The dense salt medium legal system of inertia is equipped with the method for nano-powderTechnical field the present invention relates to a kind of method for preparing nano-powder with the precipitator method.
The background technology liquid-phase precipitation method is a kind of method comparatively commonly used in the preparation nano-powder, and its advantage is to need not harsh physical condition, just may obtain the more excellent nano-powder of performance.It is the material of different chemical composition to be mixed to produce precipitation under solution state, to produce nanoparticle product or presoma throw out.The product throw out washs with the washing composition that contains dispersion agent, filtration then, the dry nano-powder material that gets; The presoma throw out carries out drying, pulverizing, thermolysis after the filtration, cool off then, with the washing composition that contains dispersion agent wash, filter, dry nano-powder material.
The precipitator method can be divided into direct precipitation method, the indirect precipitator method, hydrolytic precipitation method etc. again by its characteristics.
Direct precipitation method is under certain conditions, in comprising one or more ionic soluble salt solution, add precipitation agent and dispersion agent, directly generate precipitation, from solution, separate out, foreign ion is removed, and operations such as throw out drying, thermolysis make nano-powder.Because the precipitation agent that adds can not be scattered in the whole solution in moment, cause nucleation, grow up, sedimentary process is difficult to control, heterogeneous nucleation easily takes place, and makes the powder granularity that makes inhomogeneous.
Indirectly the precipitator method also are sluggish precipitation, be utilize a certain chemical reaction make configurational ion in the solution from the solution that contains dispersion agent lentamente, discharge equably, other step is identical with direct precipitation method.In reaction process, the precipitation agent that adds is not to react with precipitated component at once, but precipitation agent is slowly separated out in whole solution by chemical reaction, it is more even to make that configurational ion distributes in whole solution, so sedimentary uniform particles and densification, be convenient to filter and washing, product granularity is little, narrowly distributing, reunion are little.
The hydrolytic precipitation method is to utilize alkoxide in water hydrolysis can take place fast, forms precipitation of hydroxide, more after filtration, processes such as drying, roasting prepare nano-powder.Existing more than the 30 kind of element of the hydrolyzable metal alkoxide of having developed at present.The outstanding advantage of this method is the reaction conditions gentleness, and is simple to operate.But raw materials cost is higher, and its application is subjected to certain limitation.
More than the key of three kinds of precipitator method be how to promote sedimentary generating rate, suppress sedimentary growth velocity, prevent sedimentary secondary aggregation, people have summed up many effective successful experience, and continuing to explore new method, as " a kind of precipitator method prepare ultra-fine nano-powder technology continuously " (patent No. application number 03113326), be that material is reinforced to reactor simultaneously with speed by a certain percentage through measurement charging device, in certain temperature, under the stir speed (S.S.), after mixing the generation nucleation, enter nucleus rapidly and become long tube, under the effect of mixing of materials device, push ahead, finally become the pipe end outlet of long tube to collect suspension through suitably getting ultra-fine nano-powder after the drying at nucleus.Controlling factors such as the proportioning by adjusting reactor becomes long tube with nucleus temperature, reaction mass respectively, feed rate, stir speed (S.S.) realize the control to grain size.This invention can make precipitin reaction carry out continuously, with the nucleation process in the precipitin reaction and process of growth separately, nucleation, is grown in formation metastable environment under, the grain diameter that generates can obtain regulation and control, the particulate monodispersity is good, narrowly distributing, and pattern difference is little." a kind of technology for preparing nano-powder " (patent No. application number 01142821), adopt following steps: two kinds of reactants are formed the high speed fluid by the pressurization back, two kinds of high-velocity fluids carry out moment by certain angle to be mixed, in mixing process, react, generate the solid slip, the solid slip that reaction is generated separates with reaction mass, keeps the concentration unanimity of reaction mass in the reaction process, and then control generates particle grain size.The solid matter that reaction is obtained carries out obtaining nano-powder or dried powder is carried out roasting obtaining nano-powder after the drying.This technology is applicable to the preparation of metal oxide, metal hydroxides, insoluble metal-salt, nonmetal oxide nano-powder.
Summary of the invention the objective of the invention is at above-mentioned present situation, aims to provide the sedimentary growth velocity of the simple and effective inhibition of a kind of energy and prevents that the dense salt medium legal system of inertia of sedimentary secondary aggregation is equipped with the method for nano-powder.
The implementation of the object of the invention is, the dense salt medium legal system of inertia is equipped with the method for nano-powder, the material that will react is dissolved in respectively in the saturated solution of one or more indifferent salts compositions earlier, then under agitation with the reactant hybrid reaction, the product throw out that reaction is produced after filtration, wash the dense salt of most inertia with the washing composition that contains dispersion agent, drying obtains nano-powder material maybe will react the product precursor throw out that produces, carry out drying, pulverizing, thermolysis after filtering, then through cooling, washing, filtration, the dry nano-powder material that gets.
Salt in the dense salt of inertia is meant under preparation condition and does not react with reactant, product and solvent, and energy stable existence in reaction, can be dissolved in the inorganic or organic salt of a class in the solvent that carries out of reaction one or more, when generating the presoma throw out, this salt does not react with the presoma throw out yet.
Present method can be simple and effective the sedimentary growth velocity of inhibition and prevent sedimentary secondary aggregation.Present method is applicable to the preparation of nano-powders such as metal oxide, metal hydroxides, insoluble metal-salt, nonmetal oxide.
Embodiment the present invention is that the material that will react dissolves respectively in the solution of inert high salt concentration composition, then under agitation with the reactant hybrid reaction, the product throw out that reaction is produced after filtration, wash the dense salt of most inertia with the washing composition that contains dispersion agent, drying obtains nano-powder material, maybe will react the product precursor throw out that produces, carry out drying, pulverizing, thermolysis after filtering, then through cooling, filtration washing, the dry nano-powder material that gets.
The sedimentary generating mode of the present invention comprises direct precipitation method, the indirect precipitator method, hydrolytic precipitation method.
Salt in the dense salt of inertia is meant under preparation condition and do not react with reactant, product and solvent, and can stable existence in reaction, can be dissolved in the inorganic or organic salt of a class in the solvent that reaction carries out one or more.
In generating the sedimentary reaction of presoma, salt in the dense salt of inertia is meant under preparation condition and does not react with reactant, presoma throw out, product and solvent, and can stable existence in reaction, can be dissolved in the inorganic or organic salt of a class in the solvent that reaction carries out one or more.
Salt in the dense salt of above-mentioned inertia is NaCl and KCl, that is to say that with NaCl and KCl be first-selection.
The product that obtains with the inventive method comprises metal oxide, metal hydroxides, insoluble metal-salt, nonmetal oxide etc.
Enumerate embodiments of the invention below:
Example 1: the preparation of nanometer Basic Chrome Sulphate:
Get 50gCuSO45H2O is dissolved in the 100ml water, progressively adds solid NaCl under the room temperature condition until saturated, and meter consumes 144gNaCl.Other gets 8gNaOH and is dissolved in the 100ml water, also progressively adds solid NaCl until saturated after being cooled to room temperature, and meter consumes 35gNaCl.Fully stir down NaOH solution is joined CuSO4In the solution, when adding to the reaction metering, obtain blue-greenish colour Basic Chrome Sulphate nanometer slurry.Vacuum filtration, filter cake concentration are the solution washing 3～4 times of 0.3% sodium polyphosphate, and obtaining Basic Chrome Sulphate is the nanometer slurry of main body, the about 40nm of Basic Chrome Sulphate particle diameter.Use absolute ethanol washing at last 2 times as filter cake,, then obtain the Basic Chrome Sulphate nano-powder in 50 ℃ of following vacuum-dryings 3 hours.
The preparation of example 2 nano zine oxides:
Get anhydrous 21.2gNa2CO3, after the adding distil water 100ml stirring and dissolving, progressively adding the 26.5g solid sodium chloride and make its dissolving, the saturated solution when making 30 ℃ takes by weighing 27.2gZnCl2, add water 100ml dissolving, progressively add the saturated solution of 58g solid sodium chloride when making 30 ℃.Under the vigorous stirring with Na2CO3Solution joins ZnCl2In the solution, react the after-filtration that finishes, presoma is dry down in 105 ℃, pulverize the oven dry back, insert in the retort furnace, calcination is 3 hours under 300 ℃ of temperature, takes out to be the aqueous solution soaking of 0.3% sodium polyphosphate and to wash 3～4 times with concentration, sodium-chlor is removed in dissolving, use absolute ethanol washing at last 2 times, throw out promptly obtains the nano ZnO powder that loosens in 50 ℃ of following vacuum-dryings 3 hours, content 98.5%, granularity 15～20nm.
Example 3 nanometer Sb2O3The preparation of powder:
The saturated solution 1500ml of preparation NaCl is standby under the room temperature, and it is standby that other prepares 3 ‰ tripoly phosphate sodium STPP dispersion liquid.
Take by weighing the 106g antimonous sulfate and place the beaker of 2000ml, stir down and slowly adds saturated nacl aqueous solution until 1500ml, continue to stir 30 minutes, it is complete to make it hydrolysis.Centrifugation, precipitation changes in the 2000ml beaker, adds 3 ‰ the about 300ml of tripoly phosphate sodium STPP dispersion agent, is warming up to boiling, and gradation adds 30% ammoniacal liquor 142ml, and is incubated to Sb2O3Generate fully.Centrifugal settling is the solution washing precipitation 3～4 times of 0.3% sodium polyphosphate with concentration.Use methanol wash at last 2 times, vacuum-drying promptly obtains Sb in 50-60 ℃ of temperature range2O3Nanocrystalline, particle diameter 20～30nm.
Example 4 nanometer Mg (OH)2The preparation of powder:
Take by weighing 101.6gMgCl26H2O adds deionized water 500mL in the 1000mL beaker, stir down and add sodium-chlor to saturated standby, and meter consumes sodium-chlor 180g.The strong aqua 76mL of measuring 17mol/L is in the 2000mL beaker, be diluted to 300mL, add sodium-chlor to saturated, meter consumes sodium-chlor 114g, speed change stirrer stirring rake is inserted and adjusts highly and stirring velocity, be warmed up to about 60 ℃, under violent stirring, change over to magnesium chloride solution in the ammoniacal liquor slowly, violent stirring 60min after transfer finishes continues to stir 1 hour under this temperature then.Improve and also to keep temperature to 90 ℃ slowly to stir 2 hours, high speed centrifugation separates, and is 11 weak ammonia agitator treating and centrifugation to contain 0.3% stearic acid, pH value, so repeats 3 times.Use absolute ethanol washing at last 2 times, change in the furnace pot, place vacuum drying oven in 50 ℃ of following vacuum-dryings 3 hours, the white Mg (OH) that obtains loosening2Nano-powder, the about 30nm of particle diameter.