Electrorheological polishing fluid containing polyionic liquid / nano abrasive hollow composite particles

Abstract

The application discloses a kind of containing polyionic liquid / nano abrasive hollow composite particle electrorheological polishing fluid, and its dispersed phase is the polyionic liquid / nano abrasive hollow composite particle of surface inlaying commercial nano abrasive, and the continuous phase is insulating oil, and the polishing fluid is obtained by dispersing polyionic liquid / nano abrasive hollow composite particle into insulating oil, and the polyionic liquid / nano abrasive hollow composite particle is prepared by microwave polymerization method.The electrorheological polishing fluid containing polyionic liquid / nano abrasive hollow composite particle of the application can solve the uneven distribution of abrasive and the low polishing efficiency caused by the separation of abrasive particles and electrorheological particles during polishing of the electrorheological polishing fluid prepared by the existing simple mixing method, since the abrasive is inlaid on the surface of hollow electrorheological particle.The novel and efficient microwave polymerization method is convenient for large-scale and rapid preparation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polishing liquid, in particular to an electrorheological polishing liquid, which is obtained by dispersing polyionic liquid / nano abrasive hollow composite particles in insulating oil. The polyionic liquid / nano abrasive hollow composite particles are prepared by microwave polymerization method. BACKGROUND

[0002] The core technology of ultra-precision polishing mainly includes two aspects, one is polishing equipment, and the grinding disc is the key point; the other is material, i.e. polishing liquid. At present, the research on grinding disc and polishing liquid is relatively mature, but it is still difficult to obtain uniform polishing effect based on ordinary rotary polishing method, which is mainly due to the uneven distribution of abrasive between the workpiece and the polishing tool, the relative speed, pressure difference and polishing liquid. The electrorheological polishing is considered as an effective method to solve the problem of uneven distribution of abrasive, and its principle is to control the force and movement of abrasive particles by external electric field to overcome the centrifugal force and centrifugal motion generated by workpiece rotation, so that the abrasive can be well distributed in the workpiece to be polished. The principle of electrorheological polishing is to add abrasive particles to electrorheological fluid as polishing medium, and after applying an external electric field between the tool and the workpiece, the electrorheological particles form a particle chain between the tool and the workpiece after polarization, and the abrasive particles are clamped or adsorbed on the electrorheological particle chain. Under the driving of the tool electrode, the abrasive particles collide with the workpiece surface along the chain to achieve polishing. However, the practical application of electrorheological polishing technology is still lagging behind, which is mainly due to the insufficient performance of the existing electrorheological polishing liquid. At present, the electrorheological polishing liquid material is mainly prepared by simply mixing abrasive particles with electrorheological fluid, but due to the great difference in conductivity, polarization rate and electrorheological effect between abrasive particles and electrorheological particles, when subjected to the action of electric field and polishing induced shear field at the same time, the abrasive particles and electrorheological particles are prone to phase separation, resulting in uneven distribution of abrasive particles in the polishing micro area, which greatly affects the polishing efficiency and effect. SUMMARY

[0003] In order to overcome the defect that the existing electrorheological polishing liquid prepared by simple dispersion method is easy to separate under electric field, the present application provides an electrorheological polishing liquid containing polyionic liquid / nano abrasive hollow composite particles, which is composed of hollow polyionic liquid microspheres coated with nano abrasive particles on the outer surface. The abrasive particles are bound by electrorheological particles, so that the electrorheological and polishing performances are compatible on a single hollow composite particle, i.e. the polyionic liquid with strong electrorheological effect induces electrorheological effect under electric field, and the abrasive with high polishing performance is in uniform contact with the workpiece to realize polishing, which can effectively solve the problems of uneven distribution of abrasive and low polishing efficiency caused by phase separation of abrasive particles and electrorheological particles in the existing simple mixing method.

[0004] The application discloses a kind of containing polyionic liquid / nano abrasive hollow composite particles electrorheological polishing fluid, dispersed phase is the polyionic liquid / nano abrasive hollow composite particles of nano abrasive particle coating on outer surface, continuous phase is insulating oil, and the polyionic liquid / nano abrasive hollow composite particles are dispersed into insulating oil to obtain polishing fluid.

[0005] The preparation of the electrorheological polishing fluid containing polyionic liquid / nano abrasive hollow composite particles is as follows:

[0006] First, nano abrasive particles are added to ethanol solvent (the mass of ethanol solvent is 40 times that of nano abrasive), and after ultrasonic dispersion, the solubilizing agent is added dropwise to the abrasive dispersion under stirring, and after 1 hour, the silane coupling agent (the volume of silane coupling agent is 0.01% to 10% milliliter per gram of nano abrasive) is added dropwise to the dispersion, and after 5 hours, ammonia is added dropwise, and the reaction is carried out at room temperature for 16 hours. After the reaction, the excess silane coupling agent is washed away by repeated centrifugation and ultrasonic dispersion in deionized water and ethanol, and the modified nano abrasive is obtained by vacuum drying at -50°C;

[0007] Then, the initiator is dissolved in the ionic liquid monomer to form a solution (the mass ratio of initiator to ionic liquid monomer is 4%), and the modified nano abrasive is dispersed in deionized water under an ice water bath to form a dispersion according to the mass ratio of modified nano abrasive to ionic liquid monomer of 9% to 36%, wherein the mass of modified nano abrasive is 0.9% to 3.6% grams per milliliter of deionized water;

[0008] Then, the solution and the dispersion are mixed together, and the dispersion is ultrasonically treated for 15 to 30 minutes in an ice water bath using a cell disrupter, and then the ultrasonically treated dispersion is placed in a microwave synthesis instrument, the stirring speed is set to medium, the microwave power is set to 30 watts, and the reaction is carried out at 70°C for 3 hours to generate solid particles;

[0009] Finally, the solid particles are washed by centrifugation with deionized water, and vacuum drying is carried out at 40°C to 60°C for 72 to 120 hours to obtain polyionic liquid / nano abrasive hollow composite particles, and the dry dispersed hollow composite particles are dispersed into the continuous phase insulating oil by stirring to obtain the electrorheological polishing fluid, wherein the volume ratio of the dispersed phase polyionic liquid / nano abrasive hollow composite particles to the continuous phase insulating oil is 10% to 30%.

[0010] The polyionic liquid / nano abrasive hollow composite particle in the electrorheological polishing fluid is selected from one of poly(methacryloxyethyl) trimethylammonium bis(trifluoromethylsulfonyl) imide, poly(methacryloxyethyl) triethylammonium bis(trifluoromethylsulfonyl) imide, poly(methacryloxyethyl) tripropylammonium bis(trifluoromethylsulfonyl) imide, poly(methacryloxyethyl) tributylammonium bis(trifluoromethylsulfonyl) imide, poly(vinylbenzyl) trimethylammonium bis(trifluoromethylsulfonyl) imide, poly(vinylbenzyl) triethylammonium bis(trifluoromethylsulfonyl) imide, poly(vinylbenzyl) tripropylammonium bis(trifluoromethylsulfonyl) imide, poly(vinylbenzyl) tributylammonium bis(trifluoromethylsulfonyl) imide, poly(methacryloxyethyl) sulfonate trifluoromethylsulfonyl imide tetrabutylammonium, methacryloxyethyl sulfonate trifluoromethylsulfonyl imide tetrapropylammonium, methacryloxyethyl sulfonate trifluoromethylsulfonyl imide tetraethylammonium, poly(styryl sulfonate) trifluoromethylsulfonyl imide tetrabutylammonium, poly(styryl sulfonate) trifluoromethylsulfonyl imide tetrapropylammonium, poly(styryl sulfonate) trifluoromethylsulfonyl imide tetraethylammonium.

[0011] The nano abrasive in the electrorheological polishing fluid of the polyionic liquid / nano abrasive hollow composite particle is selected from one of nano alumina, nano ceria, and nano zirconia.

[0012] The insulating oil in the electrorheological polishing fluid of the polyionic liquid / nano abrasive hollow composite particle is selected from one of silicone oil, hydraulic oil, lubricating oil, and mineral oil.

[0013] The silane coupling agent used in the preparation of the polyionic liquid / nano abrasive hollow composite particle is selected from one of methacryloxypropyl trimethoxysilane, vinyl triethoxysilane, vinyl trimethoxysilane, tris(2-methoxyethoxy) vinyl silane, and allyl trimethoxysilane.

[0014] The polyionic liquid / nano abrasive hollow composite particle has the advantages that, compared with the existing electrorheological polishing fluid prepared by a simple mixing method, the abrasive is embedded on the surface of the hollow electrorheological particle to form a hollow composite particle, and the problems of uneven abrasive distribution and low polishing efficiency caused by the separation of the abrasive particles from the electrorheological particles in the existing electrorheological polishing fluid can be solved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The scanning electron microscope photo of the poly[2-(methacryloxy) ethyl] trimethylammonium bis(trifluoromethylsulfonyl) imide / modified commercial alumina nano abrasive hollow composite particle.

[0016] Figure 2 The transmission electron microscope photo of the poly[2-(methacryloxy) ethyl] trimethylammonium bis(trifluoromethylsulfonyl) imide / modified commercial alumina nano abrasive hollow composite particle.

[0017] Figure 3Rheological curve of electrorheological polishing fluid (volume fraction 15%) formed by dispersing poly[2-(methacryloyloxy)ethyl]trimethylammonium bistrifluoromethylsulfonimide / alumina hollow composite particles in silicone oil. DETAILED DESCRIPTION

[0018] The application will be further described by way of examples and with reference to the accompanying drawings.

[0019] Example

[0020] First, 2 grams of α-Al2O3 particles with an average particle size of 300 nm were weighed, 100 milliliters of ethanol was added thereto, and the resulting dispersion was ultrasonically treated for 30 minutes using a digital cell disruptor at a horn gauge radius of 15, 75% amplitude, a mode of 2 seconds of operation and 1 second of interval. Then, the dispersion obtained after ultrasonic treatment was subjected to modification treatment, 10 milliliters of a mixed solution of ethanol and 4 milliliters of polyethylene glycol-400 was added dropwise thereto, and the mixture was stirred for 1 hour. After 1 hour, 10 microliters of ethenyl triethoxysilane dissolved in 10 milliliters of ethanol was added dropwise again, and the whole system was kept under stirring for 5 hours of reaction. After 5 hours, 2 milliliters of ammonia water and 10 milliliters of ethanol solution were thoroughly mixed and added dropwise again, and the mixture was kept under stirring for 16 hours of reaction. After 16 hours, the reaction was completed, and the modified nano zirconia particles were washed repeatedly with deionized water and ethanol, dried at -50°C using a freeze dryer for 24 hours, and α-Al2O3 white powder after modification was obtained.

[0021] Then, 0.08 grams of azobisisobutyronitrile was dissolved in 2.00 grams of [2-(methacryloyloxy)ethyl]trimethylammonium bistrifluoromethylsulfonimide to obtain a solution at a 40°C water bath, and 1.00 grams of the modified commercial alumina nano abrasive obtained in step (1) was ultrasonically dispersed in 20 milliliters of deionized water to obtain a dispersion at an ice water bath.

[0022] Then, the solution and the dispersion were mixed together, and the mixture was stirred at an ice water bath temperature using a cell disruptor at an ultrasonic amplitude of 50% for ultrasonic stirring. The dispersion after ultrasonic treatment was transferred to a microwave-assisted in-situ polymerization instrument, and the mixture was set to a microwave power of 30 watts, a medium stirring speed, and a reaction temperature of 70°C for 3 hours to generate solid particles.

[0023] Finally, the solid particles were washed with deionized water for 5 times, and vacuum dried at 60°C for 72 hours to obtain poly[2-(methacryloyloxy)ethyl]trimethylammonium bistrifluoromethylsulfonimide / modified commercial alumina nano abrasive hollow composite particles. The poly[2-(methacryloyloxy)ethyl]trimethylammonium bistrifluoromethylsulfonimide / modified commercial alumina nano abrasive hollow composite particles obtained were dispersed in silicone oil with a viscosity of 50 centistokes and a density of 0.96 g / cm 3The stirring is carried out in the silicon oil to obtain the poly[2- (methacryloyloxy) ethyl] trimethylammonium bistrifluoromethylsulfonylimide / modified commercial alumina nanometer abrasive hollow composite particle electrorheological polishing fluid.

[0024] The scanning electron microscope photo of the poly[2- (methacryloyloxy) ethyl] trimethylammonium bistrifluoromethylsulfonylimide / modified commercial alumina nanometer abrasive hollow composite particle prepared in the embodiment is shown in the figure, and it can be seen that the particle size of the hollow composite particle is 2 microns to 15 microns. Figure 1

[0025] The transmission scanning electron microscope photo of the poly[2- (methacryloyloxy) ethyl] trimethylammonium bistrifluoromethylsulfonylimide / modified commercial alumina nanometer abrasive hollow composite particle after slicing in the embodiment is shown in the figure, and it can be seen that the hollow structure of the hollow composite particle. Figure 2

[0026] The rheological curve of the poly[2- (methacryloyloxy) ethyl] trimethylammonium bistrifluoromethylsulfonylimide / modified commercial alumina nanometer abrasive hollow composite particle electrorheological polishing fluid is shown in the figure, and the maximum shear stress of the electrorheological polishing fluid gradually increases with the increase of the electric field intensity. Figure 3

[0027] The polishing result of the poly[2- (methacryloyloxy) ethyl] trimethylammonium bistrifluoromethylsulfonylimide / modified commercial alumina nanometer abrasive hollow composite particle electrorheological polishing fluid after polishing the stainless steel sheet at the electric field of 3 kV / mm and the rotating speed of 400 r / min for 4 hours is shown in the following table.

[0028] R q (nm) R a (nm) R max (nm)]]> Before polishing 311 287 266 After polishing 95 104 86

[0029] The above only describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.​​​

Claims

1. A current-rheological polishing slurry containing polyionic liquid / nanoabrasive hollow composite particles, characterized in that: The dispersed phase of the electrorheological polishing slurry containing polyionic liquid / nanoabrasive hollow composite particles is polyionic liquid / nanoabrasive hollow composite particles with commercially available nanoabrasives embedded on their surface, and the continuous phase is insulating oil. The polyionic liquid / nanoabrasive hollow composite particles are dispersed in the insulating oil to obtain the polishing slurry. The polyionic liquid / nanoabrasive hollow composite particles are prepared by microwave polymerization, and synthesized by reacting at a microwave power of 30W and a temperature of 70℃ for 3 hours.

2. The electrorheological polishing slurry containing polyionic liquid / nanoabrasive hollow composite particles according to claim 1, characterized in that: The polyionic liquid is selected from various hydrophobic polyionic liquids, including but not limited to polymethylammonium bis(trifluoromethanesulfonyl)imide, polymethylammonium bis(trifluoromethanesulfonyl)imide, polymethylammonium bis(trifluoromethanesulfonyl)imide, polymethylammonium bis(trifluoromethanesulfonyl)imide, polyvinylbenzyltrimethylammonium bis(trifluoromethanesulfonyl)imide, polyvinylbenzyltriethylammonium bis(trifluoromethanesulfonyl)imide, and polyvinylbenzyltripropylammonium bis(trifluoromethanesulfonyl)imide. One of the following: trifluoromethanesulfonylimide, polyvinylbenzyltributylammonium bistrifluoromethanesulfonylimide, polymethpropylenesulfonyltrifluoromethanesulfonylimide tetrabutylammonium, methpropylenesulfonyltrifluoromethanesulfonylimide tetrapropylammonium, methpropylenesulfonyltrifluoromethanesulfonylimide tetraethylammonium, polystyrenesulfonyltrifluoromethanesulfonylimide tetrabutylammonium, polystyrenesulfonyltrifluoromethanesulfonylimide tetrapropylammonium, and polystyrenesulfonyltrifluoromethanesulfonylimide tetraethylammonium.

3. A method for preparing the polyionic liquid / nanoabrasive hollow composite particles of claim 1, characterized in that, The process includes the following steps: Microwave polymerization is used for preparation. First, nano-abrasive particles are added to an ethanol solvent and ultrasonically dispersed. Then, under stirring, a solubilizer is added dropwise to the dispersion. After 1 hour, a silane coupling agent is added dropwise, followed by ammonia water after another 5 hours. The reaction is carried out at room temperature for 16 hours. After the reaction, excess silane coupling agent is washed away by repeated centrifugation and ultrasonic dispersion in deionized water and ethanol. The modified nano-abrasive is then freeze-dried at -50°C under vacuum to obtain the modified nano-abrasive. Next, an initiator is dissolved in an ionic liquid monomer to form a solution. The modified nano-abrasive is then mixed in an ice-water bath according to the mass ratio of the modified nano-abrasive to the ionic liquid monomer. The modified nano-abrasive was dispersed in deionized water at a ratio of 9% to 36% to form a dispersion, wherein the mass ratio of the modified nano-abrasive to the volume of deionized water was 0.9% g / mL to 3.6% g / mL. Then, the solution and dispersion were mixed together and sonicated in an ice-water bath using a cell disruptor for 15 to 30 minutes. The sonicated dispersion was then placed in a microwave synthesizer, with the stirring speed set to medium and the microwave power to 30 W, and reacted at 70°C for 3 hours to generate solid particles. Finally, the solid particles were washed with deionized water by centrifugation and vacuum dried at 40°C to 60°C for 72 to 120 hours to obtain polyionized liquid / nano-abrasive hollow composite particles.

4. The method for preparing polyionic liquid / nanoabrasive hollow composite particles according to claim 3, characterized in that, The mass of the ethanol solvent used is 40 times the mass of the nano-abrasive.

5. The method for preparing polyionic liquid / nanoabrasive hollow composite particles according to claim 3, characterized in that, The volume ratio of the silane coupling agent to the nano-abrasive is 0.01% mL / g to 10% mL / g by mass.

6. The method for preparing polyionic liquid / nanoabrasive hollow composite particles according to claim 3, characterized in that, The mass ratio of the initiator to the ionic liquid monomer is 4%.

7. A method for preparing an electrorheological polishing slurry containing polyionic liquid / nanoabrasive hollow composite particles according to claim 1, characterized in that: Dry dispersed hollow composite particles are dispersed into continuous phase insulating oil by stirring to obtain electrorheological polishing liquid, wherein the volume ratio of dispersed phase polyionic liquid / nanoabrasive hollow composite particles to continuous phase insulating oil is 10% to 30%.

8. The method for preparing the electrorheological polishing slurry containing polyionic liquid / nanoabrasive hollow composite particles according to claim 7, characterized in that: The nano-abrasive is selected from one of nano-alumina, nano-cerium oxide, and nano-zirconia.

9. The method for preparing the electrorheological polishing slurry containing polyionic liquid / nanoabrasive hollow composite particles according to claim 7, characterized in that: The insulating oil is selected from one of the following: silicone oil, hydraulic oil, lubricating oil, and mineral oil.

10. The method for preparing the electrorheological polishing slurry containing polyionic liquid / nanoabrasive hollow composite particles according to claim 7, characterized in that: The silane coupling agent is selected from one of methacryloyloxypropyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, tris(2-methoxyethoxy)vinylsilane, and allyltrimethoxysilane.

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