阅读说明：本技术 一种通过调节湿度控制胶体晶薄膜厚度的制备方法 (Preparation method for controlling thickness of colloidal crystal film by adjusting humidity ) 是由 钱卫平 董傲 于 2021-01-20 设计创作，主要内容包括：本发明公开了一种通过调节湿度控制胶体晶薄膜厚度的制备方法,采用垂直沉积法,通过在密闭箱中放置水、饱和盐溶液或干燥剂来调节制备环境的相对湿度,将亲水处理的基底竖直放置在配制的一定质量浓度的二氧化硅纳米颗粒醇悬浮液中,将包含悬浮液和基底的生长容器置于控制湿度的密闭箱中,制备2～7天,得到大面积的厚度可控的二氧化硅胶体晶薄膜。本发明的二氧化硅胶体晶薄膜制备方法解决了以往不同季节制备得到的薄膜质量参差不齐的问题,可不受季节影响地重复制备大面积、具有可控的物理厚度、稳定的光学性质的二氧化硅胶体晶薄膜,并从原理上解释了控制湿度的必要性。(The invention discloses a preparation method for controlling the thickness of a colloidal crystal film by adjusting humidity, which comprises the steps of adopting a vertical deposition method, adjusting the relative humidity of a preparation environment by placing water, saturated salt solution or drying agent in a closed box, vertically placing a substrate subjected to hydrophilic treatment in a prepared silicon dioxide nanoparticle alcohol suspension with certain mass concentration, placing a growth container containing the suspension and the substrate in the closed box with humidity control, and preparing for 2-7 days to obtain a large-area silicon dioxide colloidal crystal film with controllable thickness. The preparation method of the silica colloidal crystal film solves the problem of uneven quality of the film prepared in different seasons, can repeatedly prepare the silica colloidal crystal film with large area, controllable physical thickness and stable optical property without being influenced by seasons, and explains the necessity of controlling humidity in principle.)

1. The preparation method is characterized in that the silicon dioxide colloidal crystal films with different thicknesses are prepared by adjusting the humidity of a preparation environment.

2. The method for preparing a colloidal crystal film with controllable thickness by adjusting humidity according to claim 1, wherein the relative humidity is controlled to 5-99% by adjusting the environmental humidity with water, saturated salt solution or desiccant.

3. The method as claimed in claim 2, wherein the saturated salt solution comprises one of lithium chloride, potassium carbonate, potassium acetate, sodium chloride, and potassium chloride.

4. The method as claimed in claim 2, wherein the saturated salt solution is prepared in a state that the salt is excessive by more than 30%.

5. The method as claimed in claim 2, wherein the drying agent is one or both of anhydrous calcium chloride and silica gel drying agent.

6. The method for controlling the thickness of a colloidal crystal film according to claim 1, wherein the suspension solvent used in the vertical deposition method is ethanol or methanol.

7. The method for preparing a colloidal crystal film with controlled thickness by adjusting humidity according to claim 1, wherein the particle size of the silica suspension particles used in the vertical deposition method is 100 to 280 nm.

8. The method for preparing a colloidal crystal film with humidity control according to claim 1, wherein the mass concentration of silica particles in the alcohol suspension of silica in the vertical deposition method is 5-15 g/L.

9. The method for controlling the thickness of a colloidal crystal film according to claim 1, wherein the substrate sheet used in the vertical deposition method is a glass slide or a single crystal silicon wafer.

10. The method for preparing a colloidal crystal film with controlled thickness by adjusting humidity as set forth in claim 1, wherein the substrate sheet used in the vertical deposition method is soaked in piranha solution.

Technical Field

The invention relates to a preparation method for controlling a colloidal crystal film by adjusting humidity, belonging to the field of self-assembly of nano materials.

Background

There are many methods for preparing silica colloidal crystal films, and they can be classified into two types according to whether or not an external force is involved. Compared with preparation methods with external force participation (such as a spin coating method, a pulling method, an external electric field deposition method and the like), the preparation method without external force participation has longer preparation time, but the prepared film has a better crystal structure, so that better optical properties are brought.

The vertical deposition method is the most common preparation method without external force participation, and is characterized in that a substrate sheet is vertically inserted into ethanol or water suspension with nano particles, a colloidal crystal film is obtained after a period of time, and the thickness of the prepared colloidal crystal film is controlled by controlling the concentration of the suspension. However, when the conventional vertical deposition method is used for repeatedly preparing the silicon dioxide colloidal crystal film, a film material with uniform thickness is often not obtained, and the above results are found to be caused by different environmental humidity.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a preparation method for controlling the thickness of a colloidal crystal film by adjusting humidity, and the method can be used for repeatedly and rapidly preparing a large-area high-quality silicon dioxide colloidal crystal film.

The technical scheme is as follows: the invention relates to a preparation method for controlling the thickness of a colloidal crystal film by adjusting humidity, which is a vertical deposition method and is used for preparing silicon dioxide colloidal crystal films with different thicknesses by adjusting the humidity of a preparation environment.

Further, the relative humidity is controlled to be 5-99% by adopting water, saturated salt solution or a drying agent for adjusting the environmental humidity.

Further, the saturated salt solution comprises one of lithium chloride, potassium carbonate, potassium acetate, sodium chloride and potassium chloride saturated salt solution.

Further, the saturated salt solution must be prepared with a salt excess of more than 30% to ensure that the saturated salt solution does not become unsaturated by absorbing water vapor.

Further, the drying agent is one or two of anhydrous calcium chloride and silica gel drying agent.

Further, the suspension solvent used in the vertical deposition method is ethanol or methanol.

Furthermore, the particle size of the silicon dioxide suspension particles adopted in the vertical deposition method is 100-280 nm.

Furthermore, the mass concentration range of the silicon dioxide particles in the silicon dioxide alcohol suspension in the vertical deposition method is 5-15 g/L.

Further, the substrate slice adopted in the vertical deposition method is a glass slide or a monocrystalline silicon slice.

Further, the substrate sheet used in the vertical deposition method is subjected to soaking treatment with piranha solution.

The reason for controlling the environmental humidity can be explained by formula (1), which improves the original colloidal crystal film thickness formula:

t is the physical thickness of the colloidal crystal film, l is the length of a wetting film formed by wetting the suspension on the substrate, rho is the mass concentration of the silica particles in the suspension, j is_mIs the evaporation rate of the wetting film, j_eIs the evaporation rate of the suspension. First, the evaporation rate of the solvent in the suspension is much greater than that of water, the evaporation rate decreases after the solvent absorbs water, and the higher the water content, the lower the evaporation rate, as shown in FIG. 1, in a high humidity environment, the higher the water content after absorbing water vapor, the higher the evaporation rate (i.e., j_m) The drop is much greater; while the water content does not change much after the suspension has a large volume and absorbs water vapor, the evaporation rate (i.e., j)_e) The decrease is not so large that the physical thickness of the colloidal crystal film becomes smaller as can be derived from the formula (1).

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages:

(1) compared with a humidity meter for controlling humidity, the method for controlling humidity by using water, saturated salt solution or desiccant has the following advantages: the humidity control is stable, the controlled humidity range is large, and the relative humidity can be controlled to be 5-99%; the preparation can be repeatedly used in one time, and no extra electric energy is needed to be provided; air disturbance and vibration of the preparation platform are not brought, the assembly of the colloidal crystal film is very facilitated, and the method can be used for preparing the silica colloidal crystal film and the colloidal crystal film prepared by taking alcosol as a raw material; the anhydrous calcium chloride is used as a drying agent and can absorb the gaseous ethanol in the air in the plastic box, so that the phenomenon that the evaporation speed of the suspension is reduced due to the excessive concentration of the gaseous ethanol, and the assembly speed of the silica colloidal crystal film is reduced.

(2) By controlling the humidity, the thickness of the prepared silicon dioxide colloidal crystal film is more controllable, and the repeatability is high; the used humidity control method avoids air disturbance, so that the thickness of the prepared silicon dioxide colloidal crystal film is more uniform and can reach 100mm²The internal thickness variation is less than 3% uniformity. The thickness uniformity of the film can be observed by naked eyes facing a light source, and the interference effect can enhance light with certain wavelengths, so that the thickness of the area with consistent color of the film is uniform, and the observation is convenient.

(3) The invention provides that methanol is used as a suspension solvent, and has a faster evaporation rate compared with ethanol, the speed of assembling the silicon dioxide colloid crystal film prepared by using ethanol is about 1.8mm/day, the highest speed of assembling the silicon dioxide colloid crystal film prepared by using methanol can reach about 6.2mm/day, the preparation speed is improved by more than 3 times, and the method is more suitable for industrial production.

Drawings

FIG. 1 is a schematic diagram of adjusting the humidity of the environment to control the thickness of a silica gel crystal film;

FIG. 2 is a diagram of a growing apparatus for preparing a silica colloidal crystal film.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

Example 1 preparation of Low thickness colloidal silica Crystal film on Single Crystal silicon wafer

The growth apparatus for preparing the silica colloidal crystal film is shown in fig. 2, (1) 300mL of pure water is added into a beaker, the beaker filled with water is placed in a closed transparent plastic box, a hygrometer is arranged in the plastic box, a cover is covered, and the hygrometer in the plastic box is observed after about 12 hours, wherein the relative humidity in the plastic box reaches 99%.

(2) Preparing 190nm silicon dioxide alcohol suspension with the mass concentration of 5g/L by using ethanol as a solvent, putting the suspension into a dyeing tank, taking the monocrystalline silicon piece soaked by the piranha solution as a substrate piece, and vertically inserting the monocrystalline silicon piece into the dyeing tank filled with the silicon dioxide alcohol suspension.

(3) And (3) placing the dyeing tank filled with the silica ethanol suspension into the transparent plastic box in the step (1), and taking out the monocrystalline silicon wafer after 7 days.

And (4) measuring the thickness of the monocrystalline silicon wafer obtained in the step (3) by using an interference method. The obtained silicon dioxide colloidal crystal film has an area larger than 20mm²The inner thickness range is 500 +/-15 nm. The length of the colloidal crystal film was measured and divided by the assembly time (7 days), and the assembly speed was calculated to be about 1.8 mm/day.

Example 2 preparation of high thickness silica colloidal crystalline thin films on glass sheets

(1) 400g of anhydrous calcium chloride is added into a beaker, the beaker is placed in a closed transparent plastic box, a hygrometer is arranged in the plastic box, a cover is covered, the hygrometer in the plastic box is observed after about 24 hours, and at the moment, the relative humidity in the plastic box reaches 5%.

(2) Preparing 190nm silica alcohol suspension with the mass concentration of 15g/L by using ethanol as a solvent, putting the suspension into a staining jar, soaking a glass slide as a substrate piece by using piranha solution, and vertically inserting the glass slide into the staining jar filled with the silica alcohol suspension.

(3) And (3) placing the staining jar filled with the silicon dioxide alcohol suspension into the transparent plastic box in the step (1), and taking out the glass slide after 7 days.

And (4) measuring the thickness of the glass sheet obtained in the step (3) by using an interference method. The obtained silicon dioxide colloidal crystal film has an area larger than 100mm²The inner thickness range is 3500 +/-90 nm. The length of the colloidal crystal film was measured and divided by the assembly time (7 days), and the assembly speed was calculated to be about 1.8 mm/day.

Example 3 preparation of high thickness silica colloidal crystalline thin films on glass sheets

(1) 400g of anhydrous calcium chloride is added into a beaker, the beaker is placed in a closed transparent plastic box, a hygrometer is arranged in the plastic box, a cover is covered, the hygrometer in the plastic box is observed after about 24 hours, and at the moment, the relative humidity in the plastic box reaches 5%.

(2) Preparing 100nm silica alcohol suspension with the mass concentration of 15g/L by using ethanol as a solvent, putting the suspension into a staining jar, soaking a glass slide as a substrate piece by using piranha solution, and vertically inserting the glass slide into the staining jar filled with the silica alcohol suspension. The length of the colloidal crystal film was measured and divided by the assembly time (7 days), and the assembly speed was calculated to be about 1.8 mm/day.

(3) And (3) placing the staining jar filled with the silicon dioxide alcohol suspension into the transparent plastic box in the step (1), and taking out the glass slide after 7 days.

And (4) measuring the thickness of the glass sheet obtained in the step (3) by using an interference method. The thickness range of the obtained silicon dioxide colloidal crystal film is 3500 +/-50 nm.

Example 4 preparation of high thickness silica colloidal crystalline thin films on glass sheets

(1) 400g of anhydrous calcium chloride is added into a beaker, the beaker is placed in a closed transparent plastic box, a hygrometer is arranged in the plastic box, a cover is covered, the hygrometer in the plastic box is observed after about 24 hours, and at the moment, the relative humidity in the plastic box reaches 5%.

(2) Preparing a 280nm silica alcohol suspension with the mass concentration of 15g/L by using ethanol as a solvent, putting the suspension into a staining jar, soaking a glass slide as a substrate piece by using a piranha solution, and vertically inserting the glass slide into the staining jar filled with the silica alcohol suspension.

(3) And (3) placing the staining jar filled with the silicon dioxide alcohol suspension into the transparent plastic box in the step (1), and taking out the glass slide after 7 days.

And (4) measuring the thickness of the glass sheet obtained in the step (3) by using an interference method. The thickness range of the obtained silicon dioxide colloidal crystal film is 3500 +/-150 nm. The length of the colloidal crystal film was measured and divided by the assembly time (7 days), and the assembly speed was calculated to be about 1.8 mm/day.

Example 5 Rapid preparation of Low-thickness silica colloidal Crystal film

(1) Preparing a saturated potassium chloride salt solution with 30% salt excess, adding the saturated potassium chloride salt solution into a beaker, placing the beaker in a sealed transparent plastic box, arranging a hygrometer in the plastic box, covering a cover, observing the hygrometer in the plastic box after about 18 hours, wherein the relative humidity in the plastic box reaches 71%.

(2) The method comprises the steps of preparing 190nm silica alcohol suspension with the mass concentration of 5g/L by using methanol as a solvent, putting the suspension into a staining jar, soaking a glass slide as a substrate piece by using piranha solution, and vertically inserting the glass slide into the staining jar filled with the silica alcohol suspension.

(3) And (3) placing the staining jar filled with the silicon dioxide alcohol suspension into the transparent plastic box in the step (1), and taking out the glass slide after 3 days.

And (4) measuring the thickness of the glass sheet obtained in the step (3) by using an interference method. The obtained silicon dioxide colloidal crystal film has an area of more than 50mm²The inner thickness range is 500 +/-15 nm. The length of the colloidal crystal film was measured and divided by the assembly time (3 days), and the assembly speed was calculated to be about 4.3 mm/day.

Example 6 ultra-fast preparation of silica colloidal crystal film

(1) 200g of anhydrous calcium chloride and 200g of silica gel desiccant are added into a beaker, the beaker is placed in a closed transparent plastic box, a hygrometer is arranged in the plastic box, a cover is covered, and the hygrometer in the plastic box is observed after about 24 hours, wherein the relative humidity in the plastic box reaches 5%.

(2) The method comprises the steps of preparing 190nm silica alcohol suspension with the mass concentration of 7g/L by using methanol as a solvent, putting the suspension into a staining jar, soaking a glass slide as a substrate piece by using piranha solution, and vertically inserting the glass slide into the staining jar filled with the silica alcohol suspension.

(3) And (3) placing the staining jar filled with the silica methanol suspension into the transparent plastic box in the step (1), and taking out the glass slide after 2 days.

And (4) measuring the thickness of the glass sheet obtained in the step (3) by using an interference method. The obtained silicon dioxide colloidal crystal film has an area of more than 50mm²The inner thickness range is 1430 + -40 nm. The length of the colloidal crystal film was measured and divided by the assembly time (2 days), and the assembly speed was calculated to be about 6.2 mm/day.

Example 7 preparation of silica colloidal crystal films of different thicknesses by adjusting humidity

(1) Respectively preparing saturated salt solutions of lithium chloride, potassium carbonate, potassium acetate, sodium chloride and potassium chloride with the salt excess of 30%, placing the saturated salt solutions into different beakers, independently placing each beaker into a sealed transparent plastic box, arranging a hygrometer in the plastic box, covering a cover, observing the hygrometer in the plastic box after about 24 hours, and correspondingly displaying the relative humidity in different plastic boxes to be about: lithium chloride (31%), potassium carbonate (38%), potassium acetate (51%), sodium chloride (64%).

(2) Preparing 190nm silica alcohol suspension with the mass concentration of 13g/L by using ethanol as a solvent, putting the suspension into a staining jar, soaking a glass slide as a substrate piece by using piranha solution, and vertically inserting the glass slide into the staining jar filled with the silica alcohol suspension.

(3) And (3) placing the dyeing jars filled with the silica methanol suspension into 4 transparent plastic boxes in the step (1) respectively, and taking out the glass sheets after 7 days.

And (4) measuring the thickness of the glass sheet obtained in the step (3) by using an interference method. The thickness range and relative humidity of the obtained silicon dioxide colloidal crystal film correspond to the following steps: the thickness range of the silicon dioxide colloidal crystal film is 1910 +/-80 nm when the relative humidity is 31 percent, the thickness range of the silicon dioxide colloidal crystal film is 1583 +/-70 nm when the relative humidity is 38 percent, the thickness range of the silicon dioxide colloidal crystal film is 1362 +/-13 nm when the relative humidity is 51 percent, and the thickness range of the silicon dioxide colloidal crystal film is 1055 +/-13 nm when the relative humidity is 64 percent.