System for observing growth and evolution of ice crystals in oriented freezing process in situ

Abstract

The invention discloses a system for in-situ observation of ice crystal growth evolution in an oriented freezing process, which comprises an oriented freezing device, a horizontal optical microscopic device and an anti-atomization device, the oriented freezing device comprises a transparent container arranged in the vertical direction, a first refrigerant conveying mechanism arranged at the top end of the transparent container and a second refrigerant conveying mechanism arranged at the bottom end of the transparent container. The horizontal optical microscopic device comprises a support and a horizontal optical microscope which is arranged on the support and can move in the vertical direction of the support and rotate around the support, and the horizontal optical microscope is arranged on one side of the transparent container. The system can perform rapid capture and high-resolution imaging on the ice crystal form, can eliminate surface atomization interference and bubble precipitation interference caused by water condensation of the freezing device at low temperature, and can regulate and control the freezing working condition.

Description

Technical Field

[0001] This invention relates to the field of in-situ optical characterization technology, and more specifically to an in-situ observation system for ice crystal growth and evolution during orientation freezing. Background Technology

[0002] Orientation freezing technology, also known as ice template method, has attracted widespread attention in recent years due to its simplicity, efficiency, low cost, and versatility. This technology can be applied to various building blocks such as polymers, inorganic ceramics, biomacromolecules, carbon materials, and composite materials to prepare surprisingly high-performance ordered structural materials, demonstrating broad application value in important fields such as biomedical engineering, structural materials, energy storage, environmental remediation, thermal insulation, and flexible electronics. However, due to the lack of in-situ characterization instruments for orientation freezing, in-situ characterization of the dynamic growth evolution of solvent crystals during the orientation freezing process remains challenging.

[0003] In-situ observation of solvent crystal growth and evolution during orientation freezing is crucial for understanding the microscopic assembly mechanism of this technology. However, due to the lack of in-situ characterization instruments, research on the growth kinetics of solvent crystals during orientation freezing is limited. In recent years, thanks to advancements in synchrotron X-ray imaging and optical microscopy, researchers have utilized synchrotron X-ray three-dimensional tomography to achieve 3D morphological analysis of frozen ice crystals (Adv. Funct. Mater., 2023, 33, 2304738); and observed the polarized structure of ice crystals within polymer composite ice blocks using polarized optical microscopy (Mater. Charact., 2014, 93, 184-190). Due to the transparency of ice crystals, their optical outlines are not readily apparent in aqueous solutions, making direct observation of ice crystal growth and evolution during orientation freezing still challenging. Systematic research on the growth patterns of solvent crystals during orientation freezing places higher demands on in-situ characterization equipment. However, existing in-situ characterization techniques still face challenges to varying degrees, such as difficulty in imaging ice crystal morphology or low resolution, interference from surface fogging of freezing devices, interference from bubble precipitation, and limited control of freezing conditions.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide an in-situ observation system for ice crystal growth and evolution during orientation freezing, which aims to solve the problems of difficult or low resolution imaging of existing ice crystal morphology.

[0006] The technical solution of the present invention is as follows: A system for in-situ observation of ice crystal growth and evolution during oriented freezing includes an oriented freezing device, a horizontal optical microscope, and an anti-fogging device. The orientation freezing device includes a vertically arranged transparent container, a first refrigerant delivery mechanism located at the top of the transparent container, and a second refrigerant delivery mechanism located at the bottom of the transparent container; The horizontal optical microscope device includes a support and a horizontal optical microscope mounted on the support, which can move along the vertical direction of the support and rotate around the support. The horizontal optical microscope is located on one side of the transparent container and faces the transparent container to observe the growth and evolution of ice crystals inside the transparent container. The anti-fogging device includes a nitrogen storage container and a nitrogen delivery pipe connected to the nitrogen storage container with its outlet located next to the transparent container.

[0007] Optionally, the distance between the outlet of the nitrogen delivery pipe and the transparent container is 0.5~3cm, and the flow rate of the nitrogen gas is 0.5~30 L / min. -1 .

[0008] Optionally, the surface of the transparent container is coated with an anti-fogging hydrophilic emulsion.

[0009] Optionally, the in-situ observation system for ice crystal growth and evolution during orientation freezing also includes a movable stage supported at the bottom of the transparent container.

[0010] Optionally, the first refrigerant delivery mechanism includes a first temperature controller, a first refrigerant delivery pipe, and a first peristaltic pump connected between the two, wherein the first refrigerant delivery pipe passes through the upper end of the transparent container; The second refrigerant delivery mechanism includes a second temperature controller, a second refrigerant delivery pipe, and a second peristaltic pump connected between the two, with the second refrigerant delivery pipe passing through the lower end of the transparent container.

[0011] Optionally, the vertical distance between the first refrigerant delivery pipe and the second refrigerant delivery pipe inside the transparent container is 0.2 to 1 cm.

[0012] Optionally, the transparent container has a wedge-shaped block located at the upper end of the second refrigerant delivery pipe inside.

[0013] Optionally, the nitrogen storage container is mounted on the support and can move vertically along the support.

[0014] Optionally, the first refrigerant delivery pipe and the second refrigerant delivery pipe are made of copper, stainless steel, aluminum alloy, ceramic or plastic.

[0015] Optionally, the transparent container is a quartz glass container, an acrylic glass container, or a PET plastic transparent container.

[0016] Optionally, the temperature of the refrigerant delivered by the first refrigerant delivery mechanism is lower than the temperature of the refrigerant delivered by the second refrigerant delivery mechanism.

[0017] It should be noted that the different temperatures delivered by the two processes create a temperature gradient for orientation freezing and trigger the orientation freezing process.

[0018] Beneficial Effects: Compared to traditional synchrotron X-ray imaging and polarized / confocal optical microscopy, the system designed in this invention offers advantages in simplicity, efficiency, and controllability. Furthermore, this system can rapidly capture and image ice crystal morphology at high resolution, eliminate surface fogging and bubble precipitation interference caused by moisture condensation at low temperatures in the freezing device, and allow for the control of freezing conditions. The in-situ characterization device designed in this invention is expected to provide a characterization tool for the growth and evolution of solvent crystals during in-situ capture and orientation freezing processes. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of an in-situ observation system for ice crystal growth and evolution during orientation freezing, according to Embodiment 1 of the present invention.

[0020] Figure 2 This is a schematic diagram of the orientation freezing device according to Embodiment 1 of the present invention.

[0021] Figure 3 This is a schematic diagram of the orientation freezing device according to Embodiment 2 of the present invention. Detailed Implementation

[0022] This invention provides a system for in-situ observation of ice crystal growth and evolution during oriented freezing. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] Existing in-situ characterization techniques still face challenges to varying degrees, including difficulties in imaging ice crystal morphology or low resolution, interference from surface fogging in freezing devices, interference from bubble precipitation, and limited control over freezing conditions. Therefore, there is an urgent need to develop a simple, efficient, and controllable orientation-based freezing in-situ characterization device to accurately and clearly capture the dynamic growth process of solvent crystals in situ.

[0024] Example 1 This embodiment provides a system for in-situ observation of ice crystal growth and evolution during oriented freezing, such as... Figure 1 , Figure 2 As shown, it includes an orientation freezing device 1, a horizontal optical microscope device 2, and an anti-fogging device 3. The orientation freezing device 1 includes a vertically arranged transparent container 1-1, a first refrigerant delivery mechanism 1-2 located at the top of the transparent container 1-1, and a second refrigerant delivery mechanism 1-3 located at the bottom of the transparent container 1-1; The horizontal optical microscope device 2 includes a support 2-2 and a horizontal optical microscope 2-1 mounted on the support 2-2, which can move along the vertical direction of the support 2-2 and rotate around the support 2-2. The horizontal optical microscope 2-1 is located on one side of the transparent container 1-1 and faces the transparent container 1-1 to observe the growth and evolution of ice crystals inside the transparent container 1-1. The anti-fogging device 3 includes a nitrogen storage container 3-1 and a nitrogen delivery pipe 3-2 connected to the nitrogen storage container 3-1 with its outlet located next to the transparent container 1-1.

[0025] It should be noted that the electronic eyepiece of the horizontal optical microscope 2-1 is connected to the computer via a data cable; the nitrogen storage container 3-1 can be set on the support 2-2 and move up and down along the support together with the horizontal optical microscope 2-1.

[0026] Operating Procedures: During testing, the casting solution to be tested is loaded into the orientation cryogenic device 1. After turning on the temperature control system and the anti-fogging nitrogen flow, two cryogenic agents at different temperatures are transported to the upper and lower ends of the casting solution through the first cryogenic agent delivery mechanism 1-2 and the second cryogenic agent delivery mechanism 1-3, respectively, creating a temperature difference in the casting solution. The real-time temperature during the delivery of the two cryogenic agents is recorded using a thermometer. By controlling the stage and microscope object distance, the dynamic growth process of the solvent crystals can be tracked in real time, and three-dimensional data on the evolution of solvent crystal growth can be obtained. The relevant data is output in video or image format.

[0027] In each test, the casting solution to be tested is loaded into the orientation freezing device. After starting the first refrigerant delivery mechanism 1-2, the second refrigerant delivery mechanism 1-3, and the anti-fogging device 3, in-situ characterization can be performed.

[0028] It should be noted that the nitrogen output from the nitrogen delivery pipe 3-2 is used to purge the transparent container 1-1 with nitrogen. The weak nitrogen flow helps prevent moisture condensation, thus facilitating the observation of ice crystal growth and evolution inside the transparent container 1-1 by the horizontal optical microscope 2-1.

[0029] It should be noted that the optical path system of the horizontal optical microscope 2-1 is parallel to the ground. The horizontal optical microscope 2-1 can move vertically, that is, up and down, and can also rotate horizontally around the support 2-2, so as to facilitate finding the location of ice crystals.

[0030] This invention employs a horizontal optical microscope device 2. Unlike traditional optical microscopes, the optical path system of the horizontal optical microscope device 2 is parallel to the ground. The parallel optical path system facilitates the vertical placement of the orientation freezing device and helps eliminate interference from residual dissolved gases in the casting solution that could affect in-situ observation.

[0031] In this embodiment, the distance between the outlet of the nitrogen delivery pipe 3-2 and the transparent container 1-1 is 0.5 to 3 cm, and the flow rate of the nitrogen gas is 0.5 to 30 L / min. -1 The inner wall of the transparent container has a length, width, and height of 30 mm, 3 mm, and 10 mm, respectively. The distance between the outlet of the nitrogen delivery pipe 3-2 and the transparent container 1-1 is positively correlated with the airflow velocity; the greater the distance, the greater the velocity, and vice versa. Under these conditions, the velocity and distance effectively prevent moisture condensation and do not affect the growth of ice crystals inside the transparent container 1-1.

[0032] In this embodiment, the surface of the transparent container 1-1 is sprayed with an anti-fogging hydrophilic emulsion to form an anti-fogging surface that prevents moisture accumulation.

[0033] The in-situ observation system for ice crystal growth and evolution during orientation freezing described in this embodiment also includes a movable stage 4 supported at the bottom of the transparent container 1-1.

[0034] It should be noted that the movable platform 4 can move in three directions: x, y, and z, which means that the position of the transparent container 1-1 can be adjusted arbitrarily.

[0035] To observe the 3D structure of the dynamic growth process of solvent crystals, it is necessary to achieve the mobility of the microscope focus in the three-dimensional directions (x, y, and z). Movement in the x, y, and z directions is achieved by controlling the movable stage under the transparent container 1-1. Movement in the x direction can also be achieved by controlling the horizontal optical microscope 2-1, and movement in the z direction can be achieved by controlling the object distance of the horizontal optical microscope 2-1. Therefore, by controlling the stage and the microscope object distance, the dynamic growth process of the solvent crystals can be tracked in real time, obtaining three-dimensional data on the growth evolution of the solvent crystals. This data is output in the form of video or images.

[0036] In this embodiment, the first refrigerant delivery mechanism 1-2 includes a first temperature controller 1-21, a first refrigerant delivery pipe 1-22, and a first peristaltic pump 1-23 connected between the two. The first refrigerant delivery pipe 1-22 passes through the upper end of the transparent container 1-1. The second refrigerant delivery mechanism 1-3 includes a second temperature controller 1-31, a second refrigerant delivery pipe 1-32, and a second peristaltic pump 1-33 connected between the two. The second refrigerant delivery pipe 1-32 passes through the lower end of the transparent container 1-1.

[0037] The diameter of the portion of the first refrigerant delivery pipe 1-22 and the second refrigerant delivery pipe 1-32 that passes through the transparent container 1-1 is comparable to the cross-section of the transparent container 1-1, which can better cool the casting solution inside the transparent container 1-1 and induce crystal growth.

[0038] In this embodiment, the vertical distance between the first refrigerant delivery pipe 1-22 and the second refrigerant delivery pipe 1-32 inside the transparent container 1-1 is 1 cm, but it is not limited to 1 cm. It can also be 0.2 cm, 0.3 cm, 0.4 cm, 0.5 cm, 0.6 cm, 0.7 cm, 0.8 cm, 0.9 cm, or 1 cm.

[0039] It should be noted that the refrigerant is ethanol.

[0040] The real-time temperatures of the first refrigerant delivery pipe 1-22 and the second refrigerant delivery pipe 1-32 can also be recorded using thermometers to facilitate temperature adjustment.

[0041] In this embodiment, the nitrogen storage container 3-1 is mounted on the support 2-2 and can move vertically along the support 2-2.

[0042] The first refrigerant delivery pipe 1-22 and the second refrigerant delivery pipe 1-32 are made of copper, stainless steel, aluminum alloy, ceramic or plastic. In this embodiment, copper pipe with better thermal conductivity is selected.

[0043] The transparent container 1-1 is a quartz glass container, an acrylic glass container, or a PET plastic transparent container. In this embodiment, a quartz glass container with a thickness of approximately 5mm is selected.

[0044] Optionally, the temperature of the refrigerant delivered by the first refrigerant delivery mechanism 1-2 is lower than the temperature of the refrigerant delivered by the second refrigerant delivery mechanism 1-3.

[0045] It should be noted that the different temperatures delivered by the two processes create a temperature gradient for orientation freezing and trigger the orientation freezing process.

[0046] Example 2 like Figure 3 As shown, this embodiment differs from Embodiment 1 in that a wedge-shaped block 5 is provided inside the transparent container 1-1 at the upper end of the second refrigerant delivery pipe 1-32.

[0047] The wedge-shaped block is made of polydimethylsiloxane. As a key unit for forming a dual temperature gradient, this creates a vertical temperature gradient and a horizontal temperature gradient, resulting in inconsistent directional growth heights of ice crystals. This structure facilitates the formation of lamellar ice crystal structures.

[0048] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A system for in-situ observation of ice crystal growth and evolution during oriented freezing, characterized in that: It includes an orientation freezing device (1), a horizontal optical microscope device (2), and an anti-fogging device (3). The orientation freezing device (1) includes a vertically arranged transparent container (1-1), a first refrigerant delivery mechanism (1-2) located at the top of the transparent container (1-1), and a second refrigerant delivery mechanism (1-3) located at the bottom of the transparent container (1-1). The horizontal optical microscope device (2) includes a support (2-2) and a horizontal optical microscope (2-1) mounted on the support (2-2) that can move vertically along the support (2-2) and rotate around the support (2-2). The horizontal optical microscope (2-1) is located on one side of the transparent container (1-1) and faces the transparent container (1-1) to observe the growth and evolution of ice crystals inside the transparent container (1-1). The anti-fogging device (3) includes a nitrogen storage container (3-1) and a nitrogen delivery pipe (3-2) connected to the nitrogen storage container (3-1) and having its outlet located next to the transparent container (1-1).

2. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 1, characterized in that: The distance between the outlet of the nitrogen delivery pipe (3-2) and the transparent container (1-1) is 0.5 to 3 cm, and the flow rate of the nitrogen gas is 0.5 to 30 L / min. -1 .

3. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 1, characterized in that: The transparent container (1-1) is coated with an anti-fogging hydrophilic emulsion.

4. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 1, characterized in that: The in-situ observation system for ice crystal growth and evolution during orientation freezing also includes a movable stage (4) supported at the bottom of the transparent container (1-1).

5. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 1, characterized in that: The first refrigerant delivery mechanism (1-2) includes a first temperature controller (1-21), a first refrigerant delivery pipe (1-22), and a first peristaltic pump (1-23) connected between the two. The first refrigerant delivery pipe (1-22) passes through the upper end of the transparent container (1-1). The second refrigerant delivery mechanism (1-3) includes a second temperature controller (1-31), a second refrigerant delivery pipe (1-32), and a second peristaltic pump (1-33) connected between the two. The second refrigerant delivery pipe (1-32) passes through the lower end of the transparent container (1-1).

6. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 5, characterized in that: The vertical distance between the first refrigerant delivery pipe (1-22) and the second refrigerant delivery pipe (1-32) inside the transparent container (1-1) is 0.2~1 cm.

7. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 1, characterized in that: The transparent container (1-1) has a wedge-shaped block (5) located at the upper end of the second refrigerant delivery pipe (1-32) inside.

8. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 1, characterized in that: The nitrogen storage container (3-1) is mounted on the support (2-2) and can move vertically along the support (2-2).

9. A system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 5, characterized in that: The first refrigerant delivery pipe (1-22) and the second refrigerant delivery pipe (1-32) are made of copper, stainless steel, aluminum alloy, ceramic or plastic; The transparent container (1-1) is a quartz glass container, an acrylic glass container, or a PET plastic transparent container.

10. The system for in-situ observation of ice crystal growth and evolution during oriented freezing according to claim 1, characterized in that: The temperature of the refrigerant delivered by the first refrigerant delivery mechanism (1-2) is lower than the temperature of the refrigerant delivered by the second refrigerant delivery mechanism (1-3).

Images