阅读说明：本技术 一种离子型电活性驱动器制备方法 (Preparation method of ionic electroactive driver ) 是由 王帆 王磊 于 2021-07-20 设计创作，主要内容包括：本发明属于离子型电活性驱动器制备技术领域。目的是提供一种离子型电活性驱动器制备方法,该方法制备的离子型电活性驱动器应具有更好的电化学性能和机械特性,并具有成本低廉、容易获得、可靠性好、环保绿色的特点。技术方案是：一种离子型电活性驱动器的制备方法,按照如下步骤进行：步骤1)：制备磺化纤维素纳米晶须-微纤化纤维素-离子液体-石墨烯生物复合膜：步骤2)：将制备好的磺化纤维素纳米晶须-微纤化纤维素-离子液体-石墨烯生物复合膜浸入PEDOT:PSS溶液中,充分附着后进行干燥,得到磺化纤维素纳米晶须-微纤化纤维素-离子液体-石墨烯离子型电活性驱动器。(The invention belongs to the technical field of ionic electroactive driver preparation. The ionic type electroactive driver prepared by the method has better electrochemical performance and mechanical characteristics, and has the characteristics of low cost, easiness in obtaining, good reliability, environmental friendliness and greenness. The technical scheme is as follows: the preparation method of the ionic electroactive driver comprises the following steps: step 1): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane: step 2): and immersing the prepared sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane into a PEDOT (PSS) solution, fully adhering, and drying to obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver.)

1. The preparation method of the ionic electroactive driver comprises the following steps:

step 1): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane:

step 1.1): mixing the sulfonated cellulose nanowhisker suspension and the microfibrillated cellulose suspension to prepare a transparent sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous solution dispersion;

step 1.2): mixing graphene, ionic liquid and sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous solution dispersoid, stirring at room temperature, and performing ultrasonic treatment to obtain stable and uniform sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersoid;

step 1.3): removing air bubbles in the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion under vacuum;

step 1.4): pouring the dispersion subjected to bubble removal into a mold, and drying in a vacuum drying oven to finally obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane;

step 2): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver:

and immersing the prepared sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane into a PEDOT (PSS) solution, fully adhering, and drying to obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver.

2. The method of claim 1, wherein the method further comprises: in the step 1.1), the concentration of the sulfonated cellulose nanowhisker suspension is 4-7%, the concentration of the microfibrillated cellulose suspension is 1.5-2.5%, and the mixing temperature is 10-40 ℃.

3. The method of claim 2, wherein the method further comprises: in the step 1), the weight ratio of the sulfonated cellulose nanowhisker suspension to the microfibrillated cellulose suspension to the graphene to the ionic liquid is 6-8: 3-4: 0.035-0.07: 0.5-1 in sequence.

4. The method of claim 3, wherein the method further comprises: in the step 1.2), the ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate solution with the concentration of 98%.

5. The method of claim 4, wherein the method further comprises: and in the step 1.2), stirring at room temperature for 3-6 hours.

6. The method of claim 5, wherein the method further comprises: in the ultrasonic treatment of the step 1.2), the power of ultrasonic oscillation is 40W, and the treatment time is 0.5-2 h.

7. The method of claim 6, wherein the method further comprises: in the step 1.3), the process of removing bubbles in vacuum is carried out in a vacuum drying oven, and the process of vacuumizing the vacuum drying oven is continuously carried out for 3-5 times, wherein each time lasts for 10-15 min.

8. The method of claim 7, wherein the method further comprises: in the step 1.4), the drying temperature in the vacuum drying oven is 55-65 ℃, and the drying time is 4-6 h.

9. The method of claim 8, wherein the method further comprises: in the PEDOT/PSS solution in the step 2), the weight ratio of PEDOT to PSS is 5:8, and the concentration of the solution is 1.1-2.8%.

10. The method of claim 9, wherein the method further comprises: in the step 2), the immersion time is 8-12min, the drying temperature is 45-55 ℃, and the time is 3-5 h.

Technical Field

The invention belongs to the technical field of ionic electroactive drivers, and particularly relates to a composite material of an ionic electroactive polymer, in particular to a preparation method of an ionic electroactive driver based on graphene and sulfonated cellulose nanowhiskers.

Background

Plant cellulose is the most abundant polymer on the earth at present and is a main component of plant biomass materials such as wood, cotton and the like. The electroactive polymer taking the plant cellulose as the matrix has the advantages of light weight, biodegradability and the like, and shows driving displacement under driving voltage. However, these drivers have disadvantages of poor conductivity, large driving voltage, small tip displacement and slow response speed due to the too compact composite membrane, which is not conducive to ion transport.

Sulfonated Cellulose Nanowhiskers (SCNs) are needle-like nanomaterials prepared from natural plant cellulose by acid or alkali treatment, and can be well dispersed in water due to sulfonic groups on the surface. The sulfonated cellulose nanowhisker has the advantages of excellent emulsion stability, high biodegradability, biocompatibility and high strength.

Microfibrillated cellulose (MFC) has similar properties as sulfonated cellulose nanowhiskers, but is large in diameter and length and suitable as a highly compatible plasticizer.

Graphene (GN) is a two-dimensional carbon nanomaterial consisting of carbon atoms and an sp2 hybrid orbital hexagonal honeycomb lattice, has excellent electrical conductivity, excellent chemical stability, superior mechanical flexibility, and is also one of the thinnest, lightest, and strongest materials, inexpensive, and available in large quantities. The addition of the graphene can enhance the conductivity, the mechanical property and the like of the driver. The PEDOT, PSS, is a non-metal electrode, is an aqueous solution of a high molecular polymer, and has attracted people's interest due to the characteristics of high conductivity, good biocompatibility and biodegradability, convenient synthesis, low cost and the like. And has been applied to a variety of biosensing, biological actuator applications, even in vivo studies.

At present, biocompatible membranes for high-performance ionic electroactive actuators based on sulfonated cellulose nanowhiskers, graphene, microfibrillated cellulose as plasticizers have not been studied.

Disclosure of Invention

The invention aims to overcome the defects of the background technology and provide a preparation method of an ionic type electroactive driver, and the ionic type electroactive driver prepared by the method has better electrochemical performance and mechanical characteristics, and has the characteristics of low cost, easiness in obtaining, good reliability, environmental friendliness and greenness.

The technical scheme provided by the invention is as follows:

the preparation method of the ionic electroactive driver comprises the following steps:

step 1): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane:

step 1.1): mixing the sulfonated cellulose nanowhisker suspension and the microfibrillated cellulose suspension to prepare a transparent sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous solution dispersion;

step 1.2): mixing graphene, ionic liquid and sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous solution dispersoid, stirring at room temperature, and performing ultrasonic treatment to obtain stable and uniform sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersoid;

step 1.3): removing air bubbles in the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion under vacuum;

step 1.4): pouring the dispersion subjected to bubble removal into a mold, and drying in a vacuum drying oven to finally obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane;

step 2): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver:

and immersing the prepared sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane into a PEDOT (PSS) solution, fully adhering, and drying to obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver.

In the step 1.1), the concentration of the sulfonated cellulose nanowhisker suspension is 4-7%, the concentration of the microfibrillated cellulose suspension is 1.5-2.5%, and the mixing temperature is 10-40 ℃.

In the step 1), the weight ratio of the sulfonated cellulose nanowhisker suspension to the microfibrillated cellulose suspension to the graphene to the ionic liquid is 6-8: 3-4: 0.035-0.07: 0.5-1 in sequence.

In the step 1.2), the ionic liquid is 1-ethyl-3-methylimidazolium tetrafluoroborate solution with the concentration of 98%.

And in the step 1.2), stirring at room temperature for 3-6 hours.

In the ultrasonic treatment of the step 1.2), the power of ultrasonic oscillation is 40W, and the treatment time is 0.5-2 h.

In the step 1.3), the process of removing bubbles in vacuum is carried out in a vacuum drying oven, and the process of vacuumizing the vacuum drying oven is continuously carried out for 3-5 times, wherein each time lasts for 10-15 min.

In the step 1.4), the drying temperature in the vacuum drying oven is 55-65 ℃, and the drying time is 4-6 h.

In the PEDOT/PSS solution in the step 2), the weight ratio of PEDOT to PSS is 5:8, and the concentration of the solution is 1.1-2.8%.

In the step 2), the immersion time is 8-12min, the drying temperature is 45-55 ℃, and the time is 3-5 h.

The invention has the beneficial effects that:

1. the sulfonated cellulose nanowhisker is a treated plant cellulose, is widely existed in nature, has rich content, good biodegradability, biocompatibility and higher strength, so the sulfonated cellulose nanowhisker is adopted as a substrate, has low cost, easy obtainment, good reliability and environmental protection and green;

2. the microfibrillated cellulose is used as a plasticizer, and hydroxyl contained in the microfibrillated cellulose interacts with sulfonic acid groups in sulfonated cellulose nanowhiskers to generate hydrogen bonds, so that the plasticity of the biological composite membrane is improved, and the membrane is easier to form;

3. according to the invention, graphene is added into a cellulose mixture, and generates physical crosslinking with cellulose and ionic liquid, so that the conductivity, specific capacitance and mechanical properties of the biological composite membrane are enhanced, and the driving durability, driving tip displacement and electrochemical stability of a driver are improved;

4. the preparation method adopted by the invention is a simple solution casting method, the preparation method and the process conditions are simple, and the vacuum drying method is used for removing air bubbles in the ion exchange membrane, so that the finally prepared driver is uniform, stable in work and excellent in performance, and has the advantages of simple operation and easy popularization;

5. the invention adopts PEDOT and PSS materials as electrode materials, has the advantages of high conductivity, good thermal stability, strong adhesiveness and the like, and obviously improves the defects of high price and easy breakage of the traditional IPMC electrode materials;

6. the ionic electroactive polymer with excellent comprehensive performance is prepared, and is used as a substrate to design a driver, so that the ionic electroactive polymer has the characteristics of large bending deformation, high response speed and good durability, and is favorable for being used as a material of green electronic equipment such as wearable equipment and biomedical equipment.

Drawings

Fig. 1 is a schematic diagram of the actuator of the driver (fig. 1A is an un-applied voltage state, and fig. 1B is an applied voltage state).

Fig. 2 is a surface SEM image of the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene bio-composite membrane.

Fig. 3 is a cross-sectional SEM image of the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene bio-composite membrane.

FIG. 4 is a diagram showing an example of driving displacement of the driver at AC 1V (fig. 4A is a non-voltage-applied state; fig. 4B is a voltage-applied state).

Detailed Description

The following is further described with reference to the embodiments shown in the drawings, but the scope of the invention as claimed is not limited to the embodiments shown. Unless otherwise indicated.

Principle analysis of the invention:

the preparation method provided by the invention is based on the biological-friendly sulfonated cellulose nanowhiskers, microfibrillated cellulose, high-conductivity graphene and ionic liquid, the flexible ion network membrane is prepared by a simple solution casting method, and PEDOT: PSS as electrode (PEDOT is polymer of 3, 4-ethylene dioxythiophene monomer; PSS is sodium alginate), finally obtaining ionic electroactive actuator.

The ionic type electroactive driver has a three-layer structure: i.e. both side electrodes and the middle electrolyte layer. When voltage is applied to two sides of the electrode, positive ions in the ionic liquid are driven to move towards the negative electrode, negative ions move towards the positive electrode, and the positive ions and the negative ions have different volumes, so that the corresponding electrode material is contracted or expanded nearby, the bending deflection of the driver is caused, and the driving function of the driver under the voltage is realized.

PSS, which has excellent conductivity and mechanical property, can stably perform bending action at high frequency, and is often used as a flexible electrode. The middle electrolyte layer is a uniform and stable electrolyte layer membrane prepared from sulfonated cellulose nanowhiskers, microfibrillated cellulose, graphene and ionic liquid (1-ethyl-3-methylimidazolium tetrafluoroborate). The addition of the microfibrillated cellulose enables the membrane to be formed more easily, the graphene, the cellulose and the ionic liquid generate physical crosslinking, and the conductivity, specific capacitance and mechanical properties of the biological composite membrane are enhanced, so that the driving durability, driving tip displacement and electrochemical stability of the driver are improved. Therefore, the invention prepares the high-performance ionic electroactive driver by the materials and the method.

Example 1

The preparation method of the ionic electroactive driver comprises the following steps:

step 1): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane:

step 1.1): mixing 7g of sulfonated cellulose nanowhisker suspension (concentration: 5.6%) and 4g of microfibrillated cellulose suspension (concentration: 1.85%) at 40 ℃ to prepare a transparent sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous solution dispersion;

step 1.2): mixing 0.07g of graphene, 0.5g of 1-ethyl-3-methylimidazole tetrafluoroborate solution (with the concentration of 98%) and the sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous dispersion, stirring for 4 hours at room temperature, and performing ultrasonic treatment for 1 hour (the power of ultrasonic oscillation is 40W) to obtain a stable and uniform sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion;

step 1.3): removing air bubbles in the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion under vacuum; removing bubbles in a vacuum drying oven, and continuously vacuumizing for 3 times, wherein each time lasts for 15 min;

step 1.4): pouring the dispersion subjected to bubble removal into a mold, and drying in a vacuum drying oven at 55 ℃ for 6 hours to finally obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane;

step 2): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver:

and (2) immersing the prepared sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane into a PEDOT: PSS solution for 10min (the weight ratio of PEDOT to PSS in the solution is 5:8, the concentration of the solution is 1.3%), fully adhering, drying at the drying temperature of 45 ℃ for 5h to obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver.

Example 2

The preparation method of the ionic electroactive driver comprises the following steps:

step 1): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane:

step 1.1): mixing 6g of sulfonated cellulose nanowhisker suspension (concentration: 4%) and 3g of microfibrillated cellulose suspension (concentration: 1.5%) at 10 ℃ to prepare a transparent sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous solution dispersion;

step 1.2): mixing 0.035g of graphene, 0.6g of 1-ethyl-3-methylimidazole tetrafluoroborate solution (with the concentration of 98%) and the sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous dispersion, stirring for 3 hours at room temperature, and performing ultrasonic treatment for 0.5 hour (the power of ultrasonic oscillation is 40W) to obtain a stable and uniform sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion;

step 1.3): removing air bubbles in the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion under vacuum; removing bubbles in a vacuum drying oven, and continuously vacuumizing for 4 times, wherein each time lasts for 12 min;

step 1.4): pouring the dispersion subjected to bubble removal into a mold, and drying in a vacuum drying oven at 65 ℃ for 4 hours to finally obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane;

step 2): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver:

and (2) immersing the prepared sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane into a PEDOT: PSS solution for 8min (the weight ratio of PEDOT to PSS in the solution is 5:8, the concentration of the solution is 1.1%), fully adhering, drying at the drying temperature of 50 ℃ for 4h to obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver.

Example 3

The preparation method of the ionic electroactive driver comprises the following steps:

step 1): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane:

step 1.1): mixing 8g of sulfonated cellulose nanowhisker suspension (concentration: 7%) and 3.5g of microfibrillated cellulose suspension (concentration: 2.5%) at 27 ℃ to prepare a transparent sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous solution dispersion;

step 1.2): mixing 0.05g of graphene, 1g of 1-ethyl-3-methylimidazolium tetrafluoroborate solution (with the concentration of 98%) and the sulfonated cellulose nanowhisker-microfibrillated cellulose mixture aqueous dispersion, stirring at room temperature for 6 hours, and performing ultrasonic treatment for 2 hours (the power of ultrasonic oscillation is 40W) to obtain a stable and uniform sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion;

step 1.3): removing air bubbles in the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene dispersion under vacuum; removing bubbles in a vacuum drying oven, and continuously performing vacuum pumping for 5 times, each time for 10 min;

step 1.4): pouring the dispersion subjected to bubble removal into a mold, and drying in a vacuum drying oven at 60 ℃ for 5 hours to finally obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane;

step 2): preparing a sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver:

and (2) immersing the prepared sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane into a PEDOT: PSS solution for 12min (the weight ratio of PEDOT to PSS in the solution is 5:8, the concentration of the solution is 2.8%), fully adhering, drying at the drying temperature of 55 ℃ for 3h to obtain the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene ionic electroactive driver.

Performance testing

1. SEM test

The surface SEM image of the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene bio-composite membrane obtained in example 1 was tested, and the test results are shown in fig. 2, which shows that graphene is tightly embedded in cellulose and IL (ionic liquid); the SEM image of the section of the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane is shown in figure 3, and shows that the PEDOT with high conductivity is that a PSS layer is well adhered to the surface of the sulfonated cellulose nanowhisker-microfibrillated cellulose-ionic liquid-graphene biological composite membrane, which plays an important role in high performance of a driver.

2. Response testing

The ionic electroactive driver based on graphene and sulfonated cellulose nanowhiskers obtained in the test example has an excitation response under AC (i.e. alternating current) 1V, and the driving test result is shown in fig. 4 and attached table 1.

According to the ionic electroactive driver based on the graphene and the sulfonated cellulose nanowhiskers, microfibrillated cellulose is used as a plasticizer, so that the film is easier to form, the graphene is added, the conductivity and the mechanical property of the biological composite film are greatly improved, finally IL (ionic liquid) is added, PEDOT: PSS is uniformly and fully coated on two sides of the composite film, and the driver with excellent performance and stable work is obtained.

3. Performance testing (see Table below)

	Amount of deformation	Speed of response	Driving voltage	Specific capacitance
					Existing drives	3.5mm	1.5s	4V	46mF/cm2
Example 1	6.5mm	0.51s	1V	93mF/cm2
					Example 2	6.7mm	0.50s	0.9V	91mF/cm2
Example 3	6.6mm	0.49s	1.1V	92mF/cm2

Finally, the above examples are only intended to illustrate the technical solution of the present invention and not to be construed as nature, and although the present invention has been described in detail with reference to the examples, those skilled in the art of the present invention can modify the technical idea of the present invention in various forms and all such modifications are intended to be included in the scope of the claims of the present invention.