阅读说明：本技术 一种表面粗糙的纳米阵列结构的制备方法 (Preparation method of nano array structure with rough surface ) 是由 王雅新 温嘉红 赵晓宇 张永军 于 2020-03-16 设计创作，主要内容包括：本发明涉及复合材料的微纳加工技术领域,公开了一种表面粗糙的纳米阵列结构的制备方法,包括以下步骤：通过自组装的方法制备有序的单层聚苯乙烯微球阵列；利用等离子体刻蚀技术对聚苯乙烯微球阵列进行刻蚀,使聚苯乙烯微球直径缩小；利用离子束轰击技术对刻蚀完成的聚苯乙烯微球阵列进行轰击,使聚苯乙烯微球表面变得粗糙；利用磁控溅射技术在轰击完成的聚苯乙烯微球阵列表面溅射纳米阵列结构材料,即获得表面粗糙的纳米阵列结构。通过本发明的制备方法获得的纳米阵列结构中,各纳米粒子表面粗糙,因而具有比表面积大、活性大、光散射增加的优点,且各纳米粒子体积小,整个纳米阵列结构周期性好,在应用上更具优势。(The invention relates to the technical field of micro-nano processing of composite materials, and discloses a preparation method of a nano array structure with a rough surface, which comprises the following steps: preparing an ordered single-layer polystyrene microsphere array by a self-assembly method; etching the polystyrene microsphere array by using a plasma etching technology to reduce the diameter of the polystyrene microsphere; bombarding the etched polystyrene microsphere array by using an ion beam bombardment technology to roughen the surface of the polystyrene microsphere; and sputtering a nano array structure material on the surface of the bombarded polystyrene microsphere array by utilizing a magnetron sputtering technology to obtain the nano array structure with a rough surface. In the nano array structure obtained by the preparation method, the surface of each nano particle is rough, so that the nano array structure has the advantages of large specific surface area, high activity and increased light scattering, and each nano particle has small volume, and the whole nano array structure has good periodicity and is more advantageous in application.)

1. A preparation method of a nano array structure with a rough surface is characterized by comprising the following steps:

(1) preparing an ordered single-layer polystyrene microsphere array by a self-assembly method;

(2) etching the polystyrene microsphere array prepared in the step (1) by using a plasma etching technology to reduce the diameter of the polystyrene microsphere;

(3) bombarding the polystyrene microsphere array etched in the step (2) by using an ion beam bombardment technology to roughen the surface of the polystyrene microsphere;

(4) and (4) sputtering a nano array structure material on the surface of the polystyrene microsphere array bombarded in the step (3) by utilizing a magnetron sputtering technology to obtain a nano array structure with a rough surface.

2. The method for preparing a nano array structure with a rough surface according to claim 1, wherein the specific steps of the step (1) are as follows:

(1.1) mixing the polystyrene microspheres with an ethanol solution according to a volume ratio of 1: 1-4;

(1.2) dripping the mixed liquid obtained in the step (1.1) onto a hydrophilic silicon wafer, and slowly immersing the silicon wafer into deionized water;

(1.3) after the polystyrene microspheres on the water surface form a single-layer film which is orderly arranged, dripping 1.5-4% of sodium dodecyl sulfate solution to ensure that the polystyrene microspheres are tightly arranged;

and (1.4) slowly taking out the single-layer film by using a hydrophilic silicon wafer, absorbing water and drying to obtain the ordered single-layer polystyrene microsphere array.

3. The method for preparing the nano array structure with the rough surface according to claim 2, wherein the polystyrene microsphere is a modified polystyrene microsphere, and the preparation method comprises the following steps: mixing styrene, acrylic acid, a potassium persulfate solution and deionized water, and reacting under the conditions of heating and stirring to obtain modified polystyrene microsphere emulsion; in the step (1.2), the silicon wafer is slowly immersed into deionized water, and then hydrochloric acid is dripped to make the deionized water acidic.

4. The method for preparing a surface roughness nano array structure as claimed in claim 1, wherein in the step (1), the diameter of the polystyrene microsphere is 400-600 nm.

5. The method for preparing the nano array structure with the rough surface according to claim 4, wherein in the step (2), the diameter of the etched polystyrene microspheres is 300-400 nm, and the gap between adjacent polystyrene microspheres is 100-200 nm.

6. The method for preparing the nano array structure with the rough surface according to claim 5, wherein in the step (2), the etching power is 10-40W, and the etching time is 1-2 min.

7. The method for preparing the nano array structure with the rough surface according to claim 1, wherein in the step (3), the vacuum degree during ion beam bombardment is 2 to 5Pa, the discharge voltage is 60 to 70V, the filament current is 4 to 5A, the acceleration voltage is 200 to 300V, and the bombardment time is 10 to 20 min.

8. The method for preparing the nano array structure with the rough surface according to claim 1, wherein in the step (4), the sputtering power is 50-70W, and the sputtering time is 5-10 s.

9. The method for preparing a nano array structure with a rough surface according to claim 1, wherein in the step (4), the sputtering direction of magnetron sputtering is vertical sputtering; or in the step (4), the sputtering direction of magnetron sputtering is inclined sputtering, and the horizontal deflection angle of the substrate is positioned at 65-75 degrees.

10. The method for preparing a surface-roughened nano array structure according to claim 1, wherein in step (4), the nano array structure material is Au, Ag or TiO₂At least one of (1).

Technical Field

The invention relates to the technical field of micro-nano processing of composite materials, in particular to a preparation method of a nano array structure with a rough surface.

Background

The highly ordered nano array is a nano system which is constructed in two-dimensional or three-dimensional space by using nano particles, nano wires or nano tubes as basic units and adopting physical and chemical methods and the like. The highly ordered nano array structure has the properties of common nano materials, has outstanding quantum effect and has more excellent performance than disordered nano materials. The nano array structure can easily realize the control of the performance of the nano-device through external fields such as electricity, magnetism, light and the like, thereby enabling the nano-array structure to become the basis for designing nano-ultramicro devices. At present, ordered nanostructured materials have begun to find applications in many areas such as perpendicular magnetic recording, microelectrode beams, optoelectronic devices, lubrication, sensors, chemical power supplies, heterogeneous catalysis, Surface Enhanced Raman Scattering (SERS), and the like. Compared with a nano array structure with smooth surfaces of nanoparticles, the nano array structure with the rough surface is widely applied to the fields of Surface Enhanced Raman Scattering (SERS), new energy, nanophotonics and the like due to the characteristics of large specific surface area, high activity, increased light scattering and the like.

For example, Chinese patent document with application number CN201110120345.7 discloses a gold nanostar-based surface enhanced Raman scattering active substrate and a preparation method thereof, comprising the following steps of (1) adding 1M sodium hydroxide aqueous solution to 100M L aqueous solution with concentration of 0.04M N- (2-hydroxyethyl) -piperazine-N' -2 sulfonic acid for adjusting the pH of the system to 7.4, then adding 700L mass-volume ratio aqueous solution of chloroauric acid with concentration of 1%, uniformly mixing, placing in a water bath at 28 ℃ for standing for reaction for 1h, wherein the color of the solution changes from pale yellow to pale pink to purple to blue to triethyl, the solution color is stable and does not change any more to indicate that the reaction is terminated, a star-like gold nanoparticle solution required for assembling the substrate is generated, the solution is characterized under ultraviolet-visible light, the gold-infrared-like nanoparticle solution should have two magnetic force changes, wherein the glass-like gold nanoparticles should have two positive charges, the glass-like nano-array structure should have two positive charges, the glass-like nano-array structure should be prepared by a chemical method, the main process comprises the steps of preparing rough surface-like nanoparticles and assembling into a highly ordered nano-array structure, the highly ordered nano-array structure is prepared by a conventional method of preparing a dry-based on a glass substrate with stirring process, the following steps of adding 2-based on the following steps of adding 1M of N- (2-piperazine-N- (2-piperazine-N- (2) of 2 sulfonic acid aqueous solution, stirring, standing for standing and standing, standing for standing, standing for standing, standing for reaction, the aqueous solution with a 2-piperazine-2 sulfonic acid aqueous solution with concentration of 1-2 sulfonic acid aqueous solution with concentration of 1, standing for reaction, standing for reaction, standing for reaction, the concentration of 1-2-.

In addition, the electrostatic spinning method can also prepare the nano-array structure with rough surface. For example, chinese patent application No. CN201910325424.8 discloses a unidirectional electrospun three-dimensional raman-enhanced substrate, a method for preparing the same, and applications of the same, wherein the method for preparing the same comprises the following steps: mixing the silver colloid solution and a polyvinyl alcohol aqueous solution, preparing a polyvinyl alcohol silver nanoparticle spinning substrate by an electrostatic spinning method, and depositing silver nanoparticles on the surface of the PVA @ Ag nanofibres spinning substrate by a thermal evaporation method to obtain a polyvinyl alcohol silver nanoparticle/silver nanoparticle Raman enhanced substrate. The nano array with the rough surface is prepared by the electrostatic spinning and evaporation method, the arrangement periodicity among all fibers in a spinning substrate is poor, and the size of each fiber structure is large, which can affect the properties and the application of the nano array structure.

Disclosure of Invention

In order to solve the technical problems, the invention provides a preparation method of a nano array structure with a rough surface. In the nano array structure obtained by the preparation method, the surface of each nano particle is rough, so that the nano array structure has the advantages of large specific surface area, high activity and increased light scattering, and each nano particle has small volume, and the whole nano array structure has good periodicity and is more advantageous in application.

The specific technical scheme of the invention is as follows:

a preparation method of a nano array structure with a rough surface comprises the following steps:

(1) preparing an ordered single-layer polystyrene microsphere array by a self-assembly method; 6 polystyrene microspheres are uniformly distributed around each polystyrene microsphere in the polystyrene microsphere array;

(2) etching the polystyrene microsphere array prepared in the step (1) by using a plasma etching technology to reduce the diameter of the polystyrene microsphere;

(3) bombarding the polystyrene microsphere array etched in the step (2) by using an ion beam bombardment technology to roughen the surface of the polystyrene microsphere;

(4) and (4) sputtering a nano array structure material on the surface of the polystyrene microsphere array bombarded in the step (3) by utilizing a magnetron sputtering technology to obtain a nano array structure with a rough surface.

The preparation method of the invention firstly leads the polystyrene microspheres to self-assemble to form an ordered hexagonal close-packed array, namely a monolayer array with 6 microspheres uniformly distributed around each microsphere. And then etching the polystyrene microspheres by a plasma etching technology to reduce the volume of the polystyrene microspheres and reserve a space for the subsequent sputtering of the nano array material. Plasma etching is carried out by activating reactive gas into active particles, such as atoms or radicals, by high-frequency glow discharge reaction, and the active particles are diffused to the part to be etched, and react with the etched material to form volatile reactant to be removed. The etching method has the advantages of high etching rate and good uniformity. After the etching is finished, holes and gully-shaped fluctuation are formed on the surface of the polystyrene microsphere through an ion beam bombardment technology, and the polystyrene microsphere keeps the shape after the bombardment is finished. And then sputtering the nano array structure material on the rough surface of the polystyrene microsphere by a magnetron sputtering technology. The magnetron sputtering technology establishes a magnetic field orthogonal to the electric field on the surface of the target material, and the ionization rate of argon is improved, so that the deposition rate of sputtering coating is higher; and by accurately controlling the size of the magnetic field and the electric field, the compactness and uniformity of the magnetron sputtering film formation are better, and the sputtering thickness on each polystyrene microsphere in a large-area array can be ensured to be similar.

In the nano array structure obtained by the preparation method, the surface of each nano particle is rough, compared with the nano array structure with a smooth surface, the nano array structure has the characteristics of large specific surface area, high activity, increased light scattering and the like, and has more advantages when being applied to the fields of SERS, new energy, nanophotonics and the like.

In addition, compared with the nano array structure with rough surface prepared by a chemical method and an electrostatic spinning method in the prior art, in the nano array structure obtained by the preparation method, all the nano particles are arranged into an ordered single-layer array, and 6 nano particles are uniformly distributed around each nano particle, so that the whole nano array structure has good periodicity, and the nano array structure has more advantages in application, such as: for the SERS substrate, when the metal nanoparticles are organized into a dense arrangement, hot spots on a specific surface are increased so as to provide additional Raman enhancement, and the nano array with good periodicity has better SERS enhancement effect, so that the sensitivity of SERS detection can be improved; moreover, due to good periodicity, the signal intensity detected at each position of the substrate is similar, so that the accuracy and the repeatability of SERS detection can be improved. In addition to the advantage of good periodicity, the nano-array structure obtained by the preparation method of the present invention has smaller volume of nano-particles compared to the nano-array structure with rough surface prepared by the electrostatic spinning method, and is also beneficial to the application thereof, for example: when the SERS substrate is used as the SERS substrate, gaps are more in a laser irradiation range, so that the area of a hot spot is larger, a Raman scattering signal is stronger, and the sensitivity of SERS detection is higher.

Preferably, the specific steps of step (1) are as follows:

(1.1) mixing the polystyrene microspheres with an ethanol solution according to a volume ratio of 1: 1-4;

(1.2) dripping the mixed liquid obtained in the step (1.1) onto a hydrophilic silicon wafer, and slowly immersing the silicon wafer into deionized water;

(1.3) after the polystyrene microspheres on the water surface form a single-layer film which is orderly arranged, dripping 1.5-4% of sodium dodecyl sulfate solution to ensure that the polystyrene microspheres are tightly arranged;

and (1.4) slowly taking out the single-layer film by using a hydrophilic silicon wafer, absorbing water and drying to obtain the ordered single-layer polystyrene microsphere array.

In the step (1.1), the volume ratio of the polystyrene microspheres to the ethanol solution is controlled, so that the self-assembly can be controlled to form an ordered single-layer polystyrene microsphere array, and 6 polystyrene microspheres are uniformly distributed around each polystyrene microsphere.

Preferably, the polystyrene microsphere is a modified polystyrene microsphere, and the preparation method comprises the following steps: mixing styrene, acrylic acid, a potassium persulfate solution and deionized water, and reacting under the conditions of heating and stirring to obtain modified polystyrene microsphere emulsion; in the step (1.2), the silicon wafer is slowly immersed into deionized water, and then hydrochloric acid is dripped to make the deionized water acidic.

The surface of the polystyrene microsphere is carboxylated through modification, and hydrogen bonds can be formed between carboxyl groups of adjacent polystyrene microspheres in the self-assembly process, so that the polystyrene microspheres are arranged on the water surface more closely and orderly.

The method for preparing the modified polystyrene microsphere takes potassium persulfate as an initiator, deionized water as a dispersion medium and styrene and acrylic acid as monomers, and adopts a soap-free emulsion polymerization method to copolymerize the styrene and the acrylic acid, so as to obtain the modified polystyrene microsphere with carboxyl on the surface. In the preparation process, the relative dosage of the styrene, the acrylic acid and the initiator, the reaction temperature and the stirring speed are slightly higher than those of the finally prepared modified polystyreneThe particle size of the spheres has an important influence. Acrylic acid is used as a monomer to participate in copolymerization reaction and provide carboxyl for the polystyrene microsphere; the addition of acrylic acid increases the solubility of the oligomer in water, which results in a longer nucleation time and thus an increased particle size of the finally produced microspheres. Decomposition of initiator to produce SO₄ ^2-Initiating polymerization reaction, and distributing the polymerization reaction on the surface of the microsphere as the end group of a polymer chain, so that electrostatic repulsion exists between the microspheres, and the polystyrene microspheres stably exist in the emulsion; through a large number of experiments, the increase of the dosage of the initiator is beneficial to the growth of the microspheres with small particle size, but the excessive dosage can cause the reduction of the particle size. The reaction temperature affects the particle size of the microspheres by affecting the rate of decomposition of the initiator. The agitation causes the monomer droplets to be sheared and then each monomer droplet forms a polystyrene microsphere, so the larger the agitation rate, the smaller the microsphere size. After a large number of experiments, the inventor sets the volume ratio of the styrene solution to the acrylic acid solution to the potassium persulfate solution to be 1: 0.7-0.8: 0.01-0.015, sets the concentration of the potassium persulfate solution to be 0.1-0.2%, sets the temperature to be 50-60 ℃, sets the mechanical stirring speed to be 50-100 r/s, and can prepare the modified polystyrene microspheres with the particle size of 400-600 nm under the condition.

When the polystyrene microspheres are self-assembled on a water surface, hydrochloric acid is dripped to enable the liquid to become acidic, negative charges carried by the polystyrene microspheres can be neutralized, carboxylate ions and sulfate ions used as polymer chain end groups are introduced after modification, so that electrostatic repulsion among the microspheres is reduced, hydrogen bonds are formed among carboxyl groups of adjacent microspheres, and the microspheres are self-assembled to form a compact and ordered array structure.

Preferably, in the step (1), the polystyrene microspheres have a diameter of 400-600 nm.

Preferably, in the step (2), the diameter of the etched polystyrene microspheres is 300-400 nm, and the gaps between adjacent polystyrene microspheres are 100-200 nm.

Preferably, in the step (2), the etching power is 10-40W, and the etching time is 1-2 min.

Preferably, in the step (3), the vacuum degree during ion beam bombardment is 2-5 Pa, the discharge voltage is 60-70V, the filament current is 4-5A, the acceleration voltage is 200-300V, and the bombardment time is 10-20 min.

Preferably, in the step (4), the sputtering power is 50-70W, and the sputtering time is 5-10 min.

Preferably, in the step (4), the sputtering direction of magnetron sputtering is vertical sputtering; or in the step (4), the sputtering direction of magnetron sputtering is inclined sputtering, and the horizontal deflection angle of the substrate is positioned at 65-75 degrees.

Preferably, in the step (4), the nano-array structure material is Au, Ag, TiO₂At least one of (1).

Compared with the prior art, the invention has the following advantages:

(1) in the nano array structure obtained by the preparation method, the surface of each nano particle is rough, so that the nano array structure has the advantages of large specific surface area, high activity and increased light scattering, and is beneficial to application;

(2) in the nano array structure obtained by the preparation method, each nano particle has smaller volume, and the whole nano array structure has good periodicity, thereby being beneficial to the application of the nano array structure.

Drawings

FIG. 1 is a scanning electron microscope photograph of the nanostructure array prepared in example 1 at a magnification of 10000 ×;

FIG. 2 is a scanning electron microscope photograph of the array of rough-surfaced polystyrene microspheres prepared in example 1 at a magnification of 10000 ×;

FIG. 3 is a scanning electron microscope photograph of the nanostructure array prepared in example 1 at 50000 × magnification;

FIG. 4 is a scanning electron microscope photograph of the nanostructure array prepared in example 2 at a magnification of 10000 ×;

FIG. 5 is a scanning electron microscope photograph of the nanostructure array prepared in example 3 at a magnification of 10000 ×;

FIG. 6 is a scanning electron microscope photograph of the nanostructure array prepared in example 4, at a magnification of 10000 ×.

Detailed Description

The present invention will be further described with reference to the following examples.

General examples

A preparation method of a nano array structure with a rough surface comprises the following steps:

(1) the method for preparing the ordered single-layer polystyrene microsphere array by the self-assembly method comprises the following specific steps:

(1.1) mixing polystyrene microspheres with the diameter of 400-600 nm with an ethanol solution according to a volume ratio of 1: 1-4;

(1.2) dripping the mixed liquid obtained in the step (1.1) onto a hydrophilic silicon wafer, and slowly immersing the silicon wafer into deionized water;

(1.3) after the polystyrene microspheres on the water surface form a single-layer film which is orderly arranged, dripping 1.5-4% of sodium dodecyl sulfate solution to ensure that the polystyrene microspheres are tightly arranged;

and (1.4) slowly taking out the single-layer film by using a hydrophilic silicon wafer, absorbing water and drying to obtain the ordered single-layer polystyrene microsphere array.

(2) Etching the polystyrene microsphere array prepared in the step (1) by using a plasma etching technology, wherein the etching gas is a mixed gas of 80% of oxygen and 20% of argon, the etching power is 10-40W, and the etching time is 1-2 min, so that the diameter of the polystyrene microsphere is reduced to 300-400 nm;

(3) bombarding the polystyrene microsphere array etched in the step (2) by using an ion beam bombardment technology, wherein the vacuum degree during bombardment is 2-5 Pa, the discharge voltage is 60-70V, the filament current is 4-5A, the acceleration voltage is 200-300V, and the bombardment time is 10-20 min, so that the surface of the polystyrene microsphere becomes rough, and the obtained polystyrene microsphere array with the rough surface is obtained;

(4) sputtering Au, Ag and TiO on the surface of the polystyrene microsphere array bombarded in the step (3) by utilizing a magnetron sputtering technology₂To obtain a rough surface nanoarray structure by loading the target onto a magnetic target in a magnetron sputtering chamber at a background gas pressure of less than 1.0 × 10 before starting^-6Pa, target material andthe distance between the sample substrates is kept at 15-20 cm, the sputtering direction is vertical sputtering or inclined sputtering (the horizontal deflection angle of the substrate is positioned at 65-75 degrees), the sputtering power is 50-70W, and the sputtering time is 5-10 s.

Optionally, the polystyrene microspheres are modified polystyrene microspheres; in the step (1.2), slowly immersing the silicon wafer into deionized water, and then dropwise adding hydrochloric acid to make the deionized water acidic; the preparation method of the modified polystyrene microsphere comprises the following steps: mixing styrene, acrylic acid, a potassium persulfate solution and deionized water, wherein the volume ratio of the styrene to the acrylic acid to the potassium persulfate solution is 1: 0.7-0.8: 0.01-0.015, the concentration of the potassium persulfate solution is 0.1-0.2%, mechanically stirring at the rotating speed of 50-100 r/s, and reacting for 10-12 h at the temperature of 50-60 ℃ to obtain the modified polystyrene microsphere emulsion.