A two-dimensional colloidal glass containing pinning on a substrate and a method for preparing the same

Abstract

The present application belongs to the field of two-dimensional colloidal glass preparation, and particularly relates to a two-dimensional colloidal glass containing pegs on a substrate and a preparation method thereof. The present application uses a method for preparing a two-dimensional colloidal glass on a substrate containing pegs, which can study the influence of pegs on the structure and dynamics of the two-dimensional colloidal glass, and provide a new idea for people to understand the physical mechanism of glass transition. Meanwhile, the method can also be applied to the preparation of other two-dimensional colloidal systems containing pegs, such as two-dimensional colloidal crystals, to study the influence of pegs on the crystal structure, which is conducive to the preparation of defect-free microstructure materials and has important application value in the fields of sensors, optoelectronic functional materials and the like.

Description

Technical Field

[0001] This invention belongs to the field of two-dimensional colloidal glass preparation, specifically relating to a two-dimensional colloidal glass with pins on a substrate and its preparation method. Background Technology

[0002] Glass is a common state of matter with wide applications in production, daily life, and industry. Although glass has been used for thousands of years, the physical mechanism by which a liquid transforms into a glassy state is not yet fully understood; the physical mechanism of the glass transition remains a global scientific challenge. Traditional experimental methods induce the transition from liquid to glass by increasing the area fraction of the glass system. Although the dynamics of the system change, its structure remains unchanged. Pinning, which fixes some particles to a substrate, disrupts the system's structure. Therefore, studying the structure and dynamics of glass systems by increasing pinning is highly meaningful. However, in traditional methods of preparing two-dimensional colloidal glass by adding liquid between two glass plates, particles tend to stick together. If two-dimensional colloidal glass is prepared on a pinned substrate, large-area adhesion easily occurs. Summary of the Invention

[0003] The purpose of this invention is to solve the problem of large-area adhesion that occurs when preparing two-dimensional colloidal glass on a pinned substrate using traditional methods. Therefore, this invention designs a method for preparing two-dimensional colloidal glass on a pinned substrate, which is low-cost, simple to operate, and has a high success rate.

[0004] To address the aforementioned technical problems, this application provides the following technical solution:

[0005] This invention provides a method for preparing a two-dimensional colloidal glass containing pins on a substrate, comprising the following steps:

[0006] S1: Press the two coverslips, whose surfaces are coated with solution, together tightly;

[0007] The solution contains particles, the solvent is water, and the material of the particles is polystyrene.

[0008] S2: After the coverslip is tightly bonded, it is dried in a vacuum environment and then heated at 90-110℃ for 1-3 minutes to obtain a coverslip with pinned particles.

[0009] S3: Seal the coverslip with pinned particles and a clean coverslip together using a plastic tube; the surface of the plastic tube is respectively connected to a colloidal suspension and a syringe;

[0010] The colloidal suspension comprises polystyrene microspheres and ethanol;

[0011] S4: The gas in the plastic tube is extracted by the syringe, and the colloidal suspension flows into the plastic tube and is left to stand, so that the cover glass with pinned particles at the bottom forms a two-dimensional colloidal glass containing pins on the substrate.

[0012] Preferably, in step S1, the particle size is 2-4 μm.

[0013] Preferably, in step S1, the concentration of particles in the solution is 2.5-8.2%.

[0014] Preferably, in step S1, the method for tight bonding is to place several glass slides in the vertical direction of each of the two cover glass slides and then clamp them together with long-tail clips.

[0015] Furthermore, the number of glass slides is 2-4.

[0016] Preferably, in step S2, the drying temperature is 45-65℃ and the drying time is 1-3 hours.

[0017] Preferably, the number density of polystyrene microspheres in the colloidal suspension is 65-70%.

[0018] Preferably, the inner diameter of the plastic tube is 6-10 mm.

[0019] Preferably, in step S4, the settling time is greater than 24 hours.

[0020] Specifically, the method for preparing the pinned two-dimensional colloidal glass on the substrate includes the following steps:

[0021] The steps for preparing the pinned substrate are as follows:

[0022] (11) Take two coverslips;

[0023] (12) Take an appropriate amount of a solution of 4 μm polystyrene particles of suitable concentration and drop it evenly between two coverslips;

[0024] (13) Place three glass slides on top of each of the two coverslips;

[0025] (14) Clamp the sample with a long-tail clamp;

[0026] (15) Place the sample in a vacuum environment at 60°C and dry for two hours;

[0027] (16) The sample was placed on a hot plate at 100°C and heated for 2 minutes.

[0028] Preparation of two-dimensional colloidal glass on pinned substrates:

[0029] (21) Take a plastic tube with an inner diameter of 8 mm and cut two small grooves from the side at the top of the plastic tube;

[0030] (22) Connect the two ends of the plastic tube with a coverslip with pinned particles as the bottom and a clean coverslip as the top;

[0031] (23) Insert two microfluidic tubes of appropriate length slightly into the small groove at the top of the plastic tube, and seal the entire device with optical adhesive;

[0032] (24) One of the microfluidic tube ports is connected to the syringe needle, and the other port is connected to a container containing a colloidal glass suspension;

[0033] (25) Insert one end of the microfluidic tube into the colloidal glass suspension and use the syringe at the other end to draw the suspension into the sample cell until there is no more air in the sample cell; under the action of gravity, the particles will slowly sink to the bottom and form a quasi-two-dimensional colloidal glass system on the pinned substrate.

[0034] The present invention also provides a two-dimensional colloidal glass containing pins on a substrate prepared by the above preparation method.

[0035] The technical solution of the present invention has the following advantages compared with the prior art:

[0036] By utilizing a method for preparing two-dimensional colloidal glasses on pinned substrates, the effects of pinning on the structure and dynamics of two-dimensional colloidal glasses can be studied, providing a new approach to understanding the physical mechanism of glass transition. Simultaneously, this method can also be applied to the preparation of other pinned two-dimensional colloidal systems, such as two-dimensional colloidal crystals, to study their impact on crystal structure. This is beneficial for preparing defect-free microstructured materials, and has significant application value in fields such as sensors and optoelectronic functional materials. Attached Figure Description

[0037] Figure 1 This is a diagram illustrating the pinning process of the present invention.

[0038] Figure 2 This is a diagram of the experimental setup for the present invention.

[0039] Figure 3 These are the original microscope images and trajectory diagrams of the particles.

[0040] Figure 4 This is a diagram of the radial distribution function of the colloidal system.

[0041] Figure 5 This is a diagram of the intermediate scattering function of a colloidal system.

[0042] Figure 6 This is a four-point polarizability diagram for a colloidal system.

[0043] Explanation of reference numerals in the attached figures: 1-glass slide, 2-coverslip, 3-polystyrene microspheres, 4-colloidal suspension, 5-coverslip, 6-moving particles, 7-microscope objective lens, 8-pinning particles, 9-plastic tube, 10-syringe, 11-clean coverslip. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0045] Example 1: Specific Preparation Process

[0046] like Figure 1 As shown, first take two coverslips 2 and prepare a solution of 4μm polystyrene microspheres with a concentration of 2.5% ( Figure 1 (3) Evenly drop the solution between two coverslips 2. Place three glass slides 1 on top of and below each of the two coverslips 2.

[0047] To prevent the particles from agglomerating, the sample was clamped tightly with a long-tail clamp. The sample was then placed in a vacuum environment at 60°C to dry for two hours. Due to the loss of the water solvent, the particles also became stationary and ceased to move.

[0048] To prevent the particles from falling off during subsequent use, the sample is placed on a hot plate at 100°C and heated for 2 minutes. This will cause the polystyrene particles to sinter onto the glass substrate and prevent them from falling off.

[0049] 9 (with an inner diameter of 8mm) plastic tube Figure 2 As shown, two small grooves are cut out from the side of the upper part of the plastic tube 9, with a nailed coverslip 5 as the bottom and a clean coverslip 11 as the top, connecting the two ends of the plastic tube 9. Two microfluidic tubes of appropriate length are inserted slightly into the small grooves at the top of the plastic tube 9, and the entire device is sealed with optical adhesive, leaving only two microfluidic tube ports exposed. One port is connected to the needle of the syringe 10, and the other port is connected to the container containing the colloidal suspension 4.

[0050] A polystyrene microsphere ethanol solution (colloidal suspension 4) with a ratio of N3:N4=1:1 (where N3 is the number of polystyrene microspheres and N4 is the number of ethanol molecules) is prepared for later use. The molecular number density of the particles in the resulting solution is 67%. One end of the microfluidic tube is inserted into the solution, and the solution is drawn into the sample cell through the syringe 10 at the other end until there is no more air in the sample cell. Due to gravity, the particles will slowly sink to the bottom. The colloidal suspension 4 entering the plastic tube 9 will not cause vortex phenomena, and the suction of the suspension by the syringe 10 will not affect the distribution of particles. Therefore, the particles entering the sample cell are uniform and will be evenly distributed at the bottom under the action of gravity. A quasi-two-dimensional colloidal glass system is formed on the base plate with pinned coverslip 5.

[0051] Example 2

[0052] Example 2 is the same as Example 1, except that: after taking two coverslips 2, a solution of 4μm polystyrene microspheres with a concentration of 4.1% is prepared.

[0053] Example 3

[0054] Example 3 is the same as Example 1, except that: after taking two coverslips 2, a solution of 4μm polystyrene microspheres with a concentration of 5.0% is prepared.

[0055] Example 4

[0056] Example 4 is the same as Example 1, except that: after taking two coverslips 2, a solution of 4μm polystyrene microspheres with a concentration of 6.5% is prepared.

[0057] Example 5

[0058] Example 5 is the same as Example 1, except that: after taking two coverslips 2, a solution of 4μm polystyrene microspheres with a concentration of 8.2% is prepared.

[0059] Comparative Example 1

[0060] Comparative Example 1 is the same as Example 1, except that: two coverslips 2 are used to prepare a solution that does not contain 4μm polystyrene microspheres.

[0061] Effect Evaluation 1

[0062] After more than 24 hours of sedimentation and equilibration, the entire sample device finally obtained in Example 1 was placed on an inverted camera microscope for observation. Figure 3 (a)). The camera can record the state of particle motion in the system, set its shooting speed to 2 frames per second, and shoot continuously for 5000 seconds.

[0063] A standard algorithm, namely particle trajectory tracking technology, is used to identify the positions of colloidal particles in an image. Particles whose displacement does not change within a certain time period are identified as pinned particles. Figure 3 As shown by the blue dots in (b), particles whose displacement changes are in motion, such as... Figure 3 The red dot is shown in (b).

[0064] The static structure of the system is described by calculating the radial distribution function. Figure 4 It was found that the structure of the system did not change significantly with increasing pinning concentration; the dynamic properties of the system were studied by calculating the intermediate scattering function of the system. Figure 5 It was found that the kinetics of the system slowed down with increasing pinning concentration; the kinetic heterogeneity of the system was studied by calculating the four-point polarizability of the system. Figure 6 It was found that the kinetic heterogeneity of the system decreased with increasing pinning concentration.

[0065] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for producing a two-dimensional colloidal glass containing pinning on a substrate, characterized by, The method comprises the following steps: S1: tightly adhere two pieces of cover glass (2) coated with solution; The solution comprises particles, and the solvent is water, and the material of the particles is polystyrene; S2: dry the tightly adhered cover glass under vacuum environment, and then heat at 90-110 ℃ for 1-3 min to obtain cover glass (5) with pinned particles; S3: open two small grooves on the upper part of the plastic tube (9) from the side, take the cover glass (5) with pinned particles as the bottom, take clean cover glass (11) as the top, connect the two ends of the plastic tube (9); insert two pieces of microfluidic tube into the small grooves on the upper part of the plastic tube (9), seal the whole device with optical cement, and only leave two microfluidic tube ports, one of which is connected with the needle of the syringe (10), and the other is connected with the container containing the colloidal suspension (4); the colloidal suspension (4) comprises polystyrene microspheres and ethanol; S4: remove the gas in the plastic tube (9) through the syringe (10), and let the colloidal suspension (4) flow into the plastic tube (9) and stand, so that the bottom cover glass (5) with pinned particles forms the two-dimensional colloidal glass with pinning on the substrate; in the colloidal suspension (4), the number density of polystyrene microspheres is 65-70%; the inner diameter of the plastic tube (9) is 6-10 mm; in step S4, the standing time is greater than 24 h.

2. The production method according to claim 1, wherein In step S1, the particle size of the particles is 2-4 μm.

3. The production method according to claim 1, wherein In step S1, the concentration of the particles in the solution is 2.5-8.2%.

4. The production method according to claim 1, wherein In step S1, the method for tightly adhering is to place several pieces of glass slide (1) in the vertical direction of the two pieces of cover glass (2), and then clamp them with long tail clips.

5. The production method according to claim 4, wherein The number of glass slides (1) is 2-4.

6. The production method according to claim 1, wherein In step S2, the drying temperature is 45-65 ℃, and the drying time is 1-3 h.

7. The two-dimensional colloidal glass with pinning on the substrate prepared by the preparation method of any one of claims 1-6.

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