersed in an acidic solution, and the specific block is formed by electrostatic action with a metal anion. Precipitates by binding a metal to In this case, various metal layers may be formed according to the form of the substrate. For example, when the copolymer substrate is in the form of a brush, a metal may be bonded to the surface of the brush and a rod-shaped metal layer may grow. In contrast, in the case of a thin film form, since the metal is electrostatically coupled to the entire thin film, the metal layer may be in the form of a film.

2 is a process schematic diagram of a metal layer manufacturing method according to the embodiment of the present invention.

Referring to FIG. 2, a P4VP polymer substrate deposited on a silicon substrate is immersed in an acid solution containing metal anion (M−) to electrostatically bond a metal anion to the polymer substrate charged with a cation, thereby providing the metal Anions are deposited on the polymer substrate. Thereafter, the polymer substrate is removed to prepare a metal layer deposited in a form corresponding to the polymer substrate.

Hereinafter, a method of manufacturing a nanoparticle array and a method of using the same according to an embodiment of the present invention will be described in detail.

Example

matter

Polystyrene-block-poly (4-vinylpyridine) (PS-b-P4VP, molecular weight: 24 kg mol-1 PS, 9.5 kg mol-1 P4VP), asymmetric block copolymer, potassium hexacyanoate (III) (Potassium ferricyanide), pure ammonia and acetylene gas were prepared.

Metal Nanoparticle Array Deposition

The silicon wafer was immersed in a piranha solution ((7: 3 H 2 SO 4: H 2 O 2) for 1 hour at 110 ° C. and washed several times with deionized water. Ps-b-P4VP block copolymer (0.5 wt%) was added to the toluene / THF mixture. A 25 nm thick PS-b_P4VP thin film from 0.5 wt% toluene was dissolved and spincoated onto the washed silicon The spinned film was solvent annealed in a small sealed container, first toluene and THF (toluene: THF). 20:80 v / v) A homogeneous mixed solution was introduced into the closed container and the solvent was evaporated spontaneously for several minutes at room temperature (25 2 ° C.) to render the vessel saturated with toluene and THF steam. The volume ratio of was inconsistent with the ratio of the mixed liquor, which is due to the different vapor pressures of toluene and THF, and then the spin film was annealed for 0 to 5 hours, creating a laterally arranged cylindrical nano-zone. The solvent annealed sample was immersed in a 1 mM K 3 [Fe (CN) 6]: 0.1% HCl aqueous solution for a given time (loading time) After metal ion bonding (loading), the sample was washed several times with deionized water, The metal ions were removed, and then dried with nitrogen, and then subjected to oxygen plasma treatment to remove the polymer template to prepare an array of Fe 2 O 3 nanoparticles of iron oxide on a silicon substrate.

PECVD growth of vertical carbon nanotubes

The present invention selected the catalyst as one of the applications of the prepared nanoparticle array. To this end, the carbon nanotubes were grown by PECVD using the nanoparticle array according to the present invention as a catalyst. In order to grow carbon nanotubes, the substrate on which the Fe 2 O 3 nanoparticle array was prepared was first heated to 600 ° C. while flowing hydrogen and ammonia mixed gas. The hydrogen and ammonia content was 80: 20% by volume and the total mixed gas flow rate was maintained at 100 sccm. As the substrate temperature reached 600 ° C., the substrate was annealed (usually less than 2 minutes) and the Fe 2 O 3 nanoparticles were reduced to Fe metal particles. Thereafter, the chamber pressure was increased to 5 torr, and the direct current plasma proceeded according to the application of the cathode DC voltage of 470V. Next, acetylene gas was slowly flowed at a flow rate of 5 sccm for 1 to 2 minutes to prepare carbon nanotubes grown densely and vertically.

analysis

Block copolymer template analysis

3 to 5 are PS-b-P4VP thin film SEM images (FIG. 1B) after spin on a silicon substrate, and PS-b-P4VP thin film images (FIG. 1C, 1D) after solvent-annealing. After spin, it can be seen that the nanocylinders of the P4VP blockpolymer are oriented vertically, which is due to the high directional vapors generated during the spin-cast process. However, it can be seen that the arrangement density in the horizontal direction of the cylinder is not uniform and the size distribution is also wide (see Fig. 3). However, the horizontal orientation and size uniformity of the cylinder is greatly improved after solvent annealing at room temperature in toluene: THF (20:80 v: v). Samples annealed for 2 hours are orderly ordered in a hexagon and exhibit a relatively small grain size (see FIG. 4). Samples annealed for 5 hours show a hexagonal orientation structure with large grain size (see FIG. 5).

Fast Fourier transform (FFT) results illustrate the improvement of the horizontal array structure.

Referring to the above results, six spot spots with strong multiple high order reflection properties indicate that the hexagonal structures arranged in orderly horizontally are densely packaged (inset in FIG. 5).

6 to 8, since the P4VP vertical cylinder structure is directly exposed to the water-soluble complex solution, the anionic metal complex easily binds to the quantized pyridine group even in mildly acidic conditions. Thus, the resulting Fe2O3 nanoparticle array accurately replicates the morphology of the block copolymer template. The particles obtained after the spin, or from an insufficiently annealed block copolymer template, have a large particle diameter and a wide size distribution (10.84 nm 2.98 nm after spin, 8.40 nm 1.79 nm after 2 hours annealing). In contrast, nanoparticles obtained from well grown molds have a cylinder structure of small size and narrow size distribution (6.03 nm to 1.0 nm).

9-11 are statistical distributions of Fe 2 O 3 nanoparticle diameters.

In addition to the results of FIGS. 9 to 11, Table 1 below summarizes the nanosize characteristics of the block copolymer nano template and the obtained nanoparticle array of FIG. 1.

Table 1

	Block Copolymer Mold		Iron Oxide Nanoparticle Array
	Average diameter (nm)	Average center-to-center distance (nm)	Average diameter (nm)	Average Center-to-Center Distance (nm)
After spin	11.04 ± 3.9	24.58 ± 4.6	10.84 ± 2.98	25.38 ± 6.1
2 hours	10.35 ± 2.3	22.39 ± 2.6	8.40 ± 1.79	23.95 ± 4.5
5 hours	9.01 ± 1.2	19.23 ± 1.3	6.03 ± 1.0	19.71 ± 1.7

9 to 11 and Table 1 results, the average diameter of the nanoparticles is somewhat smaller than the block copolymer cylinder diameter, due to the particle density that occurs when the block copolymer is removed by plasma treatment.

Nanoparticle Array Analysis

Referring to FIG. 12, the size of monodispersed nanoparticles gradually increases with loading time. Precise control of particle size down to nanometer-sized sizes is possible at relatively low concentrations of aqueous metal complex ions (1 mM K3 [Fe (CN) 6]). The difference in average diameter and height is graphed according to loading time, which is shown in FIG. 13. The growth rate was fast at short loading times but gradually slowed down. The growth behavior may correspond to a typical power law curve, Atα. According to the least square fit, an index α of 0.16 in diameter and 0.39 in height is obtained. These low values are due to the low concentration of metal ions as well as the limited diffusion of metal ions through the P4VP nanosize cylinder. In other words, in the block copolymer template, the PS matrix functions as a barrier to diffusion of metal ions around the P4VP cylinder structure, but the nanoparticles are adsorbed as the loading time gradually increases. 14 is an XPS spectrum of an Fe ₂ O ₃ nanoparticle array obtained after oxygen plasma treatment. Referring to Figure 14 results, Fe-2p3 / 1 peak of 710.5eV proves that the Fe ₂ O ₃ Fe state exists.

Carbon Nanotube Analysis

The catalytic functionality of monodisperse nanoparticle arrays was analyzed through catalyst-based carbon nanotube growth experiments. Among various carbon nanotube synthesis methods, plasma vapor deposition (PECVD) was used to induce vertically oriented carbon nanotube growth. PECVD enables low temperature growth at temperatures below 600 ° C., which is one of the important conditions for device integration. The Fe 2 O 3 particle array prepared in the present invention is converted into Fe particles by thermal reduction before carbon nanotube growth. That is, vertically oriented carbon nanotubes were prepared with high yield by slowly adding nitrogen, ammonia, and acetylene mixed gas (FIG. 15). Such high yield growth of carbon nanotubes proves the high purity and high functionality of the monodisperse nanoparticle array prepared according to the present invention.

In the present invention, carbon nanotubes having a height of 26.7 μm were grown after one minute under optimum conditions. FIG. 16 is an SEM image of the lower portion of the carbon nanotube at high magnification. FIG. The carbon nanotube diameter is 5.3 nm, which corresponds to 2/3 of the diameter of the catalyst particles of 8.6 nm. 17 and 18 are high-resolution TEM images of carbon nanotubes grown from monodisperse catalyst particles prepared according to the present invention. When the images are analyzed, average diameters of 5.8 and 9.9 nm appear. The narrow distribution of carbon nanotube diameters and the number of carbon walls in the graphite structure is due to the monodisperse nature of the catalyst particles. That is, 88% of the carbon nanotubes grown from the 5.6 nm catalyst particles were double walls, whereas 72% of the carbon nanotubes grown from the 9.9 nm catalyst particles were triple walls (see FIG. 17). FIG. 18 is a statistical comparison of the number of carbon walls prepared from the block copolymer template in the spin state with the block copolymer template after annealing for 5 hours. The loading of the complex ion was maintained at 5 minutes. Since spinned nanoparticle arrays have a wide size distribution, carbon nanotubes grown from them also exhibit a wide carbon wall number distribution. In contrast, the carbon wall numbers of the carbon nanotubes obtained from the blow copolymer templates annealed for 5 hours showed a much narrower distribution.

FIG. 19 shows single-walled carbon nanotubes (SWNTs), double-walled carbon nanotubes (DWNTs), triple-walled carbon nanotubes (TWNTs) and four-walled multi-walled carbon nanotubes (MWNTs) prepared from a block copolymer template annealed for 5 hours. The relative fractions of) were analyzed according to the ion complex loading time. The relative fraction of each carbon wall number varied with catalyst size as a function of loading time. In the case of carbon nanotube growth in the NH3 environment, even the smallest particle size, the growth of single-walled carbon nanotubes was suppressed, which is thought to be due to the nitrogen doping effect. In FIG. 20, the average diameter of the carbon nanotubes is graphed according to the ion loading time. Growth characteristics were similar to catalyst particle growth, which means that the carbon nanotube diameter is closely related to the catalyst particle size, and the size-controlled nanoparticle deposition according to the present invention is a layer of catalyst and the corresponding carbon nanotube array. Enable enemy patterning. FIG. 21 illustrates a process of growing carbon nanotubes in a desired substrate region through selective deposition of block copolymers.

As described above, the monodisperse nanoparticle array deposition method according to the present invention can be controlled in size, which can be achieved by block copolymer lithography. Vertically aligned cylindrical block copolymer nanoregions are prepared by a solvent annealed PS-b-P4VP block copolymer thin film, which is immersed in a water soluble ion metal complex solution, whereby the anionic metal complex is transferred to the P4VP cylinder core. Diffusion, which is achieved by very specific electrostatic interactions. The specific dispersion of metal ions in nanoscale confined spaces enables the production of monodisperse nanoparticle arrays arranged sideways at sub-nanometer levels to the desired size. In addition, the catalytic functionality of monodisperse nanoparticle arrays was demonstrated through carbon nanotubes grown vertically by catalytic PECVD. The present invention, which controls the catalyst particle size to a size less than nanometers, enables the growth of carbon nanotubes in a vertical orientation, in particular where the number of carbon walls can be selectively determined. It is also possible to align nanoparticle arrays within the trenches through graphoepitaxy. That is, in the case of Graphoepitaxy, since the block copolymer is aligned in the trench formed in the substrate, it is possible to form a nanostructure having a single domain, and to form a single or dissimilar metal array according to various methods described below. Can be formed in the desired trench structure.

Referring to FIG. 22, another heterogeneous metal is deposited on the metal nanoparticle array (first metal array) manufactured according to the present invention to an area other than the first metal array formation region by electrostatic interaction. , Shows a step of manufacturing a nanoparticle thin film composed of two or more types of metal nanopoints spaced apart from each other.

Referring to FIG. 23, first, a block copolymer is raised, followed by solvent annealing or heat treatment to form nanolines parallel to the substrate. After applying the block copolymer again on the formed nano-line again, to form a nano dot by the method according to the invention. As a result, nanodots are located between the spaces of the pre-formed nanoline.

24 illustrates a method of depositing alloy nanopoints of dissimilar metal on a substrate using two kinds of metal precursor solutions together. Even in this case, the dissimilar metal precursor solution must be selectively electrostatically bonded to the self-assembled block copolymer. That is, when loading a metal anion, alloy nanoparticles can be obtained by using a heterogeneous sample, and the properties of the alloy nanoparticles can be observed by heat treatment and recrystallization thereof.

FIG. 25 illustrates a process of depositing nanoparticles of a so-called core-shell structure on a substrate, in which a plurality of nanopoint deposition processes according to the present invention are sequentially performed, in which a second nanopoint is sequentially stacked on a first nanopoint. The method is shown. Yet another embodiment of the present invention provides a method of manufacturing a dissimilar metal array according to such an electrostatic loading method.

Dissimilar Metal Array Manufacturing

Amphiphilic 33.5 kg / mol or 59 kg / mol of poly (styrene-block-4-vinylpyridine) (PS-b-P4VP, 0.5 wt%) was mixed on a silicon substrate with a toluene: tetrahydrofuran (THF) solution. After dissolution in, the PS-b-P4VP thin film was prepared by spin coating on the silicon substrate in a thickness of 30 nm to perform first block copolymer lithography. The spin-coated thin film was then solvent annealed. For 33.5 kg / mol PS-b-P4VP block copolymer, a homogeneous toluene: tetrahydrofuran mixture (760/30 v / v or 80/20 v / v) is injected into the annealed vessel to form a cylinder array. In-plane structures and planar protrusion structures of are derived, respectively. A 59 kg / mol PS-b-P4VP block copolymer thin film was treated with THF vapor to assemble into a cylinder array of planar protrusion structures. The vessel was saturated with solvent vapor which spontaneously evaporated at room temperature for several minutes.

The spin-coated thin film was then annealed for 1 to 5 hours to form orderly arranged cylindrical nanodomains. The solvent annealed sample was immersed in an aqueous HCl solution containing metal ions to load the metal ions into the thin film.

In one embodiment of the present invention, the first metal ion-containing solution was 2 mM Na ₂ PdCl ₄ / 0.1% HCl solution, and another second metal ion-containing solution was 1 mM Na ₂ PtCl ₄ / 0.1% HCl. As a result, Pt and Pd electrostatically bond with the protonated P4VP, and the structure of the Pt and Pd arrays follows the P4VP form.

After the loading, the sample was washed several times with deionized water, excess metal ions were removed, and the thin film was dried again with nitrogen. Thereafter, an oxygen plasma treatment was performed on the entire area to remove the block polymer template. Thereafter, for the second block copolymer lithography process, a 33.5 kg / mol PS-b-P4VP block copolymer thin film was spin-coated to a thickness of 30 nm on the substrate on which the metal nanopattern was formed. Subsequent solvent annealing was performed to form a cylindrical array included in the planar layer, or to form an array of cylindrical structures projecting from the planar layer. Various composite multicomponent assemblies were prepared on the substrate by removing the block copolymer template of the second layer following an oxygen plasma process. The manufactured assembly pattern may be in the form of a dot-point, a line-line, a dot-line, as shown in FIG. 1, and various types of metals are formed in a desired shape on a large-area substrate by repeating the above steps. You can.

FIG. 26 is a photograph after the Pt line (34 nm period, 10 nm width) is formed according to the first block copolymer lithography prepared according to the present invention, and FIG. 27 is protruded in plane at the 34 nm period and 10 nm diameter. Photograph showing that the P4VP cylinder structure was correctly formed between Pt lines. FIG. 28 is a photograph showing that 10 nm diameter Pd nanopoints are formed at the position of the P4VP cylinder nanodomain of FIG. 27.

26 to 28, it can be seen that line-point nanostructures on the substrate can be effectively formed through the electrostatic attraction between the metal anion and the polymer.

29-32, it can be seen that a fairly regularly arranged metal array can be formed in the substrate. Also, in one embodiment of the present invention, Pt was deposited by first polymer lithography and Pd was deposited by second polymer lithography, but this can be varied through different metal ion loading steps.

33 to 37 show various heterogeneous metal arrays fabricated on a substrate in an electrostatic manner according to the present invention, wherein Pt line-Co point, Pt line-Au point, Pd line-Fe ₂ O ₃ point, Pt point, respectively -Images of Fe ₂ O ₃ point and Pd line-Pd line.

33 to 37, it can be seen that a multi-component metal array of various forms can be formed according to the selection of metal ions.

As described above, the present invention can form metal arrays of various shapes and components on a substrate through electrostatic coupling between block copolymer lithography and polymer-metal ions.

Another embodiment of the present invention is not a multi-step process to configure the first metal array and the second metal array in different positions, but rather a block copolymer mold according to the present invention in a solution containing two or more metal ions. Is immersed to form a composite metal array.

Referring to FIG. 38, a block copolymer prepared according to the present invention is immersed in a mixed solution of Fe (CN) 6-3 and PtCl4-2, and the two kinds of metal ions are protonated polymers in the block copolymer. In electrostatic bonding with, a FePt alloy pattern is formed on the substrate. In one embodiment of the present invention, the alloy pattern corresponds to the electrostatically coupled polymer pattern, when the polymer pattern is in the form of dots, the alloy pattern may be in the form of dots. Alternatively, when the polymer pattern is in the form of a line, the alloy pattern may be in the form of a line.

Subsequently, a FePt alloy nanoarray is formed through heat treatment. As shown in FIG. 20, in one embodiment of the present invention, first, a vertical cylinder PS-b-P4VP thin film formed on a substrate is immersed in an aqueous hydrochloric acid solution in which ferricyanide and chloroplatinate anions are dissolved. At the nitrogen position of the protonated pyridine, metal complex anions are located by electrostatic attraction. If this is removed and only the polymer is removed by oxygen plasma, the metal sample remaining in the cylinder block remains in the form of nanoparticles. When the specimen is flowed a little hydrogen and heat treated at an appropriate high temperature, the specimen is aggregated to form an array of single crystal nanopoints. If the polymer pattern is in the form of a line, an array of alloys in the form of a line may be formed on a substrate by the same method as described above.

39 to 41, by heat-treating the deposited alloy at a high temperature, the metals are aggregated to form a single crystal nanopoint array. In addition, as can be seen in the size distribution diagram, a metal nanostructure array of about 8 nanometers can be obtained from a cylinder block of about 11 to 12 nanometers, and the nano-structure having a narrow size distribution of about 4.5 nanometers is subjected to heat treatment. You will get an array of points. In particular, it can be seen that the alloy particles deposited on the substrate through the heat treatment proceeding at more than 650 degrees Celsius to grow into a narrow nano-dots.

In another embodiment of the present invention, only a specific block copolymer (P4VP in one embodiment of the present invention) that is protonated in an acidic solution is immersed in an acidic solution, and the specific block is formed by electrostatic action with a metal anion. Precipitates by bonding a metal to it. In this case, various metal layers may be formed according to the form of the substrate. For example, when the copolymer substrate is in the form of a brush, a metal may be bonded to the surface of the brush and a rod-shaped metal layer may grow. In contrast, in the case of a thin film form, since the metal is electrostatically coupled to the entire thin film, the metal array may be aggregated and converted into a film form.

Referring to FIG. 2 described above, various metal array manufacturing methods according to the present invention will be described. A P4VP polymer substrate deposited on a substrate (for example, a silicon substrate) is immersed in an acidic solution containing metal anion (M-). Contact in such a way. This causes the cation-charged polymer substrate and the metal anion to electrostatically interact and bind, thereby depositing the metal anion on the polymer substrate to form a metal thin film. Thereafter, the polymer substrate is removed to prepare a metal thin film deposited in a form corresponding to the polymer substrate. The polymer may be in the form of a thin film, or a polymer in which an anion is charged electrostatically may include a brush. Although the above description has been made with reference to a preferred embodiment of the present invention, those skilled in the art will have the following claims It will be understood that various modifications and changes can be made in the present invention without departing from the spirit and scope of the invention as set forth in the following.

Nanoparticle array according to the present invention has the industrial applicability to produce a catalyst, using nanoparticle growth.

Claims

Contacting a metal ion solution with a charged polymer that electrostatically bonds with the metal ion in the solution, thereby bonding the metal ion to the polymer.
The method of claim 1, wherein the polymer is a block copolymer of two or more polymers, and at least one of the block copolymers has a charge opposite to the metal ion in the solution. .
The method of claim 2, wherein the method comprises: self-assembling the block copolymer;

Immersing the self-assembled block copolymer in the metal ion solution;

Coupling the metal ion and the metal ion with an electrostatic force in the metal ion solution opposite to the metal ion; And

Method for producing a nanoparticle array comprising the step of removing the block copolymer.
A method of manufacturing a nanoparticle array using a block copolymer comprising a first polymer and a second polymer, the method comprising: self-assembling the block copolymer; Selectively bonding the first polymer of the self-assembled block copolymer and the metal ion of the nanoparticle to be deposited by electrostatic interaction; And removing the block copolymer, the nanoparticle array manufacturing method using the block copolymer, characterized in that it comprises a.
The method of claim 4, wherein the second polymer and the metal ion do not electrostatically interact with each other.
The nanoparticle array using block copolymers according to claim 4, wherein the selective bonding of the metal ions is performed by immersing the self-assembled block copolymer in the solution containing the metal ions. Way.
7. The method of claim 6, wherein the metal ion is in the form of an anion metal complex, and the first polymer has a cation in the aqueous solution.
The method of claim 7, wherein the first polymer comprises nitrogen, and the aqueous solution is characterized in that the acidic condition of pH <7, nanoparticle array manufacturing method using a block copolymer.
The method of claim 4, wherein the block copolymer is poly (styrene-block-4-vinylpyridine).
10. A nanoparticle array produced by the method according to claim 4.
A method for producing carbon nanotubes, comprising growing carbon nanotubes using the nanoparticle array according to claim 10 as a catalyst.
Self-assembling the first block copolymer deposited on the substrate;

Contacting the self-assembled first block copolymer with the first metal ion solution;

Bonding the polymer of the block copolymer having a charge opposite to the first metal ion and the metal ion in the first metal ion solution with an electrostatic force;

Removing the first block copolymer to produce a first metal array on the substrate;

Stacking a second block copolymer on a substrate on which the first metal array is manufactured, and then self-assembling the second block copolymer;

Contacting the self-assembled second block copolymer with the second metal ion solution;

Coupling the polymer and the metal ion of the block copolymer having a charge opposite to the second metal ion in the second metal ion solution with an electrostatic force; And

Removing the second block copolymer to simultaneously form a first metal array and a second metal array on the substrate.
13. The method of claim 12, wherein the step is repeated a plurality of times to form a plurality of kinds of metal arrays on the substrate.
13. The method of claim 12 wherein the first and second metal arrays are in the form of lines or dots.
15. The method of claim 14, wherein the first and second block copolymers comprise a first polymer charged in the metal ion solution and a second polymer uncharged in the metal ion, wherein in the first polymer region And the first and second metal arrays are formed.
Alloy nanoparticle array method as the method

Self-assembling the block copolymer laminated on the substrate;

Immersing the self-assembled block copolymer in a metal ion solution containing two or more metal ions;

Coupling the metal ion and the metal ion with an electrostatic force in the metal ion solution opposite to the metal ion;

Removing the block copolymer to form an alloy pattern on the substrate; And

And heat-treating the alloy pattern to produce the alloy array.
17. The method of claim 16, wherein the alloy array is in the form of nanodots or nanowires.
18. The method of claim 17, wherein the heat treatment is performed at 650 degrees Celsius or more.
Contacting a solution containing a metal ion with a polymer thin film having a charge opposite to the metal ion in the solution;

Bonding the polymer thin film and metal ions in an electrostatic interaction to deposit metal ions on the polymer substrate; And

Method of producing a metal thin film, characterized in that it comprises the step of removing the polymer substrate.
Contacting a solution containing a metal ion with a polymer substrate comprising a brush charged in the solution opposite to the metal ion in the solution;

Bonding the metal ions to the brush of the polymer by electrostatic interaction, thereby depositing metal ions on the brush; And

And removing the polymer substrate comprising the brush.