CN107603712B

CN107603712B - Flower-like polyaniline nanoparticle electrorheological fluid and preparation method thereof

Info

Publication number: CN107603712B
Application number: CN201710990874.XA
Authority: CN
Inventors: 王宝祥; 西振宇; 马佳斌; 于寿山; 郝春成; 陈克正
Original assignee: Qingdao University of Science and Technology
Current assignee: Qingdao University of Science and Technology
Priority date: 2017-10-23
Filing date: 2017-10-23
Publication date: 2020-08-11
Anticipated expiration: 2037-10-23
Also published as: CN107603712A

Abstract

The invention relates to a flower-shaped polyaniline nano-particle electrorheological fluid material and a preparation method thereof, wherein the dispersed phase of the electrorheological fluid is flower-shaped polyaniline nano-particles and is prepared by a modified rapid mixing method; the electrorheological fluid prepared from the material and the methyl silicone oil has excellent characteristics including excellent electrorheological effect, excellent anti-precipitation stability, low current density and good chemical stability. The attached figure shows the scanning electron microscope photo of the flower-like polyaniline nanoparticles.

Description

Flower-like polyaniline nanoparticle electrorheological fluid and preparation method thereof

Technical Field

The invention relates to an electrorheological fluid and a preparation method thereof, in particular to a flower-shaped polyaniline nanoparticle electrorheological fluid and a preparation method thereof.

Background

Electrorheological is the subject of studying the mutation of yield stress, modulus, viscosity, etc. of dispersion system under the action of electric field. The effect of the electric field on the internal structure and the rheological properties of the dispersion is called electrorheological effect. Dispersions with electrorheological effects are called electrorheological fluids or electrorheological variants, called ER fluids. Usually it is a suspension with two or more phases, which can undergo a large change in its rheological properties within a given time (typically milliseconds) when an applied electric field is applied, and which can be reversible and recover its properties if the electric field is removed, for example: change from a solid-like to the original liquid.

Electrorheological fluids are intelligent materials that respond rapidly to electric fields, and are typically suspensions of high dielectric constant, small particles dispersed in low dielectric constant insulating liquids. Under the action of an external electric field, the material is constructed into a chain or columnar structure between two parallel electrodes, so that the rheological properties of the material, including shear stress, elastic modulus, shear viscosity and the like, can be converted from liquid to solid-like, the viscosity and the shear strength of the material can be rapidly improved, and the material has the characteristic of rapid reversibility. The electrorheological material has great application prospect in the fields of vibration reduction, mechanical transmission, automatic control, electromechanical integration, micro-driving and the like due to low energy consumption and controlled and changed quality.

Polyaniline is one of the best known conductive polymers which are widely researched and controlled in conductivity because of easy synthesis, low cost, good chemical and thermal stability, sensitive reaction to an electric field and reversible acid (alkali) doping (dedoping), and plays an important role in the preparation process of electrorheological materials. As is well known, the change of the surface morphology of the dispersed phase nano particles has great influence on the electrorheological property, and the polyaniline nano particles with different structures have great influence on the interfacial polarization among the particles, thereby playing a great role in improving the electrorheological efficiency.

The invention aims to provide flower-shaped polyaniline nano-particle electrorheological fluid, wherein the dispersed phase is flower-shaped polyaniline nano-particles, and the continuous phase is simethicone. The flower-shaped polyaniline nanoparticles have unique morphology, and scanning electron microscope results show that the flower-shaped polyaniline nanoparticles are of a multi-stage structure assembled by nano-flaky polyaniline. The preparation process is a modified rapid mixing method, adopts polyvinylpyrrolidone (PVP) surfactant as a morphology inducer, belongs to a soft template method, and is green and environment-friendly. The electrorheological fluid prepared from the material and methyl silicone oil has excellent suspension stability due to the anti-settling property of the flower-like polyaniline nanoparticles, and solves a great problem of electrorheological fluid. The process can also regulate and control the appearance, the size and the like of the product by changing the type of the surfactant, and has strong adjustability.

The invention also aims to provide a method for preparing the flower-shaped polyaniline nano-particles by a modified rapid mixing method, the preparation process is simple, the raw materials are easy to obtain, and the electrorheological fluid prepared from the material and the methyl silicone oil has excellent characteristics, including extremely strong electrorheological effect, excellent anti-precipitation stability, good chemical stability and the like. The purpose of the invention can be realized by the following technical scheme:

the dispersed phase of the electrorheological fluid prepared by the invention is flower-like polyaniline nano-particles, and the continuous phase is dimethyl silicone oil. The preparation process of the electrorheological fluid comprises the following steps:

(1) adding 1.2mL aniline monomer into 40mL 1M HCl and 0.4g PVP mixed solution, stirring for 30min, then adding 0.6568g Ammonium Persulfate (APS) and 10mL 1M HCl mixed solution into the solution, stirring for reaction for 10 hours, and then centrifugally washing with absolute ethyl alcohol to obtain flower-shaped polyaniline nanoparticles; soaking the flower-like polyaniline nanoparticles in 100mL of 1M ammonia water solution for 12 hours, then carrying out centrifugal washing with absolute ethyl alcohol for three times, and then putting the obtained product into an oven to be dried to obtain solid powder;

(2) the sample and the dimethyl silicone oil are prepared into the electrorheological fluid according to the weight ratio of the solid particles to the silicone oil of 10wt percent.

Drawings

FIG. 1 SEM photograph of flower-like polyaniline nanoparticles prepared by reaction of PVP (polyvinyl pyrrolidone) as surfactant in 1M HCl for 10 hours by modified rapid mixing method

FIG. 2 shows XRD pattern of polyaniline nanoparticles prepared by reaction of PVP as surfactant in 1M HCl for 10 hours by modified rapid mixing method

FIG. 3 shows the electrorheological behavior curve of the flower-like polyaniline nanoparticles prepared by the modified rapid mixing method using PVP as a surfactant and reacting in 1M HCl for 10 hours

FIG. 4 is SEM photograph of modified polyaniline nanoparticles prepared by reacting PEG as surfactant in 1M HCl for 10 hours by rapid mixing method

FIG. 5 shows XRD pattern of polyaniline nanoparticles prepared by modified rapid mixing method using PEG as surfactant and reacting in 1M HCl for 10 hours

FIG. 6 is a diagram showing the electrorheological properties of polyaniline nanoparticles prepared by a modified rapid mixing method using PEG as a surfactant and reacting in 1M HCl for 10 hours

FIG. 7 SEM photograph of modified polyaniline nanoparticles prepared by rapid mixing method using PVP as surfactant and reacting in 0.1M HCl for 10 hours

FIG. 8 SEM photograph of modified polyaniline nanoparticles prepared by rapid mixing method using PEG as surfactant and reacting in 0.1M HCl for 10 hours

Detailed Description

The first embodiment is as follows:

adding 1.2mL aniline monomer into 40mL 1M HCl and 0.4g PVP mixed solution, stirring for 30min, then adding 0.6568g APS and 10mL 1M HCl mixed solution into the solution, stirring for reaction for 10 h, and then centrifugally washing with absolute ethyl alcohol to obtain flower-shaped polyaniline nanoparticles; soaking the flower-like polyaniline nanoparticles in 100mL of 1M ammonia water solution for 12 hours for dedoping treatment, then centrifugally washing the flower-like polyaniline nanoparticles for three times by using absolute ethyl alcohol, and then drying the flower-like polyaniline nanoparticles in a drying oven at 80 ℃ for 10 hours to obtain solid powder; the sample and the dimethyl silicone oil are prepared into the electrorheological fluid according to the weight ratio of the solid particles to the silicone oil of 10wt percent.

FIG. 1 is an SEM photograph of flower-like polyaniline nanoparticles prepared by reacting PVP (polyvinyl pyrrolidone) as a surfactant in 1M HCl for 10 hours under a modified rapid mixing method, wherein the shapes of the particles are similar to flower shapes, the diameters of the flower-like particles are 600-800 nm, and the thickness of the nano-flaky polyaniline with the flower-like morphology is 20 nm. Fig. 2 is an XRD spectrum of the obtained polyaniline nanoparticles. It can be seen from the figure that polyaniline exists mainly in a semi-crystalline state and an amorphous state. And the peak corresponding to the nano layered polyaniline under the low angle of 6.3 degrees is consistent with the layered morphology obtained under a scanning electron microscope.

FIG. 3 is the relationship between the shear stress and the shear rate of the flower-like polyaniline nanoparticle electrorheological fluid under different field strengths. As can be seen, the voltage can be increased to 3kV at most, and the measured current density is small (less than 10 muA/cm)²) The electric rheologic liquid of the system has better breakdown resistance. As can be seen from the graph, in the absence of an applied electric field, the shear stress increases linearly with increasing shear rate, and the fluid exhibits Newtonian fluid behavior; after an electric field is added, the particles are quickly polarized in the electric field, dipoles attract each other, the particles are arranged into a chain structure, the shearing stress continuously rises under the improvement of the electric field intensity, and a platform area appears in a high-shearing rate area, and the electric current transformation device is characterized in that Bingham fluid has the electric current transformation efficiency as high as 90 and shows excellent electric current transformation effect.

Example two:

adding 1.2mL aniline monomer into 40mL mixed solution of 1M HCl and 0.4g polyethylene glycol (PEG), stirring for 30min, adding mixed solution containing 0.6568g APS and 10mL 1M HCl into the solution, stirring for reaction for 10 hours, and centrifuging and washing with absolute ethyl alcohol to obtain flower-shaped polyaniline nanoparticles; soaking flower-shaped polyaniline nanoparticles in 100mL of 1M ammonia water solution for 12 hours for dedoping treatment, then centrifugally washing the flower-shaped polyaniline nanoparticles for three times by using absolute ethyl alcohol, and then drying the flower-shaped polyaniline nanoparticles in a drying oven at 80 ℃ for 10 hours to obtain solid powder; the sample and the dimethyl silicone oil are prepared into the electrorheological fluid according to the weight ratio of the solid particles to the silicone oil of 10wt percent.

Fig. 4 is an SEM photograph of polyaniline nanoparticles prepared by a modified rapid mixing method using PEG as a surfactant and reacting in 1M HCl for 10 hours. As can be seen from the figure, when the surfactant used was PEG, the resulting product was a mixed type nanoparticle in which flower-like polyaniline and spherical polyaniline coexist. Fig. 5 is an XRD pattern of polyaniline nanoparticles prepared using PEG. It can be seen from the figure that polyaniline is mainly present in a semi-crystalline state and an amorphous state. And the peak of the nano-layered polyaniline corresponding to the strong peak at a low angle of 6.3 degrees is consistent with the layered morphology obtained under a scanning electron microscope. Fig. 6 is a diagram of the electrorheological properties of the polyaniline nanoparticles obtained by the method. As can be seen from the figure, when the surface active agent is changed into PEG, the electrorheological efficiency of the obtained product is 70, which is reduced compared with the first embodiment.

Example three:

adding 1.2mL aniline monomer into 40mL of mixed solution of 1M HCl and 0.4g PVP, stirring for 30min, then adding mixed solution containing 0.6568g APS and 10mL of 0.1M HCl into the solution, stirring for reaction for 10 hours, and then centrifugally washing with absolute ethyl alcohol to obtain flower-shaped polyaniline nanoparticles; soaking the flower-like polyaniline nanoparticles in 100mL of 1M ammonia water solution for 12 hours for dedoping treatment, then centrifugally washing the flower-like polyaniline nanoparticles for three times by using absolute ethyl alcohol, and then drying the flower-like polyaniline nanoparticles in a drying oven at 80 ℃ for 10 hours to obtain solid powder; the sample and the dimethyl silicone oil are prepared into the electrorheological fluid according to the weight ratio of the solid particles to the silicone oil of 10wt percent.

FIG. 7 is an SEM photograph of polyaniline nanoparticles prepared by reaction of PVP as surfactant in 0.1M HCl for 10 hours under modified rapid mixing method. As can be seen from the graph, when PVP was used as a surfactant after changing the HCl concentration to 0.1M, nanoparticles in which spherical polyaniline and plate-like polyaniline were mixed were obtained.

Example four:

adding 1.2mL aniline monomer into 40mL of mixed solution of 1M HCl and 0.4g PEG, stirring for 30min, adding mixed solution containing 0.6568g APS and 10mL of 0.1M HCl into the solution, stirring for reaction for 10 hours, and centrifuging and washing with absolute ethyl alcohol to obtain flower-shaped polyaniline nanoparticles; soaking the flower-like polyaniline nanoparticles in 100mL of 1M ammonia water solution for 12 hours for dedoping treatment, then centrifugally washing the flower-like polyaniline nanoparticles for three times by using absolute ethyl alcohol, and then drying the flower-like polyaniline nanoparticles in a drying oven at 80 ℃ for 10 hours to obtain solid powder; the sample and the dimethyl silicone oil are prepared into the electrorheological fluid according to the weight ratio of the solid particles to the silicone oil of 10wt percent.

Fig. 8 is an SEM photograph of polyaniline nanoparticles prepared by a modified rapid mixing method using PEG as a surfactant in 0.1M HCl for 10 hours. As can be seen from the graph, when the HCl concentration was changed while using PEG as a surfactant, nanoparticles in which spherical polyaniline and plate-shaped polyaniline were mixed were obtained.

Claims

1. An electrorheological fluid is characterized in that the dispersed phase of the electrorheological fluid is flower-like polyaniline nano-particles, and the continuous phase is simethicone; flower-like polyaniline nanoparticles are prepared by a modified rapid mixing method, and the particles are of a multi-stage structure assembled by nano flaky polyaniline; the electrorheological fluid prepared from the flower-like polyaniline nano-particles and the simethicone has excellent electrorheological property, and the preparation process of the electrorheological fluid comprises the following steps:

(1) adding 1.2mL aniline monomer into 40mL 1M HCl and 0.4g PVP mixed solution, stirring for 30min, then adding 0.6568g APS and 10mL 1M HCl mixed solution into the solution, stirring for reaction for 10 h, and then centrifugally washing with absolute ethyl alcohol to obtain flower-shaped polyaniline nanoparticles; soaking the flower-like polyaniline nanoparticles in 100mL of 1M ammonia water solution for 12 hours for dedoping treatment, then centrifugally washing the flower-like polyaniline nanoparticles for three times by using absolute ethyl alcohol, and then drying the flower-like polyaniline nanoparticles in a drying oven at 80 ℃ for 10 hours to obtain solid powder;

(2) the solid powder and the dimethyl silicone oil are prepared into the electrorheological fluid according to the weight ratio of 10 wt% of the solid powder to the silicone oil.