Sfg detection platform, measurement system and application thereof

Abstract

The application provides an SFG detection platform, which comprises a base, a lifting mechanism and a mounting mechanism; the bottom surface of the lifting mechanism is fixedly connected with the top surface of the base, the lifting mechanism comprises a lifting column and a lifting driving assembly for driving the lifting column to perform lifting movement; the mounting mechanism comprises a mounting block, a first sealing ring and a fastening assembly; the mounting block is located above the lifting mechanism, the top surface of the mounting block is concavely provided with a detection groove, a lifting channel for the lifting movement of the lifting column is formed in the mounting block, and the upper end of the lifting channel extends to the inner bottom surface of the detection groove; the first sealing ring is installed in the detection groove and surrounds the upper end of the lifting channel; and the fastening assembly is installed on the top surface of the mounting block and is detachably fixedly connected with a solid to be detected. The SFG detection platform can be used for detecting the molecular arrangement rule of the monomolecular layer of the solid-liquid interface limited domain.

Description

Technical Field

[0001] This invention relates to the determination of molecular arrangement rules within a finite domain space at a solid-liquid interface, and particularly to an SFG detection platform, measurement system, and their applications. Background Technology

[0002] Sum-frequency vibrational spectroscopy (SFG) is a molecular spectral analysis method based on second-order nonlinear optics theory. If two laser beams interact with a nonlinear optical medium, and these two beams are matched in time and space, the medium will exhibit a second-order nonlinear optical response: the frequency of the emitted light is the difference between the frequencies of the two incident beams (difference-frequency process), and the frequency of the emitted light is the sum of the frequencies of the two incident beams (sum-frequency process). It can detect buried interfaces in situ and in real time, providing molecular-level structural information, such as the presence of various chemical components, quantitative molecular functional group orientations, and time-dependent dynamics or kinetics at these interfaces. It also possesses high selectivity and ultra-high interface sensitivity. Therefore, it has rapidly become a powerful tool for studying material interfaces.

[0003] The SFG measurement system comprises four parts: a picosecond laser system, a frequency doubling system, an optical parametric and difference frequency generation system, and a signal generation and acquisition system. Its workflow is as follows: The picosecond laser generates a 1064nm near-infrared fundamental frequency output with a pulse width of 30-40 picoseconds and a pulse repetition frequency of 10 Hz. This fundamental frequency output passes through a harmonic conversion unit, outputting two new wavelengths of light: one is ultraviolet 355nm, and the other is visible 532nm. The 532nm visible light is used as one beam for sum-frequency generation. The 355nm ultraviolet light is used as the pump light for the optical parametric generator. The 355nm ultraviolet light pumps the parametric generator and amplifier PG401, outputting signal light with a wavelength of 420-780nm and near-infrared idle light with a wavelength of 780nm-2.3µm. The idle light output from the PG401, with wavelengths ranging from 780nm to 2.3µm, is compared with the 1064nm near-infrared light from the picosecond laser. After frequency doubling and third-harmonic conversion, the remaining portion is further frequency-differencing in the DFG2-10P difference generator to output a tunable far-infrared beam with wavelengths from 2.3µm to 10µm. This beam will be used as another incident beam participating in the sum-frequency process. Using grating compression linewidth technology, the linewidth of the final tunable laser can be controlled to be less than 6cm. -1Two incident beams participating in the sum-frequency process are guided by complex polarization, intensity, optical path, and optical path control components to illuminate the surface of the sample at the appropriate angle, intensity, polarization direction, and maximum surface overlap, at the most similar times possible. The resulting sum-frequency spectral signal is carefully filtered spatially, temporally, and by polarization state to achieve the highest possible signal-to-noise ratio before being received by the photodetector and transmitted to the system control and data analysis computer. Based on the obtained sum-frequency spectral signal and the corresponding excitation far-infrared laser wavelength, the computer automatically plots the sum-frequency spectral curve.

[0004] While sum-frequency generation (SFG) spectroscopy is a powerful tool for probing the molecular-level structure of interfaces—SFG can detect the topmost interfacial water molecules in bulk and is sensitive to molecular conformation—experimental SFG still has some limitations. For example, SFG cannot provide information about the interfacial depth or how molecular orientation changes with distance from the surface; it cannot delve into the molecular level to explore the interactions between different target molecules; therefore, SFG cannot detect the molecular arrangement patterns of finite-domain monolayers at solid-liquid interfaces.

[0005] In view of this, it is necessary to provide an SFG detection platform, measurement system and its application to solve or at least alleviate the technical defect of the above-mentioned SFG measurement system that cannot detect the molecular arrangement of a finite domain monolayer at the solid-liquid interface. Summary of the Invention

[0006] The main objective of this invention is to provide an SFG detection platform, measurement system, and its application, aiming to solve the technical problem that the above-mentioned SFG measurement system cannot detect the molecular arrangement rules of a finite domain monolayer at the solid-liquid interface.

[0007] To achieve the above objectives, the present invention provides an SFG detection platform for in-situ determination of molecular arrangement at the solid-liquid interface, comprising a base, a lifting mechanism, and an installation mechanism;

[0008] The bottom of the lifting mechanism is fixedly connected to the top of the base. The lifting mechanism includes a lifting column and a lifting drive assembly for driving the lifting column to move up and down.

[0009] The installation mechanism includes an installation block, a first sealing ring, and a fastening assembly; the installation block is located above the lifting mechanism, the top surface of the installation block is recessed with a detection groove, and the installation block is provided with a lifting channel for the lifting column to perform lifting movements, the upper end of the lifting channel extending to the inner bottom surface of the detection groove;

[0010] The first sealing ring is installed in the detection groove and is arranged around the upper port of the lifting channel;

[0011] The fastening assembly is installed on the top surface of the mounting block and is detachably and fixedly connected to the solid to be tested.

[0012] Furthermore, the lifting drive assembly includes a housing, a lifting block, a first screw, and a second screw;

[0013] The housing has a lifting chamber inside, and the lifting block is installed inside the lifting chamber;

[0014] The wide end of the lifting block faces upward and the narrow end faces downward; the wide end of the lifting block is fixedly connected to the lower end of the lifting column, and the narrow end of the lifting block forms a first inclined surface and a second inclined surface, with the bottoms of the first inclined surface and the second inclined surface being close to each other.

[0015] The upper end of the housing is provided with a lifting port, and the lifting column passes through the lifting port from the lifting chamber and extends to the lifting channel;

[0016] The side end of the housing has a first threaded opening and a second threaded opening. The first screw passes through the first threaded opening and abuts against the first inclined surface; the second screw passes through the second threaded opening and abuts against the second inclined surface.

[0017] Furthermore, the first inclined surface and the second inclined surface are arranged facing each other, and the dimensions of the first inclined surface and the second inclined surface are the same; and the first threaded opening and the second threaded opening are arranged facing each other in the horizontal direction.

[0018] The first screw includes a first hand-held portion, a first rod portion, and a first abutting portion arranged sequentially, and the first abutting portion has a first contact surface that is fitted to the first inclined surface;

[0019] The second screw includes a second hand-held portion, a second rod portion, and a second abutting portion arranged sequentially, wherein the second abutting portion has a second contact surface that is fitted to the second inclined surface.

[0020] Furthermore, a spring is sleeved on the outer side of the lifting column, the upper end of the spring abutting against the inner top surface of the housing, and the lower end of the spring abutting against the wide end of the lifting block.

[0021] Furthermore, the mounting block includes a first mounting plate and a second mounting plate arranged sequentially from top to bottom; the first mounting plate and the second mounting plate are detachably fixedly connected, and the second mounting plate is fixedly connected to the top surface of the lifting mechanism;

[0022] The bottom surface of the first mounting plate is recessed with a mounting groove, and the top surface of the second mounting plate is protruded with a protrusion; the protrusion is embedded in the mounting groove and matches the mounting groove.

[0023] The first mounting plate has a first connecting opening in the vertical direction, which passes through the mounting groove; the second mounting plate has a second connecting opening in the vertical direction, which passes through the protrusion; the first connecting opening and the second connecting opening constitute the lifting channel;

[0024] A second sealing ring is installed on the top surface of the protrusion, and the second sealing ring is arranged around the second communication port.

[0025] Furthermore, the fastening assembly includes a first fixing block, a first locking block, a second fixing block, and a second locking block;

[0026] The first fixing block and the first locking block are detachably fixedly connected, and the second fixing block and the second locking block are detachably fixedly connected.

[0027] Both the second fixing block and the first fixing block are fixed to the top surface of the mounting block and are both located close to the detection groove;

[0028] The first locking block has a first engaging portion located above the detection groove, and the second locking block has a second engaging portion located above the detection groove.

[0029] Furthermore, the first fixing block and the second fixing block are arranged opposite each other in the horizontal direction; the bottom surfaces of the first engaging part and the second engaging part are both recessed upwards with engaging grooves for engaging with the solid to be tested.

[0030] The present invention also provides an SFG measurement system, including the SFG detection platform as described in any of the above claims.

[0031] The present invention also provides an application of the SFG detection platform or the SFG measurement system as described in any of the above claims in the in-situ determination of the molecular arrangement law at the solid-liquid interface.

[0032] This invention also provides a method for in-situ determination of the molecular arrangement at the solid-liquid interface, comprising the following steps:

[0033] S1, perform a sample addition operation on the SFG detection platform as described in any of the above;

[0034] The sample addition operation includes the following sub-steps:

[0035] S11, control the top surface of the lifting column to be lower than the bottom surface of the detection groove;

[0036] S12, add the test liquid into the detection tank, so that the test liquid submerges the first sealing ring and flows into the lifting channel;

[0037] S13, the solid to be tested is fixedly installed in the detection groove, and the bottom surface of the solid to be tested is fitted with the first sealing ring;

[0038] S2, control the lifting column to move upward to form a confined space; and use the SFG measurement system to determine the molecular arrangement law of the solid-liquid interface in situ.

[0039] Compared with the prior art, the present invention has at least the following advantages:

[0040] The SFG detection platform provided by this invention can be used to detect the molecular arrangement of a finite domain monolayer at a solid-liquid interface. Specifically, this invention can measure the molecular arrangement of a finite domain monolayer structure at a solid-liquid interface by setting up a lifting channel; it can place the sample to be tested by setting up a detection groove; it can prevent leakage of the test liquid by setting up a first sealing ring; and it can control the size of the finite domain space by controlling the lifting column's movement within the lifting channel.

[0041] The SFG detection platform provided by this invention can measure the molecular arrangement and orientation information of finite-domain monolayers at solid-liquid interfaces. Understanding the influence of finite-domain space on the properties and interactions of matter is crucial. By characterizing and controlling specific regions within the finite domain, precise regulation of its properties and functions can be achieved, leading to various applications in many fields. This invention achieves control of the finite domain through the raising and lowering of the aforementioned lifting column, thereby reaching local regions near the interface. These regions may possess specific surface properties, molecular arrangements, or chemical reactions, which are of great significance for the study of the reaction mechanism. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the SFG detection platform in this invention;

[0044] Figure 2 This is a schematic diagram of the top structure of the first mounting plate in this invention;

[0045] Figure 3 This is a schematic diagram of the bottom structure of the first mounting plate in this invention;

[0046] Figure 4 This is a schematic diagram of the top structure of the second mounting plate in this invention;

[0047] Figure 5 This is a schematic diagram of the structure after the second mounting plate, lifting mechanism and base are combined in this invention;

[0048] Figure 6 This is a schematic diagram of the lifting mechanism in this invention;

[0049] Figure 7 This is a schematic diagram of the lifting mechanism in another state of the present invention;

[0050] Figure 8 This is a schematic diagram of the fastening assembly in this invention;

[0051] Figure 9 This is a schematic diagram of the structure of the first locking block in this invention;

[0052] Figure 10 This is a data graph showing the concentration-adhesion forces of MgCl2 solution and LiCl solution of different concentrations in Example 1 of the present invention;

[0053] Among them, (a) represents the adhesion force data corresponding to the interaction between 11-mercapto-1-undecyl alcohol and the silica surface covered by Nb2CTx-PAA in magnesium chloride of different concentrations; (b) represents the adhesion force data corresponding to the interaction between 11-thioundecyl acid and the silica surface covered by Nb2CTx-PAA in magnesium chloride of different concentrations; (c) represents the adhesion force data corresponding to the interaction between 11-mercapto-1-undecyl alcohol and the silica surface covered by Nb2CTx-PVA in magnesium chloride of different concentrations; (d) represents the adhesion force data corresponding to the interaction between 11-mercapto-1-undecyl alcohol and the silica surface covered by Nb2CTx-PAA in lithium chloride of different concentrations; (e) represents the adhesion force data corresponding to the interaction between 11-thioundecyl acid and the silica surface covered by Nb2CTx-PAA in lithium chloride of different concentrations; and (f) represents the adhesion force data corresponding to the interaction between 11-mercapto-1-undecyl alcohol and the silica surface covered by Nb2CTx-PVA in lithium chloride of different concentrations.

[0054] Reference numerals: 1. Base; 2. Lifting column; 3. Lifting drive assembly; 4. Mounting block; 5. First sealing ring; 6. Fastening assembly; 7. Detection groove; 8. Lifting channel; 9. Housing; 10. Lifting chamber; 11. Lifting block; 12. Wide end; 13. Narrow end; 14. First inclined surface; 15. Second inclined surface; 16. First screw; 17. Second screw; 18. Spring; 19. First mounting plate; 20. Second mounting plate; 21. Mounting groove; 22. Protrusion; 23. First connecting port; 24. Second connecting port; 25. Second sealing ring; 26. First fixing block; 27. First locking block; 28. Second fixing block; 29. ​​Second locking block; 30. First engaging part; 31. Engaging groove.

[0055] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0058] To acquire information on the molecular orientation, structure, and dynamics of finite-domain monolayer solid-liquid interfaces and to address the limitation of SFG (Solid-Fluid Gas Grafting) in measuring the arrangement of finite-domain monolayers at solid-liquid interfaces, this invention provides an SFG detection platform for in-situ determination of molecular arrangement at solid-liquid interfaces. The SFG detection platform includes a base 1, a lifting mechanism, and a mounting mechanism.

[0059] The base 1 can be used for placing and installing the SFG detection platform; the base 1 can be disc-shaped, and multiple vertical fixing holes (such as threaded holes) can be evenly opened on the base 1 to facilitate its installation on the stage of the SFG measurement system; that is, the SFG detection platform provided by the present invention can replace the original sampling box of the SFG measurement system.

[0060] As an explanation of the lifting mechanism, the bottom surface of the lifting mechanism is fixedly connected to the top surface of the base 1, and the two can be integrally formed. In order to ensure the detection of the molecular arrangement law of the finite domain monolayer at the solid-liquid interface, the lifting mechanism includes a lifting column 2 and a lifting drive assembly 3 that drives the lifting column 2 to move up and down.

[0061] Preferably, the lifting drive assembly 3 may include a housing 9, a lifting block 11, a first screw 16 and a second screw 17; the top surface of the lifting mechanism can be understood as the top surface of the housing 9, the housing 9 may be columnar, the interior of the housing 9 is hollow, thereby forming a lifting chamber 10 inside the housing 9; the lower end surface of the housing 9 may be integrally formed with the base 1.

[0062] The lifting block 11 is installed inside the lifting chamber 10. The lifting block 11 can be raised and lowered under the action of driving force, thereby driving the lifting column 2 to move up and down. The lifting block 11 has a wide end 12 and a narrow end 13 arranged vertically, that is, the wide end 12 of the lifting block 11 faces upward and the narrow end 13 faces downward. The wide end 12 and the narrow end 13 can be integrally formed. The top surface of the narrow end 13 can coincide with the bottom surface of the wide end 12. In addition, the lifting block 11 can be symmetrical in structure.

[0063] To achieve lifting control of the lifting column 2, the wide end 12 of the lifting block 11 is fixedly connected to the lower end of the lifting column 2, that is, the top surface of the lifting block 11 and the lower end of the lifting column 2 can be fixedly connected, and the lifting block 11 and the lifting column 2 can be integrally formed. To achieve lifting control of the lifting block 11, the narrow end 13 of the lifting block 11 forms a first inclined surface 14 and a second inclined surface 15. Both the first inclined surface 14 and the second inclined surface 15 extend downward, and their bottoms are close to each other, that is, both face inward towards the lifting block 11. Furthermore, the first inclined surface 14 and the second inclined surface 15 can be arranged opposite each other, and the dimensions of the first inclined surface 14 and the second inclined surface 15 can be the same.

[0064] To facilitate the raising and lowering of the lifting column 2, a lifting port is provided at the upper end of the housing 9. The size of the lifting port corresponds to that of the lifting column 2. The lifting column 2 passes through the lifting port from the lifting chamber 10 and extends to the lifting channel 8. Driven by the lifting drive assembly 3, the lifting column 2 can move up and down within the lifting channel 8. Driven by the lifting drive assembly 3, the top end of the lifting column 2 can extend upward through the lifting channel 8.

[0065] To facilitate the control of the lifting block 11's raising and lowering, thereby controlling the raising and lowering of the lifting column 2, the side end of the housing 9 is provided with a first threaded opening and a second threaded opening, which can be arranged opposite each other in the horizontal direction. Furthermore, the first threaded opening corresponds to the first inclined surface 14, and the second threaded opening corresponds to the second inclined surface 15. The first screw 16 passes through the first threaded opening and abuts against the first inclined surface 14, and is threadedly connected to the first threaded opening. The second screw 17 passes through the second threaded opening and abuts against the second inclined surface 15, and is threadedly connected to the second threaded opening. By turning the first screw 16 and the second screw 17, a driving force can be provided to the lifting block 11 for raising and lowering, thereby controlling the raising and lowering of the lifting block 11, and consequently controlling the raising and lowering of the lifting column 2. The cooperation of the first screw 16 and the second screw 17 also improves the stability of the lifting column 2.

[0066] To improve the operability of the first screw 16 and the second screw 17, the first screw 16 includes a first hand-held portion, a first rod portion, and a first abutment portion arranged sequentially from the outside to the inside (relative to the lifting chamber 10). The first abutment portion has a first contact surface that fits against the first inclined surface 14; that is, the innermost end of the first abutment portion protrudes inward from the outer edge of the first contact surface. The second screw 17 includes a second hand-held portion, a second rod portion, and a second abutment portion arranged sequentially from the outside to the inside (relative to the lifting chamber 10). The second abutment portion has a second contact surface that fits against the second inclined surface 15; that is, the innermost end of the second abutment portion protrudes inward from the outer edge of the second contact surface.

[0067] To improve the lifting stability of the lifting column 2, a spring 18 can be sleeved on the outer side of the lifting column 2. The upper end of the spring 18 abuts against the inner top surface of the housing 9, and the lower end of the spring 18 abuts against the wide end 12 of the lifting block 11. Furthermore, the upper end of the spring 18 can be fixedly connected to the inner top surface of the housing 9, and the lower end of the spring 18 can be fixedly connected to the top surface of the lifting block 11.

[0068] As an explanation of the installation mechanism, the installation mechanism includes an installation block 4, a first sealing ring 5, and a fastening assembly 6; the installation block 4 is located above the lifting mechanism, and the installation block 4 can be fixedly connected to the top surface of the lifting mechanism to achieve the fixation of the installation block 4.

[0069] The top surface of the mounting block 4 is recessed with a detection groove 7, which can be used to place a solid to be tested. The surface of the solid to be tested can be covered with a monolayer material. The solid to be tested may include or be silicon dioxide crystals. The cross-section of the detection groove 7 matches the bottom surface size of the solid to be tested, and part of the solid to be tested extends into the detection groove 7.

[0070] The mounting block 4 has a lifting channel 8 for the lifting column 2 to move up and down. The upper end of the lifting channel 8 extends to the inner bottom surface of the detection tank 7. Thus, by adding the liquid to be tested into the lifting channel 8, the lifting column 2 can be raised and lowered to move the liquid to be tested. The liquid to be tested may include one or more of water, organic liquids, and ionic solutions. Since the solid to be tested is placed in the detection tank 7, and the upper end of the lifting channel 8 extends to the inner bottom surface of the detection tank 7, by controlling the raising and lowering of the lifting column 2, the problem that SFG cannot measure the arrangement of finite-domain monolayers at the solid-liquid interface can be solved.

[0071] The first sealing ring 5 is installed inside the detection groove 7 and surrounds the upper port of the lifting channel 8; the first sealing ring 5 can prevent the liquid to be tested from overflowing, thereby ensuring the measurement of the arrangement law of the finite domain monolayer at the solid-liquid interface. Preferably, the first sealing ring 5 can be arranged to coincide with the edge of the upper port.

[0072] As a further explanation of the mounting block 4, the mounting block 4 includes a first mounting plate 19 and a second mounting plate 20 arranged sequentially from top to bottom, the top surface of the first mounting plate 19 being the top surface of the mounting block 4; the first mounting plate 19 and the second mounting plate 20 are detachably fixedly connected, and the second mounting plate 20 is fixedly connected to the top surface of the lifting mechanism.

[0073] To ensure the docking of the first mounting plate 19 and the second mounting plate 20, the bottom surface of the first mounting plate 19 is recessed with a mounting groove 21, and the top surface of the second mounting plate 20 is protruded with a protrusion 22; the protrusion 22 is embedded in the mounting groove 21 and matches the mounting groove 21.

[0074] To ensure the formation of the lifting channel 8, the first mounting plate 19 has a first connecting port 23 in the vertical direction, which is disposed through the mounting groove 21; the second mounting plate 20 has a second connecting port 24 in the vertical direction, which is disposed through the protrusion 22; the first connecting port 23 and the second connecting port 24 constitute the lifting channel 8.

[0075] To ensure a tight seal between the top surface of the protrusion 22 and the mounting groove 21, a second sealing ring 25 is installed on the top surface of the protrusion 22, and the second sealing ring 25 surrounds the second communication port 24. Furthermore, it should be noted that to ensure the sealing of the liquid to be tested within the lifting channel 8, the outer wall of the lifting column 2 can be sealed to the inner wall of the lifting channel 8, or the outer wall at the upper end of the lifting column 2 can be sealed to the inner wall of the lifting channel 8, to prevent leakage.

[0076] In order to ensure the solid under test is secure during the measurement process and to facilitate the installation of the solid under test, the fastening component 6 is installed on the top surface of the mounting block 4 and is detachably and fixedly connected to the solid under test. The fastening component 6 is used to fix the solid under test in the detection groove 7.

[0077] Preferably, the fastening assembly 6 may include a first fixing block 26, a first locking block 27, a second fixing block 28, and a second locking block 29. The first fixing block 26 and the first locking block 27 are detachably fixedly connected, as are the second fixing block 28 and the second locking block 29. Both the second fixing block 28 and the first fixing block 26 are fixed to the top surface of the mounting block 4 and are positioned close to the detection groove 7. The first locking block 27 has a first engaging portion 30 located above the detection groove 7, and the second locking block 29 has a second engaging portion located above the detection groove 7.

[0078] To improve the tightness of the solid under test, the first fixing block 26 and the second fixing block 28 are arranged opposite each other in the horizontal direction. Both the first fixing block 26 and the second fixing block 28 can be U-shaped blocks in the horizontal direction. That is, the first fixing block 26 is located on one side of the detection groove 7, and both ends of the first fixing block 26 extend inward along the edge of the detection groove 7. The second fixing block 28 is located on the other side of the detection groove 7, and both ends of the second fixing block 28 extend inward along the edge of the detection groove 7. Further, the bottom surfaces of both the first engaging portion 30 and the second engaging portion are recessed upwards with engaging grooves 31 for engaging with the solid under test. The engaging grooves 31 contact the end of the solid under test, and the shape of the engaging grooves 31 must match the upper end of the solid under test to facilitate fixing the solid under test.

[0079] It should be noted that, in this invention, the first mounting plate 19 and the second mounting plate 20 may have corresponding upper and lower fixing holes to achieve a detachable fixed connection between the first mounting plate 19 and the second mounting plate 20 through fixing members; the first fixing block 26 and the first locking block 27 may also have corresponding upper and lower fixing holes to achieve a fixed connection between the first fixing block 26 and the first locking block 27 through fixing members; the second fixing block 28 and the second locking block 29 may also have corresponding upper and lower fixing holes to achieve a fixed connection between the second fixing block 28 and the second locking block 29 through fixing members.

[0080] In this invention, the SFG detection platform operates as follows: the top surface of the lifting column 2 is adjusted to be lower than the bottom surface of the detection tank 7; the liquid to be tested is added into the lifting channel 8 until the liquid surface is flush with the bottom surface of the solid to be tested; the solid to be tested is then placed into the detection tank 7; then, the height of the lifting column 2 is adjusted until an SFG signal appears at the solid-liquid interface. During the height adjustment process, the liquid molecules gradually approach the solid crystal molecules, thereby achieving the desired finite domain space; finally, the molecular orientation and arrangement information of the solid-liquid interface can be obtained through the generated SFG signal.

[0081] The present invention also provides an SFG measurement system, including an SFG detection platform as described in any of the above claims; the SFG detection platform can replace the sampling box in the SFG measurement system and is installed on the stage of the SFG measurement system.

[0082] It should be noted that the SFG measurement system typically includes a sampling module and a detection module. The sampling module may include a movable stage on which a sampling box is mounted. The position of the sampling box can be adjusted and stabilized by moving the stage. The sampling box is used to place the sample, and the area on the sample surface is used to receive the laser beam and generate an SFG signal.

[0083] The SFG detection platform in this invention can be replaced by the sampling box and thus installed on the platform (the base 1 of the detection platform is fixedly installed on the platform by bolts or other fasteners), and the detection height of the SFG detection platform (the height of the detection slot 7) can be consistent with the height of the sampling box.

[0084] The detection module may include an optical laser unit, a beam control and combining unit, and an SFG signal detection unit. The optical laser unit consists of two laser beams: one for infrared and one for visible light. The beam control and combining unit uses optical elements such as lenses, polarizers, and beam splitters to collimate, focus, and integrate the pump and probe beams into a common optical path. The SFG signal detection unit guides the SFG signal through a narrow slit or optical fiber to a spectrometer or detector for detection and analysis. Commonly used detectors include monochromatic optical detectors, photodiodes, and photoelectric multichannel analyzers.

[0085] The present invention also provides an application of the SFG detection platform or the SFG measurement system described in any of the above claims in the in-situ determination of the molecular arrangement law at the solid-liquid interface; the application can be the process of determining the arrangement law of a finite domain monolayer at the solid-liquid interface.

[0086] As one application, the present invention also provides a method for in-situ determination of the molecular arrangement law at the solid-liquid interface using any of the SFG measurement systems described above, thereby enabling the determination of the arrangement law of a finite-domain monolayer at the solid-liquid interface, specifically including the following steps:

[0087] S1, perform a sample addition operation on any of the SFG detection platforms described above.

[0088] The sample addition operation includes the following sub-steps:

[0089] S11, control the top surface of the lifting column 2 to be lower than the bottom surface of the detection groove 7.

[0090] S12, add the test liquid to the detection tank 7 (add the test liquid from the outside of the first sealing ring 5), so that the test liquid submerges the first sealing ring 5 and flows into the lifting channel 8; the liquid level of the test liquid in the lifting channel 8 can be flush with the liquid level of the test liquid in the detection tank 7.

[0091] S13, the solid to be tested is fixedly installed in the detection groove 7, and the bottom surface of the solid to be tested is fitted with the first sealing ring 5.

[0092] S2, control the lifting column 2 to move up and down (e.g., upward) to form a confined space; and use the SFG measurement system to determine the molecular arrangement law of the solid-liquid interface in situ.

[0093] The SFG detection platform can be pre-installed on the platform of the SFG measurement system, or the SFG detection platform after the sample addition operation can be installed on the platform of the SFG measurement system before the lifting column 2 is controlled to move upward.

[0094] The SFG detection platform is installed in front of and behind the stage of the SFG measurement system. The height of the stage can be adjusted or preset. The main body can determine the molecular arrangement of the solid-liquid interface in situ through the detection module.

[0095] The method for in-situ determination of the molecular arrangement at the solid-liquid interface can be understood as follows: The liquid to be tested is added to the detection tank 7 and covered with a monolayer solid crystal. The SFG detection platform is installed on the stage, and the stage is adjusted to its initial height, which corresponds to a longitudinal coordinate of 5 cm. Then, the height of the lifting column 2 is adjusted to gradually reduce the distance between the liquid to be tested and the monolayer solid. Since the surrounding space is fixed, the reduction in distance means spatial compression, which is beneficial for forming a confined space. When the distance is shortened to a certain extent, ions and water molecules in the liquid to be tested will form ion-water crystals. The measurement parameters can be adjusted. The SFG polarization condition can be adjusted to PPP, SSS, SSP, SPS, etc., specifically PPP. Based on the condition parameters, a waveform signal diagram is obtained, and the wavelength parameter can be set to 1295 cm. -1 .

[0096] In this invention, by employing the above-mentioned in-situ method for determining the molecular arrangement of solid-liquid interfaces, finite domains can be measured. These regions may exhibit specific surface properties, molecular arrangements, or chemical reactions, which is of great significance for understanding the influence of finite domain space on the properties and interactions of matter.

[0097] To facilitate a detailed understanding of the present invention by those skilled in the art, the following examples are provided:

[0098] Example 1

[0099] The SFG measurement system used in this embodiment includes an SFG detection platform, which is mounted on the stage of the SFG measurement system during measurement. The SFG detection platform has, for example... Figure 1-9 The diagram shows the connections of all components, including the base 1, the lifting mechanism, and the mounting mechanism. The bottom surface of the lifting mechanism is fixedly connected to the top surface of the base 1. The lifting mechanism includes a lifting column 2 and a lifting drive assembly 3 that drives the lifting column 2 to move up and down. The mounting mechanism includes a mounting block 4 (composed of a first mounting plate 19 and a second mounting plate 20), a first sealing ring 5, and a fastening assembly 6. The mounting block 4 is located above the lifting mechanism. A detection groove 7 is recessed on the top surface of the mounting block 4, and a lifting channel 8 is provided on the mounting block 4 for the lifting column 2 to move up and down. The upper end of the lifting channel 8 extends to the inner bottom surface of the detection groove 7. The first sealing ring 5 is installed inside the detection groove 7 and surrounds the upper end of the lifting channel 8. The fastening assembly 6 is installed on the top surface of the mounting block 4 and is detachably fixedly connected to the solid being tested.

[0100] In this embodiment, the test solutions were MgCl2 solutions and LiCl solutions of different concentrations, with concentrations of 0 mol / L, 0.001 mol / L, 0.01 mol / L, 0.1 mol / L, 0.25 mol / L, and 1 mol / L, respectively. Equal amounts of 11-mercapto-1-undecanol (to a concentration of 2 mg / ml after addition) or equal amounts of 11-thioundecanoic acid (to a concentration of 2 mg / ml) were added to the MgCl2 and LiCl solutions of different concentrations, corresponding to different groups of experiments. Only one type of test solution was used for each experiment.

[0101] In this embodiment, the test solids are silicon dioxide with a self-assembled monolayer Nb2CTx-PAA and silicon dioxide with a self-assembled monolayer Nb2CTx-PVA. Only one of the test solids is used for each test.

[0102] In this embodiment, the combination of the test liquid and the test solid is referenced. Figure 10 The experimental process in this embodiment is as follows:

[0103] S1, add sample to the SFG testing platform.

[0104] The sample addition operation includes the following sub-steps:

[0105] S11, control the top surface of the lifting column 2 to be lower than the bottom surface of the detection groove 7.

[0106] S12, add the test liquid to the detection tank 7 (add the test liquid from the outside of the first sealing ring 5), so that the test liquid submerges the first sealing ring 5 and flows into the lifting channel 8; the liquid level of the test liquid in the lifting channel 8 and the liquid level of the test liquid in the detection tank 7 are level, and neither is lower than the top height of the first sealing ring 5.

[0107] S13, the solid to be tested is fixedly installed in the detection groove 7, and the bottom surface of the solid to be tested is fitted with the first sealing ring 5.

[0108] S2. Install the SFG detection platform after the sample addition operation onto the stage of the SFG measurement system (replace the sampling box, and the detection height of the SFG detection platform is consistent with that of the sampling box), and adjust the initial height of the stage to the 5cm longitudinal coordinate scale.

[0109] The lifting drive assembly 3 controls the upward movement of the lifting column 2, gradually reducing the distance between the liquid under test and the self-assembled monolayer solid. The molecular arrangement at the solid-liquid interface is then determined in situ using the detection module of the SFG measurement system. Measurement parameters are adjusted: SFG polarization condition is PPP, and wavelength is set to 1295 cm⁻¹. -1 Ultimately, the molecular surface properties of a finite-domain monolayer at the solid-liquid interface can be obtained.

[0110] Experimental results:

[0111] See Figure 10 As shown, Figure 10 The horizontal axis represents concentration, with units of M (mol / L), and the vertical axis represents Fad / R (adhesion force), with units of mN / m.

[0112] Reference Figure 10 It can be understood that, initially, the adhesion force decreases with increasing ion concentration. However, when the ion concentration reaches a critical point, the adhesion force increases significantly. This was observed in Li... + and Mg 2+ In solution, both the COOH-COOH interaction model (COOH-PAA) and the OH-OH interaction model (OH-PVA) share the same critical concentration point, while the critical concentration of the mixed model (OH-PAA) differs. This kinetic process can be explained by a synergistic effect between the formation of ion-water clusters and the difference in ion-water exchange rates, which occurs within the nanochannels of the Nb2CTx nanofilm. Furthermore, surface (ion-water) cluster-surface interactions may lead to a significant increase in adhesion above the critical concentration point. In the absence of ion-water clusters or water clusters, adhesion increases with increasing ion concentration.

[0113] In this embodiment, lithium ions and magnesium ions exhibit a confinement effect within a confined space, which manifests as a selective ion separation phenomenon.

[0114] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An SFG detection platform for in-situ determination of molecular arrangement at the solid-liquid interface, characterized in that, Includes base, lifting mechanism and installation mechanism; The bottom of the lifting mechanism is fixedly connected to the top of the base. The lifting mechanism includes a lifting column and a lifting drive assembly for driving the lifting column to move up and down. The installation mechanism includes an installation block, a first sealing ring, and a fastening assembly; the installation block is located above the lifting mechanism, the top surface of the installation block is recessed with a detection groove, and the installation block has a lifting channel for the lifting column to move up and down, the upper end of the lifting channel extends to the inner bottom surface of the detection groove; the liquid to be tested is added into the lifting channel; The first sealing ring is installed inside the detection groove and is arranged around the upper port of the lifting channel; The fastening assembly is installed on the top surface of the mounting block and is detachably and fixedly connected to the solid to be tested; The cross-section of the detection groove matches the bottom dimension of the solid to be tested, and part of the solid to be tested extends into the detection groove; the height of the lifting column is adjusted until the molecules at the solid interface and the liquid interface show an SFG signal. During the height adjustment process, the liquid molecules will gradually approach the solid crystal molecules, thereby achieving the desired finite domain space.

2. The SFG detection platform according to claim 1, characterized in that, The lifting drive assembly includes a housing, a lifting block, a first screw, and a second screw; The housing has a lifting chamber inside, and the lifting block is installed inside the lifting chamber; The wide end of the lifting block faces upward and the narrow end faces downward; the wide end of the lifting block is fixedly connected to the lower end of the lifting column, and the narrow end of the lifting block forms a first inclined surface and a second inclined surface, with the bottoms of the first inclined surface and the second inclined surface being close to each other. The upper end of the housing is provided with a lifting port, and the lifting column passes through the lifting port from the lifting chamber and extends to the lifting channel; The side end of the housing has a first threaded opening and a second threaded opening. The first screw passes through the first threaded opening and abuts against the first inclined surface; the second screw passes through the second threaded opening and abuts against the second inclined surface.

3. The SFG detection platform according to claim 2, characterized in that, The first inclined surface and the second inclined surface are arranged facing each other, and the dimensions of the first inclined surface and the second inclined surface are the same; and the first threaded opening and the second threaded opening are arranged facing each other in the horizontal direction. The first screw includes a first hand-held portion, a first rod portion, and a first abutting portion arranged sequentially, and the first abutting portion has a first contact surface that is fitted to the first inclined surface; The second screw includes a second hand-held portion, a second rod portion, and a second abutting portion arranged sequentially, wherein the second abutting portion has a second contact surface that is fitted to the second inclined surface.

4. The SFG detection platform according to claim 2, characterized in that, A spring is fitted on the outer side of the lifting column. The upper end of the spring abuts against the inner top surface of the housing, and the lower end of the spring abuts against the wide end of the lifting block.

5. The SFG detection platform according to claim 1, characterized in that, The mounting block includes a first mounting plate and a second mounting plate arranged sequentially from top to bottom; the first mounting plate and the second mounting plate are detachably fixedly connected, and the second mounting plate is fixedly connected to the top surface of the lifting mechanism; The bottom surface of the first mounting plate is recessed with a mounting groove, and the top surface of the second mounting plate is protruded with a protrusion; the protrusion is embedded in the mounting groove and matches the mounting groove. The first mounting plate has a first connecting opening in the vertical direction, which passes through the mounting groove; the second mounting plate has a second connecting opening in the vertical direction, which passes through the protrusion; the first connecting opening and the second connecting opening constitute the lifting channel; A second sealing ring is installed on the top surface of the protrusion, and the second sealing ring is arranged around the second communication port.

6. The SFG detection platform according to claim 1, characterized in that, The fastening assembly includes a first fixing block, a first locking block, a second fixing block, and a second locking block; The first fixing block and the first locking block are detachably fixedly connected, and the second fixing block and the second locking block are detachably fixedly connected. Both the second fixing block and the first fixing block are fixed to the top surface of the mounting block and are both located close to the detection groove; The first locking block has a first engaging portion located above the detection groove, and the second locking block has a second engaging portion located above the detection groove.

7. The SFG detection platform according to claim 6, characterized in that, The first fixing block and the second fixing block are arranged opposite each other in the horizontal direction; the bottom surfaces of the first engaging part and the second engaging part are both provided with engaging grooves for engaging with the solid to be tested.

8. An SFG measurement system, characterized in that, Includes the SFG detection platform as described in any one of claims 1-7.

9. The application of an SFG detection platform as described in any one of claims 1-7 or an SFG measurement system as described in claim 8 in the in-situ determination of the molecular arrangement law at the solid-liquid interface.

10. A method for in-situ determination of the molecular arrangement at a solid-liquid interface, characterized in that, Including the following steps: S1, perform a sample addition operation on the SFG detection platform as described in any one of claims 1-7; The sample addition operation includes the following sub-steps: S11, control the top surface of the lifting column to be lower than the bottom surface of the detection groove; S12, add the test liquid into the detection tank, so that the test liquid submerges the first sealing ring and flows into the lifting channel; S13, the solid to be tested is fixedly installed in the detection groove, and the bottom surface of the solid to be tested is fitted with the first sealing ring; S2, control the lifting column to move upward to form a confined space; and use the SFG measurement system to determine the molecular arrangement law of the solid-liquid interface in situ.

Images