CN114904596B

CN114904596B - Bubble directional conveying carrier and preparation method and application thereof

Info

Publication number: CN114904596B
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: 2023-10-27
Anticipated expiration: 2042-05-20
Also published as: CN114904596A

Abstract

The invention relates to the field of precise instruments, in particular to a bubble directional conveying carrier and a preparation method and application thereof. The bubble small-sized conveying carrier is used for directionally conveying bubbles generated by the 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 air-philic state; the hydrophobic and aerophilic surface of the matrix also contains parallel double-track-shaped track lines, and the area of the matrix surface, on which the track lines are distributed, is in a hydrophilic and aerophobic state. The track line comprises two boundary lines which are parallel to each other, and a plurality of rib-shaped lines which are distributed in the middle of the two boundary lines and are arranged at equal intervals, and the rib-shaped lines respectively extend obliquely from the boundary lines on two sides to the center; the inclined lines at the positions corresponding to the two boundary lines are symmetrical to each other and do not intersect with each other. The invention solves the problems 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 micro gas transportation in specific industries.

Description

Bubble directional conveying carrier and preparation method and application thereof

Technical Field

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

Background

In some studies in the fields of biological medicine, chemical engineering, genetic engineering, etc., it is required to transport a specific gas in a liquid fluid environment or to study properties or interactions of certain gases in a liquid fluid environment. However, since the gas in the liquid fluid generally moves only along with the movement of the liquid fluid, the relative movement of the gas with respect to the liquid fluid is difficult to realize, 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 requiring isolated reactions or quantitative analytical studies on gases. Therefore, how to achieve a controllable directional delivery of a gas in a steady liquid fluid is a technical challenge for those skilled in the art.

Disclosure of Invention

Based on the above, 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 invention provides a bubble directional conveying carrier, and a preparation method and application thereof.

The technical scheme provided by the invention is as follows:

a bubble-oriented delivery vehicle for directionally delivering bubbles generated by a target gas in a stationary 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 air-philic state. The hydrophobic and aerophilic surface of the matrix also contains parallel double-track-shaped track lines, and the area of the matrix surface, on which the track lines are distributed, is in a hydrophilic and aerophobic state.

The track line comprises two mutually parallel boundary lines extending along the target conveying direction, 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 equally spaced rib-shaped lines distributed between the two boundary lines, and the rib-shaped lines respectively extend obliquely from the boundary lines on two sides to the center. Each rib line has a length L and a width w. The spacing 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 spacing between the rib-like lines at the corresponding positions on the two boundary lines is d. The rib forms an angle alpha with the connecting boundary line.

When a certain polar substance or nonpolar liquid is selected as a conveying medium, 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 diameters larger than s and D and smaller than D at the centers of two borderlines of the conveying carrier, and the bubbles can directionally move along the inclined direction of the rib-shaped line at the center of the track line.

As a further improvement of the present invention, the rib-like line spacing d at the corresponding positions on the two boundary lines satisfies: d is more than or equal to 3.5mm and more than or equal to 1.5mm; the angle alpha between the rib line and the connected boundary line satisfies the following conditions: the angle 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 droplet contact angle of the hydrophobic part of the substrate surface is WCA1: WCA1 is less than or equal to 150 degrees; bubble contact angle BCA1: BCA1 is more than or equal to 2 degrees; the drop contact angle of the hydrophilic portion of the trace area of the substrate surface is WCA2: WCA2 is more than or equal to 0 degree; bubble contact angle BCA2: BCA2 is less than or equal to 120 degrees.

As a further improvement of the invention, the matrix is prepared from a material which does not react chemically with the transport medium and the gas to be transported; the hydrophobic surface of the matrix is obtained by adopting a super-hydrophobic modifier to generate a corresponding coating.

As a further improvement of the present invention, the superhydrophobic modifier coating is constructed using any one of the group consisting of polytetrafluoroethylene, polycarbowax, polyolefin, polycarbonate, polyamide, polyacrylonitrile, acrylate, and Glaco modifiers.

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

As a further improvement of the invention, the trace line part of the surface of the substrate is structured in a way of processing a rough surface to obtain the required hydrophilic and hydrophobic 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 method.

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

(1) According to the conveying track of the target bubble for conveying the gas, 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, setting processing parameters of the femtosecond laser processing system, and carrying out first laser scanning on a distribution area of a conveying track on the surface of the aluminum substrate by femtosecond laser to process a mirror surface of the aluminum substrate into a hydrophilic rough surface.

(3) And uniformly spraying a Glaco modifier on the hydrophilic surface after the roughening treatment of the aluminum substrate in the upper step, and further forming a hydrophobic surface formed by the Glaco modified layer after the Glaco modifier is solidified.

(4) Setting a scanning path of a femtosecond laser processing system according to a designed conveying track of a target bubble, performing 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 of the aluminum substrate, and recovering 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 directional transportation carrier as described above is obtained.

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

a liquid fluid of a certain polarity or non-polarity is selected as a conveying medium according to the property of the target gas, and a required liquid fluid environment is formed by the conveying medium.

(ii) selecting a bubble directional delivery vehicle having a trajectory of corresponding length and direction according to the transport trajectory of the target gas to be delivered; the bubble-oriented delivery vehicle is then immersed in a liquid fluid environment.

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

Wherein the diameter D of the bubble satisfying the conveying condition _bubble Meets the following conditions: d (D) _bubble ＜D；D _bubble ＞d；D _bubble > s; the transport medium selects a substance that does not chemically react with both the target gas and the bubble-oriented transport vehicle.

The bubble directional conveying carrier provided by the invention and the preparation method and application thereof 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, the target gas to be conveyed is placed in a liquid environment in a static state in the form of bubbles, so that a flat plate with hydrophilic track lines of oblique symmetrical double tracks can be used as a carrier, and the bubbles are guided to move directionally on the carrier according to a designed conveying route by utilizing the track lines.

The bubble conveying method is simple to operate, high in control precision, capable of achieving movement in any direction, and capable of actively selecting the quantity of conveyed gas (corresponding to the size of bubbles) by designing tracks of different specifications. Or the gas with different components is led to the same position through a plurality of tracks. The method realizes the programming control of the conveying amount, the conveying direction, the conveying path and the like of the gas, 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 production cost, thereby having great economic value and popularization and application prospect.

Drawings

Fig. 1 is a schematic structural diagram of a directional bubble transporting carrier according to embodiment 1 of the present invention.

Fig. 2 is a parameter map of the track line in the bubble directional transportation vehicle in embodiment 1 of the present invention.

Fig. 3 is a flowchart of a method for generating a bubble directional transportation carrier using a femtosecond laser machining system in embodiment 1 of the 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 state 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 droplet after Glaco modification.

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

Fig. 8 is a state diagram of a bubble directional transportation carrier with a meter-shaped track line layout and a transportation bubble thereof.

Fig. 9 is a state diagram of a bubble directional transportation carrier with an S-shaped track layout and a transportation bubble thereof.

Fig. 10 is a state diagram of a bubble directional transportation carrier with a U-shaped track layout and a transportation bubble thereof.

Fig. 11 is a state diagram of a bubble directional transport vehicle with a Y-shaped track layout and its transport bubbles.

Fig. 12 is a state distribution diagram of the conveying effect of the bubble directional conveying carrier in embodiment 1 under different structural parameter conditions.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the 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 herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or/and" as used herein includes any and all combinations of one or more of the associated listed items.

Example 1

The present embodiment provides a bubble directional delivery vehicle for directional delivery of bubbles generated by a target gas in a stationary liquid fluid environment. As shown in fig. 1 and 2, the conveying carrier includes a strip-shaped flat plate-shaped substrate, and the surface of the substrate is in a hydrophobic and air-philic state (corresponding to a gray shaded area in fig. 2). The hydrophobic and aerophilic surface of the matrix also contains parallel double-track shaped track lines, and the area of the matrix surface with the track lines is in a hydrophilic and aerophobic state (corresponding to the part of the white filled area in fig. 2).

As can be seen from fig. 2, the track line in the bubble directional transportation vehicle of the present embodiment includes two boundary lines parallel to each other and extending along the target transportation direction, 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 equally spaced rib-shaped lines distributed between the two boundary lines, and the rib-shaped lines respectively extend obliquely from the boundary lines on two sides to the center. Each rib line has a length L and a width w. The spacing 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 spacing between the rib-like lines at the corresponding positions on the two boundary lines is d. The rib forms an angle alpha with the connecting boundary line.

After the bubble directional conveying carrier is adopted, a certain polar substance or nonpolar liquid is selected as a conveying medium, when 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 diameters larger than s and smaller than D at the centers of two borderlines of the conveying carrier, and the bubbles can directionally move along the inclined direction of the rib-shaped line at the center of the track line.

In the product provided in this embodiment, in order to realize directional conveyance, the rib-like line spacing d at the corresponding position on the two boundary lines satisfies: d is more than or equal to 3.5mm and more than or equal to 1.5mm; the angle alpha between the rib line and the connected boundary line satisfies the following conditions: the angle 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=2l·sinα+d. And D is optimally 1/3 of D.

In the bubble directional transportation vehicle of the present embodiment, the track line of the surface of the base body corresponds to the rail of the railway 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 unpowered transmission of bubbles, and mainly utilizes the difference of interface states among substances in three different phases of solid, liquid and gas. The principle is as follows: the surface of the substrate in this embodiment has a special microstructure with alternately distributed hydrophobic and hydrophilic properties, and the microstructure extends in an orbital shape. Thus, in one aspect, the interface state of the fluid medium at the hydrophobic and hydrophilic portions of the substrate surface is non-uniform after the bubble-oriented delivery vehicle is immersed in the liquid fluid environment. On the other hand, when the bubbles are injected into the surface of the bubble directional transportation carrier of the present embodiment to form bubbles, the bubbles will contact with the fluid medium and the surface of the substrate, and since there is a significant difference in the contact angle between the "orbital area" and the "non-orbital area" of the surface of the substrate and the gas, the interface states of the bubbles and the "orbital area" and the "non-orbital area" of the surface of the substrate are also inconsistent. Under the combined action of the two aspects, the surface tension of the liquid conveying medium spontaneously drives the bubbles to continuously move forwards along the extending direction of the track until reaching the tail end of the track line. Therefore, the purpose of directionally regulating the motion track of the bubble in the liquid conveying medium, namely the gas directional 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 directional transportation of a specific target gas in a liquid fluid environment in a stationary state, the directional transportation method of the target gas is as follows:

In which it is considered that the bubbles must be constantly subjected to a "contact-release" cycle (generating an asymmetric force in the horizontal direction) with the hydrophilic and hydrophobic portions of the vehicle, so that long-distance transport is achieved. Diameter D of bubbles satisfying the conveyance condition in the present embodiment _bubble The following conditions should also be met: d (D) _bubble ＜D；D _bubble ＞d；D _bubble ＞s。

In this embodiment, the difference between the interface states of the different regions of the substrate surface and the gas and liquid is the premise and basis for achieving the directional gas delivery in this embodiment. Thus, the larger the difference in contact angle of the gas-liquid two-phase substance should be, the better in the different regions. In an ideal case, the contact angle of the hydrophobic, hydrophilic portion to the liquid phase should be 180 °, while the contact angle of the hydrophilic contact portion to the liquid phase should be 0 °. Since this ideal state is difficult to achieve, from the technical object of achieving gas transport, the droplet contact angle of the hydrophobic portion of the substrate surface in this embodiment is WCA1: WCA1 is less than or equal to 150 degrees; bubble contact angle BCA1: BCA1 is more than or equal to 2 degrees; the drop contact angle of the hydrophilic portion of the trace area of the substrate surface is WCA2: WCA2 is more than or equal to 0 degree; bubble contact angle BCA2: BCA2 is less than or equal to 120 degrees. Bubble transport is usually already achieved by only meeting the above-mentioned contact angle ranges.

In addition, the track line part mainly generates hydrophilic interface effect, so that the width of the boundary line and the rib line in the track line is not too wide in the practical application process, otherwise, the adsorption effect on the conveying medium is too strong, and the 'crossing' of bubbles is affected. However, the width of the boundary lines and the rib lines in the track line should not be too narrow, otherwise interfacial tension, in which the drive bubble is not able to move forward continuously, may be caused. In the practical application process, the width setting of the boundary line and the rib line in the track line should be adaptively adjusted according to the specific conveying medium and the target gas type, and the optimal expert experience value is determined through a large number of experiments.

In the gas directional delivery system of this example, three substances in different physical states are included, namely, a target gas (delivery object, gas state), a delivery medium (providing a steady fluid environment, liquid table) and a bubble directional delivery medium (containing material layers with different properties such as hydrophobic and hydrophilic portions, solid state inside). Therefore, in this embodiment, in order to ensure that stable gas delivery can be achieved, the objects of the three parts in the delivery system should remain stable 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 reducibility or strong oxidability. For example, under the condition of selecting an aluminum metal plate to prepare a bubble directional conveying carrier, the conveying medium should not select an acidic aqueous solution.

2) The solubility of the target gas in the liquid should be as small as possible. For example, when directed delivery of HCl gas is desired, then water should not be selected at all as the delivery medium.

3) The solid substance should be compact and stable in form, and have no adsorption cavity inside, and cannot absorb liquid or gaseous substances in the conveying system. For example, the matrix material in the bubble-oriented delivery vehicle should be selected from dense metals such as aluminum plates, and not porous zeolites.

4) The transport matrix should be selected from materials with low viscosity and good fluidity. Such as water, methanol, ethanol, etc.

Specifically, in this 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.

In the embodiment, the surface of the matrix is distributed with two areas with different properties of hydrophobic and hydrophilic and hydrophobic; wherein, the hydrophobic and the aerophilic part of the surface of the matrix is obtained by adopting a superhydrophobic modifier to generate a corresponding coating. The superhydrophobic modifier coating is constructed using a material that can be any of polytetrafluoroethylene, polycarbon wax, polyolefin, polycarbonate, polyamide, polyacrylonitrile, acrylate, and Glaco modifiers. Or can be obtained by performing special surface processing on a specific matrix material so as to form a specific microstructure.

Specifically, the present example uses a Glaco modifier to achieve the desired hydrophobic and aerophilic surface on the aluminum substrate surface. And the required hydrophilic-hydrophobic surface structure is obtained by constructing the rough surface on the trace line 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. Specifically, there are two different types of hydrophilic and hydrophobic surfaces. With such surface features, the bubble transport capability required for the present implementation can be created. The shape of the surface of the substrate is not limited, and the substrate can be a flush smooth structure or a non-smooth uneven structure, for example, in the actual production process, a hydrophilic track line can be generated through a specific process and is slightly higher than a hydrophobic surface, and the hydrophilic track line is in a 'scar shape'. Or slightly lower than the hydrophobic surface, and has a groove shape. It should be noted that the recesses and protrusions are relatively microscopic differences, and the difference in the dimensions of the height of the hydrophobic surface and the hydrophilic surface is small. In fact, this particular microstructure of "scars" or "grooves" has, to some extent, a promoting effect on the differences in the interface action of the different phases.

The hydrophobic structure and the hydrophilic structure on the surface of the bubble directional conveying carrier provided by the embodiment can be constructed by different materials, so that the product meeting the conditions can be produced by subtraction processing or addition processing by combining different material properties. For example, the required bubble directional conveying carrier can be prepared by any one process of a template method, an etching method, a chemical vapor deposition method, a coating transfer method and the like.

Specifically, the embodiment processes the sample of the required bubble directional transportation carrier through an etching method. The generation process of the embodiment adopts a femtosecond laser processing technology, as shown in fig. 3, the preparation technology provided in the embodiment mainly comprises four process steps, namely: material selection, first laser scanning, coating preparation and second laser scanning.

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

(1) According to the conveying track of the target bubble for conveying the gas, 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. In addition, the surface of the aluminum substrate may be subjected to a mirror-surface pretreatment by polishing.

In this embodiment, the aluminum substrate is a substrate with a hydrophobic layer and a hydrophilic layer, and the substrate is subjected to mirror surface treatment, so that the surface structures with different properties processed in the later stage are more uniform and more consistent. This is advantageous in improving the properties of the processed hydrophobic and hydrophilic coatings.

In the embodiment, the roughening of the surface of the aluminum substrate is realized by irradiating the aluminum substrate with laser, and the roughened surface of the aluminum substrate becomes a hydrophilic surface. The roughening of the surface of the aluminum substrate in this embodiment mainly includes two reasons: 1. in the later stage of the embodiment, a special superhydrophobic coating is attached to an aluminum substrate, so that a required hydrophobic surface is obtained. Therefore, after the surface of the aluminum substrate is roughened, the adhesive force strength between the superhydrophobic modified coating material and the aluminum alloy substrate can be improved, so that the constructed hydrophobic structure layer is firmer. 2. In this embodiment, the hydrophilic region (i.e., the trace portion) is also processed inside the hydrophobic layer, and after the hydrophilic structure has been formed below the hydrophobic coating, the hydrophobic modified layer on the surface layer of the specific region is removed in the subsequent processing, so that the hydrophilic layer below is "exposed". The preparation method of the embodiment exactly adopts the technical design thought.

In this example, the femtosecond laser machining system consisted of a Chameleon Vision-S seed laser from Coherent corporation and a Legend Elite F HE-1K titanium sapphire chirped pulse amplification system. Wherein the laser wavelength, pulse width and frequency of the femtosecond laser processing system are respectively set to 800nm,104fs and 1kHz. The laser power and scanning speed during processing were set at 40mW and 40mm/s, respectively. In the laser scanning process, the processing area is a rectangular area with a long strip shape.

(3) And uniformly spraying a Glaco modifier on the hydrophilic surface after the roughening treatment of the aluminum substrate in the upper step, and further forming a hydrophobic surface formed by the Glaco modified layer after the Glaco modifier is solidified. The Glaco modifier adopted in the embodiment is a super-hydrophobic modifier product with excellent performance, and the surface of the aluminum substrate can be subjected to hydrophobization treatment in a simple spraying mode. After the Glaco modifier is used, the required hydrophobic and aerophilic layer can be constructed on the surface of the aluminum substrate after the modified layer material is solidified by only naturally standing for 2-3 min.

(4) Finally, setting a scanning path of a femtosecond laser processing system according to a designed conveying track of the target bubble, 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 of the aluminum substrate, and recovering 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 directional transportation carrier as described above is obtained.

The preparation method of the embodiment adopts femtosecond laser processing, and mainly utilizes the 'non-hot-melting' advantage of the femtosecond laser processing process. Therefore, the diffusion of heat energy to the processing area is greatly reduced, the formation of a heat affected zone is remarkably reduced, and the type of the matrix material is not selective. When the femtosecond laser processing is adopted in the embodiment, the existence of heat diffusion can be avoided in the duration of interaction between each laser pulse and the substance, the influence and the heat 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 basically eliminated, the space range involved in the processing process is greatly reduced, the accuracy of the laser processing is improved, and convenience is provided for the diversification of processing structures.

Of course, femtosecond laser processing still belongs to an etching processing method for removing materials by utilizing local high-energy light. In order to avoid that the gasified or sputtered material (such as the modified layer and the aluminum substrate) may resolidify and fall back out of the trace area in the aluminum substrate during the second femtosecond laser processing, the performance of the hydrophobic structure processed in the previous step is affected. In the embodiment, vacuum adsorption equipment can be arranged in the laser processing platform to adsorb air flow or flying dust generated in the processing process of the 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 the embodiment, a corresponding test is formulated in the embodiment, and the bubble directional conveying carrier produced by using the aluminum substrate and the Glaco modifier is tested.

1. Surface Performance test

In the test process, the implementation firstly verifies the contact angle of liquid drops and the contact angle of bubbles on the roughened aluminum alloy substrate surface after the first laser etching. Under microscopic observation conditions, the states of the two are shown in fig. 4 and 5. And the measurement shows that at the moment, the contact angle wca1=0° of the liquid drop on the surface of the aluminum substrate and the contact angle bca1=116° of the air bubble are in a hydrophilic and hydrophobic state.

The drop contact angle and bubble contact angle on the aluminum substrate surface after the Glaco modification treatment were then verified. Under microscopic observation conditions, the states of both are shown in fig. 6 and 7. And it was found that the droplet contact angle wca2=142° of the surface modification layer portion of the aluminum substrate at this time and the bubble contact angle bca1=2° were shown to be in a hydrophobic and hydrophilic state. From this, it can be seen that the properties of the product processed by this example are expected.

2. Structural layout of track line

The foregoing has defined the structure of the track line in the bubble-oriented delivery vehicle of the present embodiment. The basic unit of the track line must contain boundary lines and rib lines, but in the practical application process, based on the repeated unit, track lines with different layouts can be designed so as to adapt to the conveying paths of bubbles in different scenes.

Specifically, at this performance test stage, four typical trace patterns (upper half) as shown in fig. 8 to 11 were actually generated, and the bubble transporting effects under four different conditions (lower half) were studied.

In fig. 8, the track lines are arranged in a zig-zag pattern, which is a typical multidirectional straight track. When the generated bubble is positioned at the center of the m-shaped structure, if the bubble is initially driven in any direction, the bubble continues to move along the track in that direction until the end of the track line is reached.

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

In fig. 10, the track lines are in a U-shaped distribution, which is a typical composite track, comprising three separate straight tracks, and two curved tracks at the ends of the intermediate connection. Under such a turntable, the transport characteristics of the bubbles are the same as in the first two embodiments. In particular, the movement state of the bubbles is also changed when the bubbles reach the curved track communicated with the straight track during the test, which proves the analysis of the change reason of the movement state of the bubbles caused by the curved track in a certain degree.

In fig. 11, the track line is Y-shaped, which is a bifurcated track, and the width of the track at the bifurcation is narrowed relative to the original track. In this type of track, larger bubbles can be transported over a wider track, but cannot reach the bifurcated narrow track. Whereas smaller bubbles can transition from a wide track to a narrow track. The reason for this phenomenon is that: the size of the air bubbles which can be transported by the air bubble directional transportation carrier in the embodiment is related to the specification of the track line, and the diameter D of the air bubbles needs to be satisfied _bubble The range is as follows: d (D) _bubble ＜D；D _bubble ＞d；D _bubble > s. Therefore, when a large bubble reaches a narrow track from a wide track, the conveying condition is not satisfied because the bubble diameter is already larger than the boundary line width D, and at this time, the bubble is automatically lifted and broken. While the diameter of the small bubbles is smaller than the width of the wide rail and the narrow rail at the same time, thusAnd conveying the two sections simultaneously.

3. Study of delivery Performance

In the trajectory line of the bubble directional transportation vehicle designed in the present embodiment, the inclination angle direction α of the rib line in the center of the boundary line determines the transportation direction of the final bubble. Namely: the included angle between the rib line and the boundary line has an influence on the conveying capability of the bubble, particularly, when the included angle alpha is smaller, (the rib line and the boundary line tend to coincide), the directional conveying effect of the bubble is gradually deteriorated, but when the included angle is larger, (the rib line and the boundary line tend to be perpendicular), the revealing orbit loses 'polarity', the bubble cannot be guided to move to a certain direction, and random bidirectional conveying of the bubble can occur, which does not meet the design target of the invention.

The combination study found that the transport performance of the bubble-oriented transport vehicle had the greatest correlation with the structural parameters d and α, and that for the sake of clarity both effects were also plotted in the test trials in combination with a number of control trials as shown in fig. 12, with the profile of the bubble transport effect under different d and α conditions.

In fig. 12, the bubble transport effect is divided into three areas, respectively: in the region (I), the bubbles exhibit a pinned state, i.e., are not normally transported. In zone (ii), the bubbles exhibit unidirectional transport, i.e. directional transport is enabled. In zone (iii) the bubbles appear to be bi-directionally transported, i.e. capable of being transported, but uncontrollable. It can be seen that only the region (ii) falls within the effective structural parameters of the bubble-oriented delivery vehicle in the present embodiment during the design process. Specifically, the rib-like line spacing d at the corresponding position on the two boundary lines satisfies: d is more than or equal to 3.5mm and more than or equal to 1.5mm; the angle alpha between the rib line and the connected boundary line satisfies the following conditions: the angle alpha is more than or equal to 60 degrees and more than or equal to 10 degrees.

The skilled person can also solve for the selectable ranges of d and α by linear programming in combination with the profile of fig. 12. Specifically, the linear programming process is: firstly, fitting a first curve d1=f1 (alpha) according to the boundary of the region (I) and the region (II); then fitting a second curve according to the boundary between the area (II) and the area (III), d2=f2 (alpha); and then d1, d2 and 60 degrees or more than or equal to alpha and 10 degrees or more are respectively used as constraint conditions to obtain the required d and alpha ranges.

The above examples illustrate only one embodiment of the invention, which is described in more detail and is not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of the invention should be assessed as that of the appended claims.

Claims

1. A bubble directional conveying carrier, which is characterized in that; for the directional delivery of bubbles generated by a target gas in a stationary 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 air-philic state; the hydrophobic and aerophilic surface of the matrix also comprises parallel double-track-shaped track lines, and the area of the matrix surface, on which the track lines are distributed, is in a hydrophilic and aerophilic state; the track 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 the two boundary lines is D; the track line also comprises a plurality of rib-shaped lines which are distributed between the two boundary lines and are arranged at equal intervals, and the rib-shaped lines respectively extend from the boundary lines at two sides to the center in an inclined way; each rib-shaped line has the length of L and the width of w; the spacing 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 rib line spacing at the corresponding position on the two boundary lines is d, and the following is satisfied: d is more than or equal to 3.5mm and more than or equal to 1.5mm; the included angle alpha between the rib-shaped line and the connected boundary line meets the following conditions: alpha is more than or equal to 60 degrees and more than or equal to 10 degrees;

when a certain polar or nonpolar liquid is selected as a conveying medium, 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 diameters larger than s and D and smaller than D at the centers of two borderlines of the conveying carrier, and the bubbles can directionally move along the inclined direction of the rib-shaped line at the center of the track line;

the droplet contact angle of the hydrophobic portion of the substrate surface was WCA1: WCA1 is less than or equal to 150 degrees; bubble contact angle BCA1: BCA1 is more than or equal to 2 degrees; the drop contact angle of the hydrophilic portion of the substrate surface trace area is WCA2: WCA2 is more than or equal to 0 degree; bubble contact angle BCA2: BCA2 is less than or equal to 120 degrees.

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

3. The bubble directional delivery vehicle of claim 2, 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.

4. The bubble directional delivery vehicle of claim 2, wherein: the matrix is prepared from any one material or composite materials of any multiple materials of metal, alloy, glass base and organic resin materials.

5. The bubble directional delivery vehicle of claim 1, wherein: the track line part of the surface of the matrix is constructed in a mode of processing a rough surface to obtain a required hydrophilic-hydrophobic surface structure.

6. A method of preparing a bubble directional delivery vehicle as set forth in any one of claims 1-5, wherein the bubble directional delivery vehicle has a micro-nano structure with a specific polarity distribution on its surface; 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 printing method;

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

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

(2) Fixing an aluminum substrate on a processing machine table of a femtosecond laser processing system, setting processing parameters of the femtosecond laser processing system, and carrying out first laser scanning on a distribution area of a conveying track on the surface of the aluminum substrate by femtosecond laser to process a mirror surface of the aluminum substrate into a hydrophilic rough surface;

(3) Uniformly spraying a Glaco modifier on the hydrophilic surface after the roughening treatment of the aluminum substrate in the upper step, and further forming a hydrophobic surface formed by the Glaco modified layer after the Glaco modifier is solidified;

(4) Setting a scanning path of a femtosecond laser processing system according to a designed conveying track of a target bubble, performing secondary scanning on the aluminum substrate 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 of the aluminum substrate, and recovering the track line part on the surface of the aluminum substrate to be in a hydrophilic state after the secondary scanning.

7. An application of a bubble directional conveying carrier is characterized in that: the bubble directional delivery vehicle of any one of claims 1-5 for directional delivery of a specific target gas in a liquid fluid environment in a stationary state; the directional transportation method of the target gas comprises the following steps:

selecting a liquid fluid with a certain polarity or non-polarity 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 a bubble directional delivery vehicle having a trajectory of corresponding length and direction according to the transport trajectory of the target gas to be delivered; immersing the bubble directional delivery vehicle in the liquid fluid environment;

8. The use of a bubble directed transport vehicle according to claim 7, wherein: diameter D of bubbles satisfying transport conditions _bubble Meets the following conditions: d (D) _bubble ＜D；D _bubble ＞d；D _bubble > s; the transport medium selects a substance that does not chemically react with both the target gas and the bubble-oriented transport vehicle.