CN102817089A - Electrostatic spinning device with spinning nozzle capable of doing linear reciprocating motion - Google Patents

Abstract

The invention belongs to the technical field of micro-nano fiber preparation, and relates to a spinning nozzle reciprocating linear motion electrostatic spinning device. The stainless steel needle is fixed on the needle tube of the syringe and connected to the positive pole of the high-voltage direct current power supply, and the negative pole of the high-voltage direct current power supply is connected to the collector pole of the aluminum foil. The aluminum foil collector is fixed on the base of the device; the needle tube of the syringe is fixed on one end of the linear movement rod, which runs through two parallel supports and can perform simple harmonic linear motion on the support. It has the advantages of multiple functions, centralized and orderly distribution of textiles, small textile distances, high yield and low working voltage.

Description

An electrospinning device with reciprocating linear motion of spinning nozzle

Technical field:

The invention belongs to the technical field of micro-nano fiber preparation, and relates to a reciprocating linear motion electrostatic spinning device for spinning nozzles, which is used to prepare micro-nano fibers in orderly arrangement, intersecting structure and twisted structure, as nano-optical devices, optical devices and Materials for stretchable flexible devices.

Background technique:

At present, electrospinning technology is a widely concerned method that can directly prepare continuous fibers from polymer and composite material solutions or melts. It has the advantages of simple equipment, low cost, high fiber yield, and wide application range. Gas and biosensors, filtration and separation, textile engineering, drug sustained release, battery electrode materials and many other fields have broad application prospects. The principle of electrospinning is: a high-voltage power supply provides high voltage, and a strong electrostatic field is established between the spinning nozzle and the collecting plate. Generally, the positive pole of the power supply is connected to the spinning nozzle, and the negative pole is connected to the collecting plate (grounded). , the working voltage is generally 10-30 kV, and the spinning distance is generally 8-20 cm. Due to the action of the high-voltage electrostatic field, the spinning solution is polarized and charged, ejected from the spinning nozzle, and then stretched by the electric field force to refine or split to form micro-nano-scale fibers, and finally deposited on the collecting plate. The diameter of the fiber is closely related to the experimental conditions, generally ranging from tens of nanometers to several microns.

The fibers prepared by traditional electrospinning devices are generally arranged randomly, which limits the application of electrospun fibers in certain fields. In recent years, many researchers at home and abroad have devoted themselves to improving the traditional electrospinning technology to prepare micro-nano fibers with ordered structures. At present, the commonly used electrospinning technologies and equipment include rotating cylinder (disc) collection, slit collection or parallel electrode collection, auxiliary external electric field or magnetic field collection, frame collection, etc. For example, Chinese patents "Electrospinning Device" (Application No.: 200720067712.0) and "Electrospinning Apparatus" (Application No.: 200610125960.6) adopt a cylinder collection method; Chinese Patent (Application No.: 200810102096.7) proposes a A method for preparing ordered fibers with an electrode collection device; literature (Advanced Materials, 2007, 19, 3702-3706) reported a magnetoelectric spinning technology using an auxiliary magnetic field. In addition, the Chinese patent "A device for preparing nanofibers with ordered arrangement and cross structure" (patent number: ZL201010184068.1) proposes a centrifugal electrospinning technology with spinning nozzle rotating motion; Chinese patent (application number: 201110137420.0 ) also reported an improved frame-collecting electrospinning technique to prepare ordered and strand-structured fibers. However, there are still some shortcomings in the above technical methods: for example, the working voltage is high or the spinning distance is large, and the prepared ordered fibers are generally linear and rarely twisted. And the twisted structural fibers arranged in an orderly manner have application prospects in stretchable and flexible electronic devices. The mass point reciprocates on a straight line, its restoring force is proportional to the displacement, and the direction is opposite, which is called simple harmonic motion; and the simple harmonic motion can be regarded as the projection made by the mass point in constant circular motion in the direction of the vertical coordinate axis sports. Therefore, in daily life, the circular motion can be transformed into a reciprocating linear motion through the crankshaft connecting rod. This linear motion is actually a reciprocating simple harmonic vibration. For example, the common linear vibrating sieve is widely used in the classification or separation of metallurgical powder, chemical industry, fertilizer, abrasive, medicine, grain and other powder and medium and small particle size materials.

Invention content:

The purpose of the present invention is to overcome the shortcomings of the prior art, seek to design and propose a new type of feasible equipment for preparing micro-nano fibers with a variety of special morphology structures, that is, a spinning nozzle reciprocating linear motion electrospinning device, which adopts Smaller spinning distance and lower operating voltage can successfully prepare ordered linear micro-nanofibers, cross-structured fibers, and ordered twisted-structured fibers.

In order to achieve the above object, the main structure of the present invention includes a governor, a plexiglass plate, a DC brushless motor, a crankshaft connecting rod, a linear motion rod, a bracket, a syringe needle tube, a stainless steel needle, a high-voltage DC power supply, an aluminum foil collector and a base; The hollow stainless steel needle with a smooth tip is fixed on the medical syringe needle, the stainless steel needle is connected to the positive pole of the high-voltage DC power supply, the negative pole of the high-voltage DC power supply is connected to the aluminum foil collector electrode with aluminum foil on the surface, and the aluminum foil collector electrode is fixed on the base of the device Above; the syringe needle tube is fixed on one end of the linear motion rod (20 cm in length), and the linear motion rod runs through two side-by-side brackets fixed on the base. The other end of the rod is connected to the plexiglass plate (5.7 cm in length) fixed on the DC brushless motor through the crankshaft connecting rod. The governor is used to control the speed of the DC brushless motor, and the speed of the DC brushless motor is determined by The scale is read out, the DC brushless motor and the governor are fixed on the base, which constitutes the reciprocating linear motion part of the syringe needle used for spinning; when collecting fibers, place the glass piece in the middle of the linear motion of the stainless steel needle. At the point, according to the characteristics of simple harmonic motion, the stainless steel needle moves the fastest near the midpoint, and the acceleration is the smallest, which is beneficial to the collection of spinning fibers.

When the present invention is used in the preparation of orderly arranged linear structure fibers, the precursor solution is first added to the needle tube of the spinning syringe, the distance between the stainless steel needle and the aluminum foil collector is adjusted to 1-2 cm, and the aluminum foil collector is placed on the aluminum foil collector. Put on the glass slide, cover the glass slide with a piece of clean and dry paper; turn on the high-voltage DC power supply, adjust the voltage to 1.7-2.5 kV, apply a little pressure to the plug of the spinning needle tube, so that the solution is under gravity and the pressure of the plug Slowly flow out from the bottom, and the stationary needle starts spinning; after the spinning is stable, turn on the power of the DC brushless motor, adjust the knob of the governor, so that the speed is about 200rpm, and the reciprocating linear motion speed of the stainless steel needle near the midpoint When the spinning speed of the stainless steel needle is equivalent, the electrospun fibers are deposited on the aluminum foil collector in an orderly manner; remove the paper covering the glass slide, start the collection of fiber samples on the glass slide, and start timing at the same time. After about 15 seconds, Turn off the high-voltage DC power supply first, and then turn off the motor power supply. At this time, electrospun fibers in an orderly linear arrangement will be obtained on the glass slide.

The present invention is used for the preparation of cross-structure fiber: the substrate is placed on the aluminum foil collector to collect the spun fiber, and after the first spinning is completed, it is rotated horizontally by 90 degrees (or other angles) before spinning, Finally, a square fiber grid array with a cross or other angles will be obtained; if suitable materials are selected, for example, the first layer is an n-type organic or inorganic semiconductor nanofiber, and the second layer is a p-type organic or inorganic semiconductor Fibers, which are assembled into nanoscale p-n junction arrays on the substrate, will have great application prospects in nanoelectronic devices.

The invention is used for the preparation of fibers with ordered arrangement and twisted structure: if the working voltage is increased while the spinning distance is constant, the spinning solution will be polarized and charged with more charge, and the charged jet will be subjected to the force during the spinning process. The electric field force will be greater, and the movement speed of the electrospun fiber will increase when it reaches the collecting plate; when the high-speed moving fiber hits the collecting plate and stops, the recoil force of the impact will form a twisted structure for the linear fiber that has not been fully solidified; The increase of charge on the dope jet will increase the bending or whipping instability of the jet, resulting in the formation of twisted structural fibers; according to the above analysis, in the process of preparing ordered linear structure fibers, if the working voltage is changed from 1.7- 2.5 kV is increased to 3.0-4.0 kV, and fibers with twisted structures arranged in an orderly manner are obtained on the collecting plate; fibers with twisted structures have broad application prospects in the preparation of stretchable and flexible electronic devices.

Compared with the prior art, the present invention has the advantages of multiple functions, concentrated textile distribution and orderly number, small textile distance, high yield and low working voltage; it is used to prepare ordered linear structures, cross structures and ordered twisted structures Fibers with three morphological structures; under the action of electric field force, the spun fibers are concentrated in the direction of needle tip movement (about 5-10 mm wide), and the fibers are arranged in a high degree of order; work at a small spinning distance, thus Reduce the impact of environmental instability on fiber order during fiber falling; because the prepared fibers are only distributed in a small space, the probability of fibers being scattered in other places is reduced, and the yield of ordered fibers is improved; due to spinning The distance is small, and the working voltage can be reduced to within 4 kV, which improves the safety of the experiment.

Fig. 1 is a schematic diagram of the structure and principle of the device of the present invention.

Fig. 2 is a scanning electron micrograph (SEM) of PVP fibers with an ordered linear structure prepared in the present invention.

Fig. 3 is an optical micrograph of the cross-structured PVP fiber prepared in the present invention.

Fig. 4 is a SEM photo of PVP fibers with ordered arrangement and twisted structure prepared in the present invention.

Detailed ways:

The present invention will be further described below in conjunction with the accompanying drawings and examples.

The main structure of this embodiment includes a governor 1, a plexiglass plate 2, a DC brushless motor 3, a crankshaft connecting rod 4, a linear movement rod 5, a bracket 6, a syringe needle tube 7, a stainless steel needle 8, a high-voltage DC power supply 9, and aluminum foil The collecting pole 10 and the base 11; the hollow stainless steel needle 8 after the sharpened tip is fixed on the medical syringe needle 7, the stainless steel needle 8 is connected to the positive pole of the high-voltage direct current power supply 9, and the negative pole of the high-voltage direct current power supply 9 is connected to the aluminum foil on the surface The aluminum foil collecting poles 10 are connected, and the aluminum foil collecting poles are fixed on the base 11 of the device; the syringe needle tube 7 is fixed on one end of the linear movement rod 5 (20 cm in length), and the linear movement rod 5 runs through two parallel and fixed on the base 11 On the support 6, the linear motion rod 5 can do simple harmonic linear motion on the support 6, and the other end of the linear motion rod 5 passes through the crankshaft connecting rod 4 and the plexiglass plate 2 (length is 5.7 cm) fixed on the DC brushless motor 3 ), the governor 1 is used to control the speed of the brushless DC motor 3, the speed of the brushless DC motor 3 is read from the scale on the governor, the brushless DC motor 3 and the governor 1 are fixed on the base 11 On the top, it constitutes the reciprocating linear motion part of the syringe needle tube 7 used for spinning; when collecting fibers, place the glass piece at the midpoint of the linear motion of the stainless steel needle 8, and according to the characteristics of simple harmonic motion, close to the midpoint The local stainless steel needle 8 has the fastest moving speed and the smallest acceleration, which is beneficial to the collection of spinning fibers.

The selected spinning precursor solution in this embodiment is a polyvinylpyrrolidone (PVP) solution with a mass percentage of 13 wt%. First weigh 1.3 grams of PVP (molecular weight 1300000) and add it to 8.7 grams of absolute ethanol under magnetic stirring. Stir under magnetic force for 5 hours, and then stand still for half an hour to obtain a uniform and transparent 13wt% PVP electrospinning precursor solution.

Example 1: Preparation of PVP fibers with a linear structure in an orderly arrangement: Use a disposable straw to extract about 1 milliliter of PVP precursor solution and inject it into the syringe needle tube 7 for spinning. 10. Adjust the distance between the stainless steel needle 8 and the aluminum foil collector 10 to 1 cm, put a glass slide on the collector, cover the glass slide with a piece of clean and dry paper, and connect the high-voltage DC power supply 9 to make The switch is in the "ON" state, the voltage is adjusted to 1.8 kV, and the stationary needle starts spinning; the power supply of the brushless DC motor 3 is turned on, and the knob of the governor 1 is rotated so that the rotating speed is 200rpm, and the stationary needle starts spinning. Reciprocating linear motion, after a few seconds of stable speed, quickly remove the paper covering the cover glass, and start timing, after 15 seconds, turn off the high-voltage DC power supply 9, make its switch in the "OFF" state, and then turn off The power supply of DC brushless motor 3, electrospinning finishes; Get the sample that collects on the glass slide, observe with scanning electron microscope SEM, the result is as shown in Figure 2, as can be seen from the figure that the morphology of spinning fiber is good, the arrangement The parallelism is high, and the diameter of the fiber spun under this condition is about 1.5-3 microns, and the thickness is relatively uniform.

Example 2: Preparation of cross-structured PVP fibers: first prepare orderly arranged PVP fibers according to the steps in Example 1, then rotate the collected samples by 90° and repeat the electrospinning once again with the same conditions and steps to obtain The optical microscope photo of the PVP fiber with cross structure is shown in Figure 3.

Embodiment 3: Preparation of PVP fiber with ordered arrangement and twisted structure: adjust the voltage in Example 1 to be 3.5 kilovolts, and keep the other steps unchanged, finally obtain the PVP fiber with ordered arrangement and twisted structure, the SEM photo of its sample is shown in Figure 4 As shown, it can be seen that the prepared fibers have a twisted structure and are arranged in an orderly manner, but due to the distribution of wave-shaped fibers on a two-dimensional scale, there is an intercrossing phenomenon between the fibers.

Claims (4)

1. A spinning nozzle reciprocating linear motion type electrostatic spinning device is characterized in that it comprises a governor, a plexiglass plate, a DC brushless motor, a crankshaft connecting rod, a linear motion rod, a support, a syringe needle tube, a stainless steel needle, a high-pressure DC power supply, aluminum foil collector and base; the hollow stainless steel needle with the tip ground flat is fixed on the medical syringe needle, the stainless steel needle is connected to the positive pole of the high-voltage DC power supply, and the negative pole of the high-voltage DC power supply is connected to the aluminum foil collector pole with aluminum foil on the surface , the aluminum foil collector is fixed on the base of the device; the syringe needle is fixed on one end of the linear movement rod, and the linear movement rod runs through two side-by-side brackets fixed on the base, and the linear movement rod can perform simple harmonic linear motion on the support. The other end of the linear motion rod is connected to the plexiglass plate fixed on the DC brushless motor through the crankshaft connecting rod. The governor is used to control the speed of the DC brushless motor, and the speed of the DC brushless motor is read from the scale on the governor. , the DC brushless motor and the governor are fixed on the base, which constitutes the reciprocating linear motion part of the syringe needle tube used for spinning; when collecting fibers, place the glass piece at the midpoint of the linear motion of the stainless steel needle, according to Due to the characteristics of simple harmonic motion, the stainless steel needle moves the fastest near the midpoint, and the acceleration is the smallest, which is beneficial to the collection of spinning fibers. 2. A kind of spinning nozzle reciprocating linear motion electrospinning device according to claim 1, characterized in that when used for the preparation of orderly arranged linear structure fibers, the precursor solution is first added to the needle tube of the spinning syringe , adjust the distance between the stainless steel needle and the aluminum foil collector to be 1-2 cm, put a glass slide on the aluminum foil collector, and cover the glass slide with a piece of clean and dry paper; turn on the high-voltage DC power supply and adjust the voltage 1.7-2.5 kV, put a little pressure on the plug of the spinning needle tube, so that the solution flows out slowly under the gravity and the pressure of the plug, and the static needle starts spinning; after the spinning is stable, turn on the power of the brushless DC motor, Adjust the knob of the governor so that the speed is 200rpm. When the reciprocating linear motion speed of the stainless steel needle near the midpoint is equivalent to the spinning speed of the stainless steel needle, the electrospun fibers are deposited on the aluminum foil collector in an orderly manner; paper on the glass slide, start to collect the fiber samples on the glass slide, and start timing at the same time, after 15 seconds, first turn off the high-voltage DC power supply, and then turn off the motor power, at this time, the electrospun fibers in an orderly linear arrangement will be obtained on the glass slide. 3. A kind of spinning nozzle reciprocating linear motion electrospinning device according to claim 1, characterized in that it is used for the preparation of cross-structure fibers: the substrate is placed on the aluminum foil collector to collect the spinning fibers, and in After the first spinning is completed, rotate it horizontally by 90 degrees or other angles before spinning, and finally a square fiber grid array with crosses or other angles will be obtained; choose the first layer as n-type organic or inorganic semiconductor Nanofibers, the second layer is p-type organic or inorganic semiconductor fibers, which are assembled into nanoscale p-n junction arrays on the substrate. 4. A spinning nozzle reciprocating linear motion electrospinning device according to claim 1, characterized in that it is used for the preparation of orderly arranged twisted structure fibers: increase the working voltage when the spinning distance is constant , so that the spinning solution is polarized and charged, and the electric field force received by the charged jet during the spinning process increases the movement speed of the electrospun fibers when they reach the collecting plate; The impulsive force makes the linear fibers that have not been fully solidified form a twisted structure; the increase in the charge on the spinning solution jet will increase the bending or whipping instability of the jet, resulting in the formation of twisted structural fibers; in the preparation of ordered linear structure fibers During the process, the operating voltage is increased from 1.7-2.5 kV to 3.0-4.0 kV, and fibers with twisted structures arranged in an orderly arrangement are obtained on the collecting plate; the twisted structure fibers are used to prepare stretchable and flexible electronic devices.

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