CN111593411B

CN111593411B - Large-area ordered PS microsphere single-layer colloidal crystal and preparation method thereof

Info

Publication number: CN111593411B
Application number: CN202010430669.XA
Authority: CN
Inventors: 罗志; 罗谱强; 胡志伟
Original assignee: Jinan University
Current assignee: Jinan University
Priority date: 2020-05-20
Filing date: 2020-05-20
Publication date: 2021-07-27
Anticipated expiration: 2040-05-20
Also published as: CN111593411A

Abstract

The invention discloses a large-area ordered PS microsphere monolayer colloidal crystal and a preparation method thereof, and the invention discloses a method for arranging nanoscale colloidal microspheres on any substrate into hexagonal close-packed monolayer colloidal crystals by in-situ annealing of self-assembled monolayer colloids by using organic solvent molecules and combining a flow control deposition technology. The large-area ordered PS microsphere single-layer colloidal crystal prepared by the method has the advantages that the PS microspheres are orderly arranged in a hexagonal close-packed mode to form a colloidal sphere single-layer structure, the PS microspheres are uniformly spaced, and the quality is high.

Description

Large-area ordered PS microsphere single-layer colloidal crystal and preparation method thereof

Technical Field

The invention belongs to the technical field of colloidal crystals, and particularly relates to a large-area ordered PS microsphere single-layer colloidal crystal and a preparation method thereof.

Background

The colloidal crystal is a two-dimensional or three-dimensional ordered structure formed by assembling monodisperse colloidal particles or microspheres, is often used as a template to prepare various ordered porous materials, and becomes a common method for preparing photonic crystals. The single-layer (two-dimensional) colloidal crystal plays a role as an efficient and universal template in the technical fields of surface patterning such as two-dimensional nanostructure pattern design, colloidal lithography, micro-nano processing and the like. In addition, the colloidal crystal has special optical diffraction characteristics and a photon forbidden band in a visible light range, so that the colloidal crystal can be used for preparing photoelectric conversion devices, chemical and biological sensors, optical integrated chips and the like. The colloidal crystal can also be used as a visual model system for researching important basic scientific problems such as nucleation and growth of the crystal. Colloidal crystals have such a wide range of applications and scientific research value that have attracted a great deal of attention from researchers.

Many methods for preparing colloidal crystals have been studied and developed over the years. Common methods for preparing the monolayer colloidal crystal mainly comprise a vertical deposition method, an electrophoretic deposition method, a Langmuir-Blodgett (LB) technology and an annealing gas-liquid interface self-assembly method. The vertical deposition method is simple and convenient to operate, but is easily interfered by environmental factors, so that the prepared Colloidal film has a plurality of defects, the preparation period is long, and the problem that large-size Colloidal spheres are easy to settle exists, see Jiang, P, Bertone, J.F, Hwang, K.S, et al, Single-crystalline Colloidal spheres of Controlled Thickness [ J ] Chemistry of Materials,11(8): 2132-; the electrophoretic deposition method has a short preparation period, and the prepared colloidal crystals have high quality, but requires that the surface of the colloidal microspheres have a considerable amount of charges and the deposition substrate has good electrical conductivity, and the intensity of the electric field also needs to be precisely controlled, and the preparation conditions are costly, see A. Black. Large-scale synthesis of silicon photonic crystal with a complex-crystal-based cathode and gap near 1[ J ] Nature,2000,405(6785): 437-440; the Langmuir-Blodgett (LB) technology is one of gas-liquid interface self-assembly, is effective for preparing ordered monolayer films, but needs to precisely control the film pressure and other parameters during assembly, has low preparation efficiency, can only prepare one sample at a time, and can cause the generation of new uncontrollable defects such as dislocation of colloidal crystal monolayers in the transferring and drying process due to the combined action of evaporation induction force and capillary force, so that large-area ordered colloidal crystal monolayers are difficult to obtain, see Reculus S, ravine S.Synthesis of colloidal crystals of controllable colloidal crystals technique of chemistry of Materials,2003,15(2): 598-; the Annealing gas-liquid Interface Self-Assembly method improves the mechanical strength of the microsphere membrane to a certain extent, but when the microsphere membrane is transferred in a manual hand-held mode, the gas-liquid Interface is affected by disturbance and other human factors, the orderliness of the single-layer membrane is damaged, only one sample can be prepared at one time, the Preparation efficiency is low, and therefore large-area ordered single-layer Colloidal crystals cannot be prepared in batches, see the literature Preparation of High-Quality Colloidal Mask for nanospheresis by a Combination of Air/Water Interface Self-Assembly and Solvent Vapor analysis. Therefore, how to rapidly prepare large-area ordered single-layer colloidal crystals in batches while reducing the production cost so as to be industrialized is a problem which is urgently needed to be solved at present.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide a method for preparing large-area ordered PS microsphere monolayer colloidal crystals, which is a method for arranging nanoscale colloidal microspheres on any substrate into hexagonal close-packed monolayer colloidal crystals by carrying out in-situ annealing on self-assembled monolayer colloids by using organic solvent molecules and combining a flow control deposition technology. The method reduces the production cost and simultaneously ensures the quality and the preparation efficiency of the single-layer colloidal crystal, thereby realizing industrial production.

The second purpose of the invention is to provide a large-area ordered PS microsphere monolayer colloidal crystal.

The primary purpose of the invention is realized by the following technical scheme:

a preparation method of large-area ordered PS microsphere monolayer colloidal crystals comprises the following steps:

(1) preparing a PS microsphere emulsion: according to the mass-volume ratio of 0.05 g: preparing PS microsphere powder and an ethanol aqueous solution by 5ml, dispersing the PS microsphere powder in an ethanol-water mixed solution with the volume ratio of 1:1, and carrying out ultrasonic oscillation to prepare PS microsphere emulsion;

(2) placing the bearing base station in the center of the culture dish, laying the glass sheet subjected to hydrophilic treatment on the bearing base station, wherein the glass sheet is a first glass sheet, placing another glass sheet in the middle of the bearing platform to serve as a PS microsphere dispersion base station, the glass sheet is a second glass sheet, and at the moment, a flow controller connected with the culture dish is in a closed state;

(3) slowly injecting deionized water into the culture dish until the liquid level is exactly equal to the upper surface of the second glass sheet, sucking the PS microsphere emulsion in the step (1) and dropwise adding on the glass sheet, and continuously dropwise adding after the emulsion is diffused to the liquid level until the liquid level is basically paved with PS microspheres;

(4) dripping a plurality of drops of emulsifier solution into the culture dish to ensure that the PS microspheres are arranged more closely, and then continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically equal;

(5) slowly moving the glass cover filled with organic solvent steam to the culture dish, covering the glass cover, annealing, and removing the glass cover after annealing for a period of time;

(6) and opening a switch of the flow controller, controlling the flow rate of the flow controller, and after the liquid level in the culture dish falls to the position of the lower edge of the bearing table, depositing the PS microsphere film on the glass sheet, taking out the bearing base table, and naturally airing to obtain a large amount of single-layer PS microsphere colloidal crystals taking the glass sheet as the substrate.

Preferably, the particle size of the PS microsphere powder in the step (1) is 406-872 nm.

Preferably, the time of the ultrasonic oscillation in the step (1) is 30-60 s.

Preferably, the glass sheet, the culture dish and the bearing base platform in the step (2) are soaked in the piranha solution for 3 hours in advance for hydrophilic treatment;

preferably, the piranha solution in step (2) is prepared by concentrating 98% wt of concentrated H₂SO₄And 30% wt of H₂O₂Mixing and preparing according to the volume ratio of 3: 1.

Preferably, the emulsifier in step (3) is an SDS solution.

Preferably, the organic solvent in the step (5) is at least one of toluene or chloroform, and the annealing time is 30min to 60 min.

Preferably, the flow rate of the flow meter in the step (6) is controlled to be 200ml/h to 800 ml/h.

The second purpose of the invention is realized by the following technical scheme:

a large-area ordered PS microsphere monolayer colloidal crystal is prepared by the preparation method.

Compared with the prior art, the invention has the following advantages and beneficial effects:

the invention discloses a method for arranging nano-scale colloidal microspheres on any substrate into hexagonal close-packed monolayer structure colloidal crystals by in-situ annealing self-assembled monolayer colloids by using organic solvent molecules and combining a flow control deposition technology. The large-area ordered PS microsphere single-layer colloidal crystal prepared by the method has the advantages that the PS microspheres are orderly arranged in a hexagonal close-packed mode to form a colloidal sphere single-layer structure, the PS microspheres are uniformly spaced, and the quality is high.

Drawings

FIG. 1 is a schematic diagram of the process for preparing large-area ordered PS microsphere monolayer colloidal crystals according to examples 1 to 4.

FIG. 2 is a partially enlarged SEM image of large area ordered colloidal crystals of a monolayer of PS microspheres prepared in example 1.

FIG. 3 is an SEM image of large-area ordered PS microsphere monolayer colloidal crystals prepared in example 1

FIG. 4 is a partially enlarged SEM image of large area ordered colloidal crystals of a monolayer of PS microspheres prepared in example 2.

FIG. 5 is a partially enlarged SEM image of large area ordered colloidal crystals of a monolayer of PS microspheres prepared in example 3.

FIG. 6 is a partially enlarged SEM image of large area ordered colloidal crystals of a monolayer of PS microspheres prepared in example 4.

FIG. 7 is a partially enlarged SEM image of large area ordered colloidal crystals of monolayer PS microspheres prepared in example 5.

Fig. 8 is an SEM image of large area ordered monolayer colloidal crystals of PS microspheres prepared in comparative example 1.

Fig. 9 is an SEM image of large area ordered monolayer colloidal crystals of PS microspheres prepared in comparative example 2.

The device comprises a flow control valve 1, a culture dish 2, a bearing base station 3, a glass slide substrate 4, a glass cover 5 and a crucible 6.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.

The specifications of the experimental equipment and the specifications of the reagents used in examples 1 to 5 of the present invention and comparative examples 1 to 2 were as follows: glass sheet (1cm x 0.5cm), glass culture dish (phi 12cm) and bearing base (phi 10cm) are used with piranha solution (98% wt concentration H) in advance₂SO₄And 30% wt of H₂O₂Mixing and preparing according to the volume ratio of 3: 1) soaking for 3 hours for hydrophilic treatment, and placing a crucible (phi 4cm) containing toluene solution in a vacuum glass cover (phi 20cm multiplied by 30cm) to make the toluene steam fill the whole glass cover; those in the examples of the present invention and comparative examples, for which no specific conditions are indicated, were conducted under conventional conditions or conditions recommended by the manufacturer. The raw materials, reagents and the like which are not indicated for manufacturers are all conventional products which can be obtained by commercial purchase. FIG. 1 is a schematic diagram of the process for preparing large-area ordered PS microsphere monolayer colloidal crystals according to examples 1 to 5.

The monodisperse submicron PS microsphere powders used in examples 1 to 5 and comparative examples 1 to 2 were prepared by emulsion polymerization, and the specific preparation method is described in Szekeres, m.; kamalin, o.; schoonheydt, r.a.; wostyn, K.; claus, k.; personons, a.; dk-ny, I.J. Mater. chem.2002,12,3268.

Example 1:

dispersing 0.05g of the prepared PS microsphere powder with the particle size of 583nm in 5ml of ethanol-water mixed solution with the volume ratio of 1:1, and performing ultrasonic oscillation for 30s by using a cell disruptor to form diluted 1 wt% PS microsphere emulsion; spreading a glass sheet on a bearing base station as a glass sheet substrate, wherein the glass sheet is marked as a first glass sheet; placing the bearing base station in the center of the culture dish, placing another glass sheet in the middle of the bearing platform as a PS microsphere dispersion base station, marking the glass sheet as a second glass sheet, and closing a flow controller connected with the culture dish at the moment; then slowly injecting deionized water into the culture dish to ensure that the liquid level is exactly level to the upper surface of the second glass sheet, sucking the diluted PS microsphere emulsion by a 50ul micro-injector and dropwise adding the emulsion onto the second glass sheet, and continuously dropwise adding the emulsion after the emulsion is diffused to the liquid level until the liquid level is basically fully paved by the PS microspheres, wherein the dropwise added PS microsphere emulsion is about 500 ul; and dropwise adding 1 wt% of SDS solution into the culture dish for a plurality of drops to enable the PS microspheres to be arranged more tightly, continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically flat, and dropwise adding 1 wt% of SDS solution to ensure the compactness of the PS microspheres. And slowly moving the glass cover filled with toluene vapor to the culture dish, covering the glass cover, annealing for 30min, and then removing the glass cover. And opening a flow controller switch, controlling the flow rate to be 200ml/h, after about 20min, lowering the liquid level to the position of 0.5cm at the lower edge of the bearing table, attaching the deposited PS microsphere film on the glass sheet, taking out the bearing table, and naturally airing to obtain a large number of single-layer PS microsphere colloidal crystals taking the glass sheet as the substrate.

Fig. 2 is a partially enlarged SEM image of the large-area ordered PS microsphere monolayer colloidal crystal prepared in this example, and fig. 3 is a SEM image of the large-area ordered PS microsphere monolayer colloidal crystal prepared in this example, it can be seen from the SEM image of the monolayer colloidal crystal prepared under this condition that the PS microspheres are orderly arranged in a hexagonal close-packed form into a colloidal sphere monolayer structure, the PS microspheres are uniformly spaced, no obvious defect is present in the range of 40um to 40um, and the PS microspheres have high quality, and the ordered area can reach 1cm²And about 50 samples can be prepared at one time, and the preparation efficiency is high.

Example 2:

dispersing 0.05g of the prepared PS microsphere powder with the particle size of 583nm in 5ml of ethanol-water mixed solution with the volume ratio of 1:1, and performing ultrasonic oscillation for 30s by using a cell disruptor to form diluted 1 wt% PS microsphere emulsion; spreading a glass sheet on a bearing base station as a glass sheet substrate, wherein the glass sheet is marked as a first glass sheet; placing the bearing base station in the center of the culture dish, placing another glass sheet in the middle of the bearing platform as a PS microsphere dispersion base station, marking the glass sheet as a second glass sheet, and closing a flow controller connected with the culture dish at the moment; then slowly injecting deionized water into the culture dish to ensure that the liquid level is exactly level to the upper surface of the second glass sheet, sucking the diluted PS microsphere emulsion by a 50ul micro-injector and dropwise adding the emulsion onto the second glass sheet, and continuously dropwise adding the emulsion after the emulsion is diffused to the liquid level until the liquid level is basically fully paved by the PS microspheres, wherein the dropwise added PS microsphere emulsion is about 500 ul; and dropwise adding 1 wt% of SDS solution into the culture dish for a plurality of drops to enable the PS microspheres to be arranged more tightly, continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically flat, and dropwise adding 1 wt% of SDS solution to ensure the compactness of the PS microspheres. And slowly moving the glass cover filled with toluene vapor to the culture dish, covering the glass cover, annealing, and removing the glass cover after annealing for 45 min. And opening a flow controller switch, controlling the flow of the flow controller switch to be 800ml/h, after about 5min, lowering the liquid level to the position of 0.5cm at the lower edge of the bearing table, attaching the deposited PS microsphere film on the glass sheet, taking the bearing table out, and naturally airing to obtain a large number of single-layer PS microsphere colloidal crystals taking the glass sheet as the substrate.

Fig. 4 is a partially enlarged SEM image of the large-area ordered PS microsphere monolayer colloidal crystal prepared in this example, and it can be seen from the SEM image of the colloidal crystal prepared under this condition, the PS microspheres are also ordered in a hexagonal close-packed manner to form a colloidal sphere monolayer structure, but compared with example 1, the PS microspheres are relatively unevenly spaced, have a significant crack, and also have a portion of point defects, because during the deposition process, the flow rate set by the flow control valve is too high, which causes a drop in the liquid level, and the driving force generated by the water flow will cause a certain degree of damage to the ordering of the PS microsphere film, so that the monolayer PS microsphere colloid has point defects and line defects, which results in a drop in the quality of the monolayer colloid.

Example 3:

dispersing 0.05g of the prepared PS powder with the particle size of 583nm in 5ml of ethanol-water mixed solution with the volume ratio of 1:1, and performing ultrasonic oscillation for 30s by using a cell disruptor to form diluted 1 wt% PS microsphere emulsion; spreading a glass sheet on a bearing base station as a glass sheet substrate, wherein the glass sheet is marked as a first glass sheet; placing the bearing base station in the center of the culture dish, placing another glass sheet in the middle of the bearing platform as a PS microsphere dispersion base station, marking the glass sheet as a second glass sheet, and closing a flow controller connected with the culture dish at the moment; then slowly injecting deionized water into the culture dish to ensure that the liquid level is exactly level to the upper surface of the second glass sheet, sucking the diluted PS microsphere emulsion by a 50ul micro-injector and dropwise adding the emulsion onto the second glass sheet, and continuously dropwise adding the emulsion after the emulsion is diffused to the liquid level until the liquid level is basically fully paved by the PS microspheres, wherein the dropwise added PS microsphere emulsion is about 500 ul; and dropwise adding 1 wt% of SDS solution into the culture dish for a plurality of drops to enable the PS microspheres to be arranged more tightly, continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically flat, and dropwise adding 1 wt% of SDS solution to ensure the compactness of the PS microspheres. And slowly moving the glass cover filled with toluene vapor to the culture dish, covering the glass cover, annealing, and removing the glass cover after annealing for 45 min. And opening a flow controller switch, controlling the flow rate to be 200ml/h, after about 20min, lowering the liquid level to the position of 0.5cm at the lower edge of the bearing table, attaching the deposited PS microsphere film on the glass sheet, taking out the bearing table, and naturally airing to obtain a large number of single-layer PS microsphere colloidal crystals taking the glass sheet as the substrate.

Fig. 5 is a partially enlarged SEM image of the large-area ordered PS microsphere monolayer colloidal crystals prepared in this example, and it can be seen from the SEM image of the colloidal crystals prepared under this condition that the PS microspheres are also arranged in a hexagonal close-packed ordered manner to form a colloidal sphere monolayer structure, but compared to example 1, the partial line regions of the PS microspheres are bonded together, a fusion region occurs, a concave triangle is formed between three spherical voids, and the PS spheres are slightly deformed, indicating that the spacing between the PS microspheres is reduced and the partial region bonding occurs between the spheres as the annealing time is prolonged.

Example 4:

dispersing 0.05g of the prepared PS powder with the particle size of 406nm in 5ml of ethanol-water mixed solution with the volume ratio of 1:1, and performing ultrasonic oscillation for 30s by using a cell disruptor to form diluted 1 wt% PS microsphere emulsion; spreading a glass sheet on a bearing base station, and placing the bearing base station in the center of a culture dish to be used as a glass sheet substrate, wherein the glass sheet is marked as a first glass sheet; another glass sheet is placed in the middle of the bearing platform to serve as a PS microsphere dispersion base station, the glass sheet is marked as a second glass sheet, and at the moment, a flow controller connected with the culture dish is in a closed state; then slowly injecting deionized water into the culture dish to ensure that the liquid level is exactly equal to the upper surface of the second glass sheet, sucking the diluted PS microsphere emulsion by a 50ul micro-injector and dropwise adding the PS microsphere emulsion onto the second glass sheet, and continuously dropwise adding the PS microsphere emulsion after the emulsion is diffused to the liquid level until the liquid level is basically fully paved by PS microspheres, wherein the dropwise added PS microsphere emulsion is about 500 ul; and dropwise adding 1 wt% of SDS solution into the culture dish for a plurality of drops to enable the PS microspheres to be arranged more tightly, continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically flat, and dropwise adding 1 wt% of SDS solution to ensure the compactness of the PS microspheres. And slowly moving the glass cover filled with toluene vapor to the culture dish, covering the glass cover, annealing, and removing the glass cover after annealing for 45 min. And opening a flow controller switch, controlling the flow rate to be 200ml/h, after about 20min, lowering the liquid level to the position of 0.5cm at the lower edge of the bearing table, attaching the deposited PS microsphere film on the glass sheet, taking out the bearing table, and naturally airing to obtain a large number of single-layer PS microsphere colloidal crystals taking the glass sheet as the substrate.

Fig. 6 is a partially enlarged SEM image of the large-area ordered PS microsphere monolayer colloidal crystals prepared in this example, and it can be seen from the SEM image of the colloidal crystals prepared under this condition that the PS microspheres are also ordered in a hexagonal close-packed form into a colloidal sphere monolayer structure, but compared to example 3, the PS microsphere partition line regions are bonded together, and the bonded regions are larger, even the colloidal spheres are completely closed together, so that the triangular gap regions disappear. The method shows that with the reduction of the particle size of the PS microspheres, the fusion degree between the spheres is increased and the deformation of the PS microspheres is more obvious under the same annealing time.

Example 5:

dispersing 0.05g of the prepared PS powder with the particle size of 872nm in 5ml of ethanol-water mixed solution with the volume ratio of 1:1, and performing ultrasonic oscillation for 60s by using a cell disruptor to form diluted 1 wt% PS microsphere emulsion; spreading a glass sheet on a bearing base station as a glass sheet substrate, wherein the glass sheet is marked as a first glass sheet; placing the bearing base station in the center of the culture dish, placing another glass sheet in the middle of the bearing platform as a PS microsphere dispersion base station, marking the glass sheet as a second glass sheet, and closing a flow controller connected with the culture dish at the moment; then slowly injecting deionized water into the culture dish to ensure that the liquid level is exactly level to the upper surface of the second glass sheet, sucking the diluted PS microsphere emulsion by a 50ul micro-injector and dropwise adding the emulsion onto the second glass sheet, and continuously dropwise adding the emulsion after the emulsion is diffused to the liquid level until the liquid level is basically fully paved by the PS microspheres, wherein the dropwise added PS microsphere emulsion is about 500 ul; and dropwise adding 1 wt% of SDS solution into the culture dish for a plurality of drops to enable the PS microspheres to be arranged more tightly, continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically flat, and dropwise adding 1 wt% of SDS solution to ensure the compactness of the PS microspheres. And slowly moving the glass cover filled with toluene vapor to the culture dish, covering the glass cover, annealing, and removing the glass cover after annealing for 60 min. And opening a flow controller switch, controlling the flow rate to be 200ml/h, after about 20min, lowering the liquid level to the position of 1cm at the lower edge of the bearing table, attaching the deposited PS microsphere film on the glass sheet, taking out the bearing table, and naturally airing to obtain a large number of single-layer PS microsphere colloidal crystals taking the glass sheet as the substrate.

Fig. 7 is a partially enlarged SEM image of large-area ordered colloidal crystals of PS microspheres monolayer prepared in this example, and from the SEM image of colloidal crystals prepared under this condition, it can be seen that PS microspheres are also ordered in a hexagonal close-packed form into a colloidal sphere monolayer structure, but compared to example 4, some of the line regions are also adhered together, but less adhered regions are present between PS microspheres. It shows that the PS microspheres can be deformed obviously after a longer time is needed along with the increase of the particle size of the PS microspheres.

Comparative example 1:

dispersing 0.05g of the prepared PS powder with the particle size of 583nm in 5ml of ethanol-water mixed solution with the volume ratio of 1:1, and performing ultrasonic oscillation for 30s by using a cell disruptor to form diluted 1 wt% PS microsphere emulsion; spreading a glass sheet on a bearing base station, and placing the bearing base station in the center of a culture dish to be used as a glass sheet substrate, wherein the glass sheet is marked as a first glass sheet; another glass sheet is placed in the middle of the bearing platform to serve as a PS microsphere dispersion base station, the glass sheet is marked as a second glass sheet, and at the moment, a flow controller connected with the culture dish is in a closed state; then slowly injecting deionized water into the culture dish to ensure that the liquid level is exactly level to the upper surface of the second glass sheet, sucking the diluted PS microsphere emulsion by a 50ul micro-injector and dropwise adding the emulsion onto the second glass sheet, and continuously dropwise adding the emulsion after the emulsion is diffused to the liquid level until the liquid level is basically fully paved by the PS microspheres, wherein the dropwise added PS microsphere emulsion is about 500 ul; and dropwise adding 1 wt% of SDS solution into the culture dish for a plurality of drops to enable the PS microspheres to be arranged more tightly, continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically flat, and dropwise adding 1 wt% of SDS solution to ensure the compactness of the PS microspheres. The single-layer PS microsphere colloidal crystal taking the glass sheet as the substrate can be obtained by directly depositing at the flow rate of 200ml/h without annealing treatment.

Fig. 8 is an SEM image of monolayer colloidal crystals of PS microspheres prepared in this comparative example, and it can be seen from the SEM image of colloidal crystals prepared under this condition that, in the sample that did not settle directly by annealing treatment, PS microspheres were not arranged in order in a hexagonal close-packed form into a colloidal sphere monolayer structure, but there were many defects, and it was difficult to find a more ordered region even in an atmosphere of 5um x 5 um. This is because, during the deposition process, the mechanical strength of the microsphere film is relatively low, and the driving force generated by the water flow will destroy the order of the PS microsphere film to a great extent, so that a great number of defects appear in the single-layer PS microsphere colloid.

Comparative example 2:

dispersing 0.05g of the prepared PS powder with the particle size of 583nm in 5ml of ethanol-water mixed solution with the volume ratio of 1:1, and performing ultrasonic oscillation for 30s by using a cell disruptor to form diluted 1 wt% PS microsphere emulsion; placing the bearing base platform in the center of a culture dish as a glass slide substrate, wherein the glass slide is marked as a first glass slide; placing a glass sheet in the middle of the bearing platform as a PS microsphere dispersion base station, marking the glass sheet as a second glass sheet, and closing a flow controller connected with the culture dish at the moment; then slowly injecting deionized water into the culture dish to ensure that the liquid level is exactly level to the upper surface of the second glass sheet, sucking the diluted PS microsphere emulsion by a 50ul micro-injector and dropwise adding the PS microsphere emulsion onto the glass sheet, and continuously dropwise adding the PS microsphere emulsion after the emulsion is diffused to the liquid level until the liquid level is basically fully paved by the PS microspheres, wherein the dropwise added PS microsphere emulsion is about 500 ul; and dropwise adding 1 wt% of SDS solution into the culture dish for a plurality of drops to enable the PS microspheres to be arranged more tightly, continuously injecting deionized water to continuously raise the liquid level until the height of the culture dish is basically flat, and dropwise adding 1 wt% of SDS solution to ensure the compactness of the PS microspheres. And slowly moving the glass cover filled with toluene vapor to the culture dish, covering the glass cover, annealing, and removing the glass cover after annealing for 45 min. And after annealing, the glass sheet is slowly inserted below the liquid level and moved to the position below the PS microsphere film, the substrate is slowly lifted, the PS microsphere single-layer film is transferred to the target substrate from the water/gas interface, and after natural drying, the PS microsphere single-layer colloidal crystal with the glass sheet as the substrate can be obtained.

Fig. 9 is an SEM image of the large-area ordered PS microsphere monolayer colloidal crystals prepared in this comparative example, and it can be seen from the SEM image of the colloidal crystals prepared under this condition that in a local range, PS microspheres are also arranged in a hexagonal close-packed form into a colloidal sphere monolayer structure, but in a range of 5um × 5um, some linear defects and point defects can be found, and when the field of view is enlarged (as in fig. 9a), linear defects can be clearly observed, even some areas are blank, because when the transfer is performed in a manual manner, the microsphere film is pulled in the pulling process, and the gas-liquid interface is disturbed, so that some linear defects occur in the originally compact PS microsphere film, and the linear defects develop into block defects along with the enlargement of the linear defects.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A preparation method of large-area ordered PS microsphere single-layer colloidal crystals is characterized by comprising the following steps:

(6) opening a switch of the flow controller, controlling the flow rate of the flow controller, depositing a PS microsphere film on a glass sheet when the liquid level in the culture dish is lowered to the position of the lower edge of the bearing table, taking out the bearing table, and naturally airing to obtain a large amount of single-layer PS microsphere colloidal crystals taking the glass sheet as a substrate;

the particle size of the PS microsphere powder in the step (1) is 583 nm;

the organic solvent in the step (5) is toluene, and the annealing time is 30 min;

and (4) controlling the flow rate of the flow meter to be 200ml/h in the step (6).

2. The method for preparing large-area ordered PS microsphere monolayer colloidal crystals as claimed in claim 1, wherein the time of the ultrasonic vibration in step (1) is 30 s.

3. The method for preparing large-area ordered PS microsphere monolayer colloidal crystals as claimed in claim 1, wherein the glass plate, the culture dish and the bearing base platform in step (2) are soaked in piranha solution for 3h in advance for hydrophilic treatment.

4. The method for preparing large-area ordered PS microsphere monolayer colloidal crystals as claimed in claim 3, wherein the piranha solution in step (2) is prepared by 98 wt% concentrated H₂SO₄And 30% wt of H₂O₂Mixing and preparing according to the volume ratio of 3: 1.

5. The method for preparing large-area ordered PS microsphere monolayer colloidal crystals according to claim 1, wherein the emulsifier in step (4) is SDS solution.

6. A large area ordered monolayer colloidal crystal of PS microspheres prepared according to the method of any one of claims 1 to 5.