CN102391789B - A kind of preparation method of nano-diamond polishing liquid - Google Patents

Abstract

The invention discloses a method for preparing nano diamond polishing solution, which relates to the technical field of non-rare earth polishing material preparation, and comprises the following process steps: putting diamond micro powder, a grinding aid, a dispersing agent and deionized water into a ball mill, and carrying out wet ball milling to obtain initial slurry; adding deionized water into the initial slurry, and cleaning to obtain diamond dispersed slurry; adding concentrated acid liquor into the diamond dispersion slurry for acid treatment; cleaning the diamond dispersion slurry subjected to acid treatment, adding a dispersing agent, and grading to obtain the diamond dispersion slurry; the nano-diamond polishing solution prepared by the method is suitable for precision grinding and polishing of liquid crystal conductive glass, planar optical glass, optical spherical surfaces, optical lens glass, optical filters, filter windows and glass disc substrates, and is particularly suitable for grinding and polishing of soft spherical glass.

Description

A kind of preparation method of nano-diamond polishing liquid

technical field

The invention relates to the technical field of preparation of non-rare earth polishing materials in the technical field of new materials, and is applied in the technical field of precision grinding and polishing, in particular to a preparation method of nano-diamond polishing liquid.

Background technique

Nanodiamond has the dual characteristics of both nanomaterials and superhard materials, and its excellent mechanical, chemical, optical, electrical, and thermal properties have broad application prospects in the fields of running-in oil, composite coating, ultra-precision polishing, chemistry/medicine, etc. The coarsest particle size of a single nano-diamond particle is only 60nm, and the average particle size is 8-12nm. However, the average particle size of commercial nano-diamond particles is above 2μm, the coarsest is 10μm, and the degree of agglomeration is as high as 200-1000. The existence of agglomerates may be due to the hard agglomerates formed by the carbon droplets formed by the detonation ultra-high temperature and high pressure during the cooling process, and may also be due to the formation of interparticles during the post-treatment drying and dehydration of detonation products. Secondary hard aggregates formed by oxygen bridge bonds, etc. The hard agglomerates of nanodiamonds occupy a considerable proportion and have a certain texture tendency, so it is quite difficult to disaggregate. Hard agglomerates restrict the application and development of nano-diamond, and almost lose the excellent performance of nano-diamond. Therefore, the deagglomeration of hard agglomerates is the primary problem to be solved in the application of nano-diamond, and it is also an important problem to be solved in the preparation of nano-diamond polishing solution. In the prior art, for the depolymerization of hard aggregates of nano-diamonds, chemical-mechanical treatment is usually used to modify the surface of nano-diamonds. Under the synergistic effect of physical and chemical reagents, the hydrophilic and hydrophobic properties of the particle surface are adjusted to achieve The purpose of stable dispersion in water. Chinese patent (application number 200410022936.0) "a water-based nano-diamond polishing liquid and its manufacturing method", its main components include: nano-diamond, modifier, dispersant and/or hyperdispersant, pH regulator, wetting Regulators, additives with chemical effects and deionized water; its manufacturing method mainly includes: 1. Through mechanochemical modification, the agglomerates of nano-diamonds are dispersed into small aggregates with an average particle size of 20-100nm; 2. Coarse particles and other impurities in the suspension; 3. Add regulators (wetting agents), dispersion stabilizers, pH value regulators, additives with chemical effects and deionized water to adjust the wetting characteristics of the workpiece and polishing fluid, ultrasonic Or/and stir to disperse. Another example is Chinese patent (application number 200510030024.2) "water-based diamond polishing liquid and preparation method thereof", which discloses a water-based diamond polishing liquid, which is composed of the following components in parts by weight: special diamond powder: 0.001- 10. Dispersant: 0.02-4 parts, suspending agent: 0.01-5 parts, suspension aid: 0.01-1 part, PH regulator: 0.1-1.5 parts, preservative: 0.1-0.5 parts, deionized water: 60- 99 parts; the water-based diamond polishing liquid prepared by the invention has consistent product quality and good stability.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing a nano-diamond polishing liquid that can not only solve the problem of nano-diamond agglomeration, but also enable it to be stably suspended in a water base, and has a relatively simple process.

The technical scheme that the present invention takes is to invent a kind of preparation method of nano-diamond polishing liquid, and its technological process is as follows:

A. Take 5-20 parts of diamond powder with a particle size of 0.1-1 μm, 2-8 parts of grinding aid, 2-8 parts of dispersant, and 100 parts of deionized water by weight, and put them into a ball mill, using water as the medium , carry out wet ball milling, the ball milling time is 1-10 hours, the ball mill speed is 200-500r/min, and become the initial slurry;

B, get the deionized water of 600 parts by weight again, join in the initial slurry in the ball mill, clean out the diamond dispersion slurry, standby;

C. Stir the spare diamond dispersion slurry vigorously, and add 0.5-200 parts by weight of concentrated acid solution to the diamond dispersion slurry while stirring, and carry out acid treatment. The time is 30-60 minutes, and the temperature is 20～ 100°C;

D. Clean the diamond dispersion slurry after the acid treatment by centrifugal sedimentation method, then add 1-10 parts by weight of dispersant, adjust the pH value to 9-10 with 0.1mol/L NaOH solution, and then carry out Grading, the nano-diamond polishing liquid with high suspension stability in water can be obtained, wherein the weight percentage of diamond is 0.1-10, and the particle size of diamond is 10-100nm;

Described grinding aid can be one or two or several or all combinations in oleic acid, sodium tripolyphosphate, polyethylene glycol, sodium lauryl sulfate; When a combination of one or all of them is used, the dosage of each component is an equal part;

The dispersant can be one or two of sodium hexametaphosphate, sodium tripolyphosphate, OP-10, sodium lauryl sulfate, cetyltrimethylammonium bromide, TW-80 or A combination of several or all of them; when it is a combination of two or several or all of them, the amount of each component is an equal part;

The concentrated acid solution can be concentrated hydrochloric acid, concentrated sulfuric acid, concentrated nitric acid or a combination of two or three; when it is a combination of two or three of them, the amount of each component is equal.

The particle size of the preferred diamond micropowder is 0.3-0.5 μm.

The preferred ball milling time is 3-6 hours.

The best ball milling time is 5 hours.

The optimum acid treatment temperature is 70°C.

The best ball mill speed is 300r/min.

The weight share unit used above may be gram, kilogram or ton, or other weight units.

The preparation method of the nano-diamond polishing liquid of the present invention adopts the method of chemical mechanical treatment, and adopts three main steps of ball milling to disaggregate, pickling to remove impurities and dispersing and classifying. A nano-diamond polishing fluid in which nano-diamonds are stably suspended in a water base is obtained.

Detailed ways

Below in conjunction with embodiment, the present invention will be further described. The following description is by way of example, but the protection scope of the present invention should not be limited thereto.

Embodiment one:

The preparation process of the present embodiment is as follows:

A, getting particle diameter by weight share is 10 grams of commercially available diamond micropowder of 0.5 μ m, polyethylene glycol (grinding aid can adopt oleic acid, sodium tripolyphosphate, polyethylene glycol, sodium lauryl sulfate One or two or several or all combinations, this example adopts polyethylene glycol as grinding aid) 5 grams, OP-10 (dispersant can adopt sodium hexametaphosphate, sodium tripolyphosphate, OP-10, Sodium lauryl sulfate, hexadecyltrimethylammonium bromide, TW-80 in one or two or a combination of several or all, this example uses OP-10 as a dispersant) 5 grams, to 100 grams (i.e.: 100ml) of ionized water is placed in the ball mill tank of the high-energy ball mill, and water is used as the medium to carry out wet ball milling. The ball milling time is 5 hours, and the ball mill rotating speed is 300r/min to become the initial slurry;

B, get 600 grams (that is: 600ml) deionized water again, join in the initial slurry in the ball mill jar, clean out the diamond dispersion slurry, set aside;

C. Stir vigorously the spare diamond dispersion slurry, and add 10 grams of concentrated hydrochloric acid to the diamond dispersion slurry while stirring, and carry out acid treatment for 30 minutes at a temperature of 70°C;

D. Clean the diamond dispersion slurry after the acid treatment by centrifugal sedimentation, then add 15 grams of sodium tripolyphosphate (the dispersant can be sodium hexametaphosphate, sodium tripolyphosphate, OP-10, dodecane Sodium sulfate, cetyltrimethylammonium bromide, TW-80, one or two or a combination of several or all, this example uses sodium tripolyphosphate as a dispersant), with 0.1mol/L NaOH solution to adjust the pH value of the slurry to 9, and obtain a nano-diamond polishing solution with a diamond particle size of 10-100 nm after classification.

Embodiment two:

The preparation process of the present embodiment is as follows:

A, get particle diameter by weight and be 10 grams of commercially available diamond micropowder of 0.5 μm, polyethylene glycol 5 grams, OP-10 5 grams, deionized water 100 grams (that is: 100ml), put into the ball mill jar of high-energy ball mill In the process, using water as the medium, carry out wet ball milling, the ball milling time is 5 hours, the ball mill speed is 300r/min, and become the initial slurry;

B, get 600 grams (that is: 600ml) deionized water again, join in the initial slurry in the ball mill jar, clean out the diamond dispersion slurry, set aside;

C. Stir the spare diamond dispersion slurry vigorously, and add 10 grams of concentrated sulfuric acid to the diamond dispersion slurry while stirring, and carry out acid treatment for 30 minutes at a temperature of 70°C;

D, the diamond dispersion slurry after the acid treatment is cleaned (centrifugal sedimentation method cleaning), adds 15 grams of sodium tripolyphosphate, adjusts the pH value of the slurry to 9 with the NaOH solution of 0.1mol/L, and obtains after classification The particle diameter of diamond is nano-diamond polishing liquid of 10-100nm.

Embodiment three:

The preparation process of the present embodiment is as follows:

A, get particle diameter by weight and be 10 grams of commercially available diamond micropowder of 0.5 μm, polyethylene glycol 5 grams, OP-10 5 grams, deionized water 100 grams (that is: 100ml), put into the ball mill jar of high-energy ball mill In the process, using water as the medium, carry out wet ball milling, the ball milling time is 5 hours, the ball mill speed is 300r/min, and become the initial slurry;

B, get 600 grams (that is: 600ml) deionized water again, join in the initial slurry in the ball mill jar, clean out the diamond dispersion slurry, set aside;

C. Stir vigorously the spare diamond dispersion slurry, and add 10 grams of concentrated nitric acid to the diamond dispersion slurry while stirring, and carry out acid treatment for 30 minutes at a temperature of 70°C;

D, the diamond dispersion slurry after the acid treatment is cleaned (centrifugal sedimentation method cleaning), adds 15 grams of sodium tripolyphosphate, adjusts the pH value of the slurry to 9 with the NaOH solution of 0.1mol/L, and obtains after classification The particle diameter of diamond is nano-diamond polishing liquid of 10-100nm.

Applying the preparation method of the nano-diamond polishing liquid of the present invention, the prepared nano-diamond polishing liquid is suitable for precision grinding of liquid crystal conductive glass, flat optical glass, optical sphere, optical lens glass, optical filter, filter window and glass disc substrate Polishing, especially suitable for grinding and polishing soft spherical glass.

Claims (6)

1. a preparation method of nano-diamond polishing liquid, is characterized in that technological process is as follows: A. Take 5-20 parts of diamond powder with a particle size of 0.1-1 μm, 2-8 parts of grinding aid, 2-8 parts of dispersant, and 100 parts of deionized water by weight, and put them into a ball mill, using water as the medium , carry out wet ball milling, the ball milling time is 1-10 hours, the ball mill speed is 200-500r/min, and become the initial slurry; B, get the deionized water of 600 parts by weight again, join in the initial slurry in the ball mill, clean out the diamond dispersion slurry, standby; C. Stir the spare diamond dispersion slurry vigorously, and add 0.5-200 parts by weight of concentrated acid solution to the diamond dispersion slurry while stirring, and carry out acid treatment. The time is 30-60 minutes, and the temperature is 20～ 100°C; D. Clean the diamond dispersion slurry after acid treatment by centrifugal sedimentation method, then add 1-10 parts by weight of dispersant, adjust the pH value to 9-10 with 0.1mol/L NaOH solution, and then classify , the nano-diamond polishing liquid with high suspension stability in water can be obtained, wherein the weight percentage of diamond is 0.1-10, and the particle size of diamond is 10-100nm; The grinding aid is a combination of one or two or several or all of oleic acid, sodium tripolyphosphate, polyethylene glycol, and sodium lauryl sulfate; when two or more of them or all combinations, the amount of each component is equal; The dispersant is one or two or more of sodium hexametaphosphate, sodium tripolyphosphate, OP-10, sodium lauryl sulfate, cetyltrimethylammonium bromide, TW-80 A combination of one or all of them; when it is a combination of two or more or all of them, the amount of each component is an equal part; The concentrated acid solution is one or a combination of two or three of concentrated hydrochloric acid, concentrated sulfuric acid, and concentrated nitric acid; when it is a combination of two or three of them, the amount of each component is equal. 2. The preparation method of nano-diamond polishing liquid according to claim 1, characterized in that: the particle diameter of the diamond micropowder is 0.3-0.5 μm. 3. The preparation method of nano-diamond polishing liquid according to claim 1, characterized in that: the ball milling time is 3 to 6 hours. 4. The preparation method of the nano-diamond polishing liquid according to claim 1 or 3, characterized in that: the ball milling time is 5 hours. 5. The preparation method of nano-diamond polishing liquid according to claim 1, characterized in that: the temperature during acid treatment is 70°C. 6. The preparation method of nano-diamond polishing liquid according to claim 1, characterized in that: the ball mill rotating speed is 300r/min.