In-situ XRD detection equipment and method for detecting solution crystallization process

Abstract

The present disclosure relates to an in-situ XRD detection device and method for detecting a solution crystallization process. The detection device comprises: an in-situ XRD device, which is used to collect XRD spectra of a solution sample at different temperatures during the crystallization process; an in-situ cavity, which is arranged in the in-situ XRD device; a sample holder, which is arranged inside the in-situ cavity and is configured to accommodate the solution sample to be detected; and a cooling medium circulation system. The sample holder comprises: a groove portion in which the sample holder body is defined; at least one layer of background diffraction material, which is stacked and laid on and covers the bottom of the groove portion; a porous material, which is configured to adsorb the solution sample; and a sealing film, which covers the upper surface of the porous material. The detection device and the detection method are simple in structure and easy to operate, and can monitor the crystal precipitation of the solution sample in the cooling crystallization process with high precision, filling the technical gap in this field.

Description

Technical Field

[0001] The present application relates to the technical field of in-situ XRD, and more specifically, to an in-situ XRD detection device and method for detecting a solution crystallization process. Background Art

[0002] In-situ XRD is a characterization technique used to monitor the structure and phase change behavior of materials in real time. It can be measured in the actual working environment of the material (such as high temperature, high pressure, electric field, light, etc.). This technology can provide more accurate and real material structure information, which helps to understand the phase change mechanism, stress behavior, electrochemical properties, etc. of the material. Low-temperature in-situ XRD technology is one of the important experimental methods for studying the phase transition of samples. By real-time monitoring the crystallization of samples under different temperature conditions and analyzing their diffraction patterns, information such as half-peak width, intensity, inter-crystalline spacing, and grain size under different temperature conditions can be obtained, thereby studying the phase change and crystallinity change laws of the samples. At present, the design of in-situ XRD sample stages is diverse. However, except for the electrochemical reaction sample cell, most of them are still used for solid powder samples. For the use of in-situ XRD technology to analyze the process of crystal precipitation in solution samples, there is no mature application detection device and method.

[0003] Therefore, it is urgent to develop a technology to solve the existing problems, which is of great significance for filling the current technical gap in the detection of the crystallization process of in-situ XRD solution samples and understanding the order and mechanism of the precipitation of various crystals in the solution. Summary of the invention

[0004] In order to solve the above problems, the present application provides an in-situ XRD detection device and method for detecting the crystallization process of a solution. Under special sample preparation and detection methods, the crystal precipitation of the solution during the crystallization process can be monitored with high precision and for a long time. The detection process is simple, practical and accurate, filling the technical gap in the existing in-situ XRD technology field.

[0005] In the first scheme of the present application, an in-situ XRD detection device for detecting a solution crystallization process is provided. The in-situ XRD detection device comprises: an in-situ XRD device, which comprises a Cu rotating target line light source and a two-dimensional surface detector, and is configured to collect XRD spectra of a solution sample at different temperatures during a crystallization process; an in-situ cavity, which is arranged in the in-situ XRD device; a sample holder, which is arranged inside the in-situ cavity and is configured to accommodate the solution sample to be detected; and a cooling medium circulation system, which is configured to control the circulation of a cooling medium to reduce the temperature inside the sample holder; wherein the sample holder comprises: a sample holder body, which is configured to engage with a base fixedly arranged in the in-situ cavity; , and includes a groove portion defined therein; at least one layer of background diffraction material, which is stacked and laid on and covers the bottom of the groove portion, the background diffraction material has a lower diffraction signal than the sample holder body, so as to avoid the interference of the diffraction signal of the sample holder body on the detection result; a porous material, which is stacked and laid above the at least one layer of background diffraction material and its upper surface is flush with the upper surface of the edge of the sample holder body, the porous material is configured to adsorb the solution sample; and a sealing film, which covers the upper surface of the porous material to achieve sealing of the solution sample, so as to reduce the influence of solvent volatilization on the crystallization process.

[0006] In the second scheme of the present application, a method for detecting the crystallization process of a solution using the in-situ XRD detection equipment of the first scheme is provided. The method comprises the following steps: Step 1, setting the sample holder body inside the in-situ cavity; Step 2, inserting a Cu attenuation absorption plate in front of the two-dimensional surface detector, setting the angle between the Cu target line light source and the two-dimensional surface detector to 0°, and setting the light source to the working power; Step 3, adjusting the height of the in-situ cavity so that the upper surface of the edge of the sample holder body is flush with the central axis of the X-ray optical path; Step 4, stacking and laying the at least one layer of background diffraction material and the porous material in sequence at the bottom of the groove portion so that the upper surface of the porous material is flush with the upper surface of the sample holder body; Step 5, covering the sample holder with the sealing film, closing the first sealing cover and the second sealing cover in sequence, and lowering the temperature inside the sample holder through the cooling medium circulation system. The method comprises the steps of: setting the temperature to a predetermined initial temperature and keeping the temperature constant; step 6, removing the Cu attenuation absorption sheet, and collecting a background XRD spectrum using the in-situ XRD device; step 7, opening the second sealing cover and the first sealing cover in sequence, removing the sealing film, and dripping the solution sample to be detected onto the porous material; step 8, repeating step 5; step 9, collecting an initial XRD spectrum of the solution sample at the predetermined initial temperature using the in-situ XRD device; and step 10, according to a preset cooling program, lowering the temperature inside the sample holder through the cooling medium circulation system, and according to a preset temperature detection sequence, collecting XRD spectra of the solution sample at different temperatures during the crystallization process through the in-situ XRD device, thereby obtaining a temperature sequence XRD spectrum associated with the crystallization process.

[0007] By using the in-situ XRD detection device of the first solution and the detection method of the second solution provided in the present application, the following beneficial effects can be achieved:

[0008] (1) The present invention utilizes a low-diffraction background sheet to avoid interference of the strong diffraction signal of the low-temperature sample holder on the sample signal when testing liquid samples. At the same time, the height of the sample can be flexibly adjusted to avoid the shift of the diffraction peak, thereby further improving the accuracy of sample testing;

[0009] (2) Porous materials can adsorb solution samples, reduce the impact of liquid beading caused by surface tension, or the impact of liquid flow caused by siphoning, vibration, etc. on the detection signal. At the same time, it can greatly reduce the phenomenon of crystals in the solution growing into large crystals due to preferential orientation on smooth surfaces, thus solving the problem of too few XRD diffraction peaks and difficulty in attributing similar phases due to preferential orientation. As an adsorption medium, porous materials eliminate the interference of unstable factors on the detection signal, thereby improving the analytical ability and accuracy of sample testing;

[0010] (3) Using thin film materials to seal the cryogenic sample holder can further reduce the impact of other environmental factors such as solvent evaporation on the crystallization process, and achieve fine-tuning of temperature factors and pressure to jointly drive crystal precipitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. When appropriate, the same reference numerals are used in all drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present device or method. In the drawings:

[0012] Figure 1 is a side view of the structure of a sample platform of a detection device according to an embodiment of the present application;

[0013] Figure 2 is a side view of the structure of a sample holder according to an embodiment of the present application;

[0014] Figure 3 is a schematic flow chart of a detection method according to an embodiment of the present application;

[0015] Figure 4 1 is a temperature sequence XRD pattern according to an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiment of the present application clearer, the technical solution of the embodiment of the present application will be clearly and completely described in conjunction with the drawings of the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, not all of the embodiments. Based on the described embodiment of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0017] Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. "First", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] In order to keep the following description of the embodiments of the present application clear and concise, the present application omits detailed descriptions of known functions and known components.

[0019] As mentioned above, in-situ XRD technology is usually used to detect the crystallization of powder solid samples at different temperatures, so as to study the phase change of the sample, the change law of crystallinity, etc. Therefore, in this application, an in-situ XRD diffractometer is also used to analyze the crystallization of the solution sample during the cooling process. In the in-situ XRD, the original sample platform for solid powder is removed and a self-developed sample platform is used to support the solution sample to be tested.

[0020] The in-situ XRD device used in this application is equipped with a Cu rotating target line light source, an Eiger two-dimensional surface detector and a goniometer. The Cu rotating target line light source can generate high-brightness X-rays, which can provide high-intensity incident X-rays, thereby enhancing the scattering signal of the sample. The Eiger two-dimensional surface detector is a high-speed, high-sensitivity X-ray detector that can quickly and accurately detect diffraction signals, thereby obtaining high-quality data.

[0021] Figure 1 A side view schematic diagram of the structure of a sample platform for accommodating a solution sample to be detected is shown. Figure 1 As shown, the sample platform 100 includes an in-situ cavity 110 and a sample rack 120 disposed inside the in-situ cavity 110, and the sample rack 120 is used to accommodate a solution sample to be detected. Specifically, the in-situ cavity 110 is generally square and includes a cavity wall 111. A base 112 for supporting the sample rack 120 is fixedly disposed inside the in-situ cavity 110. The base 112 defines a horizontal support platform, and the sample rack 120 is detachably engaged with the support platform. For example, Figure 1As shown, the upper surface of the base 112 is provided with a threaded hole, and the lower surface of the sample holder 120 is provided with a screw 125 with a thread ( Figure 2 As shown in FIG. 1 , the sample holder 120 and the base 112 are fixedly joined by the screw 125 and the threaded hole. It is conceivable that the joining between the two can also be achieved by other means besides the threaded fitting, such as by adhesive bonding, by magnetic connection, or by the fitting between the lower surface of the sample holder 120 and the groove on the support platform, etc., which is not specifically limited in the present invention.

[0022] The in-situ chamber 110 further includes a lifting mechanism (not shown), which includes a knob, through which the height of the in-situ chamber 110 can be adjusted. In an optional embodiment, the horizontally oriented base 112 is vertically fixed to the vertical support member ( Figure 1 The sample holder 120 and the base 112 are fixedly arranged in the in-situ chamber 110 (not shown), and this structure enables the sample holder 120 and the base 112 to be raised and lowered synchronously with the in-situ chamber 110. By flexibly adjusting the height of the sample, the deviation of the diffraction peak can be avoided, and the accuracy of sample detection can be further improved.

[0023] In order to provide a cooling environment for the solution sample, the detection device also includes a cooling medium circulation system, which controls the circulation of the liquid cooling medium to reduce the temperature of the sample holder 120, thereby achieving cooling of the solution sample. Specifically, the cooling medium circulation system includes: a cooling medium circulation pipeline 130 (such as Figure 1 ), an external medium circulation compressor, an external temperature control system and a temperature sensor, wherein the cooling medium circulation pipeline 130 includes a medium inlet pipeline 131 and a medium outlet pipeline 132, which are in fluid communication with the internal circulation pipeline disposed inside the base 112, so as to realize the circulation of the cooling medium through the base 112. Specifically, during the detection process, through a pre-set temperature detection sequence program, the temperature control system controls the medium circulation pre-shrinking machine to realize the circulation of the cooling medium in the cooling medium circulation pipeline at a predetermined rate, thereby realizing controllable temperature control. At the same time, the temperature of the base 112 is detected in real time by the temperature sensor disposed on the base 112.

[0024] Optionally, the fluid medium is liquid helium or liquid nitrogen. In the preferred embodiment where the medium is liquid helium, firstly, the cryogenic system can achieve a wide temperature range control. Liquid helium is a very low temperature medium, which can provide very low temperature and cooling rate. In this cryogenic system, the lowest temperature can reach 12K, and the fastest cooling rate can reach 6K / min. In addition, liquid helium provides cooling capacity through compression cycle, and during the compression cycle, liquid helium will not be consumed or lost and can be recycled. As a result, the cryogenic system can be used for a long time without the need to frequently replace liquid helium, which improves the convenience and economy of use.

[0025] like Figure 2 As shown, the sample holder 120 for accommodating the solution sample specifically includes a sample holder body 121 and at least one layer of background diffraction material 122, porous material 123 and sealing film 124 stacked in sequence from bottom to top.

[0026] The sample holder body 121 is generally circular and engages with the base 112 to achieve fixed engagement of the sample holder 120. In addition, the sample holder body 121 defines a groove portion 121' therein, which is also generally circular and whose axis coincides with the axis of the sample holder body 121.

[0027] At least one layer of background diffraction material 122 constituting a background diffraction layer is stacked at the bottom of the groove portion 121'. The background diffraction material 122 can generate a diffraction signal much lower than that of the sample holder body 121 (usually made of alloy material), thereby avoiding the interference of the strong diffraction signal of the sample holder body 121 on the sample diffraction signal when detecting the solution sample. In order to minimize the interference of the signal, the at least one layer of background diffraction material 122 preferably fully covers the groove portion 121'. Optionally, the background diffraction material 122 can be selected from materials such as glass or single crystal silicon that have no strong diffraction peaks within the test 2θ (2-theta) angle range.

[0028] The porous material 123 can be stacked and laid above the background diffraction material layer, and its upper surface can be flush with the upper surface of the edge (wall) of the sample holder body 121, and the solution sample to be detected can be adsorbed in the material. Through the above structure, a sample holder capable of accommodating the solution sample to be detected is provided, so as to realize reliable diffraction spectrum detection of the solution sample. Optionally, the porous material 123 can be a material without a strong diffraction peak within the test 2-theta angle range, for example, it can be a porous material with chemical inertness and insolubility in water, with a pore size of 10~80μm, a porosity of 50%~80%, and a thickness of 50~200μm, such as natural fiber, organic polymer fiber or glass fiber. Porous materials can adsorb solution samples, reduce the impact of liquid beading caused by surface tension, or the impact of liquid flow caused by siphoning, vibration and other factors on the detection signal. At the same time, it can greatly reduce the phenomenon of crystal precipitation in the solution, which is prone to grow into large crystals due to preferential orientation on the smooth surface, and solve the problem of too few XRD diffraction peaks due to preferential orientation, which makes it difficult to attribute similar phases. As an adsorption medium, porous materials eliminate the interference of unstable factors on the detection signal, thereby improving the analytical ability and accuracy of sample testing.

[0029] It should be understood that the quantity of the background diffraction material 122 and the porous material 123 can be configured more flexibly according to the detection requirements, as long as the upper surface of the porous material 123 is flush with the upper surface of the edge of the sample holder body 121 .

[0030] The sealing film 124 covers the upper surface of the porous material 123 to seal the solution sample. Optionally, the sealing material 124 can be a material without a strong diffraction peak within the test 2-theta angle range, such as a polymer film material that is chemically inert and insoluble in water, with a thickness of 10-20 μm. Using a film material to seal the low-temperature sample holder can further reduce the impact of other environmental factors such as solvent volatilization on the crystallization process, and achieve temperature factors and pressure fine-tuning to jointly drive crystal precipitation.

[0031] In an embodiment, in order to achieve a better seal of the solution sample, the sample platform 100 may further include a first sealing cover 140 and a second sealing cover 150. Figure 1 As shown, the first sealing cover 140 (or referred to as the "inner sealing cover") is installed on the support base 160 around the sample holder 120 inside the in-situ cavity 110, for example, by screws, so that the first sealing cover 140 can isolate and seal the sample holder 120 from the outside world, thereby reducing the influence of external factors on the sample. The second sealing cover 150 (or referred to as the "outer sealing cover") is installed on the top of the cavity wall 111 of the in-situ cavity 110, for example, by screws, thereby ensuring the stability of the sample under low temperature conditions.

[0032] In the embodiment including both the first sealing cover 140 and the second sealing cover 150, the space between the two can also be evacuated and sealed; when conducting low-temperature experiments, it is usually necessary to evacuate the in-situ cavity 110 to reduce the heat conduction of the gas and the impact on the sample. The design of the two-layer sealing cover can effectively seal the cavity and ensure the stability and reliability of the system under vacuum. Of course, in an alternative embodiment, only the second sealing cover 150 of the above two sealing covers can be set to facilitate the vacuum operation, so as to achieve a sealing effect at a lower cost.

[0033] In the above embodiment, an implementation scheme is provided in which the temperature of the sample holder 120 is controlled by a cooling medium circulation system to achieve crystallization of the solution sample inside the sample holder 120, thereby detecting the XRD spectrum in the low-temperature crystallization process. The in-situ XRD detection device may also be provided with a crystallization pressure regulating system (not shown in the figure), which is configured to change the pressure inside the sample holder 120, thereby regulating the crystallization pressure of the solution sample, so that the crystallization process can be regulated by the crystallization pressure in a controllable manner. In the implementation process, the crystallization pressure inside the sample holder 120 can be changed only by the crystallization pressure regulating system to achieve crystallization of the sample, and the XRD spectrum under different crystallization pressures can be collected, or the temperature of the sample holder 120 can be controlled only by the cooling medium circulation system to achieve crystallization of the solution sample inside the sample holder 120, or the temperature and crystallization pressure inside the sample holder 120 can be changed by both the cooling medium circulation system and the crystallization pressure regulating system, thereby collecting the XRD spectrum under different temperature and crystallization pressure combinations during the crystallization process.

[0034] Figure 3 FIG. 4 is a schematic flow chart of a method for detecting a crystallization process of a solution using an in-situ XRD detection device according to an embodiment of the present application. Figure 3 As shown, the detection method 200 includes:

[0035] S210, placing the sample holder body 121 inside the in-situ cavity 110;

[0036] S220, inserting a Cu attenuation absorption sheet in front of the two-dimensional surface detector, setting the angle between the Cu rotating target line light source and the two-dimensional surface detector to 0°, and setting the light source to a working power;

[0037] S230, adjusting the height of the in-situ cavity 110 so that the upper surface of the edge of the sample holder body 121 is flush with the central axis of the X-ray optical path;

[0038] S240, at least one layer of background diffraction material 122 and porous material 123 is sequentially laid on the bottom of the groove portion 121', so that the upper surface of the porous material 123 is flush with the upper surface of the sample holder body 121;

[0039] S250, using the sealing film 124 to cover the sample rack 120, closing the first sealing cover 140 and the second sealing cover 150 in sequence, and setting the temperature inside the sample rack 120 to a predetermined initial temperature and keeping it warm through the cooling medium circulation system;

[0040] S260, removing the Cu attenuation absorption sheet and detecting the background XRD spectrum using an in-situ XRD device;

[0041] S270, opening the second sealing cover 150 and the first sealing cover 140 in sequence, removing the sealing film 124, and dripping the solution sample to be detected onto the porous material 123;

[0042] S280, repeat S250;

[0043] S290, collecting an initial XRD pattern of the solution sample at a predetermined initial temperature using in-situ XRD;

[0044] S300, according to a preset cooling program, the temperature inside the sample holder 120 is lowered by a cooling medium circulation system, and at the same time, according to a preset temperature detection sequence, the XRD spectrum of the solution sample at different temperatures during the crystallization process is detected by an in-situ XRD device, so as to obtain a temperature sequence XRD spectrum associated with the crystallization process.

[0045] Among them, in S220, the X-ray working power is 42kV*100mA; the XRD spectrum acquisition parameters in S260, S290 and S300 are: 2theta angle scanning range 10°~80°, step size 0.02° / step, scanning speed 0.05s / step, and data is collected in 1D mode through a two-dimensional surface detector in the form of an Eiger detector.

[0046] It should be understood that in the embodiment of regulating the crystallization process of the solution sample by controlling the temperature, in S250 , after the first sealing cover 140 and the second sealing cover 150 are closed in sequence, the sample holder 120 needs to be vacuumed.

[0047] The following embodiments and Figure 4 The above detection method 200 is described in detail.

[0048] The sample used in this scheme is a saturated aqueous solution of Na2SO4, and the specific steps are as follows:

[0049] Step 1, loading a low temperature in-situ XRD dedicated sample holder 120 into a low temperature in-situ chamber 110;

[0050] Step 2: insert a Cu attenuation absorber in front of the two-dimensional surface detector, place the in-situ XRD light source and detector at 0°, and increase the X-ray voltage to 42 kV and 100 mA;

[0051] Step 3, by adjusting the height adjustment knob of the in-situ chamber 110, the height of the sample holder 120 is reduced to the lowest, and the shutter is opened. At this time, the light intensity is direct light without obstruction, and the light intensity is slowly increased until it becomes half of the direct light intensity, that is, the upper edge of the sample holder 120 is aligned with the center of the light path;

[0052] Step 4, laying two layers of glass sheets at the bottom of the groove portion 121' of the sample holder 120 as a background diffraction material layer;

[0053] Step 5, laying a layer of porous material on the glass sheet so that the surface of the porous material is substantially flush with the upper edge of the sample holder 120, and the material is a natural fiber porous material with a pore size of 40 μm and a thickness of 200 μm;

[0054] Step 6, using PVC film material as a sealing film 124 to cover and seal the entire low-temperature sample holder 120;

[0055] Step 7, cover the first sealing cover 140 and the second sealing cover 150 of the low-temperature in-situ chamber 110 in sequence, set the temperature of the in-situ chamber 110 to 298K and keep it warm for a certain period of time;

[0056] Step 8, remove the Cu attenuation absorber, test the background XRD spectrum, scan the 2-theta angle range of 10°~40°, step length of 0.02° / step, and scan speed of 0.05s / step;

[0057] Step 9, open the second sealing cover 150 and the first sealing cover 140 of the in-situ cavity 110 in sequence, remove the sealing film 124, use a pipette to absorb 0.1 mL of the prepared constant temperature Na2SO4 saturated aqueous solution sample, and drop the sample into the porous material;

[0058] Step 10, re-use the PVC film material to cover and seal the entire low-temperature sample holder 120, and then put the cavity sealing cover back on to test the initial XRD spectrum of the sample;

[0059] Step 11: Set the cooling program from 298K to 268K, the cooling rate is 2K / min, set the test sequence to collect data 15 times continuously, then start cooling, run the temperature detection sequence at the same time, and collect the temperature sequence XRD spectrum (see Figure 4 ).

[0060] Figure 4The diffraction pattern in the figure shows that the temperature gradually decreases from bottom to top. It can be seen that as the temperature decreases, a series of diffraction peaks first appear at 17.2° and 19.4°, then quickly disappear, and a series of strong diffraction peaks appear at 16.1°. According to the analysis, the peaks at 17.2° and 19.4° belong to the unstable Na2SO4•7H2O, and the final crystallized peak is the more stable Na2SO4•10H2O.

[0061] By utilizing the detection equipment and detection method provided in the present application, which have a simple structure and are easy to operate, the crystal precipitation of a solution sample during the cooling and crystallization process can be monitored with high precision, thus filling the technical gap in this field.

[0062] In addition, although exemplary embodiments have been described herein, the scope includes any and all embodiments based on the present disclosure with equivalent elements, modifications, omissions, combinations (e.g., various embodiments intersecting schemes), adaptations or changes. The elements in the claims are to be interpreted broadly based on the language adopted in the claims, and are not limited to the examples described in this specification or during the practice of the present disclosure, and the examples are to be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered as examples only, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0063] The above description is intended to be illustrative rather than restrictive. For example, the above examples (or one or more schemes thereof) may be used in combination with each other. For example, a person of ordinary skill in the art may use other embodiments when reading the above description. In addition, in the above-mentioned specific embodiments, various features may be grouped together to simplify the present disclosure. This should not be interpreted as an intention that a feature of an application that does not require protection is necessary for any claim. On the contrary, the subject matter of the present disclosure may be less than all the features of an embodiment of a particular application. Thus, the claims are incorporated herein into the specific embodiments as examples or embodiments, wherein each claim is independently a separate embodiment, and it is considered that these embodiments may be combined with each other in various combinations or arrangements. The scope of the present invention should be determined with reference to the appended claims and the full scope of equivalent forms to which these claims are entitled.

[0064] The above embodiments are only exemplary embodiments of the present disclosure and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present disclosure, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. An in-situ XRD detection device for detecting the crystallization process of a solution, characterized in that: The in-situ XRD detection equipment comprises: An in-situ XRD device, which includes a Cu rotating target line light source and a two-dimensional surface detector, and is configured to collect XRD spectra of a solution sample at different temperatures during a crystallization process; An in-situ cavity, which is arranged in the in-situ XRD device; a sample holder, which is disposed inside the in-situ cavity and is configured to accommodate the solution sample to be detected; and a cooling medium circulation system configured to control the circulation of a cooling medium to reduce the temperature inside the sample holder; Wherein, the sample rack comprises: a sample holder body configured to engage with a base fixedly disposed in the in-situ cavity and including a recessed portion defined therein; At least one layer of background diffraction material, which is stacked and laid on and covers the bottom of the groove portion, the background diffraction material has a lower diffraction signal than the sample holder body, so as to avoid the interference of the diffraction signal of the sample holder body on the detection result; a porous material, which is stacked and laid above the at least one layer of background diffraction material and whose upper surface is flush with the upper surface of the edge of the sample holder body, and the porous material is configured to adsorb the solution sample; and A sealing film is covered on the upper surface of the porous material to seal the solution sample, so as to reduce the influence of solvent volatilization on the crystallization process.

2. The in-situ XRD detection device according to claim 1, characterized in that: Also includes: a first sealing cover, which is mounted on a support seat fixedly arranged inside the in-situ cavity, wherein the support seat is used to support and accommodate the sample holder, and / or A second sealing cover is installed on the in-situ cavity.

3. The in-situ XRD detection device according to claim 2, characterized in that: The cooling medium circulation system includes a medium circulation pipeline, a medium circulation compressor, a temperature control system and a temperature sensor, wherein the medium circulation pipeline is in communication with the internal fluid of the base of the in-situ cavity to realize the circulation of the cooling medium.

4. The in-situ XRD detection device according to claim 2, characterized in that: The cooling medium is liquid helium, and the cooling medium circulation system is configured to make the temperature of the solution sample within the range of 12K to 300K, with a cooling rate of at most 6K / min.

5. The in-situ XRD detection device according to claim 2, characterized in that: The background diffraction material is glass or a single crystal silicon wafer with zero background diffraction.

6. The in-situ XRD detection device according to claim 2, characterized in that: The porous material is natural fiber, organic polymer fiber or glass fiber, is chemically inert and insoluble in water, has a pore size of 10-80 μm, a porosity of 50%-80%, and a thickness of 50-200 μm.

7. The in-situ XRD detection device according to claim 2, characterized in that: The sealing film is a polymer film material that is chemically inert and insoluble in water, and has a thickness of 10-20 μm.

8. The in-situ XRD detection device according to claim 2, characterized in that: Also included is a crystallization pressure regulating system, which is configured to change the pressure inside the sample holder, thereby regulating the crystallization pressure of the solution sample, so that the crystallization process can be regulated by the crystallization pressure in a controllable manner; The in-situ XRD device is further configured to collect the XRD patterns of the solution sample at different combinations of temperature and crystallization pressure during the crystallization process.

9. A method for detecting a solution crystallization process using the in-situ XRD detection device according to any one of claims 2 to 8, characterized in that: The steps include: Step 1, placing the sample holder body inside the in-situ cavity; Step 2, inserting a Cu attenuation absorption sheet in front of the two-dimensional surface detector, setting the angle between the Cu rotating target line light source and the two-dimensional surface detector to 0°, and setting the light source to a working power; Step 3, adjusting the height of the in-situ cavity so that the upper surface of the edge of the sample holder body is flush with the central axis of the X-ray optical path; Step 4, laying the at least one layer of background diffraction material and the porous material in sequence at the bottom of the groove portion, so that the upper surface of the porous material is flush with the upper surface of the sample holder body; Step 5, covering the sample rack with the sealing film, closing the first sealing cover and the second sealing cover in sequence, setting the temperature inside the sample rack to a predetermined initial temperature through the cooling medium circulation system and keeping the temperature; Step 6, removing the Cu attenuation absorption sheet, and collecting a background XRD spectrum using the in-situ XRD device; Step 7, opening the second sealing cover and the first sealing cover in sequence, removing the sealing film, and dripping the solution sample to be detected onto the porous material; Step 8, repeat step 5; Step 9, collecting an initial XRD pattern of the solution sample at the predetermined initial temperature using the in-situ XRD device; Step 10, according to a preset cooling program, the temperature inside the sample holder is lowered by the cooling medium circulation system, and at the same time, according to a preset temperature detection sequence, the XRD spectrum of the solution sample at different temperatures during the crystallization process is collected by the in-situ XRD device, so as to obtain a temperature sequence XRD spectrum associated with the crystallization process.

10. The method according to claim 9, characterized in that In step 5, after the first sealing cover and the second sealing cover are closed in sequence, the sample holder is evacuated.

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