Organic crystals with low-temperature plastic torsional capability, and methods of making and using the same
Organic crystals constructed using 4,4'-difluorobenzoyl molecules achieve plastic torsion and bending deformation at extremely low temperatures, solving the problems of brittle fracture and unstable optical waveguide performance of organic crystals, and can be applied to low-temperature flexible optoelectronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- JILIN UNIVERSITY
- Filing Date
- 2026-04-29
- Publication Date
- 2026-06-05
AI Technical Summary
Existing organic crystals are prone to brittle fracture at extremely low temperatures, lack plastic deformation capabilities, especially torsional deformation, and have unstable optical waveguide properties, making them difficult to apply to flexible optoelectronic devices in low-temperature environments.
Organic crystals formed by 4,4'-difluorobenzoyl molecules are used to construct slip plane structures through CH···O and CH···F hydrogen bonds and π-π stacking interactions, enabling the crystals to achieve plastic torsion and maintain deformation at low temperatures. Needle-like crystals are prepared by combining specific solvent growth methods.
It achieves controllable plastic torsion and bending deformation at low temperatures while maintaining excellent optical waveguide performance, and is suitable for low-temperature flexible optical waveguide devices, polarization rotators, polarization modulators and mechanical actuators.
Smart Images
Figure CN122145292A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of organic optical functional materials technology, specifically to an organic crystal with low-temperature plastic torsion capability, its preparation method, and its application. Background Technology
[0002] Organic molecular crystals, as an important class of optoelectronic functional materials, have broad application prospects in flexible electronics, photonic devices, sensors, and biomimetic actuators due to their structural diversity, light weight, low cost, and excellent optical and electrical properties (such as light emission and semiconductor transmission). However, in current technological understanding, organic crystals are generally considered to be brittle. Because intermolecular forces (such as van der Waals forces and hydrogen bonds) are anisotropic and relatively weak, crystals are prone to slip plane separation under external mechanical stress, leading to fracture or breakage and making them unable to withstand large mechanical deformations. In recent years, with the development of crystal engineering, researchers have developed some organic crystals with a certain degree of mechanical flexibility at room temperature (approximately 298 K), including elastically bending crystals and plastically bending crystals. These materials can adapt to external forces through molecular cooperative rearrangement at room temperature, thereby achieving a certain degree of deformation. However, existing technologies still have the following significant drawbacks and limitations:
[0003] 1. The problem of brittleness at low temperatures: Existing organic molecular crystal materials are generally brittle and hard with weak intermolecular forces, making them prone to mechanical fracture. Although some crystals with elastic or plastic bending capabilities at room temperature have been developed in recent years, when the temperature drops to extreme low temperatures (such as liquid nitrogen temperature, 77K), the molecular thermal motion of most organic materials is frozen, and the materials become extremely hard and brittle, completely losing their flexibility. They will brittlely fracture under slight external forces and cannot function normally in low-temperature environments.
[0004] 2. Lack of low-temperature plastic deformation capability: Currently, no organic crystals have been reported to undergo plastic deformation at extremely low temperatures. Plastic deformation refers to the ability of a material to retain its deformed shape after the external force is removed, without returning to its original state. Achieving this property at low temperatures is crucial for constructing cryogenically shaped devices, but it is extremely challenging.
[0005] 3. Limited Deformation Mode: Most existing flexible crystals can only achieve simple two-dimensional bending, making it difficult to achieve more complex three-dimensional deformations, such as twisting. In particular, achieving controllable plastic twisting is extremely rare in existing technologies, which cannot meet the requirements for three-dimensional complex plastic processing of materials at low temperatures (i.e., maintaining shape after deformation).
[0006] 4. Stability of Optical Waveguide Performance: Ensuring efficient transmission of optical signals within the crystal (i.e., optical waveguide performance) under extreme conditions of low temperature and mechanical deformation remains undamaged is a major challenge for existing materials. In existing organic optoelectronic crystals, mechanical deformation is often accompanied by the destruction of the crystal structure or the generation of microcracks, leading to a sharp increase in light loss during transmission. This makes it difficult to balance mechanical flexibility with excellent optical waveguide performance, limiting their application in flexible optoelectronic devices.
[0007] Therefore, developing a novel organic crystal material that can not only avoid brittle fracture at extreme low temperatures (such as 77K) but also achieve plastic torsion while maintaining excellent optical waveguide performance is of great scientific significance and practical value for expanding the application of organic optoelectronic materials in deep space exploration, low-temperature superconducting systems and extreme environments. Summary of the Invention
[0008] The purpose of this invention is to provide an organic crystal with low-temperature plastic torsion capability, its preparation method, and its application, so as to solve the problems mentioned in the background art.
[0009] To achieve the above objectives, the present invention provides the following technical solution:
[0010] An organic crystal with low-temperature plastic torsion capability comprises 4,4'-difluorobenzoyl molecules; the 4,4'-difluorobenzoyl molecules in the organic crystal are arranged in parallel in the crystal lattice, and the molecules form a slip plane structure through CH···O and CH···F hydrogen bonds and π-π stacking interactions, enabling the organic crystal to undergo plastic torsion at a low temperature not higher than 77K, and to permanently maintain the deformed state after torsion.
[0011] Furthermore, the organic crystal exhibits optical waveguide properties at temperatures ranging from 77 to 298 K, and its optical loss coefficient under bending or torsion conditions is no higher than 0.1193 dB·mm. -1 .
[0012] Another object of the present invention is to provide a method for preparing the above-mentioned organic crystal with low-temperature plastic torsion capability, comprising the following steps:
[0013] The 4,4'-difluorobenzoyl compound was dissolved in a first organic solvent to prepare a saturated solution;
[0014] Place the saturated solution at the bottom of the container, and then slowly add the second organic solvent along the container wall to form a liquid-liquid separation interface;
[0015] The organic crystals were obtained by sealing the container and allowing them to diffuse and grow at rest.
[0016] Furthermore, the first organic solvent is dichloromethane; the second organic solvent is ethanol.
[0017] Furthermore, the volume ratio of the saturated solution to the second organic solvent is 1:(1.5-2.5).
[0018] Further, the steps of sealing the container and allowing it to diffuse and grow at rest to obtain needle-like organic crystals specifically include:
[0019] The container containing the saturated solution was sealed with a sealing film and left to stand, allowing the compound molecules to diffuse and grow at the interface between the two phases. After being cultured at 20-30℃ for 3-5 days, needle-shaped organic crystals were obtained.
[0020] Another object of the present invention is to provide an application of the above-mentioned organic crystal with low-temperature plastic torsion capability in the fabrication of low-temperature flexible optical waveguide devices, wherein the organic crystal can still maintain a resistance of no more than 0.1193 dB·mm² after mechanical deformation. -1 Low-loss optical signal transmission.
[0021] Another object of the present invention is to provide an application of the above-mentioned organic crystal with low-temperature plastic torsion capability in the preparation of low-temperature polarization rotators or polarization modulation devices, wherein the organic crystal has polarization light modulation function, and the polarization direction of the emitted light can be linearly controlled by changing the torsion angle or physical rotation angle of the organic crystal.
[0022] Another object of the present invention is to provide an application of the above-mentioned organic crystal with low-temperature plastic torsion capability in the preparation of low-temperature mechanical actuators or micro / nano optical switches.
[0023] This invention provides an organic crystal with low-temperature plastic torsion capability, overcoming the limitation of traditional organic crystals that suffer from brittleness due to molecular thermal freezing at extremely low temperatures. Utilizing the unique layered slip surface structure within this organic crystal, rare controllable plastic torsion is achieved at liquid nitrogen temperature (77K), and the deformed crystal permanently retains its shape. Compared to existing technologies, this organic crystal achieves a perfect coupling between extreme mechanical deformation and excellent optical waveguide performance, maintaining extremely low optical transmission loss even under severe torsion. Simultaneously, this organic crystal exhibits unique mechano-optical response characteristics, enabling precise linear modulation of the polarization state of emitted light through physical rotation or plastic torsion. This provides a novel key material for constructing flexible micro / nano optoelectronic devices (such as cryogenic polarization rotators and optical switches) in deep space exploration and cryogenic superconducting environments. Attached Figure Description
[0024] Figure 1Figure 1 shows the crystal structure characterization results of DFBZL. In the figure, (A) and (B) show the crystallographic parameters of the DFBZL molecule at room temperature (298 K) and low temperature (100 K), respectively. By comparing the changes in bond length, torsion angle, and interlayer spacing (e.g., the interlayer spacing shortens from 3.520 Å to 3.417 Å), the lattice contraction and fine-tuning of the molecular configuration at low temperature are revealed. Figure (C) is a schematic diagram of the macroscopic morphology and microstructure of the DFBZL crystal, detailing the molecular arrangement along the crystal axis, the π-π columnar packing mode, and the structure formed by CH… The hydrogen bond network composed of O and CH···F exhibits obvious layered slip surface structure characteristics; (D) shows the Hirshfeld surface analysis results of the molecule, in which the red area intuitively locates key interaction sites such as π-π, CH···O and CH···F; (E) quantifies the percentage contribution of each intermolecular interaction to crystal stacking, and the results show that FH (28.0%), CH (22.5%) and OH (16.4%) are the main forces maintaining the stability of the DFBZL crystal structure.
[0025] Figure 2 The graph shows the emission / absorption spectrum (A) and fluorescence lifetime test results (B) of the DFBZL crystal.
[0026] Figure 3 The graph shows the optical loss test results of the DFBZL crystal in the straight (AC) and bent (DF) states at 298K.
[0027] Figure 4 The graph shows the optical loss test results of the DFBZL crystal in the straight (AC) and bent (DF) states at 77K.
[0028] Figure 5 Figure 1 shows the results of the low-temperature plastic torsion properties study of DFBZL crystals; in the figure, (A) shows the DFBZL crystals under liquid nitrogen (In). (a) Photographs of the DFBZL crystal undergoing left-handed plastic torsion in a liquid nitrogen environment. The image shows the DFBZL crystal immersed in liquid nitrogen emitting green fluorescence. Under external force, it undergoes torsion deformation along the left-hand direction. After the external force is removed, the DFBZL crystal can maintain the torsioned spiral shape (as shown in the dotted circle area in the figure), proving its low-temperature plasticity; (b) Photographs of the DFBZL crystal undergoing right-handed plastic torsion in a liquid nitrogen environment; (c) Scanning electron microscope (SEM) microscopic morphology of the DFBZL crystal after left-handed plastic torsion. The left image shows the overall spiral shape of the DFBZL crystal, and the right image is a magnified view of the area within the white dotted box on the left. The image shows that the surface of the torsioned DFBZL crystal is smooth and flat, and no fractures or obvious microcracks were observed, confirming the integrity of the DFBZL crystal structure; (d) Scanning electron microscope (SEM) microscopic morphology of the DFBZL crystal after right-handed plastic torsion.
[0029] Figure 6 Figure 1 shows the results of verifying the polarization modulation function of DFBZL crystal. In the figure, (A) is a schematic diagram of the single-crystal photoluminescence polarization test device, showing the optical path settings of DFBZL crystal under ultraviolet light excitation in the initial linear state, plastic torsion state and rotation test process, respectively; (B) and (C) record the normalized fluorescence intensity of DFBZL crystal in the initial linear state, plastic torsion state (covering different crystal rotation angles from 0° to 180°) and restored linear state as a function of the analyzer rotation angle in the right-handed and left-handed plastic torsion experimental groups, respectively; (D) and (E) reveal the significant linear correlation between the maximum value of the analyzer angle and the physical rotation angle of the crystal in the right-handed and left-handed torsion DFBZL crystal (including the restored state), confirming the excellent polarization preservation and modulation ability of DFBZL crystal. Detailed Implementation
[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0031] To address the problems that existing organic crystal materials are generally brittle and hard, especially in extreme low-temperature environments (such as liquid nitrogen temperature, 77K) where they almost completely lose their flexibility and are prone to brittle fracture, this invention provides an organic crystal that can undergo plastic torsion at low temperatures.
[0032] Specifically, in one embodiment of the present invention, an organic crystal with low-temperature plastic torsion capability is provided, which comprises a 4,4'-difluorobenzoyl (DFBZL) molecule; the structural formula of the DFBZL molecule is as follows:
[0033] ;
[0034] In this embodiment of the invention, the 4,4'-difluorobenzoyl molecules in the organic crystal exhibit parallel stacking in the crystal lattice. Intermolecular forces are formed through CH···O and CH···F hydrogen bonds and π-π stacking interactions, creating a slip surface structure. This allows the organic crystal to undergo plastic torsion at temperatures not exceeding 77 K, and to permanently maintain its deformed state after torsion. This layered slip surface structure, maintained by weak interactions such as CH···O and CH···F, is the physical basis for achieving low-temperature plasticity. Furthermore, this organic crystal exhibits optical waveguide properties at temperatures ranging from 77 to 298 K, and its optical loss coefficient under bending or torsion conditions is no higher than 0.1193 dB·mm. -1 .
[0035] The organic crystal provided in this invention not only exhibits elasticity at room temperature but also overcomes the brittleness limitations of traditional organic materials at low temperatures, achieving controllable torsional deformation. Furthermore, it maintains excellent optical waveguide performance even under deformation, solving the technical challenge of a lack of flexible optoelectronic materials in low-temperature environments. Specifically, this organic crystal overcomes the technical bottleneck of traditional organic materials inevitably undergoing brittle fracture at low temperatures (such as liquid nitrogen at 77K), achieving controllable plastic torsion and plastic bending deformation at extreme low temperatures, and permanently maintaining its geometric shape after deformation without returning to its original state.
[0036] In another embodiment of the present invention, a method for preparing the above-mentioned organic crystal with low-temperature plastic torsion capability is also provided, comprising the following steps:
[0037] S1. Dissolve the 4,4'-difluorobenzoyl compound in a first organic solvent to prepare a saturated solution;
[0038] S2. Place the saturated solution at the bottom of the container, and then slowly add the second organic solvent along the container wall to form a liquid-liquid layer interface;
[0039] S3. Seal the container and allow it to diffuse and grow at rest to obtain needle-shaped organic crystals.
[0040] Preferably, the first organic solvent is dichloromethane; the second organic solvent is ethanol; and the volume ratio of the saturated solution to the second organic solvent is 1:(1.5-2.5).
[0041] Preferably, the step of sealing the container and allowing it to diffuse and grow at rest to obtain needle-like organic crystals specifically includes:
[0042] The container containing the saturated solution was sealed with a sealing film and left to stand, allowing the compound molecules to diffuse and grow at the interface between the two phases. After being cultured at 20-30℃ for 3-5 days, needle-shaped organic crystals were obtained.
[0043] In another embodiment of the present invention, an application of the above-mentioned organic crystal with low-temperature plastic torsion capability is provided in the fabrication of low-temperature flexible optical waveguide devices, wherein the organic crystal can maintain a strength not exceeding 0.1193 dB·mm² after undergoing severe mechanical deformation (bending or torsion). -1 Low-loss optical signal transmission.
[0044] In another embodiment of the present invention, the above-mentioned organic crystal with low-temperature plastic torsion capability is also provided for use in the preparation of low-temperature polarization rotators or polarization modulation devices, wherein the organic crystal has polarization light modulation function, that is, the polarization direction of the emitted light can be precisely controlled linearly by changing the torsion angle or physical rotation angle of the crystal.
[0045] Another object of the present invention is to provide an application of the above-mentioned organic crystal with low-temperature plastic torsion capability in the preparation of other low-temperature optoelectronic devices such as low-temperature mechanical actuators or micro / nano optical switches.
[0046] Example 1: This example provides a method for preparing the above-mentioned organic crystal with low-temperature plastic torsion capability, including the following steps:
[0047] The purified 4,4'-difluorobenzoyl (DFBZL) compound was dissolved in dichloromethane to prepare a saturated solution of 0.25 g / mL. 3 mL of this saturated solution was then pipetted into the bottom of a test tube. Next, 6 mL of anhydrous ethanol was slowly poured along the inner wall of the test tube, carefully covering the lower layer of solution to form a clear liquid-liquid interface. Finally, the test tube was tightly sealed with a sealing film and allowed to stand, allowing the DFBZL compound molecules to diffuse and grow at the interface. After 4 days of incubation at room temperature, needle-like organic crystals were obtained in the test tube, denoted as DFBZL crystals.
[0048] Example 2: This example is a crystal structure characterization experiment, as detailed below:
[0049] The DFBZL crystal prepared in Example 1 was characterized using a single-crystal X-ray diffractometer. Figure 1 As shown. Figure 1 Characterization results show that DFBZL molecules exhibit a parallel stacking structure in the crystal lattice, possessing a linear conjugated framework. Intermolecular assembly and stabilization primarily occur through CH···O and CH···F hydrogen bonds and π-π stacking interactions. In particular, crystal structure analysis reveals the presence of distinct slip planes within the DFBZL crystal. This unique layered stacking mode allows the molecular layers to slide relative to each other under external forces without compromising the integrity of the overall crystal structure, thus confirming that the DFBZL crystal prepared in the embodiments of this invention possesses a structural basis for mechanical plastic deformation.
[0050] Example 3: This example is an experiment for testing the photophysical properties of a crystal, as detailed below:
[0051] DFBZL crystals exhibit excellent luminescence properties under 365nm ultraviolet light excitation: the crystals display bright green light emission, and at room temperature (298K), their maximum emission wavelength is 520nm (e.g., ...). Figure 2 As shown in Figure A), the luminescence lifetime is 1.57 ms (as shown in Figure A). Figure 2 (As shown in B).
[0052] Studies have shown that the DFBZL crystal can be used as an optical waveguide device to efficiently transmit optical signals, and it still maintains low-loss transmission characteristics under mechanical deformation (bending or twisting).
[0053] In addition, the optical loss coefficient of DFBZL crystal at different temperatures (298K and 77K) and mechanical states (straight and bent states) was quantitatively tested, and the results are as follows: Figure 3 and Figure 4 As shown; where the optical loss coefficient is obtained by fitting a single exponential function, the fitting formula is: I tip / I body =Aexp(-αD). Where, I tip and I body The fluorescence intensities were measured at the fixed end and the excitation position, respectively; α is the optical loss coefficient, and D is the distance between the fixed end and the excitation position.
[0054] like Figure 3 As shown, the room-temperature (298K) optical waveguide performance of the DFBZL crystal is as follows: the optical loss coefficient of the straight-state crystal is approximately 0.0707 dB·mm. -1 The optical loss coefficient of the bent crystal is approximately 0.0767 dB·mm. -1 .
[0055] like Figure 4 As shown, the low-temperature (77K) optical waveguide performance of the DFBZL crystal is as follows: the optical loss coefficient of the straight-state crystal is approximately 0.1187 dB·mm. -1 The optical loss coefficient of the bent crystal is approximately 0.1193 dB·mm. -1 .
[0056] The above data shows that the DFBZL crystal can maintain extremely low optical transmission loss regardless of whether it is in a normal or low temperature environment, or in a straight or deformed state, proving that it has excellent signal transmission stability as a flexible optical waveguide device material.
[0057] Example 4: This example is an experiment for studying the low-temperature plastic torsion properties of crystals, as detailed below:
[0058] The study found that DFBZL crystals exhibit rare plastic torsion behavior in the cryogenic environment of liquid nitrogen, breaking the traditional understanding that organic crystals usually undergo brittle fracture at low temperatures.
[0059] Experimental process and macroscopic phenomenon analysis: such as Figure 5As shown in Figures A and B, the DFBZL crystal was completely immersed in liquid nitrogen (77K). At this extremely low temperature, the DFBZL crystal did not become brittle due to rapid cooling. Under external force, the DFBZL crystal could undergo continuous torsion in both the left-hand and right-hand directions. The deformation of this DFBZL crystal exhibited significant plastic characteristics: when the torsional force applied to both ends of the crystal was removed, the DFBZL crystal did not spring back to its initial straight state, but instead overcame internal energy storage and permanently maintained its torsional helical geometry. This phenomenon directly demonstrates that the DFBZL crystal prepared in this embodiment of the invention undergoes irreversible plastic rheology at low temperatures, rather than simple elastic deformation.
[0060] Microscopic morphology analysis and conclusions: To further verify the structural integrity of the DFBZL crystal after undergoing severe deformation, scanning electron microscopy (SEM) was performed to characterize the DFBZL crystal after plastic torsion. Figure 5 Microscopic images of C (left-handed twisted crystal) and D (right-handed twisted crystal) are shown:
[0061] Surface integrity: Despite undergoing significant mechanical torsion, the surface of the DFBZL crystal remains highly smooth and continuous at the micrometer scale.
[0062] Non-damaging characteristics: No obvious micro-cracks, fracture cavities, or crystal delamination were observed in the torsional region where stress was concentrated.
[0063] Combining the macroscopic shape retention capability with the microscopic surface non-destructive characteristics, we can conclude that DFBZL crystals exhibit excellent plastic deformation capabilities at the extreme low temperature of 77K. Their specific internal molecular packing structure (presumably involving a slip surface mechanism) allows DFBZL crystals to dissipate enormous mechanical stress through the relative slippage of molecular layers, thus achieving controllable and non-destructive plastic torsion at low temperatures. This characteristic makes them highly promising low-temperature shaping flexible materials.
[0064] Example 5: To further explore the optical application potential of DFBZL crystals after low-temperature plastic deformation, this example tested the response and control capability of DFBZL crystals to polarized light, as detailed below:
[0065] Experimental setup: To accurately characterize the optical waveguide polarization properties of DFBZL crystals under different mechanical deformation states, this embodiment constructs a high-precision single-crystal microscopic photoluminescence polarization detection system (e.g., Figure 6(As shown in A). This system uses a focused ultraviolet laser with a wavelength of 365nm as the excitation source for local excitation at one end of the DFBZL crystal; the sample stage uses a high-precision optical rotary stage, which can fix the DFBZL crystal and make it rotate precisely around its own long axis; in the optical path at the output end of the DFBZL crystal, a linear polarizer that can rotate freely around the optical axis 360° is configured as an analyzer, which is then connected to a high-sensitivity spectrometer or CCD detector to collect and analyze the polarization state and intensity of the emitted fluorescence signal after transmission through the DFBZL crystal waveguide.
[0066] Test Procedure: First, the well-grown needle-shaped DFBZL crystal from Example 1 was selected and horizontally suspended and fixed at the center of the rotating stage, ensuring that the long axis of the DFBZL crystal coincided with the rotation axis of the system. During the test, the DFBZL crystal was controlled to rotate in steps within the range of 0° to 180° around its own long axis (the selected test points included 0°, 45°, 90°, 135°, and 180°). At each fixed crystal rotation angle, the analyzer at the emission end was synchronously controlled to perform a full-angle scan within the range of 0° to 360°, and the intensity spectrum data of the emitted fluorescence at different analysis angles were recorded in real time to obtain a complete polarization response curve.
[0067] Experimental Results and Analysis: The collected spectral data were normalized (e.g., Figure 6 As shown in Figures B and C), the results indicate that regardless of the mechanical state of the DFBZL crystal (linear or plastic torsion), the emitted fluorescence intensity exhibits a strictly periodic cosine square function relationship with the analyzer rotation angle (compliant with Malus's law). This proves that the optical signal propagating along the DFBZL crystal waveguide has extremely high linear polarization. Further analysis was performed by extracting the analyzer angle corresponding to the maximum light intensity in each data set and correlating it with the physical rotation angle of the DFBZL crystal itself (e.g., ...). Figure 6 As shown in D and E), a highly linear positive correlation was found between the two, meaning that the physical rotation of the DFBZL crystal directly and precisely determines the polarization direction of the emitted light.
[0068] The above experimental phenomena confirm that the DFBZL crystal prepared in this embodiment of the invention not only possesses excellent low-temperature plastic deformation capability but is also a polarization-preserving optical waveguide material. Even after undergoing severe low-temperature plastic torsion, the ordered molecular stacking structure inside the DFBZL crystal remains intact, maintaining the polarization characteristics of the optical signal. More importantly, this DFBZL crystal exhibits functions similar to an optical waveplate, enabling continuous and reversible modulation of the polarization state of the optical signal through simple mechanical rotation. This provides a solid experimental basis and application foundation for its use in fabricating tunable micro / nano polarization optoelectronic devices (such as polarization rotators and optical switches) at low temperatures.
[0069] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification.
Claims
1. An organic crystal with low-temperature plastic torsion capability, characterized in that, The organic crystal contains 4,4'-difluorobenzoyl molecules; the 4,4'-difluorobenzoyl molecules in the organic crystal are stacked in parallel in the crystal lattice, and the molecules form a slip plane structure through CH···O and CH···F hydrogen bonds and π-π stacking interactions, which enables the organic crystal to undergo plastic torsion at a low temperature not higher than 77K, and to permanently maintain the deformed state after torsion.
2. The organic crystal with low-temperature plastic torsion capability according to claim 1, characterized in that, The organic crystal exhibits optical waveguide properties at temperatures ranging from 77 to 298 K, and its optical loss coefficient under bending or torsion conditions is no higher than 0.1193 dB·mm. -1 .
3. A method for preparing an organic crystal with low-temperature plastic torsion capability as described in claim 1 or 2, characterized in that, Includes the following steps: The 4,4'-difluorobenzoyl compound was dissolved in a first organic solvent to prepare a saturated solution; Place the saturated solution at the bottom of the container, and then slowly add the second organic solvent along the container wall to form a liquid-liquid separation interface; The organic crystals were obtained by sealing the container and allowing them to diffuse and grow at rest.
4. The method for preparing an organic crystal with low-temperature plastic torsion capability according to claim 3, characterized in that, The first organic solvent is dichloromethane; the second organic solvent is ethanol.
5. The method for preparing an organic crystal with low-temperature plastic torsion capability according to claim 3 or 4, characterized in that, The volume ratio of the saturated solution to the second organic solvent is 1:(1.5-2.5).
6. The method for preparing an organic crystal with low-temperature plastic torsion capability according to claim 3, characterized in that, The steps for obtaining needle-like organic crystals by sealing a container and allowing it to diffuse and grow at rest include: The container containing the saturated solution was sealed with a sealing film and left to stand, allowing the compound molecules to diffuse and grow at the interface between the two phases. After being cultured at 20-30℃ for 3-5 days, needle-shaped organic crystals were obtained.
7. The application of an organic crystal with low-temperature plastic torsion capability as described in claim 1 or 2 in the fabrication of low-temperature flexible optical waveguide devices, characterized in that, The organic crystal, after mechanical deformation, can still maintain a value not exceeding 0.1193 dB·mm. -1 Low-loss optical signal transmission.
8. The application of an organic crystal with low-temperature plastic torsion capability as described in claim 1 or 2 in the fabrication of a low-temperature polarization rotator or polarization modulation device, characterized in that, The organic crystal has a polarization modulation function, which linearly controls the polarization direction of the emitted light by changing the twist angle or physical rotation angle of the organic crystal.
9. The application of an organic crystal with low-temperature plastic torsion capability as described in claim 1 or 2 in the fabrication of low-temperature mechanical actuators or micro / nano optical switches.