CN101538067B - Method for chemically synthesizing potassium sodium niobate nano-powder - Google Patents

Abstract

The invention discloses a method for chemically synthesizing potassium sodium niobate nano-powder, comprising the following steps of mixing sodium ethoxide (NaOCH2CH3), potassium ethoxide (KOCH2CH3) and columbium ethoxide (Nb[OCH2CH3]5) by the following stoichiometric ratio of Na0.5K0.5NbO3; and hydrolyzing in a micro-emulsion, carrying out heat treatment, and finally preparing the potassium sodium niobate nano-powder with the grain dimension less than 20 nanometers. The potassium sodium niobate nano-powder prepared by the method has fine grain and uniform distribution of grain size and meetsthe requirement of different electronic ceramic fields; and the method is simple, energy-saving and exhaust-reducing, has low cost and is suitable for batch production.

Description

A kind of chemical synthesis process of potassium-sodium niobate nano-powder

Technical field

The present invention relates to a kind of chemical synthesis process of potassium-sodium niobate nano-powder, belong to field of chemical engineering.

Background technology

Adopt chemical process to prepare the inorganic salt nano-powder is a very effective method always.It is lithium sodium kalium niobate powder about 20 nanometers that document " ChaoWang; Yudong Hou; Haiyan Ge; Sol-gel synthesis and characterization oflead-free LNKN nanocrystalline powder, Journal of Crystal Growth 310 (2008) 4635-4639 " adopts sol-gel process to prepare median size.But the method raw material that is adopted in the document is handled very complicated and with high costs in earlier stage, and the powder calcination temperature in later stage is than higher, not only bad for industrial and large-scale production, does not also have great advantage on the simplification of technology and energy consumption cost.

Summary of the invention

Purpose of the present invention is exactly to prepare the production cost of potassium-sodium niobate nano-powder and simplify preparation technology in order to reduce sol-gel method, adopt a kind of microemulsion system, in this individual system, the small globule is uniformly distributed in the oil phase, add after the presoma, droplet is as the container of chemical reaction, and the powder of reaction gained is through low-temperature heat treatment, just can obtain narrow size distribution, nano particle that the reunion degree is little.Prepare the potassium-sodium niobate nano-powder of particle size by this method less than 20 nanometers.

Concrete steps are:

(1) with sodium ethylate (NaOCH ₂CH ₃), potassium ethylate (KOCH ₂CH ₃), ethanol niobium (Nb[OCH ₂CH ₃] ₅), be Na by stoichiometric ratio _0.5K _0.5NbO ₃Batching is dissolved in the dehydrated alcohol;

(2) with mass percent be 10～20% alkylphenol polyoxyethylene, mass percent is 4～12% propyl carbinol, mass percent is that 60～90% hexanaphthene and mass percent are that 5～15% pure water is mixed with water/oil type microemulsion system, each component concentration sum is 100%, and temperature remains on 20～30 ℃;

(3) solution that step (1) is made stirs while dripping with in 2～6 droplets/minute microemulsions that slowly are added drop-wise to step (2), and stirring velocity is 40～120 rev/mins, and restir is 1～3 hour after dropwising, and leaves standstill then 4～10 hours; The powder of washing precipitation, and thermal treatment under 200～600 ℃ of temperature 1～3 hour;

(4) use X-ray diffractometer to detect thing phase, the crystalline structure of step (3) gained powder, calculate grain-size;

(5) use laser particle size analyzer and transmission electron microscope to detect the particle size of step (3) gained powder.

The invention has the beneficial effects as follows: adopted microemulsion system as the chemical reaction carrier, the small globule is dispersed in the oil based system, forms a kind of stable microemulsion liquid system.The presoma that contains sodium, potassium and niobium joins in the microemulsion system, can enter into the globule at once, and the globule through hydrolysis reaction, just can obtain containing the compound of sodium, potassium and niobium as the container of a chemical reaction at this moment.Because reaction vessel is very small, therefore the compound particle that forms is also very tiny.Compound just can obtain the uniform nano-powder of particle size distribution after Overheating Treatment, microemulsion system can reclaim again and utilize.The present invention has effectively reduced the technological process and the production cost of chemosynthesis nanometer potassium-sodium niobate powder, greatly reduce energy consumption and environmental pollution, successful preparation 20 nanometers potassium-sodium niobate nano-powders once, for reduce the pottery sintering temperature and the preparation nano ceramics strong assurance is provided.

Description of drawings

Fig. 1 is the grain-size of the potassium-sodium niobate powder of different heat treatment temperature of the present invention.

Fig. 2 is the X ray collection of illustrative plates of potassium-sodium niobate powder of the present invention.

Fig. 3 is a potassium-sodium niobate powder TEM photo of the present invention.

Embodiment

Embodiment 1:

Sodium ethylate (NaOCH with the analytical pure level ₂CH ₃), potassium ethylate (KOCH ₂CH ₃), ethanol niobium (Nb[OCH ₂CH ₃] ₅) (laboratory oneself preparation), be Na by stoichiometric ratio _0.5K _0.5NbO ₃Batching, three kinds of material dissolutions are in dehydrated alcohol; With mass percent 8% alkylphenol-polyethenoxy (10) ether (OP-10), mass percent is 6% propyl carbinol, mass percent is that 80% hexanaphthene and mass percent are that 4% pure water is mixed with water/oil type microemulsion system, and temperature remains on 25 ℃; The ethanolic soln that will contain sodium, potassium and niobium slowly is added drop-wise in the microemulsion system with 4 droplets/minute, stirs while dripping, and stirring velocity is 80 rev/mins, and restir is 1 hour after dropwising, and leaves standstill then 5 hours; The powder of washing precipitation, and 300 ℃ of thermal treatments 1 hour.Use X-ray diffraction to differentiate the thing phase of powder, crystalline structure and calculating grain-size; Use transmission electron microscope and laser particle size analyzer to measure the particle size of powder.Fig. 1 has provided the average grain size of 300 ℃ of heat treated potassium-sodium niobate powders, about 11 nanometers (calculating) by the X ray collection of illustrative plates, and provided the average grain size of the potassium-sodium niobate powder of other thermal treatment temps.

Embodiment 2:

Sodium ethylate (NaOCH with the analytical pure level ₂CH ₃), potassium ethylate (KOCH ₂CH ₃), ethanol niobium (Nb[OCH ₂CH ₃] ₅) (laboratory oneself preparation), be Na by stoichiometric ratio _0.5K _0.5NbO ₃Batching, three kinds of material dissolutions are in dehydrated alcohol; With mass percent 10% alkylphenol-polyethenoxy (10) ether (OP-10), mass percent is 10% propyl carbinol, mass percent is that 70% hexanaphthene and mass percent are that 10% pure water is mixed with water/oil type microemulsion system, and temperature remains on 25 ℃; The ethanolic soln that will contain sodium, potassium and niobium slowly is added drop-wise in the microemulsion system with 6 droplets/minute, stirs while dripping, and stirring velocity is 100 rev/mins, and restir is 1 hour after dropwising, and leaves standstill then 8 hours; The powder of washing precipitation, and 200 ℃ of thermal treatments 1 hour.Use X-ray diffraction to differentiate the thing phase of powder, crystalline structure and calculating grain-size; Use transmission electron microscope and laser particle size analyzer to measure the particle size of powder.Fig. 2 has provided the X ray collection of illustrative plates of 200 ℃ of heat treated potassium-sodium niobate powders, and calculating grain-size is 18 nanometers.

Embodiment 3:

Sodium ethylate (NaOCH with the analytical pure level ₂CH ₃), potassium ethylate (KOCH ₂CH ₃), ethanol niobium (Nb[OCH ₂CH ₃] ₅) (laboratory oneself preparation), be Na by stoichiometric ratio _0.5K _0.5NbO ₃Batching, three kinds of material dissolutions are in dehydrated alcohol; With mass percent 5% alkylphenol-polyethenoxy (10) ether (OP-10), mass percent is 5% propyl carbinol, mass percent is that 85% hexanaphthene and mass percent are that 5% pure water is mixed with water/oil type microemulsion system, and temperature remains on 25 ℃; The ethanolic soln that will contain sodium, potassium and niobium slowly is added drop-wise in the microemulsion system with 4 droplets/minute, stirs while dripping, and stirring velocity is 80 rev/mins, and restir is 1 hour after dropwising, and leaves standstill then 6 hours; The powder of washing precipitation, and 300 ℃ of thermal treatments 1 hour.Use X-ray diffraction to differentiate the thing phase of powder, crystalline structure and calculating grain-size; Use transmission electron microscope and laser particle size analyzer to measure the particle size of powder.Fig. 3 has provided transmission electron microscope (TEM) photo of 300 ℃ of heat treated potassium-sodium niobate powders, and average grain size is 15 nanometers as can be seen.

Claims (1)

1. the chemical synthesis process of a potassium-sodium niobate nano-powder is characterized in that concrete steps are:

(1), be Na by stoichiometric ratio with sodium ethylate, potassium ethylate, ethanol niobium _0.5K _0.5NbO ₃Batching is dissolved in the dehydrated alcohol;

(2) with mass percent be 10～20% alkylphenol polyoxyethylene, mass percent is 4～12% propyl carbinol, mass percent is that 60～90% hexanaphthene and mass percent are that 5～15% pure water is mixed with water/oil type microemulsion system, each component concentration sum is 100%, and temperature remains on 20～30 ℃;

(3) solution that step (1) is made stirs while dripping with in 2～6 droplets/minute microemulsions that slowly are added drop-wise to step (2), and stirring velocity is 40～120 rev/mins, and restir is 1～3 hour after dropwising, and leaves standstill then 4～10 hours; The powder of washing precipitation, and thermal treatment 1～3 hour under 200～600 ℃ of temperature;

(4) use X-ray diffractometer to detect thing phase, the crystalline structure of step (3) gained powder, calculate grain-size;

(5) use laser particle size analyzer and transmission electron microscope to detect the particle size of step (3) gained powder.

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