In-situ characterization device and method for liquid-liquid interfacial polymerization

Abstract

The invention discloses an in-situ characterization device and method for liquid-liquid interfacial polymerization, and the method comprises the following steps: during an experiment, adding a water-phase solution into a reaction container through a first injection capillary until the liquid level is higher than the reaction container, and dropwise adding an organic solution onto the liquid level of the water-phase solution through a second injection capillary; moving the interface of the two solutions to a pre-adjusted X-ray light spot, so that X-rays are grazing-incident to the interface at a total reflection angle; starting a continuous exposure mode of an SAXS instrument, carrying out real-time characterization on the formation and evolution of the nano-film structure in the interfacial polymerization process, keeping the interface position unchanged in real time in the experimental process, and controlling the process and rate of the interfacial polymerization reaction. According to the invention, a real-time and high-resolution characterization means is provided for the formation and evolution of the nano-film in the liquid-liquid interfacial polymerization process.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid-liquid interfacial polymerization, and in particular relates to a novel in-situ characterization device and method for liquid-liquid interfacial polymerization. Background Art

[0002] Small-angle X-ray Scattering (SAXS) is a characterization technique that analyzes the nanostructure of a material by irradiating a thin beam of X-rays onto the material and collecting scattered signals within a small angle range (usually less than 5°) that deviates from the original beam. The scattered signals within this small angle range mainly reflect the microstructural characteristics of the material on the scale of a few nanometers to hundreds of nanometers. Depending on the size and morphology of the sample, in actual testing, the X-ray optical path can adopt transmission mode or grazing incidence mode (Grazing Incidence SAXS, GISAXS). In transmission mode, the X-rays directly penetrate the entire sample; while in grazing incidence mode, the X-rays are incident on the surface of the material to be tested at a smaller angle, thereby increasing the irradiation volume. Grazing incidence mode is suitable for detecting nanometer-scale layer-thick materials loaded on a substrate or the surface structure of the material. In existing SAXS instruments, the X-ray light source is usually fixed in position. To achieve GISAXS testing, the sample can be rotated so that it forms a small-angle grazing incidence state with the X-ray beam.

[0003] Liquid-liquid interfacial polymerization (LIIP) involves dissolving two reactive monomers in two immiscible solvents and allowing them to polymerize at the interface of the two liquid phases, forming functional thin films tens of nanometers thick. Due to its unique reaction site, high efficiency, and robustness, LIP has become an important method for preparing functional nanofilms. In situ characterization of the nanostructure formation and evolution of nanofilms generated at the LLII interface, from monomer to polymer, is crucial for understanding the relationship between structure and properties. However, in transmission mode, the strong absorption of X-rays by liquids results in weak scattering signals, making it difficult to measure and interpret nanostructure information. Therefore, GISAXS has become an effective method for real-time tracking of the formation and evolution of nanofilm structures at the LLII interface. To achieve this goal, two conditions must be met: 1) grazing X-ray illumination of the film sample at a low angle on the liquid surface; and 2) the design of an in situ reaction apparatus suitable for high-quality data acquisition during LLII. Under normal conditions, large liquid surfaces typically remain horizontal, making it impossible to rotate the sample to achieve small-angle grazing incidence of X-rays, as is the case with solid-substrate samples. This issue can be addressed by rotating the X-ray source. Furthermore, a dedicated in-situ setup for GISAXS studies of liquid-liquid interfacial polymerization processes is required to ensure smooth experimental execution and accurate data.

[0004] Conventional interfacial polymerization is typically performed in a beaker or reagent bottle. Specifically, the lower layer is an aqueous solution containing one monomer, and the upper layer is an organic solvent containing another monomer. The two monomers polymerize at the interface between the aqueous and organic phases, producing a functional film approximately tens of nanometers thick. However, the glass container walls of this conventional setup significantly absorb and scatter X-ray signals, making it difficult to effectively capture SAXS signals from films as thin as tens of nanometers. Therefore, this setup cannot be directly used for in situ GISAXS measurements.

[0005] Therefore, in order to realize the study of liquid-liquid interface polymerization process using GISAXS technology, it is necessary to design an in-situ reaction device suitable for this scenario. Summary of the Invention

[0006] The main purpose of the present invention is to provide a novel in-situ characterization device and method for liquid-liquid interfacial polymerization.

[0007] To achieve the aforementioned object of the invention, the technical solution adopted by the present invention includes: an in-situ characterization device for liquid-liquid interfacial polymerization, the device being installed on a SAXS instrument and comprising:

[0008] The reaction unit includes a reaction container and an anti-evaporation cover provided on the reaction container, wherein a closed space for experiments is formed between the reaction container and the anti-evaporation cover;

[0009] an injection unit, comprising a first injection capillary and a second injection capillary, wherein the first injection capillary and the second injection capillary pass through the anti-evaporation cover and extend above the reaction container, and are used to inject an aqueous solution and an organic solution into the reaction container respectively;

[0010] Liquid level stabilization module, used to maintain the interface position unchanged in real time during the experiment;

[0011] Reaction control module, used to control the progress and rate of the reaction;

[0012] During the experiment, an aqueous solution is added to the reaction vessel through the first injection capillary until the liquid level of the aqueous solution is higher than the reaction vessel, and an organic solution is added dropwise through the second injection capillary and stabilized on the liquid level of the aqueous solution, so that the interface between the two solutions is higher than the reaction vessel; the interface is moved to a pre-adjusted X-ray spot so that the X-rays are directly incident on the interface at an angle of total reflection; the SAXS instrument is turned on in continuous exposure mode, and the formation and evolution of the nanofilm structure during the interfacial polymerization process are characterized in real time. During the experiment, the liquid level stabilization module is used to maintain the interface position unchanged in real time, and the reaction control module is used to control the progress and rate of the interfacial polymerization reaction.

[0013] In a preferred embodiment, an X-ray entrance window and an X-ray exit window for X-ray entry and exit are respectively provided on opposite sides of the anti-evaporation cover, and the X-ray entrance window and the X-ray exit window are both sealed with a polyimide film material.

[0014] In a preferred embodiment, the liquid level stabilization module includes a liquid level monitoring unit, a liquid level adjustment unit and a liquid replenishment unit. The liquid level monitoring unit is used to monitor the liquid level heights of the aqueous solution and the organic solution in real time. The liquid level adjustment unit is used to adjust the interface height in real time according to the monitoring results of the liquid level monitoring unit. The liquid replenishment unit is connected to the first injection capillary and the second injection capillary, and is used to replenish the aqueous solution and / or organic solution in real time according to the monitoring results of the liquid level monitoring unit.

[0015] In a preferred embodiment, the liquid level monitoring unit includes a SAXS through-light intensity monitoring unit and a camera, and the SAXS through-light intensity monitoring unit monitors the change of the SAXS through-light intensity, and the camera monitors the liquid level height of the aqueous solution and the organic solution in real time; and / or, the liquid level adjustment unit includes a drive motor and a SAXS instrument sample stage connected to the drive motor, and the in-situ characterization device is installed on the SAXS instrument sample stage, and the SAXS instrument sample stage dynamically adjusts the interface position under the drive of the drive motor to maintain the interface position unchanged; and / or, the liquid replenishment unit includes a peristaltic pump, and the peristaltic pump is connected to the first injection capillary and the second injection capillary.

[0016] In a preferred embodiment, the reaction control module includes an ultraviolet catalytic unit and a temperature control unit. The ultraviolet catalytic unit is used to trigger a chemical reaction by irradiating the interface with ultraviolet light of optional wavelength and control the start time and progress of the reaction; the temperature control unit is used to adjust the solution temperature in real time and regulate the chemical reaction rate.

[0017] In a preferred embodiment, the ultraviolet catalytic unit includes a UV lamp and a UV light control module connected to the UV lamp, the UV lamp is located above the reaction container, and the UV lamp irradiates ultraviolet light to the interface under the control of the UV light control module; and / or, the temperature control unit includes a PID control module and a heating module, a refrigeration component and a temperature sensor connected to the PID control module, the temperature sensor is arranged close to the reaction container, and is used to monitor the reaction temperature and transmit the reaction temperature to the PID control module, and the PID control module controls the heating module to heat the reaction container and / or controls the refrigeration component to cool the reaction container.

[0018] On the other hand, the present invention also provides an in situ characterization method for liquid-liquid interfacial polymerization, comprising:

[0019] S1, providing a sealed reaction vessel, adding an aqueous solution into the reaction vessel using a first injection capillary until the liquid level of the aqueous solution is higher than the reaction vessel, and adding an organic solution dropwise onto the liquid level of the aqueous solution through a second injection capillary, such that the interface between the two solutions is higher than the reaction vessel;

[0020] S2, moving the interface to a pre-adjusted X-ray spot so that the X-rays are directly incident on the interface at an angle of total reflection;

[0021] S3, turn on the continuous exposure mode of the SAXS instrument, and perform real-time characterization of the formation and evolution of the nanofilm structure during the interfacial polymerization process. During the experiment, the interface position is maintained unchanged in real time and the progress and rate of the interfacial polymerization reaction are controlled.

[0022] In a preferred embodiment, the process of pre-adjusting the grazing incidence angle of the X-ray spot relative to the liquid surface includes: placing an evaporating dish in a sample chamber of the SAXS instrument, injecting deionized water into the evaporating dish so that the liquid level is higher than the wall of the evaporating dish, rotating the X-ray light source pitch angle device so that the X-ray light source is in a total reflection state with the horizontal plane when looking down at the water surface, locking the X-ray source's downward angle, and finally removing the evaporating dish.

[0023] In a preferred embodiment, in S3, maintaining the interface position unchanged in real time during the experiment includes: real-time monitoring of the liquid level heights of the aqueous solution and the organic solution, if the height changes, using a peristaltic pump to add the aqueous solution through the first injection capillary and / or adding the organic solution through the second injection capillary, and real-time monitoring of the interface height, if it changes, dynamically adjusting the interface position by adjusting the SAXS instrument sample stage to maintain the interface position unchanged.

[0024] In a preferred embodiment, in S3, the real-time control of the progress and rate of the interfacial polymerization reaction during the experiment includes: using ultraviolet light with optional wavelength to irradiate the interface to trigger a chemical reaction, and controlling the start time and progress of the reaction, and real-time monitoring of the reaction temperature in the reaction container and heating, cooling or isothermalizing the reaction container according to the reaction temperature to control the rate of the chemical reaction.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention provides an in-situ device suitable for GISAXS studies of liquid-liquid interfacial polymerization processes. This device can illuminate samples at a low-angle grazing incidence on the liquid surface, resolving the data acquisition difficulties inherent in existing devices due to their simplistic and limited functionality. It provides a real-time, high-resolution method for characterizing the formation and evolution of nanofilms during liquid-liquid interfacial polymerization, enabling high-precision, real-time tracking of the formation and evolution of nanofilms at the liquid-liquid interface. This device fills a gap in existing GISAXS technology for in-situ characterization of liquid-liquid interfacial polymerization processes, providing a key tool for in-depth study of the relationship between the structure and properties of nanofilms and promoting the development of liquid-liquid interfacial polymerization technology and related materials science fields.

[0027] 2. The present invention leverages the surface tension characteristics of liquids and, through design, enables the liquid level to be higher than the edge of the container wall (i.e., the "full but not overflowing" phenomenon). This allows X-rays to directly irradiate the liquid-liquid interface, avoiding obstruction and absorption of X-ray signals by the container wall. This design effectively reduces the impact of the container wall on the quality of experimental data and improves the accuracy of GISAXS detection.

[0028] 3. The present invention introduces a capillary structure to fix the position of the upper solution and restrict its flow, thereby ensuring that the upper solution can maintain long-term stability during the liquid-liquid interface polymerization process.

[0029] 4. The present invention solves the problem of the position stability of the liquid-liquid interface relative to the X-ray: a) Closed space design: By constructing a closed experimental environment, the evaporation rate of the liquid is effectively reduced, thereby reducing the possibility of changes in the liquid level. b) SAXS direct light intensity monitoring and camera assistance: Utilizing the changes in the SAXS direct light intensity and the camera to monitor the liquid level in real time, the liquid level position deviation is promptly detected and adjusted. c) SAXS instrument sample stage adjustment: By adjusting the position of the sample stage of the SAXS instrument, the liquid level is dynamically corrected to ensure that the liquid-liquid interface is always in the optimal test position. d) Peristaltic pump solution replenishment: A peristaltic pump is used to drip the solution. When the liquid level drops due to evaporation, the solution is replenished in time to restore the liquid level, which can flexibly adapt to different experimental needs.

[0030] 5. This invention incorporates chemical reaction control modules: a) UV irradiation module: This module triggers specific chemical reactions through UV irradiation and precisely controls the reaction start time and progress. b) Temperature control module: This module regulates the solution temperature through cooling and heating to achieve precise control of the chemical reaction rate, meeting the requirements of different experimental conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 Schematic diagram of the structure of the in-situ characterization device of the present invention installed on the SAXS instrument;

[0033] Figure 2 It is a structural diagram of the connection between the in-situ characterization device and the functional module of the present invention;

[0034] Figure 3 It is a schematic diagram of the explosion structure of the in-situ characterization device of the present invention;

[0035] Figure 4 This is a schematic diagram of the GISAXS test liquid-liquid interfacial polymerization reaction of the present invention;

[0036] Figure 5 It is a schematic flow chart of the in situ characterization method of the present invention.

[0037] Reference numerals:

[0038] 1. Adapter plate, 2. Insulation substrate, 3. Heating module, 4. Refrigeration assembly, 5. Temperature sensor, 6. Reaction vessel, 7. Anti-evaporation cover, 8a. X-ray incident window, 8b. X-ray exit window, 9. First injection capillary, 10. UV lamp, 11. Second injection capillary. DETAILED DESCRIPTION

[0039] The present invention will be more fully understood through the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the present invention, which can be embodied in various forms. Therefore, the specific functional details disclosed herein should not be construed as limiting, but rather as a basis for the claims and as a representative basis for teaching those skilled in the art to employ the present invention in various ways in virtually any appropriately detailed embodiment.

[0040] The present invention provides an in-situ characterization device suitable for GISAXS research on liquid-liquid interfacial polymerization processes. By integrating liquid surface stability control, chemical reaction regulation and SAXS coupling modules, etc., it can realize irradiation of samples at a small angle grazing incidence on the liquid surface, solving the data acquisition difficulties caused by the simple and single function of the device in the prior art, and providing a real-time, high-resolution characterization method for the formation and evolution of nanofilms in the liquid-liquid interfacial polymerization process. Moreover, by optimizing the device design, the interference of the container wall on the X-ray signal is significantly reduced, and the chemical reaction is stable for a long time and the chemical reaction can be controlled, thereby improving the reliability and accuracy of the experimental data. The present invention fills the gap in the field of in-situ characterization of liquid-liquid interfacial polymerization processes in the prior art, provides a key tool for in-depth research on the relationship between the structure and performance of nanofilms, and promotes the development of liquid-liquid interfacial polymerization technology and related materials science fields. The device can be widely used in the fields of COF material synthesis, gas-liquid interface self-assembly, etc., and provides a high-precision in-situ characterization tool for nanomaterial mechanism research.

[0041] Combine Figures 1 to 4 As shown, an in-situ characterization device for liquid-liquid interfacial polymerization disclosed in an embodiment of the present invention is installed as a whole on a SAXS instrument, and is specifically fixed on a sample stage of the SAXS instrument (not shown) in a detachable manner to ensure the stability of the overall structure and facilitate replacement or maintenance.

[0042] The in-situ characterization device is used as an in-situ reaction device for a grazing-incidence small-angle X-ray scattering (SAXS) instrument. It mainly includes a reaction unit, a microfluidic injection unit, a liquid level stabilization module, and a reaction control module. Through the coordinated cooperation between these components, precise control and real-time monitoring of the liquid-liquid interface polymerization process can be achieved.

[0043] The reaction unit specifically includes a reaction vessel 6 and an evaporation-proof cover 7. The evaporation-proof cover 7 is mounted on the reaction vessel 6 and can effectively reduce the evaporation rate of the liquid, ensuring the long-term stability of the liquid level. A sealed space for experimentation is formed between the evaporation-proof cover 7 and the reaction vessel 6. By creating a sealed experimental environment, the evaporation rate of the liquid in the reaction vessel 6 can be effectively reduced, thereby reducing the possibility of changes in the liquid level. An X-ray entrance window 8a and an X-ray exit window 8b are provided on opposite sides of the evaporation-proof cover 7. The X-ray entrance window 8a and the X-ray exit window 8b allow X-rays to enter and exit the evaporation chamber, respectively, and are symmetrically arranged. Preferably, both the X-ray entrance window 8a and the X-ray exit window 8b are sealed with an ultra-thin polyimide film material to minimize X-ray absorption and meet GISAXS detection requirements.

[0044] The microfluidic injection unit specifically includes a first injection capillary 9 and a second injection capillary 11. The first injection capillary 9 and the second injection capillary 11 extend through the above-mentioned evaporation-proof cover 7 and extend above the reaction vessel 6. They are used to inject the aqueous solution and organic solution required for the polymerization reaction into the reaction vessel 6 respectively. By introducing capillary feed, the injection amount and speed of the two monomer solutions can be accurately controlled. It is also used to fix the position of the upper solution (i.e., the organic solution) and restrict its flow, thereby ensuring that the upper solution can maintain long-term stability during the liquid-liquid interface polymerization process. In this embodiment, the top of the evaporation-proof cover 7 is perforated to allow the first injection capillary 9 and the second injection capillary 11 to pass through.

[0045] The liquid level stabilization module is used to maintain the interface position unchanged in real time during the experimental process. In this embodiment, the liquid level stabilization module specifically includes a liquid level monitoring unit (not shown), a liquid level adjustment unit and a liquid replenishment unit, wherein the liquid level monitoring unit is used to monitor the liquid level heights of the above-mentioned aqueous solution and organic solution in real time. In this embodiment, the liquid level monitoring unit specifically includes a SAXS through-light intensity monitoring unit and a camera. The SAXS through-light intensity monitoring unit monitors the changes in the SAXS through-light intensity and cooperates with the camera to monitor the liquid level heights of the aqueous solution and the organic solution in real time, and promptly detects and adjusts the liquid level position deviation. The liquid level adjustment unit is connected to the liquid level monitoring unit and is used to adjust the interface height in real time according to the monitoring results of the liquid level monitoring unit. In this embodiment, the liquid level adjustment unit specifically includes a drive motor (not shown) and the above-mentioned SAXS instrument sample stage connected to the drive motor. The in-situ characterization device is installed on the SAXS instrument sample stage. The drive motor can drive the SAXS instrument sample stage to move in the three directions of the X-axis, Y-axis, and Z-axis. The SAXS instrument sample stage dynamically adjusts the interface position under the drive of the drive motor to maintain the interface position unchanged, ensuring that the liquid-liquid interface is always in the optimal test position. The rehydration unit is connected to the liquid level monitoring unit and is also connected to the above-mentioned first injection capillary 9 and second injection capillary 11, and is used to replenish the aqueous solution and / or organic solution in real time according to the monitoring results of the liquid level monitoring unit. In this embodiment, the rehydration unit includes a peristaltic pump, which is connected to the first injection capillary 9 and the second injection capillary 11. If the liquid level of the aqueous solution is monitored to change during the experiment, the peristaltic pump is used to drip the aqueous solution to keep the droplet position unchanged. Similarly, if the liquid level of the organic solution is monitored to change, the peristaltic pump is used to drip the organic solution to keep the droplet position unchanged. The present invention adopts a peristaltic pump to drip the solution. When the liquid level drops due to evaporation, the solution is replenished in time to restore the liquid level. This method can drip the lower layer of aqueous solution and add the upper layer of organic solution, and flexibly adapt to different experimental needs. The rehydration unit is also the above-mentioned sampling unit. When the liquid is injected, the first injection capillary 9 and the second injection capillary 11 are driven by the peristaltic pump to inject the aqueous solution and the organic solution into the reaction vessel 6 respectively.

[0046] The reaction control module is used to control the process and rate of the reaction, in order to achieve effective regulation of the liquid-liquid interfacial polymerization reaction. In the present embodiment, the reaction control module includes an ultraviolet catalytic unit and a temperature control unit, wherein the ultraviolet catalytic unit is used to trigger a chemical reaction by irradiating the interface with ultraviolet light of a selectable wavelength and controlling the start time and process of the reaction. In the present embodiment, the ultraviolet catalytic unit specifically includes a UV lamp 10 and a UV light control module connected to the UV lamp 10, wherein the top of the anti-evaporation cover 7 is perforated for the UV lamp 10 to pass through and enter the anti-evaporation cover 7, that is, the top of the anti-evaporation cover 7 is integrated with the functional modules of the first injection capillary 9, the second injection capillary 11 and the UV lamp 10 here. The UV lamp 10 is located above the reaction vessel 6. Under the control of the UV light control module, the UV lamp 10 irradiates the interface with ultraviolet light. The wavelength of the ultraviolet light is selectable, such as 365nm, 302nm and 256nm, etc., triggering a specific chemical reaction (i.e., the liquid-liquid interfacial polymerization chemical reaction here) by ultraviolet light irradiation and accurately controlling the start time and process of the reaction.

[0047] The temperature control unit is used to adjust the solution temperature in real time and to regulate the chemical reaction rate. In the present embodiment, the temperature control unit specifically includes a PID temperature control module and a temperature sensor 5, a heating module 3 and a refrigeration assembly 4 connected to the PID temperature control module, wherein the temperature sensor 5 is arranged near the reaction vessel 6 for monitoring the reaction temperature in the reaction vessel 6, and the reaction temperature is fed back to the PID temperature control module, and the PID temperature control module controls the heating module 3 to heat the solution in the reaction vessel 6 and / or controls the refrigeration assembly 4 to cool the solution in the reaction vessel according to the reaction temperature, so as to realize the execution of temperature control programs such as heating / cooling / constant temperature for the solution in the reaction vessel 6, thereby realizing the accurate regulation of the temperature of the reaction system, meeting the temperature control requirements under different experimental conditions. In the present embodiment, the refrigeration assembly is a liquid nitrogen blowing refrigeration assembly, which is specifically located below the reaction vessel 6, and the above-mentioned anti-evaporation cover 7 is specifically fixedly connected to the refrigeration assembly 4 by screws. After fixing, the above-mentioned sealed space is formed therein, and the reaction vessel 6 is located in the sealed cavity. The heating module 3 is located below the refrigeration component 4 , that is, the refrigeration component 4 and the heating module 3 are integrated in sequence below the reaction container 6 .

[0048] In this embodiment, a thermal insulation substrate 2 and an adapter plate 1 are sequentially positioned below the heating module 3. The in-situ characterization device is removably secured to the SAXS instrument sample stage via the adapter plate 1, ensuring overall structural stability and facilitating replacement or maintenance. The thermal insulation substrate 2 is mounted on the supporting surface of the adapter plate 1 to reduce thermal interference from the external environment on the reaction system.

[0049] Before the experiment, a SAXS instrument sample chamber system was first built in an air environment to achieve grazing incidence of X-rays on the liquid surface at an angle of total reflection. The specific method in this embodiment is as follows: a Teflon evaporating dish with a side length of 10cm×10cm and a depth of 1cm was placed on the sample stage of the SAXS instrument, deionized water was poured into the evaporating dish so that the liquid level was 1mm higher than the wall of the evaporating dish, and the X-ray light source was adjusted so that it formed a downward angle of 0.1° to 0.2° with the horizontal plane. The specific implementation method is as follows: 1) The water surface in the evaporating dish was coarsely adjusted to the X-ray beam using the sample Z-axis lifting platform, and the X-ray detector was moved to a distance of 4500 mm from the evaporating dish. The transmission and reflection spots on the X-ray detector were used to determine whether the liquid surface was in a grazing incidence relationship with the beam. The up and down knobs of the X-ray light source were roughly adjusted to achieve a downward angle of the X-ray beam relative to the water surface. 2) Finely adjust the downward angle while measuring the reflected beam intensity, adjusting the tilt knob to the maximum reflected light intensity. 3) Finely adjust the liquid surface position and finely adjust the downward angle again to confirm that the X-ray beam is fully reflected from the liquid surface. 4) Measure the distance between the X-ray source and the evaporating dish, and the distance between the evaporating dish and the detector, with the water surface angle at zero degrees. Calculate the angle based on the positions of the transmitted and maximum reflected intensity spots on the X-ray detector. Adjust the downward angle to 0.1° to 0.2°, and remove the evaporating dish. The angle of the X-ray beam relative to the liquid surface in this step will remain unchanged throughout subsequent experiments; a single adjustment will lock the downward angle.

[0050] The bottom of the device was then fixed to the sample stage of a SAXS instrument equipped with a drive motor. The X-ray entrance window 8a and the X-ray exit window 8b were sealed with aliphatic polyimide film. The peristaltic pump, UV lamp 10, liquid nitrogen tank, PID temperature control module, temperature sensor 5, and heating module 3 were then connected to the device via the SAXS instrument's flange interface.

[0051] During the experiment, an aqueous solution is first added to the reaction vessel 6 through the peristaltic pump and the first injection capillary 9. The temperature control unit is turned on and the required reaction temperature is set according to the experimental needs. The liquid level is added until the liquid level of the aqueous solution is higher than the wall edge of the reaction vessel 6. In this embodiment, it is 1 mm higher than the wall edge of the reaction vessel 6. Of course, the present invention does not limit the height of the liquid level above the wall edge of the reaction vessel 6, as long as it meets the requirement of being full but not overflowing.

[0052] Then, the spot monitoring camera of the SAXS instrument uses the Z-axis drive motor of the SAXS instrument to roughly move the liquid surface of the aqueous solution to the X-ray spot. Using the Z-axis scanning function of the SAXS instrument, the moving motor Z moves the liquid surface to the Z position where the X-ray spot covers half the intensity. This position is the optimized motor Z position.

[0053] The organic solution is then added dropwise to the surface of the aqueous solution via a peristaltic pump and a second injection capillary 11, and the organic solution droplets are stabilized on the surface of the aqueous solution using the second injection capillary 11. This allows the interface between the two solutions to be higher than the reaction vessel, allowing X-rays to be directly irradiated at the interface. In conventional experimental setups, commonly used container materials (such as glass materials such as silica) have strong absorption properties for X-rays (such as copper target Kα rays). This absorption effect significantly reduces the intensity of the X-ray signal, making it difficult to effectively collect and analyze the scattered signal. Unlike existing solutions in which the X-rays need to pass through the container wall, the present invention utilizes the characteristics of the liquid surface tension and, through design, allows the liquid level to be higher than the edge of the container wall (i.e., the "full but not overflowing" phenomenon), thereby allowing the X-rays to be directly irradiated at the liquid-liquid interface, avoiding the container wall from blocking and absorbing the X-ray signal. This design effectively reduces the impact of the container wall on the quality of experimental data and improves the accuracy of GISAXS detection.

[0054] The interface is then moved to a pre-adjusted X-ray spot by a monitoring camera on the sample stage of the SAXS instrument using the instrument's X-axis drive motor, so that the X-rays are incident on the interface at a total reflection angle.

[0055] Finally, the SAXS instrument was activated in continuous exposure mode to monitor the formation and evolution of nanostructures at the interface between the droplet and the liquid surface in real time. The nanostructures were analyzed by analyzing the acquired SAXS patterns. During the experiment, the liquid level stabilization module monitored the liquid level in real time to maintain the interface position, and the reaction control module controlled the progress and rate of the interfacial polymerization reaction.

[0056] An embodiment of the present invention provides an in-situ characterization method for liquid-liquid interfacial polymerization, comprising at least the following steps:

[0057] S1, provide a sealed reaction vessel 6, use the first injection capillary 9 to add an aqueous solution into the reaction vessel 6, add until the liquid level of the aqueous solution is higher than the reaction vessel 6, and add the organic solution dropwise onto the liquid level of the aqueous solution through the second injection capillary 11. The interface between the two solutions is higher than the reaction vessel 6, so that X-rays can directly irradiate the interface.

[0058] Specifically, an aqueous solution is first added to the reaction vessel 6 through a peristaltic pump and a first injection capillary 9. The temperature control unit is turned on and the required reaction temperature is set according to the experimental needs. The liquid level is added until the liquid level of the aqueous solution is higher than the wall edge of the reaction vessel 6. Then, the Z-axis drive motor of the SAXS instrument is used to roughly move the liquid level of the aqueous solution to the X-ray spot through the spot monitoring camera of the SAXS instrument. The Z-axis scanning function of the SAXS instrument is used to move the liquid level to block the X-ray spot to a half-intensity position. Then, an organic solution is added dropwise to the liquid level of the aqueous solution through a peristaltic pump and a second injection capillary 11, and the droplets of the organic solution are stabilized on the liquid level of the aqueous solution using the second injection capillary 11. This makes the interface between the two solutions higher than the reaction vessel, so that X-rays can be directly irradiated to the interface.

[0059] S2, moving the interface to a pre-adjusted X-ray spot, so that the X-rays are incident on the interface at a total reflection angle.

[0060] Specifically, the monitoring camera of the SAXS instrument sample stage uses the instrument's X-axis drive motor to move the interface to a pre-adjusted X-ray spot, so that the X-rays are incident on the interface at a grazing angle of total reflection. The pre-adjustment process of the X-ray spot includes: before the experiment, first setting up a SAXS instrument sample chamber system in an air environment so that the X-rays can be incident on the liquid surface at a grazing angle of total reflection. The specific method in this embodiment is: placing a Teflon evaporating dish with a side length of 10cm×10cm and a depth of 1cm on the SAXS instrument sample stage, injecting deionized water into the evaporating dish so that the liquid level is 1mm higher than the evaporating dish wall, and adjusting the X-ray light source so that it forms a downward angle of 0.1° to 0.2° with the horizontal plane. The specific implementation method is as follows: 1) Using the sample Z-axis lift, coarsely adjust the water surface in the evaporating dish to the X-ray beam. Simultaneously, move the X-ray detector to a distance of 4500 mm from the evaporating dish. The transmitted and reflected light spots on the X-ray detector are used to determine whether the liquid surface is at grazing incidence with the beam. Roughly adjust the X-ray source's tilt knob to achieve a downward angle of the X-ray beam relative to the water surface. 2) Finely adjust the downward angle while measuring the reflected beam intensity, adjusting the knob to the maximum reflected light intensity. 3) Finely adjust the liquid surface's vertical position and finely adjust the downward angle again to confirm that the X-ray beam is in a state of total reflection from the liquid surface. 4) Measure the distance between the X-ray source and the evaporating dish, as well as the distance between the evaporating dish and the detector. The angle of the water surface is zero degrees. Calculate the angle based on the positions of the transmitted and reflected light spots on the X-ray detector. Then adjust the downward angle to 0.1° to 0.2°, and remove the evaporating dish.

[0061] S3, turn on the continuous exposure mode of the SAXS instrument, and perform real-time characterization of the formation and evolution of the nanofilm structure during the interfacial polymerization process. During the experiment, the interface position is maintained unchanged in real time and the progress and rate of the interfacial polymerization reaction are controlled.

[0062] Specifically, the SAXS instrument is activated in continuous exposure mode to monitor the formation and evolution of nanostructures at the interface between the droplet and the liquid surface in real time. The nanostructures are analyzed by analyzing the resulting SAXS patterns. During the experiment, the liquid level stabilization module is used to monitor the liquid level in real time to maintain the interface position, and the reaction control module is used to control the progress and rate of the interfacial polymerization reaction. The structures and principles of the liquid level stabilization and reaction control modules can be found in the description of the aforementioned apparatus and are not detailed here.

[0063] The present invention has the following advantages: 1. The present invention provides an in-situ device suitable for GISAXS research on liquid-liquid interfacial polymerization processes, which can irradiate samples at a small angle grazing incidence on the liquid surface, solving the data acquisition difficulties caused by the simple and single function of the device in the prior art, and providing a real-time, high-resolution characterization method for the formation and evolution of nanofilms during liquid-liquid interfacial polymerization, thereby achieving high-precision real-time tracking of the formation and evolution of nanofilms at the liquid-liquid interface. The present invention fills the gap in the field of in-situ characterization of liquid-liquid interfacial polymerization processes in the prior art, provides a key tool for in-depth research on the relationship between the structure and properties of nanofilms, and promotes the development of liquid-liquid interfacial polymerization technology and related materials science fields. 2. The present invention utilizes the characteristics of liquid surface tension and is designed to make the liquid level higher than the edge of the container wall (i.e., the "full but not overflowing" phenomenon), so that X-rays can be directly irradiated to the liquid-liquid interface, avoiding the obstruction and absorption of X-ray signals by the container wall. This design effectively reduces the impact of the container wall on the quality of experimental data and improves the accuracy of GISAXS detection. 3. The present invention introduces a capillary structure to fix the position of the upper solution and restrict its flow, thereby ensuring that the upper solution can maintain long-term stability during the liquid-liquid interface polymerization process. 4. The present invention solves the problem of the stability of the liquid-liquid interface relative to the X-ray position: a) Closed space design: By constructing a closed experimental environment, the liquid evaporation rate is effectively reduced, thereby reducing the possibility of changes in the liquid level. b) SAXS direct light intensity monitoring and camera assistance: Utilizing the changes in the SAXS direct light intensity and the camera to monitor the liquid level in real time, the liquid level position deviation is promptly detected and adjusted. c) SAXS instrument sample stage adjustment: By adjusting the position of the sample stage of the SAXS instrument, the liquid level is dynamically corrected to ensure that the liquid-liquid interface is always in the optimal test position. d) Peristaltic pump solution replenishment: A peristaltic pump is used to drip the solution. When the liquid level drops due to evaporation, the solution is replenished in time to restore the liquid level, flexibly adapting to different experimental needs. 5. The present invention introduces a chemical reaction control functional module: a) Ultraviolet lamp irradiation module: Triggers a specific chemical reaction through ultraviolet light irradiation and accurately controls the start time and progress of the reaction. b) Temperature control module: It adjusts the solution temperature through cooling and heating to achieve precise control of chemical reaction rates to meet the needs of different experimental conditions.

[0064] The various aspects, embodiments, features and examples of the present invention should be considered as illustrative in all respects and are not intended to limit the present invention, the scope of which is defined solely by the claims. Other embodiments, modifications and uses will be apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0065] The use of headings and sections in this disclosure is not meant to limit the disclosure; each section may apply to any aspect, embodiment, or feature of the disclosure.

Claims

1. An in-situ characterization device for liquid-liquid interfacial polymerization, characterized by: The device is installed on a SAXS instrument and comprises: The reaction unit includes a reaction container and an anti-evaporation cover provided on the reaction container, wherein a closed space for experiments is formed between the reaction container and the anti-evaporation cover; an injection unit, comprising a first injection capillary and a second injection capillary, wherein the first injection capillary and the second injection capillary pass through the anti-evaporation cover and extend above the reaction container, and are used to inject an aqueous solution and an organic solution into the reaction container respectively; Liquid level stabilization module, used to maintain the interface position unchanged in real time during the experiment; Reaction control module, used to control the progress and rate of the reaction; During the experiment, an aqueous solution is added to the reaction vessel through the first injection capillary until the liquid level of the aqueous solution is higher than the reaction vessel, and an organic solution is added dropwise through the second injection capillary and stabilized on the liquid level of the aqueous solution, so that the interface between the two solutions is higher than the reaction vessel; the interface is moved to a pre-adjusted X-ray spot so that the X-rays are directly incident on the interface at an angle of total reflection; the SAXS instrument is turned on in continuous exposure mode, and the formation and evolution of the nanofilm structure during the interfacial polymerization process are characterized in real time. During the experiment, the liquid level stabilization module is used to maintain the interface position unchanged in real time, and the reaction control module is used to control the progress and rate of the interfacial polymerization reaction.

2. The in-situ characterization device for liquid-liquid interfacial polymerization according to claim 1, characterized in that: An X-ray entrance window and an X-ray exit window for X-ray entry and exit are respectively provided on two opposite sides of the anti-evaporation cover, and both the X-ray entrance window and the X-ray exit window are sealed with a polyimide film material.

3. The in-situ characterization device for liquid-liquid interfacial polymerization according to claim 1, characterized in that: The liquid level stabilization module includes a liquid level monitoring unit, a liquid level adjustment unit and a liquid replenishing unit. The liquid level monitoring unit is used to monitor the liquid level heights of the aqueous solution and the organic solution in real time. The liquid level adjustment unit is used to adjust the interface height in real time according to the monitoring results of the liquid level monitoring unit. The liquid replenishing unit is connected to the first injection capillary and the second injection capillary, and is used to replenish the aqueous solution and / or organic solution in real time according to the monitoring results of the liquid level monitoring unit.

4. The in-situ characterization device for liquid-liquid interfacial polymerization according to claim 3, characterized in that: The liquid level monitoring unit includes a SAXS through-light intensity monitoring unit and a camera, and the SAXS through-light intensity monitoring unit monitors the change of the SAXS through-light intensity, and the camera monitors the liquid level height of the aqueous solution and the organic solution in real time; and / or, the liquid level adjustment unit includes a drive motor and a SAXS instrument sample stage connected to the drive motor, and the in-situ characterization device is installed on the SAXS instrument sample stage. The SAXS instrument sample stage dynamically adjusts the interface position under the drive of the drive motor to maintain the interface position unchanged; and / or, the liquid replenishment unit includes a peristaltic pump, and the peristaltic pump is connected to the first injection capillary and the second injection capillary.

5. The in-situ characterization device for liquid-liquid interfacial polymerization according to claim 1, characterized in that: The reaction control module includes an ultraviolet catalytic unit and a temperature control unit. The ultraviolet catalytic unit is used to trigger a chemical reaction by irradiating the interface with ultraviolet light of optional wavelength and control the start time and progress of the reaction; the temperature control unit is used to adjust the solution temperature and regulate the chemical reaction rate.

6. The in-situ characterization device for liquid-liquid interfacial polymerization according to claim 5, characterized in that: The ultraviolet catalytic unit includes a UV lamp and a UV light control module connected to the UV lamp, the UV lamp is located above the reaction container, and the UV lamp irradiates ultraviolet light to the interface under the control of the UV light control module; and / or, the temperature control unit includes a PID temperature control module and a heating module, a refrigeration component and a temperature sensor connected to the PID temperature control module, the temperature sensor is arranged close to the reaction container, and is used to monitor the reaction temperature and transmit the reaction temperature to the PID temperature control module, and the PID temperature control module controls the heating module to heat the reaction container and / or controls the refrigeration component to cool the reaction container.

7. An in-situ characterization method for liquid-liquid interfacial polymerization, characterized in that: The method comprises: S1, providing a sealed reaction vessel, adding an aqueous solution into the reaction vessel using a first injection capillary until the liquid level of the aqueous solution is higher than the reaction vessel, and adding an organic solution dropwise onto the liquid level of the aqueous solution through a second injection capillary, such that the interface between the two solutions is higher than the reaction vessel; S2, moving the interface to a pre-adjusted X-ray spot so that the X-rays are directly incident on the interface at an angle of total reflection; S3, turn on the continuous exposure mode of the SAXS instrument, and perform real-time characterization of the formation and evolution of the nanofilm structure during the interfacial polymerization process. During the experiment, the interface position is maintained unchanged in real time and the progress and rate of the interfacial polymerization reaction are controlled.

8. The in-situ characterization method of liquid-liquid interfacial polymerization according to claim 7, characterized in that: The process of pre-adjusting the grazing incidence angle of the X-ray spot relative to the liquid surface includes: placing an evaporating dish in the sample chamber of the SAXS instrument, injecting deionized water into the evaporating dish so that the liquid level is higher than the wall of the evaporating dish, rotating the X-ray light source pitch angle device so that the X-ray source is in a total reflection state with the horizontal plane when looking down at the water surface, locking the X-ray source's downward angle, and finally removing the evaporating dish.

9. The in-situ characterization method for liquid-liquid interfacial polymerization according to claim 7, characterized in that: In S3, maintaining the interface position unchanged in real time during the experiment includes: real-time monitoring of the liquid level heights of the aqueous solution and the organic solution, and if the height changes, using a peristaltic pump to add the aqueous solution through the first injection capillary and / or adding the organic solution through the second injection capillary, and real-time monitoring of the interface height. If it changes, dynamically adjusting the interface position by adjusting the SAXS instrument sample stage to maintain the interface position unchanged.

10. The in-situ characterization method of liquid-liquid interfacial polymerization according to claim 7, characterized in that: In said S3, the real-time control of the progress and rate of the interfacial polymerization reaction during the experimental process includes: using ultraviolet light with an optional wavelength to irradiate the interface to trigger a chemical reaction, and controlling the start time and progress of the reaction, as well as real-time monitoring of the reaction temperature in the reaction container and heating, cooling or isothermalizing the reaction container according to the reaction temperature to control the rate of the chemical reaction.

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