阅读说明：本技术 水下虹吸管材料及其制备方法和应用 (Underwater siphon material and preparation method and application thereof ) 是由 张小龙 董洋 徐翔 何钊 龚瀚源 梅鑫 于 2019-10-09 设计创作，主要内容包括：本发明涉及一种水下虹吸管材料及其制备方法和应用,所述材料在水下对气泡的接触角为0°,所述材料为将毛线浸入低表面能的修饰试剂FAS-SiO<Sub>2</Sub>/PDMS中,对毛线进行疏水改性处理,然后烘干得到能稳定运输水下气泡的超疏水毛线。其制备流程简单易操作,试剂廉价易得且环境友好,随后利用超疏水毛线在水下超疏水超亲气特性,组装水下虹吸管装置实现了对水下气体的运输,实验证明这种运输方式可以长时间保持稳定,并且当某一部分损坏或者断裂时,只需要将毛线两端打结就可以恢复运输,优势明显。这在水下气泡的定向运输,水下气体分离与收集等新技术领域的开发与应用有着广泛的应用前景。(The invention relates to an underwater siphon material and a preparation method and application thereof, wherein the contact angle of the material to bubbles underwater is 0 degree, and the material is a modifying reagent FAS-SiO for immersing wool into low surface energy 2 In PDMS, the wool is subjected to hydrophobic modification treatment and then dried to obtain the super-hydrophobic wool capable of stably transporting underwater bubbles. The preparation process is simple and easy to operate, the reagents are cheap and easy to obtain and environment-friendly, then the super-hydrophobic and super-hydrophilic characteristics of the super-hydrophobic wool are utilized under water, the underwater siphon device is assembled to realize the transportation of the gas under water, experiments prove that the transportation mode can be kept stable for a long time, and when a certain part is damaged or broken, the two ends of the wool can be recovered by knottingThe advantages of the compound fertilizer are obvious after the compound fertilizer is transported. The method has wide application prospect in the development and application of new technical fields of directional transportation of underwater bubbles, separation and collection of underwater gas and the like.)

1. An underwater siphon material, characterized in that the material is modified reagent FAS-SiO with low surface energy by immersing the wool into₂In PDMS, the wool is subjected to hydrophobic modification treatment and then dried to obtain super-hydrophobic wool capable of absorbing and transporting underwater bubblesAnd (4) water wool.

2. A method of making an underwater siphon material, the method comprising the steps of:

step 1, preparation of modified silica nanoparticles:

sequentially adding absolute ethyl alcohol, ammonia water, tetraethyl orthosilicate and FAS, stirring, standing, taking the lower-layer turbid liquid, washing and drying to obtain FAS-SiO₂A nanoparticle;

step 2, preparing a low surface energy modification reagent:

FAS-SiO prepared by step 1₂Dispersing the nano particles by using normal hexane, then adding PDMS and a curing agent, stirring, stopping stirring after the gel-sol reaction is fully performed, and obtaining a modified low surface energy modification reagent FAS-SiO₂/PDMS；

Step 3, performing hydrophobic modification treatment on the wool:

and (3) immersing the wool into the low-surface-energy modifying reagent prepared in the step (2), performing hydrophobic modification treatment on the wool, and drying to obtain the super-hydrophobic wool capable of stably transporting underwater bubbles.

3. The method of claim 2, wherein: in the step 1, the volume ratio of ammonia water, tetraethyl orthosilicate, absolute ethyl alcohol and FAS is (65-75): (12-16):(200-220):(0.001-0.003).

4. The method of claim 2, wherein: in the step 1, the modifying reagent FAS with low surface energy is 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane or hexadecyltrimethoxysilane or a combination thereof.

5. The material of claim 2, wherein: in the step S1, the stirring conditions are: the temperature is 18-25 ℃, the speed is 450-550r/min, and the time is 2-4 h; standing for 8-10 h.

6. The method of claim 2, wherein: in the step S1, absolute ethyl alcohol is adopted for washing for 2-3 times; the drying conditions are as follows: the temperature is 70-85 ℃, and the drying time is 6-10 h.

7. The method of claim 2, wherein: in the step S2, FAS-SiO₂The solid-to-liquid ratio of the nano particles to the n-hexane solution is (2-3): (55-65) (g/mL), the n-hexane concentration is 97% -98%.

8. The method of claim 2, wherein: in the step S2, the PDMS is polydimethylsiloxane, which is used in combination with a curing agent, and the weight ratio of the PDMS to the curing agent is (8-10): 1, PDMS and FAS-SiO₂The weight ratio of the nano particles is (1.2): 2.

9. The method of claim 2, wherein: in the step S3, the hydrophobic modification treatment time is 6-8 min; the drying conditions were: drying at 70-85 deg.C for 20-30 min.

10. The material of claim 1 or the material prepared by the preparation method of any one of claims 2 to 9 is used for carrying out the absorption and transportation of underwater gas.

Technical Field

The invention belongs to the technical field of super-hydrophobic materials, and particularly relates to an underwater siphon material and a preparation method and application thereof.

Background

Generally, the realization of superhydrophobicity of a material interface depends on two points: firstly, the construction of a rough structure and secondly the modification of a low surface energy substance. At present, methods for preparing a super-hydrophobic surface are various, such as an etching method, an electrospinning method, a vapor deposition method and the like, but most of preparation methods have the defects of complex preparation process, complex flow, high price, environment friendliness and the like.

In addition, the super-hydrophobic material has the excellent non-wetting property, so that the super-hydrophobic material has wide application prospects in various fields such as oil-water separation, self-cleaning property, metal protection and the like. However, most of the applications are based on the non-wettability of the super-hydrophobic material in air, and the research on the principle of hydrophilicity of the super-hydrophobic material under water is very little. If the super-hydrophilicity of the super-hydrophobic material under water can be utilized, the absorption, transportation and collection of bubbles can be realized by adopting the principle of the siphon, so that the underwater bubble behavior of the super-hydrophobic surface is analyzed, and guidance is provided for controlling the behavior of bubbles on the surface of a solid in a liquid environment, such as the development and application of the new technical fields of underwater bubble directional transportation and collection.

At present, pipelines are generally adopted for realizing underwater gas transportation, although the transportation efficiency is high, the pipelines generally need to provide extra large power, cannot capture gas in water, and only can realize gas transportation at two ends of a pipe orifice. In addition, if a certain part is damaged or broken, on one hand, the repair is difficult, on the other hand, the cost is high, and the transportation has obvious defects.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides an underwater siphon material and a preparation method and application thereof. In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:

an underwater siphon tube material is prepared by immersing wool into low-surface-energy modifying reagent FAS-SiO₂In PDMS, the wool is subjected to hydrophobic modification treatment and then dried to obtain the super-hydrophobic wool capable of absorbing and transporting underwater bubbles.

A method of making an underwater siphon material, the method comprising the steps of:

step 1, preparation of modified silica nanoparticles: sequentially adding absolute ethyl alcohol, ammonia water, tetraethyl orthosilicate and FAS, stirring, standing, taking the lower-layer turbid liquid, washing and drying to obtain FAS-SiO₂A nanoparticle;

step 2, preparing a low surface energy modification reagent: FAS-SiO prepared by step 1₂Dispersing the nano particles by using normal hexane, then adding PDMS and a curing agent, stirring, stopping stirring after the gel-sol reaction is fully performed, and obtaining a modified low surface energy modification reagent FAS-SiO₂/PDMS；

Step 3, performing hydrophobic modification treatment on the wool: and (3) immersing the wool into the low-surface-energy modifying reagent prepared in the step (2), performing hydrophobic modification treatment on the wool, and drying to obtain the super-hydrophobic wool capable of stably transporting underwater bubbles.

Preferably, in step 1, the mass concentration of the reagent is: ammonia (25% -28%), tetraethyl orthosilicate (97% -99%), absolute ethyl alcohol (98% -99.7%) and FAS (96% -98%); the volume ratio of the ammonia water, the tetraethyl orthosilicate and the absolute ethyl alcohol is (65-75): (12-16):(200-220):(0.001-0.003).

Further preferably, in the step 1, the volume ratio of the ammonia water, the tetraethyl orthosilicate and the absolute ethyl alcohol is 70:14:210: 0.002.

Preferably, in step 1, the low surface energy modifying reagent FAS is 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane or hexadecyltrimethoxysilane or a combination thereof.

Preferably, in step S1, the stirring conditions are: the temperature is 18-25 ℃, the speed is 450-550r/min, and the time is 2-4 h; standing for 8-10 h.

Preferably, in the step S1, the washing is performed 2 to 3 times by using absolute ethyl alcohol; the drying conditions are as follows: the temperature is 70-85 ℃, and the drying time is 6-10 h.

Preferably, in the step S2, FAS-SiO₂The solid-to-liquid ratio of the nano particles to the n-hexane solution is (2-3): (55-65) (g/mL), the n-hexane concentration is 97% -98%. Reacting FAS-SiO₂The nano particles are fully dispersed, and a foundation is laid for fully carrying out the subsequent reaction.

Preferably, in step S2, the PDMS is polydimethylsiloxane, which is used in combination with a curing agent (dow corning 184), and the weight ratio of the PDMS to the curing agent is (8-10): 1, PDMS and FAS-SiO₂The weight ratio of the nano particles is (1.2): 2.

Preferably, in the step S3, the hydrophobic modification treatment time is 6 to 8 min; the drying conditions were: drying at 70-85 deg.C for 20-30 min.

The material or the material prepared by the preparation method is used for absorbing and transporting underwater gas.

The invention has the following beneficial effects:

1. the super-hydrophobic wool material is based on the inherent micron structure of wool, and then uses the prepared low-surface-energy modifying reagent FAS-SiO₂The PDMS is modified, washed and dried to obtain the material. The contact angle of the super-hydrophobic wool material to bubbles under water is close to 0 degree. The device can realize the absorption, transportation and collection of bubbles in water, further analyze the behavior of the bubbles under the water on the super-hydrophobic surface, and provide guidance for controlling the behavior of the bubbles on the solid surface in a liquid environment, such as the development and application of new technical fields of directional transportation and collection of the bubbles under the water. The prepared material has good hydrophilicity under water, and once gas contacts with the material, the gas can be absorbed, so that a good foundation can be provided for absorbing and transporting the gas in water.

2. The method is realized by utilizing the super-hydrophobicity and super-hydrophilicity of the super-hydrophobic wool material under water based on the prepared super-hydrophobic wool materialThe super-hydrophobic wool material can be used as a 'pipeline' by using a method similar to a liquid siphon, so that the underwater gas can be transported. The preparation method of the super-hydrophobic knitting wool can be roughly divided into three steps: first, prepare pure and dry FAS-SiO₂And (3) nanoparticles. Secondly, modifying the silicon dioxide nano particles, and mixing the modified silicon dioxide nano particles with PDMS and n-hexane to obtain FAS-SiO₂A PDMS modifying reagent. And finally, the prepared wool is put into a prepared modifying reagent for modification, and the required super-hydrophobic wool can be obtained after multiple times of washing and drying. The preparation process is simple and easy to operate, the reagent is cheap and easy to obtain, and the method is environment-friendly, and then the transportation of underwater gas is realized by utilizing the super-hydrophobic and super-gas-affinity characteristics of the super-hydrophobic wool yarns under water.

3. The wool is a cheap and common material, has good ductility and repairability, has a micron structure on the surface naturally, and can be modified to prepare the super-hydrophobic wool. The underwater bubble collecting and transporting device has good hydrophily under water, can stably transport bubbles, can quickly capture the bubbles in the water on the surface of the underwater bubble collecting and transporting device, and can realize the collection and transportation of the bubbles in the water. If a certain part is damaged or broken, stable transportation can be recovered only by knotting two ends, and compared with the traditional mode, the advantages are obvious. If the collection and transportation of methane gas in the ocean are hopeful to be realized, the environmental pollution can be relieved, and the energy crisis can be relieved.

4. In the step S1, the stirring conditions are: the temperature is 18-25 ℃, the speed is 450-550r/min, and the time is 2-4 h; standing for 8-10 h. The reaction condition is relatively mild, and the stirring time which is long enough is beneficial to refining and homogenizing the obtained modified silicon dioxide nano particles and is also beneficial to fully carrying out the reaction. Washing with anhydrous ethanol for 2-3 times; the drying conditions are as follows: the temperature is 70-85 ℃, and the drying time is 6-10 h. After being washed for many times, the impurities on the surface of the fabric can be effectively removed, the drying temperature is not too high or too low, the surface structure of the fabric is broken when the drying temperature is too high, the complete drying effect cannot be achieved when the drying temperature is too low, and the necessary drying time is required to be ensured in addition to the proper temperature for complete drying.

5. N-hexane for FAS-SiO₂The nano particles are fully dispersed, and a foundation is laid for fully carrying out the subsequent reaction. The PDMS is matched with a certain curing agent for mixed use, so that the nano particles can be better and more stably attached to the surface of the wool material, and the stability of the prepared super-hydrophobic material is further improved.

Drawings

FIG. 1 is a general flow chart of the process for preparing super-hydrophobic knitting wool as a raw material of an underwater siphon tube in the embodiment of the invention;

FIG. 2 is a comparison of the hydrophobicity in air and the hydrophilicity under water of the superhydrophobic wool material prepared in the example of the invention and the common wool;

FIG. 3 is a photograph of a part of an experiment for demonstrating the transportation of underwater gas by the super-hydrophobic knitting wool material prepared in the example of the present invention;

FIG. 4 is a photograph of a portion of a demonstration experiment of knotting and recovery from transportation after breakage of a superhydrophobic wool material prepared in an example of the present invention;

FIG. 5 is an application of the super-hydrophobic wool material prepared in the embodiment of the invention to transport underwater gas by imitating the root system structure of a plant;

FIG. 6 is an application of the underwater siphon tube prepared in the embodiment of the present invention to self-transport underwater gas using the "siphon" phenomenon.

FIG. 7 is a schematic diagram of an underwater siphon pipe constructed according to an embodiment of the present invention for transporting underwater gas and a schematic diagram of a transportation process.

FIG. 8 is a graph of the velocity of the gas transported underwater by the underwater siphon tube prepared in the example of the present invention as a function of the difference in height (differential pressure) between the two ends of the wool.

Detailed Description

The technical scheme of the invention is further explained by combining the following examples:

in the following examples, the general flow chart of the process for preparing the super-hydrophobic wool is shown in the attached figure 1. A method for preparing a super-hydrophobic wool material related to a novel underwater gas transportation method comprises the following steps:

(1) modified silica (FAS-SiO)₂) And (4) preparing nanoparticles. Ammonia with the concentration of 25-28 percentWater, 98% tetraethyl orthosilicate and 99.7% absolute ethyl alcohol are sequentially added into a 500mL clean beaker according to the volume ratio of 70mL:14mL:210mL, then 2.0 μ L FAS (1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane) is added dropwise, in order to reduce the volatilization of reagents, the upper end of the beaker is sealed by a film, and then the beaker is placed on an 85-2A double-display constant-temperature magnetic stirrer, the reaction temperature is controlled to be 20 ℃, the stirring speed is 500r/min, and the stirring duration is 2H. Standing for 8h, taking the lower layer turbid liquid, washing with absolute ethyl alcohol for 2-3 times to remove impurities, and finally continuously drying for 6-10h at the temperature of 80 ℃ by using a special oven to obtain the modified silicon dioxide nano particles.

(2) Low surface energy modifying reagents (FAS-SiO)₂/PDMS). 2.0g of the modified silica nanoparticles prepared previously was weighed with a high-precision balance and placed in a 100mL beaker, and then dispersed by adding 60mL of 98% n-hexane. And then adding 1.2g of PDMS and 0.12g of curing agent (Dow Corning DC184 available from Alibara) matched with the PDMS into a beaker in sequence according to the proportion of 10:1, sealing the upper end of the beaker by using a film, controlling the room temperature to be 20 ℃ by using a double digital display magnetic stirrer, and continuously stirring for 20min at the stirring speed of 500r/min to obtain the required modifying reagent with low surface energy.

(3) And (4) carrying out hydrophobic modification treatment on the wool. Repeatedly cleaning and drying the wool for many times by using deionized water and absolute ethyl alcohol, soaking the wool in the prepared low-surface-energy modifying reagent for 6-8min, taking out the wool and drying the wool in an oven at the temperature of 80 ℃ for 20min to obtain the super-hydrophobic wool material. Comparing the hydrophobicity of the prepared superhydrophobic woolen yarn material with that of the common woolen yarn in air and the hydrophilicity of the material under water as shown in fig. 2, it can be found that the phenomenon is greatly different when 5 μ L of deionized water is dropped on the prepared superhydrophobic woolen yarn and the common woolen yarn, respectively (fig. 2 a-c). On the super-hydrophobic surface, water drops are spherical and are kept stable for a long time, and on the surface of the common woolen yarn, the water drops are quickly absorbed, which shows that the prepared super-hydrophobic woolen yarn has good hydrophobicity in the air. When the two materials are put into water at the same time, the common yarns are found to be quickly wetted and sunk, and the prepared super-hydrophobic yarn material floats on the water surface due to hydrophobicity (shown in figures 2d-f), when bubbles are respectively dripped on the surfaces of the materials, the contact angle of the bubbles on the surface of the common yarns is found to be large and is kept stable for a long time through the measurement of an instrument, and the bubbles are absorbed on the surface of the super-hydrophobic yarn material within a very short time (0.8 s). The prepared super-water wool material has good air affinity under water, and provides a foundation for realizing underwater gas transportation. Fig. 3 shows that when gas is injected at the lower part of the super-hydrophobic wool, the gas can be separated from the highest point without additional power, and the feasibility of transporting the gas underwater is proved. Fig. 4 shows that when such a "pipeline" transporting underwater gas is damaged or broken, it is not necessary to repair or replace it on a large scale, but only to tie both ends thereof to restore the stability of the transportation. Fig. 5 shows that the material can imitate a plant root system structure model to realize the collection and directional transportation of underwater gas in multiple directions. Fig. 6 shows that the material has the characteristic similar to that of an underwater siphon tube in water, and can self-transport underwater gas as long as the two ends have pressure difference. Under water and under otherwise identical conditions, even normal yarns with a pressure difference across them are not able to transport underwater gas (fig. 7-a), (fig. 7-b) shows that it is not possible to transport underwater gas when there is no pressure difference across the siphon, and that it is known that gas is transported when there is a pressure difference across the siphon produced all the time (fig. 7-c). Fig. 8 shows that when the height difference (differential pressure) between two ends of the underwater siphon is different, the velocity of the transported gas is different, and the larger the differential pressure is, the faster the velocity of the transported gas is, and conversely, the smaller the differential pressure is, the slower the velocity of the transported gas is.

The underwater siphon has wide application prospect, such as: bubbles are always remained near the two sides of the valve due to the vortex, so that the bubbles are not easy to discharge, and the problem of removing the bubbles can be solved by using the material.