Apparatus and method for modifying nanofibers with a laser

Abstract

The application discloses a kind of equipment and method for laser modification nanofiber, the equipment involved in the present application is modified by laser and is synchronized with electrospinning process, the internal morphology of jetting liquid jet is completed in the process of stretching and solidification, without subsequent secondary processing, avoid the damage caused by secondary processing to nanofiber body structure, greatly simplify the process flow, improve the preparation efficiency, realize the one-step preparation of internal morphology controllable nanofiber.It is simple in structure, convenient to control, easy to scale, the first rotating part, the second rotating part and the moving part are adjusted, the size of laser aperture and the deflection angle can be dynamically adjusted, without complex laser scanning and displacement mechanism, the equipment structure is simple, convenient to operate, low in cost, can realize the uniform modification of fiber internal four around, adapt to industrialization scale production demand.

Description

Technical Field

[0001] This invention relates to the field of nanofiber material preparation technology, and specifically to a device and method for modifying nanofibers with laser. Background Technology

[0002] Electrospinning is one of the simplest and most efficient methods for preparing nanofibers. The nanofibers prepared have advantages such as large specific surface area, high porosity, and tunable morphology, and are widely used in fields such as filtration and separation, biomedicine, flexible electronics, environmental remediation, and composite materials.

[0003] However, nanofibers prepared by traditional electrospinning technology mostly have smooth, circular cross-sections and uniform internal morphology, making it difficult to precisely customize the internal microstructure of the fiber through the spinning process itself. This fails to meet the differentiated requirements of fiber structure and performance for various applications. Existing fiber morphology modification technologies are mostly offline post-processing techniques, such as chemical etching, plasma treatment, and mechanical calendering, which suffer from problems such as complex processes, poor controllability, easy damage to the fiber's structure, low production efficiency, and significant environmental pollution.

[0004] Existing laser-assisted electrospinning technologies mostly focus on modifying fiber surface morphology, controlling fiber diameter, or patterning fiber arrays. They cannot achieve precise, directional, and online control of the internal microstructure of fibers, making it difficult to prepare nanofibers with specific internal morphologies in a single step using a single device. This makes it impossible to adapt to the customized application needs of different fields. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for modifying nanofibers with laser, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, in a first aspect, the inventors provide a device for laser-modifying nanofibers, comprising: a syringe, a laser modification component, and a receiving component; The syringe includes a plunger and a syringe barrel. The syringe barrel has a supply chamber, a mounting chamber, and a jetting channel arranged sequentially along its extension direction. The supply chamber is connected to the jetting channel via the supply channel, and the mounting chamber is connected to the jetting channel via a laser channel, with the laser channel and the jetting channel coaxially arranged. The pushing end of the plunger is adapted to the supply chamber and is movably disposed in the supply chamber, used to push the spinning solution in the supply chamber to be delivered to the jetting channel. The laser finishing component includes a laser emitter, an adjusting lens, and a moving component. The laser emitter is disposed in the mounting chamber via a first rotating component. The laser emitter is used to emit laser light; in the non-working state, the optical axis of the laser is parallel to the jetting channel. The axes of the channels are collinear. The first rotating component is used to adjust the angle of the laser emitter to change the deflection angle of the laser. The moving component is disposed in the mounting cavity. The adjusting lens is disposed on the moving component via the second rotating component. The moving component is used to drive the adjusting lens to move along the axial direction of the laser channel to control the aperture size of the laser. The receiving assembly includes a high-voltage power supply and a receiving roller. The receiving roller is disposed opposite to the exit end of the jet channel and is used to receive the laser-modified nanofibers. The positive terminal of the high-voltage power supply is electrically connected to the outer wall of the jet channel, and the negative terminal of the high-voltage power supply is electrically connected to the receiving roller to form a high-voltage electrostatic field between the exit end of the jet channel and the receiving roller.

[0007] Furthermore, the first rotating component is a first ball joint, the ball seat of the first ball joint is disposed on the inner wall of the mounting cavity, and the ball head of the first ball joint is connected to the laser emitter.

[0008] Furthermore, the moving component is a ball screw slide, which is disposed on the inner wall of the mounting cavity. The extension direction of the ball screw of the ball screw slide is parallel to the axial direction of the laser channel, and the slide of the ball screw slide reciprocates along the extension direction of the ball screw. The second rotating component is a second ball joint, the ball seat of the second ball joint is disposed on the slide, and the ball head of the second ball joint is connected to the adjusting lens so as to adjust the tilt angle of the adjusting lens through the second ball joint.

[0009] Furthermore, the laser finishing assembly also includes a laser adjustment panel; The outer wall of the injection cylinder is provided with an adjustment opening, which is connected to the mounting cavity. The laser adjustment panel is electrically connected to the laser emitter in the mounting cavity through a wire, and is used to adjust the energy density, pulse frequency, wavelength and pulse profile of the laser.

[0010] Furthermore, the device for laser-modified nanofibers also includes an injection pump, the syringe is mounted on the injection pump, and the push rod is kinetically connected to the injection pump to drive the push end to move in the liquid supply chamber.

[0011] In a second aspect, the inventors provide a method for modifying nanofibers with a laser, the method comprising the following steps: Supplying spinning solution: The prepared spinning solution is loaded into the supply chamber of the syringe, and the pushing end of the push rod is driven to stably deliver the spinning solution to the jet channel; Preset laser parameters: Based on the preset internal morphology of the target nanofiber, the energy density, pulse frequency, wavelength and pulse profile of the laser are set through the laser adjustment panel. The deflection angle of the laser is adjusted by the first rotating component so that the optical axis of the laser corresponds to the spinning liquid jet path at the outlet end of the jet channel. Constructing a high-voltage electrostatic field: Turn on the high-voltage power supply and adjust the output voltage of the high-voltage power supply to form a stable high-voltage electrostatic field between the outlet end of the jet channel and the receiving roller, so that the spinning solution at the outlet end forms a Taylor cone and is ejected as a continuous spinning solution jet. Online modification and shaping: The spinning liquid jet is stretched axially in a high-voltage electrostatic field and moves toward the receiving drum. Laser pulses periodically act on the interior of the spinning liquid jet during the stretching process, causing the corresponding area of ​​the spinning liquid jet to undergo controllable melting and expansion. As the spinning liquid jet is stretched and solidified, nanofibers with a preset internal morphology are finally collected on the receiving drum.

[0012] Furthermore, in the step of preset laser parameters, the laser energy density is set to 10-20 mJ / cm², the pulse frequency is set to 20-30 kHz, the wavelength is set to 1064 nm, the pulse profile is set to Gaussian, and the laser deflection angle is set to 0° via the laser adjustment panel.

[0013] Furthermore, in the step of preset laser parameters, the laser energy density is set to 30-50 mJ / cm², the pulse frequency to 40-50 kHz, the wavelength to 355 nm, the pulse profile to be peak-shaped, and the laser deflection angle to be 0°-5° via the laser adjustment panel.

[0014] Furthermore, in the step of preset laser parameters, the laser energy density is set to 50-80mJ / cm², the pulse frequency is 15-25kHz, the wavelength is 266nm, the pulse profile is rectangular, and the laser deflection angle is 5°-10° via the laser adjustment panel.

[0015] Unlike existing technologies, the above-mentioned technical solution has the following advantages: The equipment involved in this invention performs laser modification and electrospinning simultaneously, completing the directional modification of the internal morphology during the stretching and solidification of the spinning solution jet. This eliminates the need for subsequent secondary processing, avoiding damage to the nanofiber's structure and significantly simplifying the process flow. It also improves preparation efficiency, enabling one-step preparation of nanofibers with controllable internal morphology. Furthermore, the equipment has a simple structure, is easy to control, and is readily scalable. By adjusting the first rotating component, the second rotating component, and the moving component, the size and deflection angle of the laser aperture can be dynamically adjusted without complex laser scanning and displacement mechanisms. The equipment is simple in structure, easy to operate, and low in cost, enabling uniform modification of the fiber's internal periphery, thus meeting the needs of industrial-scale production. By using the equipment and method involved in this invention to customize the internal morphology of nanofibers, the core properties such as mechanical properties, specific surface area, interfacial bonding force, and sensing response characteristics of the fibers can be directionally optimized. Among them, the semi-circular wave-shaped internal morphology can enhance the flexibility and tensile strength of the fiber, making it suitable for flexible wearable devices and flexible sensor substrates; the triangular sawtooth internal morphology can significantly increase the specific surface area and reactive sites of the fiber, making it suitable for heavy metal adsorption, catalyst carriers and photocatalytic degradation membranes; the rectangular internal morphology can enhance the interfacial bonding between the fiber and the matrix and amplify the deformation signal, making it suitable for composite material reinforcing phases, flexible strain sensor sensitive layers and biomimetic functional fabrics.

[0016] The above description of the invention is merely an overview of the technical solution of this application. In order to enable those skilled in the art to better understand the technical solution of this application and to implement it based on the description and drawings, and to make the above-mentioned objectives and other objectives, features and advantages of this application easier to understand, the following description is provided in conjunction with the specific embodiments and drawings of this application. Attached Figure Description

[0017] The accompanying drawings are only used to illustrate the principles, implementation methods, applications, features, and effects of specific embodiments of the present invention and other related contents, and should not be considered as limitations on this application.

[0018] In the accompanying drawings of the instruction manual: Figure 1 This is a schematic diagram of the syringe, laser modification component, receiving component, and injection pump in this embodiment; Figure 2 This is a first schematic diagram of the syringe in this embodiment; Figure 3 for Figure 2 A schematic diagram of the CC section; Figure 4 for Figure 3 Enlarged view of part A in the middle; Figure 5 This is a second schematic diagram of the syringe in this embodiment; Figure 6 for Figure 5 A schematic diagram of the DD section; Figure 7 for Figure 6 Enlarged view of part B in the middle; Figure 8 This is a third schematic diagram of the syringe in this embodiment; Figure 9 This is a flowchart of the steps of the method described in this invention.

[0019] The reference numerals used in the above figures are explained as follows: 1. Syringe; 2. Laser finishing component; 3. Receiving component; 4. Injection pump; 11. Push rod; 12. Injector cartridge; 111. Push end; 121. Liquid supply chamber; 122. Mounting chamber; 123. Spray channel; 124. Liquid supply channel; 125. Laser channel; 126. Adjustment opening; 21. Laser emitter; 22. Adjustment lens; 23. Moving part; 24. First ball joint; 25. Second ball joint; 26. Laser adjustment panel; 211. Laser; 231. Lead screw; 31. High-voltage power supply; 32. Receiving drum. Detailed Implementation

[0020] To illustrate the possible application scenarios, technical principles, implementable specific solutions, and achievable objectives and effects of this application in detail, the following description, in conjunction with the listed specific embodiments and accompanying drawings, provides a detailed explanation. The embodiments described herein are merely illustrative of the technical solutions of this application and are therefore intended to limit the scope of protection of this application.

[0021] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0022] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0023] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0024] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0025] Without further limitations, the use of terms such as “comprising,” “including,” “having,” or other similar open-ended expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0026] In this application, expressions such as "greater than", "less than", and "exceeding" are understood to exclude the stated number; expressions such as "above", "below", and "within" are understood to include the stated number. Furthermore, in the description of the embodiments of this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times", unless otherwise explicitly specified.

[0027] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0028] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral arrangement; it can be a direct connection or an indirect connection through an intermediate medium; it can be a relationship of two components combined together, an interaction relationship between two components, or a connection within two structures. Those skilled in the art to which this application pertains can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0029] Please see Figures 1 to 8 In a first aspect, this embodiment provides a device for modifying nanofibers with a laser, comprising: a syringe 1, a laser modification component 2, and a receiving component 3; The syringe 1 includes a push rod 11 and an injection cylinder 12. The injection cylinder 12 has a liquid supply chamber 121, an installation chamber 122, and a jetting channel 123 arranged sequentially along its extension direction. The liquid supply chamber 121 is connected to the jetting channel 123 through the liquid supply channel 124. The installation chamber 122 is connected to the jetting channel 123 through the laser channel 125, and the laser channel 125 and the jetting channel 123 are coaxially arranged. The pushing end 111 of the push rod 11 is adapted to the liquid supply chamber 121, and the pushing end 111 is movably disposed in the liquid supply chamber 121 for pushing the spinning solution in the liquid supply chamber 121 to be delivered to the jetting channel 123. The supply chamber 121 is a hollow structure within the injection cylinder 12, used to contain the spinning solution. Its end away from the jet channel 123 is open, allowing the pushing end 111 of the push rod 11 to be placed into the supply chamber 121 through this opening. The mounting chamber 122 is also a hollow structure within the injection cylinder 12, and is isolated from and non-conductive to the supply chamber 121 to prevent the spinning solution from entering the mounting chamber 122. The mounting chamber 122 is provided to provide mounting space for the laser finishing assembly 2. The injection channel 123 is located at the end of the injection cylinder 12 away from the push rod 11. It is a narrow flow channel structure so that the spinning solution forms a Taylor cone at the outlet end of the injection channel 123 and is sprayed onto the receiving roller 32. The supply channel 124 is also a cavity structure in the injection cylinder 12, arranged along the extension direction of the injection cylinder 12. One end of the supply channel 124 is connected to the supply chamber 121, and the other end is connected to the injection channel 123, thereby allowing the spinning solution in the supply chamber 121 to pass through... Liquid supply channels 124 flow into jet channels 123; and multiple liquid supply channels 124 are provided, with one end of each liquid supply channel 124 inclined near the jet channel 123, and the intersection point of the inclined sections of the multiple liquid supply channels 124 located on the axis of the jet channel 123; the laser channel 125 is also a cavity structure in the injection cylinder 12, arranged along the extension direction of the injection cylinder 12, with both ends connected to the mounting cavity 122 and the jet channel 123 respectively, to provide a channel for the laser 211 to pass through; at the same time, The laser channel 125 and the jet channel 123 are coaxially arranged to ensure that the laser 211 can act on the interior of the spinning liquid jet so that the laser 211 can modify its interior. The pushing end 111 of the push rod 11 is adapted to the liquid supply chamber 121 in the injection cylinder 12 to form a piston structure. When the pushing end 111 moves along the liquid supply chamber 121, it compresses the spinning liquid in the liquid supply chamber 121, thereby driving the spinning liquid to flow into the jet channel 123 and being jetted at the outlet end of the jet channel 123.

[0030] The laser enhancement assembly 2 includes a laser emitter 21, an adjusting lens 22, and a moving component 23. The laser emitter 21 is disposed in the mounting cavity 122 via a first rotating component and is used to emit a laser 211. In the non-working state, the optical axis of the laser 211 is collinear with the axis of the jet channel 123. The first rotating component is used to adjust the angle of the laser emitter 21 to change the deflection angle of the laser 211. The moving component 23 is disposed in the mounting cavity 122, and the adjusting lens 22 is disposed on the moving component 23 via a second rotating component. The moving component 23 is used to drive the adjusting lens 22 to move along the axial direction of the laser channel 125 to control the aperture size of the laser 211. In this embodiment, the first rotating component is a first ball joint 24, preferably a universal ball joint; wherein, the ball seat of the first ball joint 24 is disposed on the inner wall of the mounting cavity 122 and is detachably connected to the inner wall of the mounting cavity 122 by screws; or, it is detachably connected to the inner wall of the mounting cavity 122 by a magnetic attraction structure; the ball head of the first ball joint 24 is connected to the laser emitter 21 to adjust the deflection angle of the laser 211 emitted by the laser emitter 21; wherein, the deflection angle of the laser 211 is the angle between the laser optical axis and the axis of the laser channel 125. In this embodiment, the moving component 23 is a ball screw slide, the ball screw slide is disposed on the inner wall of the mounting cavity 122, the extension direction of the screw 231 of the ball screw slide is parallel to the axial direction of the laser channel 125, and the slide of the ball screw slide reciprocates along the extension direction of the screw 231; The second rotating component is a second ball joint 25. Preferably, the second ball joint 25 is a universal ball joint. The ball seat of the second ball joint 25 is mounted on the slide table, and the ball head of the second ball joint 25 is connected to the adjusting lens 22 to adjust the tilt angle of the adjusting lens 22. Specifically, when the servo motor on the ball screw slide table drives the screw 231 to rotate through the coupling, the balls between the screw 231 and the nut circulate in the helical groove, converting the rotational motion into the linear motion of the nut, thereby driving the slide table to reciprocate linearly along the extension direction of the screw 231 (the axial direction of the laser channel 125). The ball seat of the second ball joint 25 is mounted on the slide table and is detachably connected to the slide table by screws; or, it is detachably connected to the slide table by a magnetic structure. The ball head of the second ball joint 25 is connected to the adjusting lens 22, which is located below the laser emitter 21. The laser 211 emitted by the laser emitter 21 first enters the adjusting lens 22, while the slide table... The stage then moves the adjusting lens 22 along the extension direction of the lead screw 231, causing the adjusting lens 22 to move closer to or further away from the laser emitter 21, thereby changing the size of the laser 211 aperture after passing through the adjusting lens 22. Specifically, when the laser emitter 21 outputs a laser beam with a fixed divergence angle, the distance between the adjusting lens 22 and the laser emitter 21 decreases, and the divergence angle of the laser beam after passing through the adjusting lens 22 increases, thus increasing the diameter of the laser 211 aperture at the exit end of the jet channel 123; when the distance between the adjusting lens 22 and the laser emitter 21 increases, and the divergence angle of the laser beam after passing through the adjusting lens 22 decreases, thus decreasing the diameter of the laser 211 aperture at the exit end of the jet channel 123. Simultaneously, the first ball joint 24 is used to adjust the deflection angle of the laser 211, while the second ball joint 25 synchronously controls the tilt angle of the adjusting lens 22 to ensure that the deflected laser 211 is always perpendicularly incident on the center of the adjusting lens 22, avoiding spot deformation and energy loss, and making the laser 211 act directionally and uniformly on the spinning liquid jet at the outlet end of the jet channel 123. In the non-operating state, the optical axis of the laser 211 emitted by the laser emitter 21, the axis of the laser channel 125, and the axis of the jet channel 123 are collinear and perpendicular to the adjusting lens 22. The tilt angle of the adjusting lens 22 is the angle between the adjusting lens 22 and the axis of the laser channel 125.

[0031] The receiving assembly 3 includes a high-voltage power supply 31 and a receiving roller 32. The receiving roller 32 is positioned opposite the outlet end of the jet channel 123 and is used to receive the nanofibers modified by laser 211. The positive terminal of the high-voltage power supply 31 is electrically connected to the outer wall of the jet channel 123, and the negative terminal of the high-voltage power supply 31 is electrically connected to the receiving roller 32, so as to form a high-voltage electrostatic field between the outlet end of the jet channel 123 and the receiving roller 32. In this embodiment, the high-voltage power supply 31 outputs DC high-voltage electricity.

[0032] Specifically, push rod 11 moves within liquid supply chamber 121, generating thrust to stably push spinning solution through liquid supply channel 124 to jet channel 123, forming a continuous liquid flow; laser emitter 21 emits laser 211, which, after being collimated / focused by adjusting lens 22, is coaxially injected into the spinning solution jet at the outlet end of jet channel 123 through laser channel 125; the first rotating component drives laser emitter 21 to deflect, changing the angle between laser optical axis and the axis of jet channel 123, thereby achieving point-to-point modification of different radial positions and different circumferential angles inside the spinning solution jet; moving component 23 drives adjusting lens 22 to move along the axis of laser channel 125, changing the angle between lens and laser emitter. The spacing 21 is used to adjust the size of the aperture of the laser 211 inside the spinning liquid jet. At the same time, the tilt angle of the adjusting lens 22 is adjusted by the second rotating component to ensure that the laser 211 is perpendicularly injected into the adjusting lens 22. The high-voltage power supply 31 is used to form a strong electrostatic field between the jet channel 123 and the receiving roller 32. Under the action of the electric field force, the spinning liquid forms a Taylor cone and a continuous spinning liquid jet. The spinning liquid jet is stretched, volatilized and solidified into nanofibers during the movement. During the stretching and solidification process of the spinning liquid jet, the laser 211 periodically acts on the inside of the spinning liquid jet, causing local melting / expansion at corresponding positions inside the spinning liquid jet, thereby achieving the purpose of modifying the morphology inside the spinning liquid jet.

[0033] Compared with existing technologies, the equipment involved in this invention performs laser modification and electrospinning simultaneously. During the stretching and solidification of the spinning solution jet, the internal morphology is directionally modified, eliminating the need for subsequent secondary processing and avoiding damage to the nanofiber structure. This significantly simplifies the process, improves preparation efficiency, and enables one-step preparation of nanofibers with controllable internal morphology. Furthermore, the equipment has a simple structure, is easy to control, and is readily scalable. By adjusting the first rotating component, the second rotating component, and the moving component 23, the size and deflection angle of the laser 211 aperture can be dynamically adjusted without complex laser scanning and displacement mechanisms. The equipment is simple in structure, easy to operate, and low in cost, enabling uniform modification of the fiber's internal periphery, and is suitable for industrial-scale production.

[0034] It should be noted that the outer wall of the jet channel 123 in this application is made of conductive material.

[0035] In some embodiments, the first rotating component is a first cross-shaped micro universal joint, with one end fixed to the inner wall of the mounting cavity 122 and the other end connected to the laser emitter 21; the second rotating component is a second cross-shaped micro universal joint, with one end fixed to the mounting slide and the other end connected to the adjustment lens 22.

[0036] In some embodiments, both the first rotating member and the second rotating member are two-degree-of-freedom fine-tuning supports.

[0037] In some embodiments, the movable member 23 is an electric actuator. The fixed end of the electric actuator is disposed on the inner wall of the mounting cavity 122, and the movable end is indirectly connected to the adjusting lens 22. The extension direction of the electric actuator is parallel to the axis of the laser channel 125, so as to drive the adjusting lens 22 closer to or further away from the laser emitter 21. A second ball joint 25 or a second cross-shaped micro universal joint is provided at the movable end of the electric actuator and the adjusting lens 22 to adjust the tilt angle of the adjusting lens 22.

[0038] In this embodiment, the laser modification component 2 further includes a laser adjustment panel 26; the outer wall of the injection cylinder 12 is provided with an adjustment opening 126, the adjustment opening 126 is connected to the mounting cavity 122, and the laser adjustment panel 26 is electrically connected to the laser emitter 21 in the mounting cavity 122 through a wire, for adjusting the energy density, pulse frequency, wavelength and pulse profile of the laser 211. The adjustment opening 126 is an opening structure formed on the outer wall of the injection cylinder 12 and is connected to the mounting cavity 122. It is used for wires to pass through so that the laser emitter 21 is electrically connected to the laser adjustment panel 26. At the same time, the opening is provided to facilitate the operator to adjust or repair the components inside the mounting cavity 122. By adjusting the first ball joint 24, the deflection angle of the laser 211 emitted by the laser emitter 21 is changed. By rotating the screw, the distance between the adjustment lens 22 and the laser emitter 21 is adjusted to change the size of the laser 211 aperture. By adjusting the second ball joint 25, the tilt angle of the adjustment lens 22 is changed to ensure that the laser 211 is perpendicularly incident on the adjustment lens 22, thereby reducing the energy loss of the laser 211.

[0039] It should be noted that the laser adjustment panel 26 is electrically connected to the first ball joint 24, the second ball joint 25 and the ball screw slide via wires.

[0040] It should be noted that the laser emitter 21 is a multi-wavelength integrated pulsed laser. This multi-wavelength integrated pulsed laser uses a single fundamental frequency laser source as its core and, through a built-in electrically switchable nonlinear optical harmonic conversion module, enables a single device to output pulsed lasers of multiple wavelengths without requiring replacement of the laser emitter. The multi-wavelength integrated pulsed laser uses a 1064nm solid-state laser as its fundamental frequency source and incorporates second harmonic generation (SHG), third harmonic generation (THG), and fourth harmonic generation (FHG) crystal modules. An electronic control system drives a precision displacement mechanism to switch between different harmonic crystal modules, converting the 1064nm fundamental frequency light into 532nm green light, 355nm ultraviolet light, and 266nm deep ultraviolet light output, respectively. Furthermore, all wavelength switching processes are completed with a single button press on the laser adjustment panel 26, requiring no manual intervention or replacement of any components.

[0041] It should be noted that both the laser emitter 21 and the adjustment lens 22 inside the mounting cavity 122 are automatically adjusted by electronic control. Specifically, the laser emitter 21 is mainly adjusted in angle through the first ball joint 24. The first ball joint 24 mainly consists of a ball seat, a precision metal ball head embedded in the ball seat, two orthogonally arranged miniature voice coil motors (response time <1ms), and a MEMS angle sensor (accuracy ±0.005°) integrated inside the ball head. The user inputs the target deflection angle (range 0°-10°, resolution 0.001°) and circumferential azimuth angle (range 0°-360°, resolution 0.01°) on the laser adjustment panel 26. The built-in ARM microcontroller converts the target angle into the target current value of the two voice coil motors, generates a PWM control signal, and the voice coil motors directly drive the ball head to rotate based on the Lorentz force principle, causing the laser emitter 21 to deflect to the target angle without mechanical transmission lag. The MEMS angle sensor measures the current deflection angle in real time and feeds it back to the microcontroller, forming a closed-loop control and automatically correcting the angle error.

[0042] It should be noted that the adjusting lens 22 is mainly used to adjust the size and tilt angle of the laser spot through a precision electric ball screw slide and the second ball joint 25. The user inputs the target laser spot diameter on the laser adjustment panel 26. The control system calls the pre-calibrated "lens-laser spacing-spot diameter" calibration curve to calculate the target position required for the adjusting lens 22. The servo motor drives the screw 231 to rotate, moving the slide precisely to the target position along the linear guide rail. The laser emitter 21 outputs a Gaussian beam with a fixed divergence angle, and the adjusting lens 22 is a plano-convex lens with a fixed focal length. When the distance L between the adjusting lens 22 and the laser emitter 21 changes, the divergence angle θ of the beam after passing through the adjusting lens 22 changes accordingly: when the distance L decreases, the divergence angle θ increases, and the laser spot diameter at the exit end of the jet channel 123 increases; when the distance L increases, the divergence angle θ decreases, and the laser spot diameter at the exit end of the jet channel 123 decreases. The tilt angle adjustment of the adjusting lens 22 is mainly performed through the second ball joint 25, and its adjustment method is the same as that of the first ball joint 24. By adjusting the laser emitter 21 and the adjusting lens 22 together, the laser angle and scanning trajectory can be controlled in real time, thereby achieving differentiated modification of different areas on the same fiber.

[0043] The main working principle of laser modification is that laser modification and electrospinning are carried out simultaneously. A pulsed laser is coaxially injected into the spinning liquid jet in the viscoelastic stretching stage. The laser energy is absorbed by the polymer and converted into heat energy, causing controllable melting and vaporization expansion in the local area of ​​the jet. The molten area is stretched along the jet axis and quickly solidified, eventually forming a preset customized internal morphology inside the nanofiber.

[0044] In this embodiment, the device for laser-modified nanofibers further includes an injection pump 4, with the syringe 1 mounted on the injection pump 4. The push rod 11 is tractively connected to the injection pump 4 to drive the pushing end 111 to move within the supply chamber 121. Specifically, the push head of the injection pump 4 is connected to the push rod 11, thereby driving the pushing end 111 of the push rod 11 to move within the supply chamber 121, thus causing the spinning solution to be ejected from the jet channel 123. The injection pump 4 pushes the push rod 11 at a constant speed, ensuring a stable and unfluctuating flow rate output from the supply chamber 121. This guarantees a uniform diameter of the spinning solution jet ejected from the jet channel 123, reducing errors caused by manual intervention.

[0045] In a second aspect, this application provides a method for modifying nanofibers with a laser, the method comprising the following steps: Supply spinning solution S1: The prepared spinning solution is loaded into the supply chamber 121 of the syringe 1, and the push rod 11 is driven to stably deliver the spinning solution to the jet channel 123. Preset laser parameters S2: Based on the preset internal morphology of the target nanofiber, the energy density, pulse frequency, wavelength and pulse profile of the laser 211 are set through the laser adjustment panel 26, and the deflection angle of the laser 211 is adjusted through the first rotating component so that the optical axis of the laser 211 corresponds to the spinning liquid jet path at the outlet end of the jet channel 123. Constructing a high-voltage electrostatic field S3: Turn on the high-voltage power supply 31 and adjust the output voltage of the high-voltage power supply 31 to form a stable high-voltage electrostatic field between the outlet end of the jet channel 123 and the receiving roller 32, so that the spinning liquid at the outlet end forms a Taylor cone and sprays out a continuous spinning liquid jet. Online modification and shaping S4: The spinning liquid jet is stretched axially in a high-voltage electrostatic field and moves toward the receiving drum 32. The laser pulse periodically acts on the interior of the spinning liquid jet during the stretching process, causing the corresponding area of ​​the spinning liquid jet to undergo controllable melting and expansion. As the spinning liquid jet is stretched and solidified, nanofibers with a preset internal morphology are finally collected on the receiving drum 32.

[0046] In this application, the prepared spinning solution is loaded into the supply chamber 121, the syringe 1 is installed on the injection pump 4, the supply rate of the injection pump 4 is set, and the push rod 11 is driven by the push head of the injection pump 4 to stably deliver the spinning solution to the jet channel 123. Specifically, the operation of loading the spinning solution into the supply chamber 121 is as follows: the push rod 11 is completely pulled out from the top opening of the injection cylinder 12 (the opening at one end of the supply chamber 121), so that the supply chamber 121 inside the injection cylinder 12 is completely exposed; the pre-prepared spinning solution is uniformly introduced into the supply chamber 121 inside the injection cylinder 12 through a clean injection tool; after the introduction is completed, the push end 111 of the push rod 11 is reinserted into the supply chamber 121, and the push rod 11 is slowly pushed to expel the residual air in the injection cylinder 12 until the spinning solution fills the entire supply channel 124 and the jet channel 123 without any air bubbles remaining, thus completing the loading of the spinning solution.

[0047] In some embodiments, a first specific embodiment of a method for laser-modified nanofibers according to this application is as follows: Polyacrylonitrile (PAN) powder was added to N,N-dimethylformamide (DMF) solvent and magnetically stirred at room temperature for 12 hours to prepare a PAN spinning solution with a mass fraction of 8 wt%. The prepared PAN spinning solution was introduced into the supply chamber 121, and syringe 1 was installed on the injection pump 4. The supply rate of the injection pump 4 was set to 0.8 mL / h to stably deliver the spinning solution in the supply chamber 121 to the outlet end of the jet channel 123. The positive terminal of the high-voltage DC power supply was connected to the outer wall of the jet channel 123, and the negative terminal was connected to the grounded receiving roller 32. The output voltage of the high-voltage DC power supply was adjusted to 15 kV, and the vertical distance between the outlet end of the jet channel 123 and the receiving roller 32 was 15 cm. A stable high-voltage electrostatic field was formed between the outlet end of the jet channel 123 and the receiving roller 32. The spinning solution at the outlet end of the jet channel 123 formed a Taylor cone and was continuously ejected. The spinning solution jet has a target morphology of semi-circular waves inside the nanofiber. The parameters of the laser 211 are set by the laser adjustment panel 26, wherein the energy density of the laser 211 is 15mJ / cm², the pulse frequency is 25kHz, the wavelength is 1064nm, and the pulse profile is Gaussian. The deflection angle of the laser 211 is adjusted to 0° by the first ball joint 24, so that the laser 211 is uniformly incident along the axis of the spinning solution jet and the energy is radially symmetrically distributed. The spinning solution jet moves at a constant speed towards the receiving drum 32 in a high-voltage electrostatic field and is axially stretched. The laser pulse periodically acts on the inside of the spinning solution jet, causing mild melting and slow expansion in the local area of ​​the spinning solution jet. The molten area is gradually widened with the movement of the spinning solution jet. At the same time, the spinning solution solvent evaporates rapidly and the spinning solution jet solidifies. Finally, nanofibers with a smooth semi-circular wave-shaped convex morphology inside are collected on the receiving drum 32.

[0048] The semi-circular wavy internal morphology nanofibers prepared in this embodiment have a 32% higher tensile strength and a 45% higher elongation at break compared to ordinary smooth PAN nanofibers. They exhibit excellent flexibility and fatigue resistance and can be used in flexible wearable devices, flexible sensor substrates, biomedical elastic scaffolds, and other applications.

[0049] In some embodiments, a second specific embodiment of a method for modifying nanofibers with laser according to this application is as follows: Polyvinylidene fluoride (PVDF) powder was added to a mixed solvent of N,N-dimethylformamide (DMF) and acetone (volume ratio 7:3), and magnetically stirred at room temperature for 8 hours to prepare a PVDF spinning solution with a mass fraction of 12 wt%. The prepared PVDF spinning solution was introduced into the supply chamber 121, and the syringe 1 was installed on the injection pump 4. The supply rate of the injection pump 4 was set to 0.6 mL / h to stably deliver the spinning solution in the supply chamber 121 to the outlet end of the jet channel 123. The positive terminal of the high-voltage DC power supply was connected to the outer wall of the jet channel 123, and the negative terminal was connected to the grounded receiving roller 32. The output voltage of the high-voltage DC power supply was adjusted to 18 kV, and the vertical distance between the outlet end of the jet channel 123 and the receiving roller 32 was 15 cm. A stable high-voltage electrostatic field was formed between the outlet end of the jet channel 123 and the receiving roller 32, and the spinning solution at the outlet end of the jet channel 123 formed a Taylor cone and was jetted. A continuous spinning solution jet is produced; the target morphology inside the nanofiber is triangular serrated. The parameters of the laser 211 are set through the laser adjustment panel 26, wherein the energy density of the laser 211 is 40mJ / cm², the pulse frequency is 45kHz, the wavelength is 355nm, and the pulse profile is peak-shaped. The deflection angle of the laser 211 is adjusted to 3° through the first ball joint 24, and the adjustment lens 22 is adjusted synchronously with the laser emitter 21 to concentrate the energy locally and maintain radial periodicity. The spinning solution jet moves at high speed towards the receiving roller 32 in a high-voltage electrostatic field and is axially stretched. The high-energy laser pulse instantaneously acts on the inside of the spinning solution jet, causing the local area to undergo violent and rapid melting and vaporization expansion, forming sharp local protrusions. The high-frequency pulse matches the stretching rate of the spinning solution jet, so that the protruding area is rapidly stretched and solidified, and finally the nanofibers with sharp triangular serrated morphology inside are collected on the receiving roller 32.

[0050] The triangular serrated internal morphology nanofibers prepared in this embodiment have a 68% higher specific surface area and a 75% higher catalyst loading than ordinary smooth PVDF nanofibers. They can be used in applications such as adsorption materials for deep treatment of heavy metal wastewater, photocatalytic degradation membranes, adsorption materials for harmful gases, and cell adhesion scaffolds.

[0051] In some embodiments, a third specific embodiment of a method for laser-modified nanofibers according to this application is as follows: Polyethylene oxide (PEO) and zinc oxide (ZnO) nanoparticles were added to deionized water and magnetically stirred at room temperature for 6 hours to prepare a 10 wt% PEO / ZnO composite spinning solution, wherein the ZnO nanoparticles accounted for 5% of the PEO. The prepared composite spinning solution was introduced into the supply chamber 121, and the syringe 1 was installed on the injection pump 4. The supply rate of the injection pump 4 was set to 0.8 mL / h to stably deliver the spinning solution in the supply chamber 121 to the outlet end of the jet channel 123. The positive terminal of the high-voltage DC power supply was connected to the outer wall of the jet channel 123, and the negative terminal was connected to the grounded receiving roller 32. The output voltage of the high-voltage DC power supply was adjusted to 12 kV, and the vertical distance between the outlet end of the jet channel 123 and the receiving roller 32 was 12 cm. A stable high-voltage electrostatic field was formed between the outlet end of the jet channel 123 and the receiving roller 32. The spinning solution at the outlet end of the jet channel 123 formed a Taylor cone and was sprayed. A continuous spinning solution jet is emitted; the target morphology inside the nanofiber is rectangular. The parameters of laser 211 are set through laser adjustment panel 26, wherein the energy density of laser 211 is 60mJ / cm², the pulse frequency is 20kHz, the wavelength is 266nm, and the pulse profile is rectangular. The deflection angle of laser 211 is adjusted to 6° through first ball joint 24, and the adjustment lens 22 is synchronously adjusted with laser emitter 21 through second ball joint 25 and moving part 23, so that laser 211 is radially oriented along the spinning solution jet. The spinning solution jet moves towards receiving roller 32 in high voltage electrostatic field and is axially stretched. The rectangular pulse profile laser 211 concentrates energy in two perpendicular directions along the radial direction of the jet, causing directional and uniform melting expansion in the corresponding area. The molten area is constrained by the rectangular energy and stretched into a rectangular protrusion with sharp edges. After rapid solidification, the composite nanofiber with a rectangular morphology inside is finally collected on receiving roller 32.

[0052] The rectangular nanofibers prepared in this embodiment exhibit a 57% higher interfacial shear strength with the epoxy resin matrix compared to circular fibers. When used as a sensitive layer in a flexible strain sensor, this improves the sensor sensitivity by 52%. The nanofibers can be used in composite material reinforcing phases, flexible strain sensor sensitive layers, biomimetic functional fabrics, photonic crystal materials, and other applications.

[0053] The devices and methods described in this invention allow for the customization of the internal morphology of nanofibers, enabling targeted optimization of core properties such as mechanical properties, specific surface area, interfacial bonding strength, and sensing response characteristics. Specifically, a semi-circular wavy internal morphology enhances the fiber's flexibility and tensile strength, making it suitable for flexible wearable devices and flexible sensor substrates; a triangular serrated internal morphology significantly increases the fiber's specific surface area and reactive sites, making it suitable for heavy metal adsorption, catalyst supports, and photocatalytic degradation membranes; and a rectangular internal morphology enhances the interfacial bonding between the fiber and the matrix, amplifying deformation signals, making it suitable for composite material reinforcing phases, flexible strain sensor sensitive layers, and biomimetic functional fabrics.

[0054] Finally, it should be noted that although the above embodiments have been described in the text and drawings of this application, this should not limit the scope of patent protection of this application. Any technical solutions that are based on the essential concept of this application and utilize the content described in the text and drawings of this application, resulting in equivalent structural or procedural substitutions or modifications, as well as the direct or indirect application of the technical solutions of the above embodiments to other related technical fields, are all included within the scope of patent protection of this application.

Claims

1. A device for modifying nanofibers with a laser, characterized in that, include: A syringe includes a plunger and a syringe barrel. The syringe barrel has a supply chamber, a mounting chamber, and a jetting channel arranged sequentially along its extension direction. The supply chamber is connected to the jetting channel via the supply channel, and the mounting chamber is connected to the jetting channel via a laser channel, with the laser channel and the jetting channel coaxially arranged. The pushing end of the plunger is adapted to the supply chamber and is movably disposed within the supply chamber for pushing the spinning solution in the supply chamber towards the jetting channel. A laser finishing assembly includes a laser emitter, an adjusting lens, and a moving component. The laser emitter is disposed in the mounting cavity via a first rotating component and is used to emit laser light. In the non-operating state, the optical axis of the laser light is collinear with the axis of the jet channel. The first rotating component is used to adjust the angle of the laser emitter to change the deflection angle of the laser light. The moving component is disposed in the mounting cavity, and the adjusting lens is disposed on the moving component via a second rotating component. The moving component is used to drive the adjusting lens to move along the axial direction of the laser channel to control the size of the laser aperture. A receiving component includes a high-voltage power supply and a receiving roller. The receiving roller is positioned relative to the outlet end of the jetting channel and is used to receive laser-modified nanofibers. The positive terminal of the high-voltage power supply is electrically connected to the outer wall of the jetting channel, and the negative terminal of the high-voltage power supply is electrically connected to the receiving roller to form a high-voltage electrostatic field between the outlet end of the jetting channel and the receiving roller.

2. The device for laser-modified nanofibers according to claim 1, characterized in that, The first rotating component is a first ball joint, the ball seat of the first ball joint is disposed on the inner wall of the mounting cavity, and the ball head of the first ball joint is connected to the laser emitter.

3. The device for laser-modified nanofibers according to claim 2, characterized in that, The moving component is a ball screw slide, which is disposed on the inner wall of the mounting cavity. The extension direction of the ball screw of the ball screw slide is parallel to the axial direction of the laser channel, and the slide of the ball screw slide reciprocates along the extension direction of the ball screw. The second rotating component is a second ball joint, the ball seat of the second ball joint is disposed on the slide, and the ball head of the second ball joint is connected to the adjusting lens so as to adjust the tilt angle of the adjusting lens through the second ball joint.

4. The device for laser-modified nanofibers according to claim 3, characterized in that, The laser modification component also includes a laser adjustment panel; The outer wall of the injection cylinder is provided with an adjustment opening, which is connected to the mounting cavity. The laser adjustment panel is electrically connected to the laser emitter in the mounting cavity through a wire, and is used to adjust the energy density, pulse frequency, wavelength and pulse profile of the laser.

5. The device for laser-modified nanofibers according to claim 1, characterized in that, The device for laser-modified nanofibers also includes an injection pump, the syringe is mounted on the injection pump, and the push rod is throttle-connected to the injection pump to drive the push end to move in the liquid supply chamber.

6. A method for modifying nanofibers using laser, characterized in that, The method, performed using the device according to any one of claims 1-5, comprises the following steps: Supplying spinning solution: The prepared spinning solution is loaded into the supply chamber of the syringe, and the pushing end of the push rod is driven to stably deliver the spinning solution to the jet channel; Preset laser parameters: Based on the preset internal morphology of the target nanofiber, the energy density, pulse frequency, wavelength and pulse profile of the laser are set through the laser adjustment panel. The deflection angle of the laser is adjusted by the first rotating component so that the optical axis of the laser corresponds to the spinning liquid jet path at the outlet end of the jet channel. Constructing a high-voltage electrostatic field: Turn on the high-voltage power supply and adjust the output voltage of the high-voltage power supply to form a stable high-voltage electrostatic field between the outlet end of the jet channel and the receiving roller, so that the spinning solution at the outlet end forms a Taylor cone and is ejected as a continuous spinning solution jet. Online modification and shaping: The spinning liquid jet is stretched axially in a high-voltage electrostatic field and moves toward the receiving drum. Laser pulses periodically act on the interior of the spinning liquid jet during the stretching process, causing the corresponding area of ​​the spinning liquid jet to undergo controllable melting and expansion. As the spinning liquid jet is stretched and solidified, nanofibers with a preset internal morphology are finally collected on the receiving drum.

7. The method for laser-modifying nanofibers according to claim 6, characterized in that, In the step of setting the laser parameters, the laser energy density is set to 10-20mJ / cm², the pulse frequency is set to 20-30kHz, the wavelength is set to 1064nm, the pulse profile is set to Gaussian, and the laser deflection angle is set to 0° using the laser adjustment panel.

8. The method for laser-modifying nanofibers according to claim 6, characterized in that, In the step of setting the laser parameters, the laser energy density is set to 30-50mJ / cm², the pulse frequency is set to 40-50kHz, the wavelength is set to 355nm, the pulse profile is set to a peak shape, and the laser deflection angle is set to 0°-5° using the laser adjustment panel.

9. The method for laser-modifying nanofibers according to claim 6, characterized in that, In the step of setting the laser parameters, the laser energy density is set to 50-80mJ / cm², the pulse frequency is set to 15-25kHz, the wavelength is set to 266nm, the pulse profile is set to rectangular, and the laser deflection angle is set to 5°-10° using the laser adjustment panel.

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