A method for adjusting the ordered arrangement of single-layer nanomicrosphere array by using continuous acoustic waves

Abstract

The present application belongs to the technical field of micro-nano structure preparation, and particularly relates to a method for adjusting ordered arrangement of single-layer nano microsphere array by using continuous sound waves. The method comprises the following steps: S1. washing a substrate and performing hydrophilic treatment; S2. preliminarily forming a single-layer film array by self-assembly of nano microsphere suspension liquid through a gas-liquid interface; S3. adjusting the single-layer film array of nano microspheres prepared in step S2 by using continuous sound waves, so that the single-layer film array presents ordered arrangement; and S4. gathering the ordered microsphere array prepared in step S3 and transferring the ordered microsphere array to the substrate treated in step S1, and evaporating residual water of the sample. The present application can improve the ordered degree of arrangement of the nano microsphere array, solves the problems of defects in the array formed by the traditional preparation method and the problem that the unequal spacing between units cannot be independently changed, provides a brand-new reference scheme for preparation of large-area ordered array by nanosphere lithography technology, and brings a new breakthrough for NSL technology.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of micro-nano structure preparation, and particularly relates to a method for adjusting ordered arrangement of single-layer nano microsphere array by using continuous sound waves. BACKGROUND

[0002] Nanosphere lithography (NSL) is a simple, economical and effective lithography technology, which uses highly monodisperse nanospheres as deposition or etching masks to obtain nanoarrays with controllable morphology and size by combining physical or chemical deposition methods. NSL technology is a cheap method for rapidly preparing nano surfaces in the laboratory, and has been widely used in many fields due to its high throughput, low cost, parallel process design and suitability for various substrates. The current NSL technology usually uses a monolayer film of hexagonally close-packed nanometer to micrometer polystyrene (PS) microspheres, silica (SiO2) latex spheres or polymethyl methacrylate (PMMA) microspheres as a template.

[0003] It is a great challenge to prepare a high-quality monolayer microsphere array film. The traditional method for preparing a monolayer microsphere film has some shortcomings: 1) multiple layers of microsphere molecules are generated on the monolayer microsphere film due to molecular stacking; 2) different crystal orientations are generated between some microspheres during the film preparation due to external force interference, thereby causing layer dislocation cracks in the film array; 3) the monolayer microsphere array film only has short-range order but no long-range order; 4) free single-molecule microspheres and holes are formed due to the failure to participate in the self-assembly process. However, the existing preparation technology can only optimize the above problems by carefully controlling the flow rate of the microsphere solution. But for the traditional film forming method, these problems always exist due to the absence of an ideal experimental environment, so it is difficult for the NSL method to manufacture an array with "low defect density", and it is difficult to further improve the quality of the nanoarray after the film is formed. SUMMARY

[0004] In view of the shortcomings of the prior art, the present application aims to provide a method for adjusting ordered arrangement of single-layer nano microsphere array by using continuous sound waves, which solves the defect problems of the traditional method for preparing a monolayer microsphere array film. The present application solves the problem of irregular arrangement of microsphere array in microcosm by using macroscopic method and automatic means. The present application explores the influence of continuous sound waves with a frequency of 20 Hz to 20,000 Hz and a sound pressure level of 80 dB to 120 dB on the arrangement of molecular array, and finds that different sizes of nano microspheres have the best continuous sound waves for promoting their regular arrangement.

[0005] To achieve the above object, the present application provides the following technical scheme:

[0006] A method for adjusting the ordered arrangement of single-layer nanometer microsphere array by using continuous sound waves, comprising the following steps:

[0007] S1. cleaning the substrate and performing hydrophilic treatment;

[0008] S2. forming a single-layer film array by self-assembly of microsphere suspension through the gas-liquid interface;

[0009] S3. adjusting the single-layer film array prepared in step S2 by using continuous sound waves to make it present ordered arrangement;

[0010] S4. transferring the ordered arrangement single-layer film array prepared in step S3 to the substrate treated in step S1 and evaporating the residual water of the sample.

[0011] As a preferred technical solution of the present application, the substrate in step S1 is a water-stable substrate, including silicon wafer, quartz wafer and glass wafer, the cleaning step is ultrasonic water bath cleaning using anhydrous ethanol and deionized water, and the hydrophilic treatment uses a plasma cleaning machine.

[0012] Preferably, the diameter of the microspheres in step S2 is 100 nm-10 μm, including polystyrene microspheres, silica latex spheres and polymethyl methacrylate microspheres.

[0013] Preferably, the frequency of the continuous sound waves in step S3 is 20 HZ-2 MHZ, the sound intensity is 0 dB to 130 dB, and the working time is 1 min-10 h.

[0014] Meanwhile, when using the continuous sound wave generating device, the process of propagating sound should be clean and dust-free to protect the microsphere array from being polluted by external impurities.

[0015] Preferably, the ordered arrangement single-layer film array in step S4 is gathered by the method of adding surface active agent before being transferred.

[0016] Further preferably, the surface active agent is triglyceride or sodium dodecyl sulfate.

[0017] The purpose of adding surface active agent in the present application is to gather the microsphere array to the center to facilitate the transfer of the array to the substrate, and the surface active agent needs to be added frequently and repeatedly around the microsphere array until the microsphere array is gathered.

[0018] Preferably, the method of transferring the array in step S4 is deposition or sheet fishing.

[0019] Preferably, the evaporation operation in step S4 uses a constant temperature heating device, and the heating temperature is 20-80℃.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] (1) The application solves the problems of point defects and dislocations in the process of preparing a single-layer microsphere array film by the traditional NSL method, reduces the defect density of the microsphere array, makes the microsphere array ordered and compact through mechanical force, and makes large-area ordered microsphere array arrangement possible, and optimizes the long-range order of the microsphere array.

[0022] (2) The method acts on the traditional gas-liquid interface self-assembly method, optimizes the self-assembly method, and can effectively adjust the array of microspheres of different sizes to promote their regular arrangement.

[0023] (3) The device is low in price and cost, simple in operation, low in requirements for experimental environment and experimental conditions, solves scientific problems by using electronic design automation, better utilizes resources and saves human resources. The device and operation process use automatic technology, can guarantee the consistency of each running result and execution content, and greatly reduce the error compared with manual operation. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a preparation flowchart of the application.

[0025] Figure 2 is a SEM picture of the defect of the PS microsphere array film prepared by the traditional method of Comparative Example 1.

[0026] Figure 3 is a comparison chart of the PS single-layer film prepared by Comparative Example 1 and the PS single-layer film treated by various different frequency continuous sound waves for 5 hours.

[0027] Figure 4 is a UV transmission chart of the PS film glass sheet sample treated by sound waves of different frequencies and a sound intensity of 100 dB.

[0028] Figure 5 is a UV transmission chart of the PS film glass sheet sample treated by sound waves of different frequencies and a sound intensity of 105 dB.

[0029] Figure 6 is a UV transmission chart of the PS film glass sheet sample treated by sound waves of different sound intensities and a frequency of 50 Hz.

[0030] Figure 7These are SEM images of various PS films, with the top left corner showing the result of a Fast Fourier Transform (FFT). a) is an 800nm ​​PS monolayer film without any processing; b) is an 800nm ​​PS film after 5 hours of 20Hz, 100dB acoustic wave processing; c) is an 800nm ​​PS film after 5 hours of 50Hz, 100dB acoustic wave processing; d) is an 800nm ​​PS film after 5 hours of 1kHz, 100dB acoustic wave processing; e) is an 800nm ​​PS film after 5 hours of 5kHz, 100dB acoustic wave processing; f) is an 800nm ​​PS film after 5 hours of 10kHz, 100dB acoustic wave processing; g) is a 500nm PS film after 5 hours of 1kHz, 100dB acoustic wave processing; h) is a 500nm PS film after 5 hours of 50Hz, 100dB acoustic wave processing.

[0031] Figure 8 It is a microsphere monolayer film array structure with ideal effect after acoustic wave processing. Detailed Implementation

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments of the present invention, preparation is carried out according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used where the manufacturer is not specified are all conventional products that can be purchased commercially.

[0033] Example 1

[0034] A method for adjusting the ordered arrangement of a monolayer nanosphere array using continuous acoustic waves includes the following steps:

[0035] 1) Substrate cleaning and hydrophilic treatment: First, cut the silicon wafer into 2cm*2cm pieces and clean it with acetone, isopropanol, anhydrous ethanol, and deionized water in sequence for 10 minutes each. After drying, put the silicon wafer into a plasma cleaner, adjust the power parameters to 30W, the environmental parameters to air environment, and the flow rate to 10sccm. After completing the settings, start vacuuming. When the pressure is less than or equal to 38Pa, turn on the cleaning switch for 10 minutes and then turn it off. Open the air inlet, open the chamber door, take out the substrate, and put it into the sample box for sealed storage.

[0036] 2) PS microsphere array preparation: Wash a 30 cm diameter petri dish and fill it with deionized water, place the cleaned substrate at the bottom of the petri dish and let it stand for 10 minutes. Prepare a 800 nm PS solution (volume ratio of PS ball original solution: 1% H2SO4: 1% styrene: anhydrous ethanol = 300: 300: 10: 300), ultrasonic oscillation for 1 min, use a syringe with a maximum capacity of 1 mL to extract more than 700 μL of PS ball solution, put a specially designed curved metal needle on the syringe, keep the needle upwards and slowly put it into the middle of the petri dish, until the bend just touches the liquid surface, set the injection pump injection flow rate to 40 μL / min, transmission flow to 700 μL, use the injection pump to inject the solution at a constant speed to the liquid surface.

[0037] 3) Load audio file: Open the Tone Generator software, which is a web file downloaded from Github, enter the frequency of the sound wave you want to generate in the text box that pops up when you open the software, select the type of audio you want, send the software generated file to the memory card, and then insert the memory card into the player module. Use a USB power supply or a 5V battery to power the player module.

[0038] 4) Set the intensity of the sound wave: The MP3 module output is connected to the power amplifier OPA549 voltage control module, and the speaker is connected to the power amplifier output. Two external voltage stabilizers with maximum voltage greater than ±12V are connected to the power supply of the power amplifier. By adjusting the output voltage of the two external voltage stabilizers, the output power of the speaker can be controlled, thereby controlling the intensity of the sound wave. Place the speaker on the resin printed bracket to concentrate the sound wave energy and prevent external dust and impurities from contaminating the PS ball array.

[0039] 5) Experiment timing: Connect a delay relay in series to the power amplifier output. Use the timer function of the relay to set the experiment duration. Press the set key to open the interface, select P18 to enter the countdown mode, press the set key twice to set the experiment duration (in minutes), set the duration to 300 minutes, press the set key twice to exit the interface. After restarting the relay, the relay starts timing.

[0040] 6) Extract the sample: Use a pair of tweezers dipped in a surfactant called glycerol triester to draw a circle around the PS film, causing the PS film to gather in the center. Then use a syringe to slowly extract the excess water in the petri dish. During the extraction process, frequently add surfactant to the PS film to allow the PS film to deposit on the substrate at the bottom of the petri dish.

[0041] 7) Evaporate the sample: Use an infrared lamp to adjust the height above the sample to heat it to a constant temperature of 30 to 38°C to evaporate the sample and the residual water around the substrate. Remove the substrate sample containing the microsphere array and store it in a low-temperature, light-free environment.

[0042] Comparative Example 1

[0043] Comparative Example 1 and Example 1 are different in that steps 3-5 are not performed, and other preparation steps and conditions are the same as Example 1, which are not repeated here.

[0044] In order to further illustrate the technical effects achieved by the preparation method of the present application, the prepared samples of the examples and comparative examples are detected.

[0045] Morphology characterization and performance test

[0046] Figure 2 The SEM picture of the PS microsphere array film prepared by Comparative Example 1 can be seen to have defects in the traditional preparation method: a) is a multi-layer or even stacked nanosphere array, b) is a crack produced by dislocation of the nanosphere array and a point defect in the array, c) is a nanosphere array with only short-range order, and d) is a nanosphere that is free or separated from the array structure.

[0047] Figure 3 The macroscopic comparison chart of the PS monolayer film picture prepared by Comparative Example 1 and the PS monolayer film picture after treatment by various different frequency continuous acoustic waves for 5 hours shows that the appearance of the PS film has changed after acoustic wave treatment.

[0048] From Figure 4 The image results of the UV transmission test of the PS film glass sheet samples treated by different frequency acoustic waves with a sound intensity of 100 dB show that the transmission wavelength is from 1200 nm to 250 nm, and the chart shows that the UV transmission curve is an important measure to evaluate the quality of the PS film (two-dimensional optical crystal structure). The deeper the absorption peak, the thinner the shape of the absorption peak (slim), which proves that the better the quality of the PS film. Because the curve of 1000 Hz / 100 dB has the thinnest and deepest absorption peak relative to other curves, it can be seen that the treatment effect of 1000 Hz acoustic wave is optimal.

[0049] From Figure 5 The image results of the UV transmission test of the PS film glass sheet samples treated by different frequency acoustic waves with a sound intensity of 105 dB show that the transmission wavelength is from 1200 nm to 250 nm, and the results show that the treatment effect of 1000 Hz acoustic wave is optimal.

[0050] Figure 6 The image results of the UV transmission test of the PS film glass sheet samples treated by different sound intensity acoustic waves with a frequency of 50 Hz show that the transmission wavelength is from 1200 nm to 250 nm, and the chart shows that the treatment effect of 100 dB acoustic wave is optimal.

[0051] Figure 7are SEM images of various PS films, the upper left corner of which is the result of fast Fourier transform (FFT) of the image. a) is an 800 nm PS monolayer film without any treatment, b) is an 800 nm PS film treated by 20HZ, 100dB sound wave for 5 hours, c) is an 800 nm PS film treated by 50HZ, 100dB sound wave for 5 hours, d) is an 800 nm PS film treated by 1kHZ, 100dB sound wave for 5 hours, e) is an 800 nm PS film treated by 5kHZ, 100dB sound wave for 5 hours, f) is an 800 nm PS film treated by 10kHZ, 100dB sound wave for 5 hours. g) is a 500 nm PS film treated by 1kHZ, 100dB sound wave for 5 hours. h) is a 500 nm PS film treated by 50HZ, 100dB sound wave for 5 hours.

[0052] The SEM images show that the more regular the arrangement of the PS spheres is, the better the quality of the PS film array is, and the FFT image will tend to be a regular hexagon; on the contrary, the more disordered the arrangement of the PS spheres is, the worse the quality of the PS film is, and the FFT image will tend to be a circle.

[0053] Figure 8 is a nano-microsphere monolayer film array structure with ideal sound wave adjustment effect. The purpose of the present application is to prepare as large an area of regular ideal monolayer film array as possible through sound wave adjustment.

[0054] The above detailed the embodiments of the present application, but the present application is not limited to the described embodiments. For those skilled in the art, various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and spirits of the present application, and still fall within the protection scope of the present application.

Claims

1. A method for adjusting the ordered arrangement of a monolayer nanosphere array using continuous acoustic waves, characterized in that, Includes the following steps: S1. Clean the substrate and perform hydrophilic treatment; S2. The microsphere suspension is initially formed into a monolayer membrane array through self-assembly at the gas-liquid interface; S3. The monolayer film array prepared in step S2 is adjusted by continuous acoustic wave to make it present an ordered arrangement; S4. The ordered monolayer film array prepared in step S3 is aggregated by adding a surfactant, and then transferred to the substrate treated in step S1 to evaporate the residual moisture in the sample. The continuous sound wave frequency in step S3 is 20Hz-10000Hz, the sound intensity is 80dB-120dB, and the working time is 1min-10h. The process of acquiring the continuous sound wave is as follows: (1) Load audio files: Open the Tone Generator software, which is a web file downloaded from Github. Enter the frequency of the sound wave to be generated in the text box that pops up in the software, select the desired audio type, send the generated file to the memory card, insert the memory card into the player module, and power on the player module using a USB power cable or a 5V battery. (2) Setting the sound intensity: Connect the power amplifier OPA549 voltage control module to the output end of the MP3 module, connect the speaker to the output end of the power amplifier, connect two external regulated power supplies with a maximum voltage greater than ±12 V to the power supply end of the power amplifier, and adjust the output voltage of these two external regulated power supplies to control the output power of the speaker, thereby controlling the sound intensity. Place the speaker on the resin-printed bracket to concentrate the sound energy and prevent external dust and impurities from contaminating the PS ball array.

2. The method for adjusting the ordered arrangement of a single-layer nanosphere array using continuous acoustic waves according to claim 1, characterized in that, The substrate mentioned in step S1 is a water-stable substrate, including silicon wafers, quartz wafers, and glass wafers. The cleaning step involves ultrasonic water bath cleaning with anhydrous ethanol and deionized water, and the hydrophilic treatment uses a plasma cleaner.

3. The method for adjusting the ordered arrangement of a single-layer nanosphere array using continuous acoustic waves according to claim 1, characterized in that, The microspheres mentioned in step S2 have a diameter of 100 nm to 10 μm and include polystyrene microspheres, silica latex spheres and polymethyl methacrylate microspheres.

4. The method for adjusting the ordered arrangement of a single-layer nanosphere array using continuous acoustic waves according to claim 1, characterized in that, The surfactant is triglyceride or sodium dodecyl sulfate.

5. The method for adjusting the ordered arrangement of a single-layer nanosphere array using continuous acoustic waves according to claim 1, characterized in that, The transfer method in step S4 is either deposition or retrieval.

6. The method for adjusting the ordered arrangement of a single-layer nanosphere array using continuous acoustic waves according to claim 1, characterized in that, The evaporation step in step S4 uses a constant temperature heating device with a heating temperature of 20-80℃.

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