Method for realizing stable and continuous solute diffusion and slow release and diffusion and slow release device

Abstract

The invention discloses a method for realizing stable and continuous solute diffusion and slow release and a diffusion and slow release device. The method comprises the following steps: S100, manufacturing a mold; s200, the hydrogel solution is loaded in a mold, the mold is removed after a hydrogel mechanism is formed through cross-linking treatment, and the hydrogel mechanism is provided with a release cavity, a liquid inlet channel and a liquid outlet channel which are communicated with the release cavity in a limited mode; s300, continuously introducing a to-be-released solute solution into the liquid inlet channel, and continuously discharging the to-be-released solute solution from the liquid outlet channel, so that the concentration of the to-be-released solute solution in the release cavity is kept stable; and S400, at least part of the hydrogel mechanism is placed in target liquid, the to-be-released solute solution comprises to-be-released solute molecules, and the to-be-released solute molecules in the release cavity can be diffused into the bulk phase of the target liquid through the cavity wall of the release cavity. According to the method, stable, continuous and controllable solute molecule release can be realized, so that the flow controllability of the Malangoni interface can be conveniently improved.

Description

Technical Field

[0001] The invention relates to the field of experimental fluid mechanics, and in particular to a method and a diffusion-release device for realizing stable and continuous solute diffusion-release. Background Art

[0002] The Marangoni Effect refers to the phenomenon that when an interfacial tension gradient appears along the interface direction on the interface of two phases of fluid, the fluid interface will become unstable and form interfacial flow. This phenomenon is called the Marangoni Effect, and the resulting flow is called the Marangoni interfacial flow. Among them, the change in the concentration of surfactant can change the interfacial tension.

[0003] Marangoni interfacial flow plays a key role in the field of industrial application technology, involving petrochemical, food and pharmaceutical industries. It is used to regulate the interfacial morphology of dispersed phase droplets in emulsions, promote or inhibit the merging process of droplets; in membrane material-related industries, it is used to control the morphology of liquid films; in aerospace engineering, it is used to design surface tension tanks, considering the interfacial flow effect under microgravity; in the precision micro-machining manufacturing industry, special materials with complex structures are synthesized by controlling the dynamic behavior of micro-nano structures on the solution interface.

[0004] Current technologies usually induce Marangoni flow by injecting an aqueous solution containing surfactants, but the direct injection process of the aqueous solution affects the controllability of the interfacial flow. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for achieving stable and continuous solute diffusion slow release, which can achieve stable, continuous and controllable solute molecular diffusion release, thereby facilitating improving the controllability of Marangoni interface flow.

[0006] The invention also provides a diffusion slow-release device.

[0007] According to the first aspect of the present invention, a method for achieving stable and sustained solute diffusion and slow release comprises the following steps:

[0008] S100, manufacturing mold;

[0009] S200, loading the hydrogel solution into the mold, and removing the mold after forming a hydrogel structure through cross-linking treatment, wherein the hydrogel structure defines a release cavity, and a liquid inlet channel and a liquid outlet channel respectively connected to the release cavity;

[0010] S300, continuously introducing a solute solution to be released into the liquid inlet channel, the solute solution to be released can be diffused and slowly released in the release chamber, and the liquid outlet channel is used to continuously discharge the solution after diffusion and slow release, so that the concentration of the solute solution to be released in the release chamber remains stable;

[0011] S400, placing at least a portion of the hydrogel structure in a target liquid, wherein the solute solution to be released includes solute molecules to be released, and the solute molecules to be released in the release cavity can diffuse into the bulk phase of the target liquid through the cavity wall of the release cavity.

[0012] The method for achieving stable and continuous solute diffusion and slow release according to an embodiment of the present invention has at least the following beneficial effects:

[0013] By cross-linking the hydrogel solution and forming a hydrogel structure with a specific chamber structure, based on the characteristics of the hydrogel material itself, the hydrogel has a porous three-dimensional network structure with different pore sizes. These pores can accommodate a large number of water molecules and allow small molecules to penetrate and diffuse in them, thereby achieving the slow release of solutes and avoiding the disturbance caused by direct injection of aqueous solutions. In addition, the mechanical properties of the hydrogel structure after cross-linking are better and can maintain a stable and long-term release state.

[0014] According to some embodiments of the present invention, the cross-linking treatment is any one of freeze-thaw treatment and photo-cross-linking treatment.

[0015] According to some embodiments of the present invention, the freeze-thaw treatment comprises the following steps:

[0016] S210, freezing the mold carrying the hydrogel solution;

[0017] S220, immersing the mold carrying the hydrogel solution in a salt solution until the frozen hydrogel solution melts;

[0018] S230, loop step S210 and step S220 at least once.

[0019] According to some embodiments of the present invention, before step S210, the following steps are further included:

[0020] S205, performing negative pressure treatment on the mold carrying the hydrogel solution at least once, and after each negative pressure treatment, replenishing the hydrogel solution into the mold until the mold is full.

[0021] According to some embodiments of the present invention, the mold includes an inner cavity and a molding part connected to the cavity wall of the inner cavity, the hydrogel solution is loaded in the inner cavity, and after the hydrogel structure is formed, the molding part is penetrated into the hydrogel structure and defines the liquid inlet channel, the release cavity and the liquid outlet channel in the hydrogel structure.

[0022] According to some embodiments of the present invention, the molded part has a spiral segment, and the spiral segment defines a release cavity of a spiral structure in the hydrogel structure.

[0023] According to some embodiments of the present invention, the mold is formed by 3D printing, and the hydrogel structure is formed in the mold after cross-linking treatment. The step of removing the mold includes the following steps:

[0024] S240, immersing the mold and the hydrogel structure in a mold treatment liquid, and placing them in a vacuum drying oven to dissolve the mold;

[0025] S250, taking out the remaining hydrogel structure;

[0026] S260, performing ultrasonic cleaning on the hydrogel structure at least once.

[0027] According to some embodiments of the present invention, the solute to be released is sodium dodecyl sulfate, which can move to the gas-liquid interface by itself and form Marangoni flow at the gas-liquid interface.

[0028] According to some embodiments of the present invention, between step S200 and step S300, the following steps are further included:

[0029] S270, preparing a first infusion tube, a second infusion tube, an injection mechanism and a waste liquid container;

[0030] S280, respectively connect the two ends of the first infusion tube to the injection mechanism and the liquid inlet channel, and respectively connect the two ends of the second infusion tube to the liquid outlet channel and the waste liquid container.

[0031] The diffusion slow-release device according to the second aspect of the present invention comprises:

[0032] A hydrogel mechanism, the hydrogel mechanism comprising a sustained-release cavity, and a liquid inlet channel and a liquid outlet channel respectively connected to the sustained-release cavity;

[0033] A liquid injection mechanism, the liquid injection mechanism is communicated with the liquid inlet channel and is used for continuously injecting a solute solution to be slowly released into the slow-release cavity;

[0034] Wherein, the hydrogel structure is made by cross-linking a hydrogel solution.

[0035] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0037] Figure 1 A flowchart of an embodiment of the first aspect of the present invention;

[0038] Figure 2 Another flow chart of an embodiment of the first aspect of the present invention;

[0039] Figure 3 It is a schematic structural diagram of a diffusion slow-release device according to an embodiment of the second aspect of the present invention;

[0040] Figure 4 This is a schematic structural diagram of a mold and a hydrogel mechanism according to an embodiment of the present invention;

[0041] Figure 5 This is a curve diagram of the stable Marangoni flow rate achieved by the diffusion slow-release device according to the second embodiment of the present invention.

[0042] Reference numerals:

[0043] Mold 100; molded part 110;

[0044] Hydrogel mechanism 200; release chamber 210; liquid inlet channel 220; liquid outlet channel 230;

[0045] A first infusion tube 300 ; a second infusion tube 310 ; an injection mechanism 320 ; and a waste liquid container 330 . DETAILED DESCRIPTION

[0046] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0047] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., and orientations or positional relationships indicated are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0048] In the description of the present invention, "several" means more than one, "many" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0049] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0050] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0051] Marangoni interfacial flow plays a key role in the field of industrial application technology, involving petrochemical, food and pharmaceutical industries. It is used to regulate the interfacial morphology of dispersed phase droplets in emulsions, promote or inhibit the merging process of droplets; in membrane material-related industries, it is used to control the morphology of liquid films; in aerospace engineering, it is used to design surface tension tanks, considering the interfacial flow effect under microgravity; in the precision micro-machining manufacturing industry, special materials with complex structures are synthesized by controlling the dynamic behavior of micro-nano structures on the solution interface.

[0052] Current technologies usually induce Marangoni flow by injecting an aqueous solution containing surfactants, but the direct injection process of the aqueous solution affects the controllability of the interfacial flow.

[0053] To solve the above problems, the present application proposes a method for achieving stable and sustained solute diffusion and slow release, which can provide stable, controlled, and long-term sustained Marangoni flow at a microscale. Specifically, Figure 1 As shown, the method includes the following steps:

[0054] S100, manufacturing a mold 100;

[0055] It should be noted that the mold 100 can be formed by additive processing, material removal processing, etc. Taking 3D printing to form the mold 100 as an example, the model can be manufactured based on a light-curing 3D printer. The designed mold 100 model is imported into the 3D printer through three-dimensional modeling software, and the mold 100 is made using photosensitive resin.

[0056] S200, loading the hydrogel solution into the mold 100, and removing the mold 100 after forming the hydrogel structure 200 through cross-linking treatment, wherein the hydrogel structure 200 defines a release cavity 210, and a liquid inlet channel 220 and a liquid outlet channel 230 respectively connected to the release cavity 210;

[0057] In this step, the hydrogel solution is loaded into the mold 100 made in the previous step, and then a hydrogel structure 200 having a fixed shape and a certain structural strength is formed through a cross-linking treatment, and then the hydrogel structure 200 is separated from the mold 100 so that the hydrogel structure 200 can have a specific chamber structure.

[0058] The hydrogel solution can be a PVA (polyvinyl alcohol) solution, or it can be other hydrogel solutions such as PEG-DA (polyethylene glycol-diacrylate). Take the preparation of PVA solution as an example: first, take an appropriate amount of PVA particles and place them in a beaker, add a certain amount of ultrapure water to make the mass percentage of the PVA solution reach 5wt%, or 10wt%, or 15wt%, etc., stir vigorously in a 95°C water bath until the PVA particles are completely dissolved, ultrasonically treat for 1 hour, and place in a solution bottle for reserve. It should be noted that hydrogel is a 3D cross-linked polymer material with a high water content, which is widely used in soft robots, tissue engineering, implantable electronic products and other fields. As a highly cross-linked system, hydrogel can allow solute diffusion and release due to its small mesh size, which is very suitable as a carrier for solute transfer and sustained release. However, hydrogels in normal conditions have a high water content and loose cross-linking, which makes the untreated hydrogel structure 200 have weak mechanical properties, so it is rarely used.

[0059] In order to make the hydrogel structure 200 have slow expansion and stable mechanical properties, so that it can be applied to the expansion controlled release device of solute transfer, in the present application, the mechanical properties of the hydrogel are adjusted by cross-linking treatment to meet specific needs. It should be noted that the cross-linking treatment methods that can be used include but are not limited to freeze-thaw cross-linking treatment, photo cross-linking treatment, etc.

[0060] In an embodiment of the present application, the aggregation state of the polymer chains is regulated by ions based on the Hofmeister effect (different salts show different abilities to precipitate proteins from aqueous solutions, which is called the Hofmeister effect) to change the mechanical properties of the hydrogel, and a high-toughness hydrogel is prepared by soaking in a salt solution and cyclic freezing and thawing. For example, the toughness of the hydrogel structure 200 after cross-linking treatment with a PVA solution can reach 150±20MJ·m-3, which exceeds that of synthetic polymers such as polydimethylsiloxane, synthetic rubber, and natural spider silk.

[0061] Therefore, based on the characteristics of the hydrogel material itself, the hydrogel has a porous three-dimensional network structure with different pore sizes. These pores can accommodate a large number of water molecules and allow small molecules to penetrate and diffuse in them, thereby achieving a slow release of solutes and avoiding the disturbance caused by direct injection of aqueous solutions. In addition, the hydrogel structure 200 has good mechanical properties after cross-linking treatment and can maintain a stable and long-term release state.

[0062] S300, continuously introducing the solute solution to be released into the liquid inlet channel 220, the solute solution to be released can be diffused and slowly released in the release chamber 210, and the liquid outlet channel 230 is used to continuously discharge the solution after diffusion and slow release, so that the concentration of the solute solution to be released in the release chamber 210 remains stable;

[0063] It is understandable that the solute solution to be released can form a solute source of stable concentration in the release chamber 210 by continuously flowing through the hydrogel mechanism 200 to maintain the continuous release of the solute. In addition, since the solute solution to be released in the release chamber 210 continuously flows in and out, the pressure in the release chamber 210 can be kept stable by regulating the inflow rate and the outflow rate, so that the solute can enter the liquid phase in the form of diffusion through the grid structure of the hydrogel mechanism 200, realizing the release without convection and improving the controllability of the Marangoni flow. If only the liquid inlet channel 220 is set but the liquid outlet channel 230 is not set, the pressure in the sustained-release chamber gradually rises, and the solute forms convection under the action of water pressure and is released into the body phase, which is easy to cause the disorder of the Marangoni flow.

[0064] S400 , placing at least part of the hydrogel structure 200 in a target liquid, wherein the solute solution to be released includes solute molecules to be released, and the solute molecules to be released in the release cavity 210 can diffuse into the bulk phase of the target liquid through the cavity wall of the release cavity 210 .

[0065] It should be noted that, depending on the different solute molecules in the solute solution to be released, different flow effects will occur after the solute molecules to be released diffuse into the target liquid. Taking the solute molecule as SDS (sodium dodecyl sulfate) as an example, the SDS molecule has amphiphilic properties and is often called a surfactant or amphiphilic molecule. The amphiphilic property means that the SDS molecule has two completely different properties: hydrophilic (polarity) and hydrophobic (non-polarity). The SDS molecule consists of two parts: one part is a long-chain dodecyl group, which is non-polar and therefore hydrophobic; the other part is sulfate and sodium ions, which are polar and therefore hydrophilic. This structure enables the SDS molecule to coexist with water and oil (or other organic matter) at the same time. For this reason, when the SDS molecule enters the target liquid (taking the target liquid as an aqueous solution as an example), the SDS molecule will preferentially adsorb on the water-oil or water-air phase interface, with its hydrophobic tail facing the non-polar phase (such as air or oil), and the hydrophilic head facing the water phase.

[0066] In addition, the adhesion of SDS reduces the interfacial tension. As the SDS molecules aggregate at the interface, the SDS concentration increases locally, and the interfacial tension decreases further, forming a significant interfacial tension gradient.

[0067] Since the hydrogel structure 200 is designed with a liquid inlet channel and a liquid outlet channel, and a certain concentration of SDS solution is always maintained flowing therein, a solute source with a stable concentration is formed in the release chamber 210, and the continuous release of SDS molecules is achieved. Therefore, in the phase interface region near the hydrogel structure 200, the concentration of SDS molecules increases and the interfacial tension decreases, that is, a radial interfacial tension gradient is formed. The liquid flows from the low surface tension region (i.e., the region with a higher SDS concentration) to the high surface tension region (i.e., the region with a lower SDS concentration), which is the solute Marangoni effect, that is, the liquid at the phase interface flows radially from the hydrogel structure 200 as the center.

[0068] Alternatively, the solute molecules may be other solutes that can change the surface tension, such as methanol, ethanol, propanol, isopropanol, propylene glycol, etc. Such solute molecules can cause the solute Marangoni interfacial flow.

[0069] Alternatively, depending on the experimental environment or the solute molecules, the sustained release method is used to generate a stable solute concentration field to induce directional movement of particles (solid particles, microbubbles or microdroplets) driven by the concentration field, including the solute Marangoni effect and the diffusion phoresis effect. For example, the hydrogel structure 200 formed as described above is completely inserted into water, and a specific method is used to make only the liquid phase in the environment. When SDS is continuously introduced, if PS (polystyrene) particles are distributed in the body phase, they will move outward with the hydrogel structure 200 as the center of the circle, and if Decane drops are distributed, they will move inward.

[0070] In addition, the diffusion slow-release device constructed using the method of the first aspect of the present application can achieve stable, continuous and controllable release of solute molecules, thereby facilitating improving the controllability of the flow effect.

[0071] Furthermore, the cross-linking treatment is any one of freeze-thaw treatment and photo-cross-linking treatment. Taking freeze-thaw treatment as an example, Figure 2 As shown, the following steps are included:

[0072] S210, freezing the mold 100 carrying the hydrogel solution;

[0073] The mold 100 carrying the hydrogel solution needs to be placed in a freezer, the temperature of which may be -20°C, until the hydrogel solution in the mold 100 is completely frozen.

[0074] S220, immersing the mold 100 carrying the hydrogel solution in a salt solution until the frozen hydrogel solution melts;

[0075] In the step, the frozen hydrogel solution and the mold 100 are taken out of the freezing chamber, placed in a room temperature environment, and immersed in a saline solution until the frozen hydrogel solution is completely melted. The saline solution needs to be prepared in advance, and the concentration of the saline solution can be 1.5 mol / L. After the proportion is completed, the saline solution is ultrasonically treated for 15 minutes and then placed in a solution bottle for use in this step.

[0076] S230, loop step S210 and step S220 at least once.

[0077] Preferably, step S210 and step S220 are cycled for 3 times, and then the mold 100 carrying the hydrogel solution is immersed in the salt solution and soaked at room temperature for 24 hours. Under the repeated freeze-thaw treatment, the hydrogel solution is cross-linked into a hydrogel structure 200 with better mechanical strength, which can maintain a certain shape, so as to construct a specific release cavity 210 and an inlet and outlet channel 230 in the hydrogel structure 200, thereby forming a stable solute source.

[0078] Before step S210, the following steps are also included:

[0079] S205 , performing negative pressure treatment on the mold 100 carrying the hydrogel solution at least once, and after each negative pressure treatment, adding the hydrogel solution into the mold 100 until the mold 100 is full.

[0080] This step specifically includes the following steps:

[0081] S2051, take a proper amount of hydrogel solution into a container, and immerse the mold 100 in the hydrogel solution. Alternatively, use a syringe to inject the hydrogel solution into the mold 100 to ensure that the hydrogel solution evenly fills the mold 100.

[0082] S2052, sealing the container and connecting it to a vacuum pump, and performing negative pressure treatment; or, placing the mold 100 in a vacuum environment, and performing negative pressure treatment.

[0083] S2053, after each negative pressure treatment is completed, the hydrogel solution is replenished to fill the mold 100, and the negative pressure treatment is performed again, and the cycle is repeated 3 times so that the hydrogel solution can fully fill the mold 100, thereby improving the molding effect of the hydrogel structure 200.

[0084] In some embodiments, Figure 4 As shown, the mold 100 includes an inner cavity and a molding piece 110 connected to the cavity wall of the inner cavity, the hydrogel solution is loaded in the inner cavity, and after the hydrogel structure 200 is formed, the molding piece 110 is inserted into the hydrogel structure 200, and defines a liquid inlet channel 220, a release cavity 210 and a liquid outlet channel 230 in the hydrogel structure 200. Further, the molding piece 110 has a spiral section, and the spiral section defines a release cavity 210 of a spiral structure in the hydrogel structure 200. Thus, the length of the release cavity 210 can be increased in a limited space, so that the solute molecules have more time to diffuse when passing through the release cavity 210.

[0085] In such Figure 4 In the illustrated embodiment, the release chamber 210 of the hydrogel mechanism 200 has a double helical structure, so that the liquid inlet channel 220 and the liquid outlet channel 230 of the release chamber 210 are at the same end, which is conducive to the connection of the hydrogel mechanism 200 with the injection mechanism and the waste liquid recovery mechanism. It can be understood that the release chamber 210 in the hydrogel mechanism 200 can also be a single helical structure, a straight channel loop, a rectangular cavity, etc., and can be adapted to different cavity structures by adjusting the liquid inlet speed and the liquid outlet speed.

[0086] In some embodiments, in order to improve the manufacturing efficiency of the mold 100 and reduce the manufacturing difficulty of complex structures, the mold 100 is formed by 3D printing, and 3D printing includes fused deposition modeling, photo-curing molding, powder sintering, etc. In the embodiment of the present application, the mold 100 is manufactured based on a photo-curing 3D printer with an optical accuracy of 10 μm. Specifically, the following steps are included:

[0087] S110 , importing the designed three-dimensional model of the spiral structure mold 100 into a 3D printer, and making the mold 100 with photosensitive resin.

[0088] S120, post-process the printed mold 100. Clean the uncured resin material and other impurities in the mold 100 with anhydrous ethanol, and repeat for 3 times. The mold 100 is placed in a test tube filled with sufficient anhydrous ethanol and ultrasonically treated for 30 minutes. The mold 100 is placed in a test tube filled with sufficient ultrapure water, ultrasonically treated for 15 minutes, replaced with ultrapure water, ultrasonically treated for 15 minutes, replaced with ultrapure water again, and ultrasonically treated for 15 minutes. The mold 100 is placed in a test tube filled with sufficient ultrapure water for reserve.

[0089] After the cross-linking treatment, the hydrogel structure 200 is formed in the mold 100. The step of removing the mold 100 includes the following steps:

[0090] S240, immersing the mold 100 and the hydrogel structure 200 in the mold 100 treatment liquid, and placing in a vacuum drying oven to dissolve the mold 100;

[0091] Preferably, the temperature in the vacuum drying oven is set to 70°C.

[0092] S250, taking out the remaining hydrogel structure 200;

[0093] S260, performing ultrasonic cleaning on the hydrogel structure 200 at least once;

[0094] In this step, preferably, the hydrogel structure 200 is placed in a test tube filled with sufficient ultrapure water, ultrasonically treated for 15 minutes, and the ultrapure water is renewed, and the cycle is repeated 3 times.

[0095] In some embodiments, between step S200 and step S300, the following steps are also included:

[0096] S270, preparing the first infusion tube 300, the second infusion tube 310, the injection mechanism 320 and the waste liquid container 330;

[0097] The first infusion tube 300 and the second infusion tube 310 may also be capillaries or the like.

[0098] S280, connecting the two ends of the first infusion tube 300 to the injection mechanism 320 and the liquid inlet channel 220 respectively, and connecting the two ends of the second infusion tube 310 to the liquid outlet channel 230 and the waste liquid container 330 respectively.

[0099] In addition, components such as high-speed cameras and high-power laser transmitters can be deployed to facilitate the observation of flow effects.

[0100] like Figure 3As shown, the second embodiment of the present application proposes a diffusion slow release device, which is obtained by applying the method of the first embodiment. The device includes a hydrogel mechanism 200 and an infusion mechanism. The hydrogel mechanism 200 includes a slow release cavity, and a liquid inlet channel 220 and a liquid outlet channel 230 respectively connected to the slow release cavity. The injection mechanism 320 is connected to the liquid inlet channel 220 and is used to continuously inject a solute solution to be slow released into the slow release cavity. The hydrogel mechanism 200 is formed by cross-linking a hydrogel solution. Figure 5 As shown, when the solute molecule is SDS and the hydrogel structure 200 is partially or completely immersed in water in the working state, the diffusion slow-release device of the present application can continuously generate a stable Marangoni flow effect at the gas-liquid interface.

[0101] It should be emphasized that in the field of experimental fluid mechanics, a device for controllable and sustainable diffusion and release of solutes is of great significance. The present invention provides conditions for long-term and controllable diffusion and release of solutes for experimental fluid mechanics laboratory research, promoting the development of theory and experiment of fluid mechanics. In fluid dynamics research, it is very critical to control the release rate, time and amount of solutes. This ability of quantitative control enables experimental researchers to quantitatively study various interfacial flow phenomena in a controlled environment, so as to have a deeper understanding of the laws of interfacial flow. Furthermore, the diffusion and slow-release device helps to verify and expand the theory of fluid mechanics. By more accurately controlling the release conditions, researchers can experimentally verify the fluid dynamics model and further optimize and improve the theoretical framework. In addition, the diffusion and slow-release device also provides an experimental platform for studying non-classical phenomena such as abnormal transmission, which helps to reveal problems that are not yet fully understood in fluid mechanics.

[0102] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for achieving stable and sustained solute diffusion and slow release, characterized in that: The following steps are involved: S100, manufacturing mold; S200, loading the hydrogel solution into the mold, and removing the mold after forming a hydrogel structure through cross-linking treatment, wherein the hydrogel structure defines a release cavity, and a liquid inlet channel and a liquid outlet channel respectively connected to the release cavity; S300, continuously introducing a solute solution to be released into the liquid inlet channel, the solute solution to be released can be diffused and slowly released in the release chamber, and the liquid outlet channel is used to continuously discharge the solution after diffusion and slow release, so that the concentration of the solute solution to be released in the release chamber remains stable; S400, placing at least a portion of the hydrogel structure in a target liquid, wherein the solute solution to be released includes solute molecules to be released, and the solute molecules to be released in the release cavity can diffuse into the bulk phase of the target liquid through the cavity wall of the release cavity.

2. The method for achieving stable and sustained solute diffusion and release according to claim 1, characterized in that: The cross-linking treatment is any one of freeze-thaw treatment and photo-cross-linking treatment.

3. The method for achieving stable and sustained solute diffusion and release according to claim 2, characterized in that: The freeze-thaw process comprises the following steps: S210, freezing the mold carrying the hydrogel solution; S220, immersing the mold carrying the hydrogel solution in a salt solution until the frozen hydrogel solution melts; S230, loop step S210 and step S220 at least once.

4. The method for achieving stable and sustained solute diffusion and release according to claim 3, characterized in that: Before step S210, the following steps are also included: S205, performing negative pressure treatment on the mold carrying the hydrogel solution at least once, and after each negative pressure treatment, replenishing the hydrogel solution into the mold until the mold is full.

5. The method for achieving stable and sustained solute diffusion and release according to claim 1, characterized in that: The mold includes an inner cavity and a molding part connected to the cavity wall of the inner cavity, the hydrogel solution is loaded in the inner cavity, and after the hydrogel structure is formed, the molding part is penetrated into the hydrogel structure and defines the liquid inlet channel, the release cavity and the liquid outlet channel in the hydrogel structure.

6. The method for achieving stable and sustained solute diffusion and release according to claim 5, characterized in that: The molded part has a spiral segment, and the spiral segment defines a release cavity of a spiral structure in the hydrogel structure.

7. The method for achieving stable and sustained solute diffusion and release according to claim 1, characterized in that: The mold is formed by 3D printing, and the hydrogel structure is formed in the mold after cross-linking treatment. The step of removing the mold includes the following steps: S240, immersing the mold and the hydrogel structure in a mold treatment liquid, and placing them in a vacuum drying oven to dissolve the mold; S250, taking out the remaining hydrogel structure; S260, performing ultrasonic cleaning on the hydrogel structure at least once.

8. The method for achieving stable and sustained solute diffusion and slow release according to claim 1, characterized in that: The solute to be released is sodium dodecyl sulfate, which can move to the gas-liquid interface by itself and form Marangoni flow at the gas-liquid interface.

9. The method for achieving stable and sustained solute diffusion and slow release according to claim 1, characterized in that: Between step S200 and step S300, the following steps are also included: S270, preparing a first infusion tube, a second infusion tube, an injection mechanism and a waste liquid container; S280, respectively connect the two ends of the first infusion tube to the injection mechanism and the liquid inlet channel, and respectively connect the two ends of the second infusion tube to the liquid outlet channel and the waste liquid container.

10. A diffusion-slow-release device, characterized in that: include: A hydrogel mechanism, the hydrogel mechanism comprising a sustained-release cavity, and a liquid inlet channel and a liquid outlet channel respectively connected to the sustained-release cavity; A liquid injection mechanism, the liquid injection mechanism is communicated with the liquid inlet channel and is used for continuously injecting a solute solution to be slowly released into the slow-release cavity; Wherein, the hydrogel structure is made by cross-linking a hydrogel solution.

Images