CN114904596A

CN114904596A - Bubble directional conveying carrier and preparation method and application thereof

Info

Publication number: CN114904596A
Application number: CN202210552993.8A
Authority: CN
Inventors: 吴思竹; 卢嘉伟; 劳召欣
Original assignee: Hefei University of Technology
Current assignee: Hefei University of Technology
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2022-08-16
Anticipated expiration: 2042-05-20
Also published as: CN114904596B

Abstract

The invention relates to the field of precision instruments, in particular to a bubble directional conveying carrier and a preparation method and application thereof. The bubble fixed small conveying carrier is used for directionally conveying bubbles generated by target gas in a stable liquid fluid environment; the conveying carrier comprises a strip-shaped flat-plate-shaped substrate, and the surface of the substrate is in a hydrophobic and hydrophilic state; the hydrophobic and gas-permeable surface of the substrate also comprises parallel double-track-shaped traces, and the area of the substrate surface distributed with the traces is in a hydrophilic and gas-permeable state. The track line comprises two parallel boundary lines and a plurality of rib lines which are distributed in the middle of the two boundary lines and are arranged at equal intervals, and the rib lines obliquely extend from the boundary lines at the two sides to the center respectively; the inclined lines at the corresponding positions of the two boundary lines are symmetrical and do not intersect with each other. The invention solves the problem that the movement direction of the dispersed bubbles in the liquid fluid environment is difficult to effectively regulate and control and transport for a long distance; and lays a foundation for solving the problem of trace gas delivery in specific industries.

Description

Bubble directional conveying carrier and preparation method and application thereof

Technical Field

The invention relates to the field of precision instruments, in particular to a bubble directional conveying carrier and a preparation method and application thereof.

Background

In some research in the fields of biomedicine, chemistry and chemical engineering, etc., it is necessary to transport a specific gas in a liquid fluid environment, or to research the properties or mutual reactions of some gases in the liquid fluid environment. However, since the gas in the liquid fluid generally only moves along with the movement of the liquid fluid, it is difficult to realize the relative movement with respect to the liquid fluid, so that the technician cannot control the gas to be conveyed in the liquid fluid according to a required path; this presents difficulties for certain experiments that require isolation reactions or quantitative analytical studies on gases. Therefore, how to realize the controllable directional gas delivery in a stable liquid fluid becomes a technical problem to be solved by those skilled in the art.

Disclosure of Invention

Based on the above, the invention provides a bubble directional conveying carrier, a preparation method and an application thereof, in order to solve the problem that the movement direction of bubbles dispersed in a liquid fluid environment is difficult to effectively regulate and control.

The technical scheme provided by the invention is as follows:

a bubble-oriented transport vehicle for oriented transport of bubbles generated by a target gas in a quiescent liquid fluid environment. The conveying carrier comprises a strip-shaped flat-plate-shaped base body, and the surface of the base body is in a hydrophobic and hydrophilic state. The hydrophobic and gas-permeable surface of the substrate also comprises parallel double-track-shaped traces, and the area of the substrate surface distributed with the traces is in a hydrophilic and gas-permeable state.

The track line comprises two boundary lines which extend along the target conveying direction and are parallel to each other, the distance between the two boundary lines is D, and the width of each boundary line is g. The track line also comprises a plurality of rib lines which are distributed in the middle of the two boundary lines and are arranged at equal intervals, and the rib lines obliquely extend from the boundary lines at the two sides to the center respectively. Each rib line has a length L and a width w. The distance between two adjacent rib lines on each boundary line is s. The inclined lines at the corresponding positions of the two boundary lines are symmetrical and do not intersect with each other; the rib line spacing at corresponding locations on the two boundary lines is d. The rib line makes an angle alpha with the connecting borderline.

When a certain polar substance or non-polar liquid is selected as a conveying medium, and the directional conveying carrier is immersed in a liquid fluid environment formed by the conveying medium, the target gas to be conveyed forms bubbles with the diameters larger than s and D and smaller than D in the center of two boundary lines of the conveying carrier, and the bubbles can directionally move along the inclined direction of the rib line in the center of the track line.

As a further improvement of the invention, the spacing d between the rib lines at corresponding positions on the two boundary lines satisfies the following condition: d is more than or equal to 1.5mm and is more than or equal to 3.5 mm; the included angle alpha between the rib-shaped line and the connected boundary line satisfies that: alpha is more than or equal to 60 degrees and more than or equal to 10 degrees.

As a further improvement of the invention, the hydrophobic part of the substrate surface has a droplet contact angle of WCA 1: WCA1 is less than or equal to 150 degrees; the bubble contact angle is BCA 1: BCA1 is more than or equal to 2 degrees; the contact angle of the liquid drop of the hydrophilic part of the tracing line area on the surface of the substrate is WCA 2: WCA2 is more than or equal to 0 degree; the bubble contact angle is BCA 2: BCA2 is less than or equal to 120 degrees.

As a further improvement of the invention, the substrate is prepared by adopting a material which does not have chemical reaction with the conveying medium and the gas to be conveyed; the hydrophobic surface of the matrix is obtained by generating a corresponding coating by adopting a super-hydrophobic modifier.

As a further improvement of the invention, the super-hydrophobic modifier coating is constructed by adopting any one of polytetrafluoroethylene, polycarbon wax, polyolefin, polycarbonate, polyamide, polyacrylonitrile, acrylate and Glaco modifier.

As a further improvement of the invention, the substrate is prepared by selecting any one material or a composite material of any plurality of materials from metal, alloy, glass base and organic resin material.

As a further improvement of the invention, the track part on the surface of the substrate is structured in a way of processing a rough surface to obtain the required hydrophilic and air-permeable surface structure.

The invention also provides a preparation method for preparing the bubble directional conveying carrier, and the surface of the bubble directional conveying carrier is provided with a micro-nano structure with special polarity distribution. The bubble directional conveying carrier can be prepared by any one of a template method, an etching method, a chemical vapor deposition method and a coating transfer printing method.

The etching method is obtained by femtosecond laser processing, and the process flow of the bubble directional conveying carrier processed by the femtosecond laser comprises the following steps:

(1) according to the conveying track of the target bubbles of the gas to be conveyed, a strip-shaped aluminum substrate with corresponding size and shape is selected as a base material, so that the conveying track can be completely drawn on the aluminum substrate. The surface of the aluminum substrate is subjected to mirror surface treatment.

(2) Fixing the aluminum substrate on a processing machine table of a femtosecond laser processing system, then setting processing parameters of the femtosecond laser processing system, carrying out primary laser scanning on a distribution area of a conveying track on the surface of the aluminum substrate through femtosecond laser, and processing the mirror surface of the aluminum substrate into a hydrophilic rough surface.

(3) Uniformly spraying a Glaco modifier on the hydrophilic surface subjected to roughening treatment of the aluminum substrate in the previous step, and further forming a hydrophobic surface consisting of a Glaco modified layer after the Glaco modifier is cured.

(4) Setting a scanning path of a femtosecond laser processing system according to a designed target bubble conveying track, carrying out secondary scanning on the aluminum alloy plate in the last step, removing a Glaco modified layer in the scanning track in the secondary scanning process, further processing a track line conforming to the conveying track on a hydrophobic surface in the aluminum substrate, and restoring the track line part on the surface of the aluminum substrate to be in a hydrophilic state after the secondary scanning; at this time, the bubble-oriented transport carrier as described above is obtained.

The invention also comprises an application of the bubble directional conveying carrier, and the bubble directional conveying carrier is used for directionally conveying specific target gas in a liquid fluid environment in a static state. The directional transportation method of the target gas comprises the following steps:

selecting a polar or non-polar liquid fluid as the transport medium according to the properties of the target gas, and forming a required liquid fluid environment by the transport medium.

(ii) selecting bubble-oriented transport vehicles having trajectory lines of corresponding lengths and directions according to the transport trajectory of the target gas to be transported; the bubble-oriented transport carrier is then submerged in a liquid fluid environment.

And (iii) injecting the target gas to be conveyed into a stable liquid fluid environment, locating the target gas to be conveyed at the center of the boundary line of the surface of the bubble directional conveying carrier, and directionally conveying the bubbles of the target gas along the extending direction of the track line in the bubble directional conveying carrier after the bubbles formed by the target gas reach the size meeting the conveying condition.

Wherein the diameter D of the bubbles satisfying the transport conditions _bubble The following conditions are met: d _bubble ＜D；D _bubble ＞d；D _bubble S is greater than; the conveying medium is selected from substances which do not have chemical reaction with the target gas and the bubble directional conveying carrier.

The bubble directional conveying carrier and the preparation method and the application thereof provided by the invention have the following beneficial effects:

the invention designs a brand-new gas directional conveying method and a corresponding conveying carrier. In the technical scheme provided by the invention, target gas to be conveyed is placed in a liquid environment in a static state in a bubble form, a flat plate printed with a hydrophilic track line with an inclined symmetrical double track on a hydrophobic plane can be used as a carrier, and the track line is used for guiding the bubbles to directionally move on the carrier according to a designed conveying route.

The bubble conveying method provided by the invention is simple to operate, high in control precision, capable of realizing movement in any direction, and capable of actively selecting the conveyed gas quantity (corresponding to the size of bubbles) by designing the tracks with different specifications. Or different compositions of gas may be directed to the same location through multiple tracks. Namely, the method realizes the 'programming control' of the gas conveying quantity, the conveying direction, the conveying path and the like, and lays a foundation for realizing accurate gas reaction or quantitative and directional conveying of trace gas.

The bubble conveying carrier designed by the invention has excellent performance, but simple manufacturing process and low generation cost, thereby having great economic value and popularization and application prospect.

Drawings

Fig. 1 is a schematic structural diagram of a bubble-oriented transport carrier according to embodiment 1 of the present invention.

Fig. 2 is a parameter plot of the trajectory in the bubble-directed transport vehicle in embodiment 1 of the present invention.

Fig. 3 is a flowchart of a method for generating a bubble-oriented transport carrier by using a femtosecond laser processing system in embodiment 1 of the present invention.

FIG. 4 shows the interface state between the surface of the aluminum substrate and the droplet after the first laser scanning process.

FIG. 5 shows the interface between the surface of the aluminum substrate and the air bubbles after the first laser scanning process.

Fig. 6 shows the interface state between the surface of the aluminum substrate and the liquid drops after Glaco modification.

FIG. 7 shows the interface state between the surface of the aluminum substrate and the bubbles after the modification with Glaco.

FIG. 8 is a diagram showing the bubble-oriented transport vehicle with a Mi-shaped track layout and the state of transporting bubbles.

FIG. 9 is a diagram of the bubble-directing conveyor with S-shaped track layout and the state of the conveyor.

FIG. 10 is a diagram of a bubble-oriented transport carrier with a U-shaped track layout and a state diagram of transporting bubbles.

FIG. 11 is a diagram of a bubble-oriented transport carrier with a Y-shaped track layout and a state diagram of transporting bubbles.

Fig. 12 is a distribution diagram of the state of the bubble oriented transporting carrier in the embodiment 1 under different structural parameters.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

Example 1

The embodiment provides a bubble directional transport carrier which is used for directionally transporting bubbles generated by target gas in a stable liquid fluid environment. As shown in fig. 1 and 2, the transport carrier includes a strip-shaped flat plate-like substrate, and the surface of the substrate is in a hydrophobic and hydrophilic state (corresponding to the gray shaded area in fig. 2). The hydrophobic and gas-philic surface of the substrate also contains parallel double-track-shaped traces, and the area of the substrate surface distributed with the traces is in a hydrophilic and gas-phobic state (corresponding to the white filling area in fig. 2).

As can be seen from fig. 2, the track line in the bubble orienting transporting carrier of the present embodiment includes two parallel boundary lines extending along the target transporting direction, a distance between the two boundary lines is D, and a width of each boundary line is g. The track line also comprises a plurality of rib lines which are distributed in the middle of the two boundary lines and are arranged at equal intervals, and the rib lines obliquely extend from the boundary lines at the two sides to the center respectively. Each rib line has a length L and a width w. The distance between two adjacent rib lines on each boundary line is s. The inclined lines at the corresponding positions of the two boundary lines are symmetrical and do not intersect with each other; the rib line spacing at corresponding locations on the two boundary lines is d. The rib line makes an angle alpha with the connecting borderline.

After the bubble directional conveying carrier is adopted, when a certain polar substance or non-polar liquid is selected as a conveying medium and the directional conveying carrier is immersed in a liquid fluid environment formed by the conveying medium, the target gas to be conveyed forms bubbles with the diameters larger than s and D and smaller than D in the center of two boundary lines of the conveying carrier, and then the bubbles can directionally move along the inclined direction of the rib-shaped line in the center of the track line.

In the product provided by the embodiment, in order to realize directional conveying, the rib line spacing d at the corresponding position on the two boundary lines satisfies: d is more than or equal to 1.5mm and is more than or equal to 3.5 mm; the included angle alpha between the rib-shaped line and the connected boundary line satisfies that: alpha is more than or equal to 60 degrees and more than or equal to 10 degrees. Wherein, L, alpha, D and D also satisfy: d is 2L · sin α + D. And D is preferably 1/3 of D.

In the bubble oriented transport carrier of the embodiment, the track line of the surface of the base body is equivalent to the rail of the rail vehicle, and plays a role in guiding and controlling the movement direction of the bubbles.

The bubble directional conveying carrier provided by the embodiment can realize the unpowered transmission of bubbles, and the main reason is to utilize the difference of the interface states of three different phases of solid, liquid and gas. The principle is as follows: the surface of the substrate of this embodiment has a special microstructure with alternately distributed hydrophobic and hydrophilic properties, and this microstructure extends in a track shape. Thus, on the one hand, the interface state of the fluid medium at the hydrophobic and hydrophilic portions of the substrate surface is not uniform after the bubble-directed transport carrier is submerged in the liquid fluid environment. On the other hand, when bubbles are formed by injecting the bubbles into the surface of the bubble-oriented transport carrier of the embodiment, the bubbles will contact with the fluid medium and the surface of the substrate, and since there is a significant difference between the contact angles of the "orbital region" and the "non-orbital region" of the substrate surface and the gas, the interface states of the bubbles and the "orbital region" and the "non-orbital region" of the substrate surface are also inconsistent. Under the combined action of the two aspects, the surface tension of the liquid conveying medium can spontaneously drive the bubbles to continuously move forwards along the extension direction of the track until the tail end of the track line is reached. Therefore, the purpose of directionally adjusting the motion track of the bubbles in the liquid conveying medium, namely realizing the directional gas conveying can be realized by designing the trend and the length of the track line of the surface of the substrate in the bubble directional conveying carrier.

When the bubble directional transportation carrier of the embodiment is used for directionally transporting a specific target gas in a liquid fluid environment in a static state, the directional transportation method of the target gas is as follows:

selecting a polar or non-polar liquid fluid as the transport medium according to the properties of the target gas, wherein the transport medium forms a desired liquid fluid environment.

(ii) selecting a bubble directional conveying carrier with a track line with corresponding length and direction according to the transportation track of the target gas to be conveyed; the bubble-oriented transport carrier is then submerged in a liquid fluid environment.

And (iii) injecting the target gas to be conveyed into a stable liquid fluid environment, wherein the target gas is positioned in the center of the boundary line of the surface of the bubble-oriented conveying carrier, and when bubbles formed by the target gas reach the size meeting the conveying condition, the bubbles of the target gas are directionally conveyed along the extending direction of the track line in the bubble-oriented conveying carrier.

Among them, it is considered that the bubbles must be continuously subjected to a cycle of "contact-separation" (generating an asymmetric force in a horizontal direction) with the hydrophilic and hydrophobic portions in the carrier, and thus long-distance transportation can be achieved. The diameter D of the bubble satisfying the transport condition in the present embodiment _bubble The following conditions should also be met: d _bubble ＜D；D _bubble ＞d；D _bubble ＞s。

In this embodiment, the differences between different regions of the substrate surface and the state of the gas-liquid interface are the prerequisites and bases for achieving the directional gas transport in this embodiment. Therefore, in different regions, the larger the difference in contact angle between the gas-liquid two-phase substance should be, the better. Ideally, the contact angle of the hydrophobic and hydrophilic gas portion to the liquid phase should be 180 °, and the contact angle of the hydrophilic contact portion to the liquid phase should be 0 °. Since such ideal state is difficult to achieve, from the technical goal of achieving gas delivery, the droplet contact angle of the hydrophobic portion of the substrate surface in this embodiment is WCA 1: WCA1 is less than or equal to 150 degrees; the bubble contact angle is BCA 1: BCA1 is more than or equal to 2 degrees; the contact angle of the liquid drop of the hydrophilic part of the tracing line area on the surface of the substrate is WCA 2: WCA2 is more than or equal to 0 degree; the bubble contact angle is BCA 2: BCA2 is less than or equal to 120 degrees. It is only necessary to satisfy the above range of contact angles, and the bubble transport can be achieved in general.

In addition, the trace part mainly generates hydrophilic interface action, so that the widths of the boundary lines and the rib lines in the trace are not too wide in practical application, otherwise, the adsorption action on the conveying medium is too strong, and the 'crossing' of bubbles is influenced. However, the widths of the boundary lines and the rib lines in the track line are not too narrow, which may result in failure to generate interfacial tension that drives the bubble forward. In practical applications, the width settings of the boundary lines and the rib lines in the trajectory lines should be adapted according to the specific transport medium and the type of target gas, and the optimal expert experience values are determined through a large number of experiments.

In the gas directional delivery system of the present example, three substances in different states are included, namely, a target gas (delivery object, gaseous state), a delivery medium (providing a stable fluid environment, liquid stage), and a bubble directional delivery medium (containing material layers with different properties inside, such as hydrophobic and hydrophilic parts, solid state). Thus, in this embodiment, to ensure that stable gas delivery can be achieved, the three part objects in the delivery system should remain stationary during mutual dispersion or contact. Namely, the properties of the three should at least satisfy the following conditions:

1) the three should not react chemically. For example, the transport medium should be selected from neutral substances such as water, ethanol, etc., and the material should not have strong reducing or oxidizing properties. For example, under the condition that the aluminum metal plate is selected to prepare the bubble oriented conveying carrier, the conveying medium should not be selected from an acidic aqueous solution.

2) The solubility of the target gas in the liquid should be as low as possible. For example, when directional transport of HCl gas is required, then water should never be selected as the transport medium.

3) The solid substance should be compact and stable in form, have no adsorption cavity inside and cannot absorb liquid or gaseous substances in the conveying system. For example, the matrix material in the bubble-directed transport carrier should be a dense metal such as aluminum plate, but not a porous zeolite or the like.

4) The conveying matrix should be made of a material with low viscosity and good fluidity. Such as water, methanol, ethanol, and the like.

Specifically, in the present example, the base material is selected from any one material or a composite material of any plurality of materials of a metal, an alloy, a glass base, and an organic resin material.

Two regions with different properties of hydrophobic, hydrophilic and hydrophobic and gas-dispelling are distributed on the surface of the substrate in the embodiment; wherein, the hydrophobic and hydrophilic part of the surface of the matrix is obtained by adopting a super-hydrophobic modifier to generate a corresponding coating. The super-hydrophobic modifier coating can be constructed by adopting any one of polytetrafluoroethylene, polycarbon wax, polyolefin, polycarbonate, polyamide, polyacrylonitrile, acrylate and Glaco modifier. Or by special surface processing of a specific base material to form a specific microstructure.

Specifically, the Glaco modifier is adopted in the embodiment to obtain the required hydrophobic and hydrophilic surface on the surface of the aluminum substrate. And the required hydrophilic and gas-permeable surface structure is constructed by processing a rough surface on the trace part of the surface of the substrate.

The surface of the bubble directional conveying carrier provided by the embodiment has a micro-nano structure with special polarity distribution. In particular, it is a surface with two different types of hydrophilicity and hydrophobicity. The bubble transport capability required for this implementation can be produced as long as it has such surface features. The substrate surface is not limited, and may be a smooth structure with a flat surface or a non-smooth uneven structure, for example, in the actual production process, the hydrophilic trace line may be generated by a specific process and is slightly higher than the hydrophobic surface, and is in a scar shape. Or slightly lower than the hydrophobic surface, and is in a groove shape. It should be noted that, the depressions and the protrusions are relatively microscopic differences, and the difference in the height between the hydrophobic surface and the hydrophilic surface is small. In fact, the special microstructure of such "scars" or "grooves" also has a certain promoting effect on the difference in the interface action between different object states to some extent.

The hydrophobic structure and the hydrophilic structure of the surface of the bubble-oriented transport carrier provided by the embodiment can be constructed by different materials, so that the products meeting the requirements can be produced by combining different material properties through subtractive processing or additive manufacturing. For example, the required bubble-oriented transport carrier can be prepared by any one of the processes of template method, etching method, chemical vapor deposition method, coating transfer method, etc.

Specifically, the embodiment processes the required sample of the bubble-oriented transport carrier by an etching method. The generation process of this embodiment adopts a femtosecond laser processing process, and as shown in fig. 3, the preparation process provided by this embodiment mainly includes four process steps, that is: material selection, first laser scanning, coating preparation and second laser scanning.

In particular, in the process flow for generating the bubble directional transportation carrier by the femtosecond laser processing system provided by the embodiment, the detailed steps of each process are as follows:

(1) according to the conveying track of the target bubbles of the gas to be conveyed, a strip-shaped aluminum substrate with corresponding size and shape is selected as a base material, so that the conveying track can be completely drawn on the aluminum substrate. In addition, the surface of the aluminum substrate may be subjected to a pretreatment for forming a mirror surface by polishing.

In this embodiment, aluminium base board is the base member that produces the hydrophobic layer and hydrophilic layer surface, through carrying out mirrorization to the base member and handling, can be so that the different nature surface structure that the post processing was gone out is more even, more unanimous. This is advantageous in improving the properties of the hydrophobic and hydrophilic coatings that are processed.

In this embodiment, the aluminum substrate is roughened by laser irradiation, and the roughened surface of the aluminum substrate becomes a hydrophilic surface. The roughening of the aluminum substrate surface in this embodiment mainly includes two reasons: firstly, in the later stage of this embodiment, a special super-hydrophobic coating is attached to the aluminum substrate, so as to obtain a required hydrophobic surface. Therefore, after the surface of the aluminum substrate is roughened, the adhesive force strength between the super-hydrophobic modified coating material and the aluminum alloy substrate can be improved, and the constructed hydrophobic structure layer is more stable. Secondly, in the embodiment of the present invention, a hydrophilic region (i.e. a trace line portion) needs to be processed in the hydrophobic layer, and after a hydrophilic structure is constructed below the hydrophobic coating, the hydrophilic layer below can be "exposed" only by removing the hydrophobic modification layer on the surface layer of the specific region in the post-processing. The preparation method of the embodiment just adopts the process design concept.

In the embodiment, the femtosecond laser processing system consists of a Chameleon Vision-S seed laser and an Legend Elite F HE-1K titanium sapphire chirped pulse amplification system of the United states Coherent company. Wherein the laser wavelength, pulse width and frequency of the femtosecond laser processing system are respectively set to 800nm, 104fs and 1 kHz. The laser power and the scanning speed during the processing are respectively set to be 40mW and 40 mm/s. In the laser scanning process, the processing area is a strip-shaped rectangular area.

(3) Uniformly spraying a Glaco modifier on the hydrophilic surface subjected to roughening treatment of the aluminum substrate in the previous step, and further forming a hydrophobic surface consisting of a Glaco modified layer after the Glaco modifier is cured. The Glaco modifier adopted in this embodiment is a super-hydrophobic modifier product with excellent performance, and can perform hydrophobic treatment on the surface of the aluminum substrate by a simple spraying manner. After the Glaco modifier is used, the needed hydrophobic and hydrophilic layer can be constructed on the surface of the aluminum substrate only by naturally standing for 2-3min and curing the modified layer material.

(4) Finally, according to the designed conveying track of the target bubbles, setting a scanning path of a femtosecond laser processing system, carrying out secondary scanning on the aluminum alloy plate in the previous step, removing a Glaco modified layer in the scanning track in the secondary scanning process, further processing a track line conforming to the conveying track on the hydrophobic surface in the aluminum substrate, and restoring the track line part on the surface of the aluminum substrate to be in a hydrophilic state after the secondary scanning; at this time, the bubble-oriented transport carrier as described above is obtained.

The preparation method of the embodiment adopts the femtosecond laser processing, and mainly utilizes the advantage of non-hot-melting property of the femtosecond laser processing process. The diffusion of thermal energy into the processing area is thus greatly reduced, the formation of heat-affected zones is significantly reduced, and there is no selectivity for the type of base material. In the embodiment, when the femtosecond laser processing is adopted, the existence of thermal diffusion can be avoided within the duration of the interaction between each laser pulse and a substance, the influence and thermal damage to surrounding materials caused by various effects such as a melting zone, a heat affected zone, a shock wave and the like in the long-pulse processing process are fundamentally eliminated, and the spatial range related to the processing process is greatly reduced, so that the accuracy degree of the laser processing is improved, and convenience is provided for diversification of the processing structure.

Of course, femtosecond laser processing still belongs to an etching processing method for removing materials by using local high-energy light. In order to avoid that the gasified or sputtered material (such as the modified layer and the aluminum substrate) may be re-solidified during the second femtosecond laser processing and fall back to the outside of the trace area in the aluminum substrate, which may affect the performance of the hydrophobic structure processed in the previous step. In this embodiment, a vacuum adsorption device may be installed in the flying laser processing platform to adsorb the airflow or flying dust generated in the processing process in this step; keeping the surface of the aluminum substrate clean.

Performance testing

In order to verify the performance of the product produced by the preparation method provided in this embodiment, a corresponding test is also made in this embodiment, and the bubble directional transport carrier produced by using the aluminum substrate and the Glaco modifier is tested.

1. Surface Performance testing

In the test process, the present embodiment first verifies a droplet contact angle and a bubble contact angle of the surface of the roughened aluminum alloy substrate after the first laser etching. Under microscopic observation conditions, the states of both are shown in fig. 4 and 5. The measurement results showed that the surface of the aluminum substrate exhibited a hydrophilic and hydrophobic state when the droplet contact angle WCA1 was 0 ° and the bubble contact angle BCA1 was 116 °.

Then, the contact angle of the liquid drop and the contact angle of the bubble on the surface of the aluminum substrate after the Glaco modification treatment were verified. Under microscopic observation conditions, the states of both are shown in fig. 6 and 7. The measurement shows that the liquid drop contact angle WCA2 of the surface modified layer part of the aluminum substrate shows 142 degrees and the bubble contact angle BCA1 shows 2 degrees, namely, the surface modified layer part shows a hydrophobic and hydrophilic state. Therefore, the performance of the product processed by the embodiment can reach the expectation.

2. Structural layout of trajectory line

The foregoing has defined the structure of the track in the bubble-directed transport vehicle of the present embodiment. Boundary lines and rib lines must be contained in basic units of the track lines, but in the practical application process, track lines with different layouts can be designed based on the repeating units, so that the track lines are suitable for conveying paths of bubbles under different scenes.

Specifically, in the performance testing phase, four typical trace line forms (e.g., the upper half) as shown in fig. 8 to 11 are actually generated, and the bubble transport effect under four different conditions (e.g., the lower half) is studied.

In fig. 8, the trajectory lines are arranged in a shape of a meter, which is a typical multidirectional straight trajectory. When the generated bubble is located at the center of the rice-shaped structure, if the bubble is initially driven in any direction, the bubble will continue to move along the orbit in the direction until reaching the end of the trajectory line.

In fig. 9, the trajectory lines have an S-shaped layout, which is a typical curved trajectory. When the generated bubble is located at the end of the track, the bubble may slowly move along the track line toward the other end of the rib line in the oblique direction and reach the other side of the track line. It was also found by observation that: in the moving process of the bubble in this example, the moving speed is slower and more unstable than the state in fig. 8, which may be caused by the uneven distribution of the rib-like lines on both sides of the boundary line.

In fig. 10, the trajectory lines are U-shaped, which is a typical composite track comprising three separate straight tracks and two curved tracks connected in between. Under such a turntable, the bubble delivery characteristics are the same as in the previous two embodiments. In particular, the motion state of the bubbles is observed to change when the bubbles reach the curved track of the communication straight track in the test process, which confirms to some extent the analysis of the reason for the change of the motion state of the bubbles caused by the curved track.

In fig. 11, the track line is Y-shaped, which is a split track, and the track at the split is narrowed relative to the width of the original track. In such a track, the larger bubbles can be transported on the wider track, but cannot reach the narrow track after the bifurcation. Whereas smaller bubbles can transition from a wide track to a narrow track. The reason for this phenomenon is that: the size of the bubble that can be transported by the bubble-oriented transport vehicle in this embodiment is related to the specification of the traversable line, and needs to satisfy the diameter D of the bubble _bubble The ranges are as follows: d _bubble ＜D；D _bubble ＞d；D _bubble S. Therefore, when the large bubble reaches the narrow track from the wide track, since the bubble diameter is already larger than the boundary line width D, the transport condition is not satisfied, and at this time, the bubble is automatically lifted and broken. And the small bubble diameter is smaller than the width of the wide track and the narrow track at the same time, so that the small bubble diameter can be simultaneously conveyed on two sections.

3. Study of transport Properties

In the trajectory of the bubble orienting transporting carrier designed in this embodiment, the inclination angle direction α of the rib line at the center of the boundary line determines the transporting direction of the final bubble. Namely: the angle between the rib line and the boundary line has an influence on the delivery capacity of the air bubbles, and specifically, when the angle α is smaller, (the rib line tends to coincide with the boundary line), the directional delivery effect of the air bubbles is gradually deteriorated, but when the angle α is larger, (the shape line tends to be perpendicular to the boundary line), the revelation track loses the "polarity", the air bubbles cannot be guided to move in a certain direction, and the air bubbles can be randomly delivered in two directions, which is not in accordance with the design objective of the present invention.

In combination with research, the transportation performance of the bubble directional transportation vehicle has the greatest correlation with the structural parameters d and alpha, and in order to clear the influence of the two parameters, a distribution graph of the bubble transportation effect under different d and alpha conditions is also drawn in a test experiment in combination with a large number of control experiments, as shown in fig. 12.

In fig. 12, the bubble transport effect is divided into three regions: in the region (I), the bubbles exhibit a pinning state, i.e., are not normally transported. In the area (II), the bubbles are in one-way transportation, namely, the directional transportation can be realized. In zone (iii), the bubbles appear to be transported in both directions, i.e. transport is enabled, but not controllable. It can be seen that the range of only region (ii) belongs to the effective structural parameters of the bubble-oriented transport vehicle in the design process in the present embodiment. Specifically, the rib line spacing d at the corresponding position on the two boundary lines satisfies: d is more than or equal to 1.5mm and is more than or equal to 3.5 mm; the included angle alpha between the rib-shaped line and the connected boundary line satisfies that: alpha is more than or equal to 60 degrees and more than or equal to 10 degrees.

The skilled person can also solve the alternative ranges for d and alpha by linear programming in conjunction with the profile of fig. 12. Specifically, the linear programming process is: firstly, fitting a first curve d 1-f 1 (alpha) according to the boundary of the region (I) and the region (II); then, a second curve is fitted according to the boundary of the region (ii) and the region (iii), and d2 is f2(α); then the required ranges of d and alpha are obtained with d1, d2, and 60 DEG & gtalpha & gt10 DEG as constraint conditions, respectively.

The above-mentioned embodiments only express one of the embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A bubble directional conveying carrier is characterized in that; for the directional transport of gas bubbles generated by a target gas in a quiescent liquid fluid environment; the conveying carrier comprises a strip-shaped flat-plate-shaped substrate, and the surface of the substrate is in a hydrophobic and hydrophilic state; the hydrophobic and gas-philic surface of the substrate also comprises parallel double-track-shaped track lines, and the area of the substrate surface distributed with the track lines is in a hydrophilic and gas-phobic state; the trajectory line comprises two mutually parallel boundary lines extending along the target conveying direction, the width of each boundary line is g, and the distance between every two boundary lines is D; the track line also comprises a plurality of rib lines which are distributed in the middle of the two boundary lines and are arranged at equal intervals, and the rib lines obliquely extend from the boundary lines at the two sides to the center respectively; the length of each rib-shaped line is L, and the width of each rib-shaped line is w; the distance between two adjacent rib-shaped lines on each boundary line is s; the inclined lines at the corresponding positions of the two boundary lines are symmetrical and do not intersect with each other; the interval between the rib-shaped lines at the corresponding positions on the two boundary lines is d; the included angle alpha between the rib-shaped line and the connected boundary line;

when a polar or non-polar liquid is selected as a conveying medium, and the directional conveying carrier is immersed in a liquid fluid environment formed by the conveying medium, the target gas to be conveyed forms bubbles with the diameters larger than s and D and smaller than D in the center of two boundary lines of the conveying carrier, and the bubbles can directionally move along the inclined direction of the rib line in the center of the track line.

2. The bubble oriented transport vehicle of claim 1, wherein: the rib line spacing d at the corresponding positions on the two boundary lines satisfies: d is more than or equal to 1.5mm and is more than or equal to 3.5 mm; the included angle alpha between the rib-shaped line and the connected boundary line satisfies that: alpha is more than or equal to 60 degrees and more than or equal to 10 degrees.

3. The bubble oriented transport vehicle of claim 1, wherein: the contact angle of the liquid drop of the hydrophobic part of the substrate surface is WCA 1: WCA1 is less than or equal to 150 degrees; the bubble contact angle is BCA 1: BCA1 is more than or equal to 2 degrees; the contact angle of the liquid drop of the hydrophilic part of the trace area on the surface of the substrate is WCA 2: WCA2 is more than or equal to 0 degree; the bubble contact angle is BCA 2: BCA2 is less than or equal to 120 degrees.

4. The bubble oriented transport vehicle of claim 1, wherein: the matrix is prepared from a material which does not react with the conveying medium and the gas to be conveyed; the hydrophobic surface of the matrix is obtained by generating a corresponding coating by adopting a super-hydrophobic modifier.

5. The bubble directional-delivery vehicle according to claim 4, wherein: the super-hydrophobic modifier coating is constructed by adopting any one of polytetrafluoroethylene, polycarbon wax, polyolefin, polycarbonate, polyamide, polyacrylonitrile, acrylic ester and Glaco modifier.

6. The bubble oriented transport vehicle of claim 4, wherein: the substrate is prepared from any one material or a composite material of any plurality of materials of metal, alloy, glass base and organic resin material.

7. The bubble oriented transport vehicle of claim 1, wherein: the track line part of the surface of the substrate is constructed in a mode of processing a rough surface to obtain a required hydrophilic and gas-permeable surface structure.

8. The preparation method of the bubble directional conveying carrier is characterized in that the surface of the bubble directional conveying carrier is provided with a micro-nano structure with special polarity distribution; the bubble directional conveying carrier is prepared by any one of a template method, an etching method, a chemical vapor deposition method and a coating transfer method;

the etching method is obtained by femtosecond laser processing, and the process flow of processing the bubble directional conveying carrier by the femtosecond laser comprises the following steps:

(1) according to the conveying track of target bubbles of gas to be conveyed, selecting a strip-shaped aluminum substrate with corresponding size and shape as a base material, so that the conveying track can be completely drawn on the aluminum substrate; the surface of the aluminum substrate is subjected to mirror surface treatment;

(2) fixing an aluminum substrate on a processing machine table of a femtosecond laser processing system, then setting processing parameters of the femtosecond laser processing system, carrying out primary laser scanning on a distribution area of a conveying track on the surface of the aluminum substrate through femtosecond laser, and processing a mirror surface of the aluminum substrate into a hydrophilic rough surface;

(3) uniformly spraying a Glaco modifier on the hydrophilic surface subjected to roughening treatment of the aluminum substrate in the previous step, and forming a hydrophobic surface consisting of a Glaco modified layer after the Glaco modifier is cured;

(4) setting a scanning path of a femtosecond laser processing system according to a designed target bubble conveying track, carrying out secondary scanning on the aluminum alloy plate in the previous step, removing a Glaco modified layer in the scanning track in the secondary scanning process, further processing a track line which accords with the conveying track on the hydrophobic surface of the aluminum substrate, and restoring the track line part on the surface of the aluminum substrate to be in a hydrophilic state after the secondary scanning; at this time, the bubble oriented conveying carrier of claims 1-7 is obtained.

9. The application of the bubble directional conveying carrier is characterized in that: the bubble directional transport vehicle according to any one of claims 1-7, which is used for directionally transporting a specific target gas in a liquid fluid environment in a static state; the directional transportation method of the target gas comprises the following steps:

selecting a certain polar or non-polar liquid fluid as a conveying medium according to the property of the target gas, and forming a required liquid fluid environment by the conveying medium;

(ii) selecting bubble-oriented transport vehicles having trajectory lines of corresponding lengths and directions according to the transport trajectory of the target gas to be transported; then immersing the bubble directional conveying carrier in the liquid fluid environment;

10. The use of the bubble-directed transport vehicle according to claim 9, wherein: diameter D of air bubble satisfying transport condition _bubble The following conditions are met: d _bubble ＜D；D _bubble ＞d；D _bubble S is greater than; and the conveying medium is selected from substances which do not have chemical reaction with the target gas and the bubble directional conveying carrier.