阅读说明：本技术 一种生物质高介电纳米复合膜的制备方法 (Preparation method of biomass high-dielectric nano composite film ) 是由 杨全岭 栗雪倩 王锦玉 石竹群 杨智博 包江锴 熊传溪 于 2021-01-13 设计创作，主要内容包括：本发明公开了一种生物质高介电纳米复合膜的制备方法,将尿素、氢氧化钾、去离子水按比例混合,配制尿素/氢氧化钾水溶液；加入氮化硼,将所得混合液分散,制得氮化硼剥离分散液；加入钛酸铜钙,将所得混合液分散,制得氮化硼/钛酸铜钙混合分散液；将所得氮化硼/钛酸铜钙混合分散液降温至-35℃以下,加入甲壳素快速搅拌溶解,离心除气泡,得到甲壳素/氮化硼/钛酸铜钙复合溶液；所得甲壳素/氮化硼/钛酸铜钙复合溶液在凝固浴中制膜得到复合膜。本发明提供的复合材料具有层状结构,并具有很高的介电性能。并且,复合膜还具有良好的光学性能和机械强度,并且厚度可调,在光电储能材料等领域具有广泛的应用前景。(The invention discloses a preparation method of a biomass high-dielectric nano composite membrane, which comprises the steps of mixing urea, potassium hydroxide and deionized water in proportion to prepare a urea/potassium hydroxide aqueous solution; adding boron nitride, and dispersing the obtained mixed solution to prepare a boron nitride stripping dispersion solution; adding copper calcium titanate, and dispersing the obtained mixed solution to prepare boron nitride/copper calcium titanate mixed dispersion liquid; cooling the obtained boron nitride/calcium copper titanate mixed dispersion to below-35 ℃, adding chitin, rapidly stirring and dissolving, centrifuging and removing bubbles to obtain chitin/boron nitride/calcium copper titanate composite solution; and preparing a film from the chitin/boron nitride/copper calcium titanate composite solution in a coagulating bath to obtain the composite film. The composite material provided by the invention has a layered structure and high dielectric property. In addition, the composite film also has good optical performance and mechanical strength, is adjustable in thickness and has wide application prospect in the fields of photoelectric energy storage materials and the like.)

1. A preparation method of a biomass high-dielectric nano composite film is characterized by comprising the following steps:

1) mixing urea, potassium hydroxide and deionized water in proportion to prepare a urea/potassium hydroxide aqueous solution;

2) adding boron nitride into the urea/potassium hydroxide aqueous solution, and dispersing the obtained mixed solution to prepare a boron nitride stripping dispersion solution;

3) adding calcium copper titanate into the obtained boron nitride stripping dispersion liquid, and dispersing the obtained mixed liquid to prepare a boron nitride/calcium copper titanate mixed dispersion liquid;

4) cooling the obtained boron nitride/calcium copper titanate mixed dispersion to below-35 ℃, adding chitin, rapidly stirring and dissolving, centrifuging and removing bubbles to obtain chitin/boron nitride/calcium copper titanate composite solution;

5) and preparing a film from the chitin/boron nitride/copper calcium titanate composite solution in a coagulating bath to obtain the composite film.

2. The method for preparing a biomass high-dielectric nano composite film according to claim 1, wherein the mass ratio of urea, potassium hydroxide and deionized water in step 1 is (1-10): (10-20): (70-89).

3. The preparation method of the biomass high-dielectric nano composite film according to claim 1, wherein the concentration of boron nitride in the boron nitride peeling layer dispersion liquid in the step 2 is 1-20 wt%; the boron nitride is a boron nitride nanosheet with the diameter of 0.1-10 mu m and the thickness of 0.5-2 nm.

4. The preparation method of the biomass high-dielectric nano composite film according to claim 1, wherein the concentration of the calcium copper titanate in the boron nitride/calcium copper titanate mixed dispersion liquid in the step 3 is 1-20 wt%; the copper calcium titanate nano-fiber is prepared by utilizing an electrostatic spinning technology, the diameter of the copper calcium titanate nano-fiber is 100-200 nm, and the length of the copper calcium titanate nano-fiber is 10-20 mu m.

5. The method for preparing the biomass high-dielectric nano composite film as claimed in claim 1, wherein the boron nitride is added in the step 2 and then treated by 100-200W ultrasonic for 1-2 hours, and the stirring speed is 400-1300 rpm/min, so that the boron nitride is completely stripped.

6. The method for preparing the biomass high-dielectric nano composite film as claimed in claim 1, wherein the step 3 is performed with 100-200W ultrasonic treatment for 1-2 hours after adding the copper calcium titanate, and the stirring speed is 400-1300 rpm/min, so that the copper calcium titanate is uniformly dispersed.

7. The method for preparing the biomass high-dielectric nano composite membrane according to claim 1, wherein the chitin used in the step 4 is pure chitin obtained by removing protein, removing inorganic salt, purifying by bleaching and freeze-drying.

8. The method for preparing the biomass high-dielectric nano composite film according to claim 1, wherein the temperature of the chitin added in the step 4 is gradually increased from-35 ℃ to-5 ℃; the centrifugation speed was 7500 rpm/min.

9. The preparation method of the biomass high-dielectric nano composite membrane according to claim 1, wherein the step 5 is to spread the obtained chitin/boron nitride/copper calcium titanate composite solution on a glass plate according to the thickness of 15-40 μm, and soak the glass plate in ethanol, acetone, dilute sulfuric acid, sodium sulfate solution or water coagulation bath for regeneration to obtain hydrogel; and (3) taking the hydrogel off the glass plate, washing with water, soaking and drying to obtain the chitin/boron nitride/copper calcium titanate composite membrane.

Technical Field

The invention belongs to the technical field of materials, and particularly relates to a preparation method of a biomass high-dielectric nano composite film.

Background

The most commercially used dielectric energy storage films at present are BOPP films (biaxially oriented polypropylene films) with energy storage density of about 2J/cm-3, which is lower and to be improved; the PVDF dielectric film prepared by laboratory research has the defects of high raw material cost, complex preparation process, non-regenerability and incapability of recycling, so that the scarce chemical resources are greatly wasted and do not meet the requirements of sustainable development.

In addition, under the global large background of current energy crisis and environmental pollution, the development of green and environment-friendly renewable materials to replace the traditional fossil raw materials is urgently needed. Chitin, which is the second largest natural polymer material to cellulose in nature, is widely present in bones of crustaceans, molluscs and insects, has the characteristics of biodegradability, renewability, environmental friendliness, excellent mechanical properties, good light transmittance and the like, attracts wide attention in recent years, and becomes a new hotspot in the field of research of biomass nano materials. The application of the biological material reported at present in the dielectric aspect is complex in preparation process on one hand, and poor in dielectric property of the prepared composite membrane on the other hand.

The results of the method for preparing the dielectric nano composite film by compounding the chitin and the boron nitride nanosheet show that although the breakdown field strength of the composite film can be obviously improved by the boron nitride, the addition of the boron nitride inevitably reduces the dielectric constant of the composite material due to the low dielectric constant (3-4) of the boron nitride, so that the maximum increase of the energy storage density is limited.

Disclosure of Invention

The invention aims to provide a preparation method of a biomass high-dielectric nano composite film, and the obtained composite film has high dielectric property, good optical property and mechanical strength, adjustable thickness and wide application prospect in the fields of photoelectric energy storage materials and the like.

In order to achieve the purpose, the technical scheme is as follows:

a preparation method of a biomass high-dielectric nano composite film comprises the following steps:

1) mixing urea, potassium hydroxide and deionized water in proportion to prepare a urea/potassium hydroxide aqueous solution;

2) adding boron nitride into the urea/potassium hydroxide aqueous solution, and dispersing the obtained mixed solution to prepare a boron nitride stripping dispersion solution;

3) adding calcium copper titanate into the obtained boron nitride stripping dispersion liquid, and dispersing the obtained mixed liquid to prepare a boron nitride/calcium copper titanate mixed dispersion liquid;

4) cooling the obtained boron nitride/calcium copper titanate mixed dispersion to below-35 ℃, adding chitin, rapidly stirring and dissolving, centrifuging and removing bubbles to obtain chitin/boron nitride/calcium copper titanate composite solution;

5) and preparing a film from the chitin/boron nitride/copper calcium titanate composite solution in a coagulating bath to obtain the composite film.

According to the scheme, the mass ratio of the urea to the potassium hydroxide to the deionized water in the step 1 is (1-10) to (10-20) to (70-89).

According to the scheme, the concentration of boron nitride in the boron nitride stripping layer dispersion liquid in the step 2 is 1-20 wt%; the boron nitride is a boron nitride nanosheet with the diameter of 0.1-10 mu m and the thickness of 0.5-2 nm.

According to the scheme, the concentration of the calcium copper titanate in the boron nitride/calcium copper titanate mixed dispersion liquid in the step 3 is 1-20 wt%; the copper calcium titanate nano-fiber is prepared by utilizing an electrostatic spinning technology, the diameter of the copper calcium titanate nano-fiber is 100-200 nm, and the length of the copper calcium titanate nano-fiber is 10-20 mu m.

According to the scheme, after the boron nitride is added in the step 2, the boron nitride is subjected to ultrasonic treatment for 1-2 hours at 100-200W, and the stirring speed is 400-1300 rpm/min, so that the boron nitride is completely stripped.

According to the scheme, after the copper calcium titanate is added in the step 3, the mixture is subjected to ultrasonic treatment for 1-2 hours at 100-200W, and the stirring speed is 400-1300 rpm/min, so that the copper calcium titanate is uniformly dispersed.

According to the scheme, the chitin used in the step 4 is pure chitin obtained by freeze drying after protein removal, inorganic salt removal and bleaching purification.

According to the scheme, the temperature is gradually increased from-35 ℃ to-5 ℃ after the chitin is added in the step 4; the centrifugation speed was 7500 rpm/min.

According to the scheme, the chitin/boron nitride/copper calcium titanate composite solution obtained in the step 5 is spread on a glass plate according to the thickness of 15-40 microns, and is soaked in ethanol, acetone, dilute sulfuric acid, a sodium sulfate solution or a water coagulation bath for regeneration to obtain hydrogel; and (3) taking the hydrogel off the glass plate, washing with water, soaking and drying to obtain the chitin/boron nitride/copper calcium titanate composite membrane.

The invention adopts chitin, boron nitride and copper calcium titanate as raw materials, and uses urea/hydroxide aqueous solution as a medium to synthesize the nano composite film, wherein the chitin can be well dispersed and dissolved in the system at low temperature, the boron nitride and the copper calcium titanate are ultrasonically dispersed in the system to effectively peel and disperse, and the boron nitride and the copper calcium titanate are effectively dispersed in the system to be well compounded with the chitin, so that the plasticity of the chitin and the dielectric properties of the boron nitride and the copper calcium titanate can be fully exerted. The addition of the copper calcium titanate in the composite film effectively improves the dielectric constant of the chitin, the boron nitride sheet layer effectively inhibits the charge flow and the extension of an electric tree, so that the breakdown strength of the composite film is effectively improved, the dielectric loss is reduced, and finally the composite film obtains high energy storage density and efficiency. Meanwhile, the stripped boron nitride layer and the copper calcium titanate fiber are in a nanometer level, so that the composite film has good light transmittance.

Compared with the prior art, the invention has the beneficial effects that:

the preparation method has the characteristics of low pollution, low energy consumption, convenient and efficient operation and the like, and the whole preparation process has low requirements on equipment and is beneficial to industrial production.

The composite material provided by the invention has a layered structure and high dielectric property. In addition, the composite film also has good optical performance and mechanical strength, is adjustable in thickness and has wide application prospect in the fields of photoelectric energy storage materials and the like.

The chitin/boron nitride/calcium copper titanate high-dielectric nano composite film is a renewable green environment-friendly film material, and can be used for repeatedly recycling boron nitride and calcium copper titanate by degrading chitin, so that the resource recycling is realized.

Drawings

FIG. 1: SEM cross-sectional view of chitin/boron nitride/calcium copper titanate composite film prepared in example 1.

Detailed Description

The following examples further illustrate the technical solutions of the present invention, but should not be construed as limiting the scope of the present invention.

Comparative example 1

1) Preparing a urea/potassium hydroxide aqueous solution system: mixing 3g of urea, 16g of potassium hydroxide and 81g of deionized water to prepare 100g of solvent;

2) preparing a chitin solution: cooling the prepared urea/potassium hydroxide aqueous solution to-35 ℃, adding 5g of chitin, rapidly stirring at the rotating speed of 1300rpm/min for about 10min, then adjusting the temperature to-30 ℃, continuously stirring for 20min until the chitin is fully dissolved, finally sequentially adjusting the temperature to-20 ℃ and-5 ℃, stirring for 30min at each temperature to uniformly mix all the components, and then centrifugally defoaming at the rotating speed of 7500rpm/min to prepare a chitin solution;

3) preparing regenerated chitin hydrogel: spreading the prepared chitin solution on a glass plate by using a simple tape casting method, forming a specific thickness by controlling tape casting force and distance between the tape casting force and the glass plate, and then soaking the glass plate in ethanol at 0 ℃ for solidification and regeneration for 10 hours to prepare regenerated chitin hydrogel;

4) film preparation: fixing the prepared regenerated chitin hydrogel on a PMMA plate, and drying the PMMA plate at room temperature to obtain the regenerated chitin membrane.

Scanning with SEMCarrying out morphology test on the obtained chitin membrane by using a scanning electron microscope; the dielectric properties of the chitin film obtained in the comparative example were tested by using E4980A Agilent instrument and Premier II ferroelectric test system, and the dielectric constant was 7.1 and the breakdown strength was 320MVm at 1000Hz and room temperature^-1Dielectric loss of 0.021 and energy storage density of 3.3Jcm^-3(320MVm^-1). The mechanical properties of the chitin membrane obtained in the comparative example were tested by a CMT6503 universal tensile machine, and the tensile strength was 70 MPa.

Comparative example 2

1) Stripping boron nitride, preparing boron nitride dispersion liquid: mixing 3g of urea, 16g of sodium hydroxide and 81g of deionized water, adding 0.21g of boron nitride, mechanically stirring at room temperature for 1h at the stirring speed of 800rpm/min, and ultrasonically dispersing in an ice-water bath for 1h at the ultrasonic power of 102W to completely strip and disperse the boron nitride to prepare a boron nitride dispersion liquid;

2) preparing a chitin/boron nitride mixed solution: cooling the boron nitride dispersion liquid to-35 ℃, adding 5g of chitin, rapidly stirring at the rotating speed of 1250rpm/min for about 10min, then adjusting the temperature to-30 ℃, continuously stirring for 20min until the chitin is fully dissolved, finally adjusting the temperature to-20 ℃ and-5 ℃ in sequence, stirring for 30min at each temperature to uniformly mix all the components, and then centrifugally defoaming at the rotating speed of 7500rpm/min to obtain chitin/boron nitride mixed liquid;

3) preparing a hydrogel: spreading the obtained chitin/boron nitride mixed solution on a glass plate by using a simple tape casting method, forming a specific thickness by controlling tape casting force and distance between the tape casting force and the glass plate, and then soaking the glass plate in ethanol at 0 ℃ for solidification and regeneration for 10 hours to obtain chitin/boron nitride hydrogel;

4) film preparation: and (3) taking the hydrogel out of the glass plate, fixing the hydrogel on a PMMA plate, and drying the hydrogel for 24 hours at room temperature to obtain the chitin/boron nitride composite film with the chitin-boron nitride ratio of 96/4.

The dielectric properties of the chitin film obtained in this example were tested using an E4980A agilent instrument and a Premier II ferroelectric test system. The test result shows that the dielectric property of the composite film is obtained compared with the pure chitin film prepared in the comparative example 1The breakdown strength is greatly improved from 320MVm^-1Increased to 397MVm^-1Dielectric loss is reduced from 0.021 to 0.019, and energy storage density is reduced from 3.3Jcm^-1Increased to 5.4Jcm^-1The charge-discharge efficiency can still be kept around 80% even under the maximum field intensity, which is far higher than 70.12% of pure RCH (320MV m)^-1). The mechanical properties of the chitin/boron nitride composite film obtained in the embodiment are tested by using a CMT6503 universal tensile machine, and the result shows that the tensile strength of the composite film is improved from 70MPa to 82 MPa.

Example 1

The chitin/boron nitride/copper calcium titanate composite membrane is prepared by the following steps:

1) stripping boron nitride, preparing boron nitride dispersion liquid: mixing 3g of urea, 16g of sodium hydroxide and 81g of deionized water, adding 0.21g of boron nitride, mechanically stirring at room temperature for 1h at the stirring speed of 800rpm/min, and ultrasonically dispersing in an ice-water bath for 1h with the ultrasonic power of 102W, so that the boron nitride can be completely peeled and dispersed to prepare a boron nitride dispersion liquid;

2) dispersing copper calcium titanate, preparing boron nitride/copper calcium titanate mixed dispersion liquid: adding 0.10g of copper calcium titanate into the boron nitride dispersion liquid, mechanically stirring for 1h at room temperature at the stirring speed of 800rpm/min, and then ultrasonically dispersing for 1h in an ice water bath with the ultrasonic power of 102W to ensure that the copper calcium titanate can be completely dispersed, thereby preparing the boron nitride/copper calcium titanate mixed dispersion liquid.

3) Preparing a chitin/boron nitride/copper calcium titanate mixed solution: cooling the boron nitride/calcium copper titanate mixed dispersion to-35 ℃, adding 5g of chitin, rapidly stirring at the rotating speed of 1250rpm/min for about 10min, then adjusting the temperature to-30 ℃, continuously stirring for 20min until the chitin is fully dissolved, finally sequentially adjusting the temperature to-20 ℃ and-5 ℃, stirring for 30min at each temperature to uniformly mix all the components, and then centrifugally defoaming at the rotating speed of 7500rpm/min to obtain chitin/boron nitride/calcium copper titanate mixed solution;

3) preparing a hydrogel: spreading the obtained chitin/boron nitride/copper calcium titanate mixed solution on a glass plate by using a simple tape casting method, forming a specific thickness by controlling tape casting force and distance between the tape casting force and the glass plate, and then soaking the glass plate in ethanol at 0 ℃ for solidification and regeneration for 10 hours to prepare chitin/boron nitride/copper calcium titanate hydrogel;

4) film preparation: and (3) taking the hydrogel out of the glass plate, fixing the hydrogel on a PMMA plate, and drying the hydrogel at room temperature for 24 hours to obtain chitin/boron nitride/copper calcium titanate composite films with the proportions of chitin, boron nitride and copper calcium titanate being 96/4 and 98/2 respectively.

The dielectric property test of the composite film prepared in the embodiment is carried out by adopting the same method as the embodiment 1, and the test result shows that the dielectric property of the composite film is greatly enhanced and the breakdown strength is 320MVm^-1Increase to 430MVm^-1Dielectric constant is increased from 7.1 to 7.4, and energy storage density is increased from 3.3J cm^-3Increased to 9.1J cm^-3Furthermore, the composite film is at 430MVm^-1Can still maintain the high charge-discharge efficiency of more than 80 percent under the high field intensity. The mechanical properties of the chitin/boron nitride composite film obtained in the embodiment are tested by using a CMT6503 universal tensile machine, and the tensile strength of the composite film is improved from 70MPa to 90 MPa.

Fig. 1 is a cross-sectional view of SEM of the chitin/boron nitride/calcium copper titanate composite film prepared in this example, and it can be seen that the boron nitride nanosheet layer and the calcium copper titanate nanofibers are uniformly dispersed in the chitin, and have an obvious layered structure, and the chitin, the boron nitride and the calcium copper titanate are uniformly mixed in the composite film, and no obvious phase separation phenomenon occurs.

Example 2

The chitin/boron nitride/copper calcium titanate composite membrane is prepared by the following steps:

1) stripping boron nitride, preparing boron nitride dispersion liquid: mixing 3g of urea, 16g of sodium hydroxide and 81g of deionized water, adding 0.32g of boron nitride, mechanically stirring at room temperature for 1h at the stirring speed of 800rpm/min, and ultrasonically dispersing in an ice-water bath for 1h at the ultrasonic power of 102W to completely strip and disperse the boron nitride to prepare a boron nitride dispersion liquid;

2) dispersing copper calcium titanate, preparing boron nitride/copper calcium titanate mixed dispersion liquid: adding 0.43g of copper calcium titanate into the boron nitride dispersion liquid, mechanically stirring for 1h at room temperature at the stirring speed of 800rpm/min, and then ultrasonically dispersing for 1h in an ice water bath with the ultrasonic power of 102W to ensure that the copper calcium titanate can be completely dispersed, thereby preparing the boron nitride/copper calcium titanate mixed dispersion liquid.

3) Preparing a chitin/boron nitride/copper calcium titanate mixed solution: cooling the boron nitride/calcium copper titanate mixed dispersion to-35 ℃, adding 5g of chitin, rapidly stirring at the rotating speed of 1250rpm/min for about 10min, then adjusting the temperature to-30 ℃, continuously stirring for 20min until the chitin is fully dissolved, finally sequentially adjusting the temperature to-20 ℃ and-5 ℃, stirring for 30min at each temperature to uniformly mix all the components, and then centrifugally defoaming at the rotating speed of 7500rpm/min to obtain chitin/boron nitride/calcium copper titanate mixed solution;

3) preparing a hydrogel: spreading the obtained chitin/boron nitride/copper calcium titanate mixed solution on a glass plate by using a simple tape casting method, forming a specific thickness by controlling tape casting force and distance between the tape casting force and the glass plate, and then soaking the glass plate in ethanol at 0 ℃ for solidification and regeneration for 10 hours to prepare chitin/boron nitride/copper calcium titanate hydrogel;

4) film preparation: and (3) taking the hydrogel out of the glass plate, fixing the hydrogel on a PMMA plate, and drying the hydrogel at room temperature for 24 hours to obtain chitin/boron nitride/copper calcium titanate composite films with the proportions of chitin, boron nitride and copper calcium titanate being 94/6 and 92/8 respectively.

The dielectric property test of the composite film prepared in the embodiment is carried out by adopting the same method as the embodiment 1, and the test result shows that the dielectric property of the composite film is greatly enhanced and the breakdown strength is 320MVm^-1Increased to 385MVm^-1Dielectric constant is increased from 7.1 to 8.6, and energy storage density is increased from 3.3J cm^-3Increased to 7.1J cm^-3In addition, the composite film can still maintain 75% of charge and discharge efficiency under high field intensity.

Example 3

The chitin/boron nitride/copper calcium titanate composite membrane is prepared by the following steps:

1) stripping boron nitride, preparing boron nitride dispersion liquid: mixing 3g of urea, 16g of sodium hydroxide and 81g of deionized water, adding 0.43g of boron nitride, mechanically stirring at room temperature for 1h at the stirring speed of 800rpm/min, and ultrasonically dispersing in an ice-water bath for 1h at the ultrasonic power of 102W to completely strip and disperse the boron nitride to prepare a boron nitride dispersion liquid;

2) dispersing copper calcium titanate, preparing boron nitride/copper calcium titanate mixed dispersion liquid: adding 0.68g of copper calcium titanate into the boron nitride dispersion liquid, mechanically stirring for 1h at room temperature at the stirring speed of 800rpm/min, and then ultrasonically dispersing for 1h in an ice water bath to ensure that the copper calcium titanate can be completely dispersed to prepare the boron nitride/copper calcium titanate mixed dispersion liquid.

3) Preparing a chitin/boron nitride/copper calcium titanate mixed solution: cooling the boron nitride/calcium copper titanate mixed dispersion to-35 ℃, adding 5g of chitin, rapidly stirring at the rotating speed of 1250rpm/min for about 10min, then adjusting the temperature to-30 ℃, continuously stirring for 20min until the chitin is fully dissolved, finally sequentially adjusting the temperature to-20 ℃ and-5 ℃, stirring for 30min at each temperature to uniformly mix all the components, and then centrifugally defoaming at the rotating speed of 7500rpm/min to obtain chitin/boron nitride/calcium copper titanate mixed solution;

3) preparing a hydrogel: spreading the obtained chitin/boron nitride/copper calcium titanate mixed solution on a glass plate by using a simple tape casting method, forming a specific thickness by controlling tape casting force and distance between the tape casting force and the glass plate, and then soaking the glass plate in ethanol at 0 ℃ for solidification and regeneration for 10 hours to prepare chitin/boron nitride/copper calcium titanate hydrogel;

4) film preparation: and (3) taking the hydrogel out of the glass plate, fixing the hydrogel on a PMMA plate, and drying the hydrogel at room temperature for 24 hours to obtain chitin/boron nitride/copper calcium titanate composite films with the proportions of chitin, boron nitride and copper calcium titanate being 92/8 and 88/12 respectively.

The dielectric property test of the composite film prepared in the embodiment is carried out by adopting the same method as the embodiment 1, and the test result shows that the dielectric property of the composite film is enhanced and the breakdown strength is 320MVm^-1To 336MVm^-1The dielectric constant is greatly increased from 7.1 to 9.64, and the increase is 35.8%.