CN101891460B

CN101891460B - Preparation of calcium copper titanium oxide compound powder by sol-gel method

Info

Publication number: CN101891460B
Application number: CN201010223385XA
Authority: CN
Inventors: 刘来君; 吴枚霞; 方亮; 胡长征; 覃爱苗
Original assignee: Guilin University of Technology
Current assignee: Guilin University of Technology
Priority date: 2010-07-08
Filing date: 2010-07-08
Publication date: 2012-10-31
Anticipated expiration: 2030-07-08
Also published as: CN101891460A

Abstract

The invention discloses a method for preparing calcium copper titanium oxide compound powder by a sol-gel method. Tetrabutyl titanate, copper nitrate, and calcium nitrate are mixed according to the stoichiometric ratio of CaCu ₃ Ti ₄ O ₁₂ , and after the process of solution preparation, sol formation, gel formation, gel drying and heat treatment, the final preparation is uniform and dispersed. Calcium copper titanium oxide compound powder with good properties and pure phase. The method of the invention greatly improves the composition uniformity of the calcium copper titanium oxide compound, saves the production cost, and reduces the synthesis temperature of the material, thereby providing technical guarantee for preparing high-performance giant dielectric materials and pressure-sensitive materials.

Description

Sol-gel method prepares calcium copper titanium oxide powder

Technical field

The present invention relates to sol-gel method and prepare calcium copper titanium oxide powder, belong to the powder preparing technical field.

Background technology

The CaCu of calcium titanium ore structure ₃Ti ₄O ₁₂Have very large specific inductivity (ε～10 ⁴-10 ⁶) and lower loss (tan δ～0.03), particularly (100-600K) specific inductivity is almost constant in very wide warm area scope.These good comprehensive performances might become it and in a series of high-technology fields such as high density energy storage, thin-film device (like MEMS, GB-DRAM), high dielectric capacitor and voltage dependent resistor, obtain to use widely.But prepare well behaved CaCu ₃Ti ₄O ₁₂Product must have the CaCu of uniform component ₃Ti ₄O ₁₂Powder.And utilize traditional ceramic powder preparation method, be difficult to the good powder of obtained performance.Document " Yang Changhui, Zhou Xiaoli, Xu Gang, Han Gaorong, Weng Wenjian, Du Piyi, Prepared by Sol Gel Method huge dielectric constant material C aCu ₃Ti ₄O ₁₂, silicate journal, 2006,34 (6): 753-756 " and the CaCu that adopted Prepared by Sol Gel Method ₃Ti ₄O ₁₂Powder, but because it selects calcium acetate to cause the glacial acetic acid that increases greatly, selects of raw materials cost to cause technological process that human body and environmental damage calcination time big, 6～10 hours have been caused the energy consumption increase as catalyzer as the calcium source.Therefore must improve this method, so that it is practice thrift cost, energy-saving and cost-reducing.

Summary of the invention

In order to overcome the problem that raw material is with high costs in the prior art, environmental pollution is excessive and calcining temperature is too high, the purpose of this invention is to provide a kind of improvement sol-gel method and prepare CaCu ₃Ti ₄O ₁₂Powder, prepared powder uniform component, good dispersivity, thing are compared pure.The inventive method has improved CaCu greatly ₃Ti ₄O ₁₂Homogeneity of ingredients, reduced the cost of raw material and to the pressure of environment, thereby technical guarantee is provided for the high performance huge dielectric materials of preparation and pressure sensitive.

Concrete steps are:

(1) with analytical pure nitrocalcite and analytical pure cupric nitrate, be 1: 3 batching in molar ratio, be dissolved in the ethylene glycol monomethyl ether, the ethylene glycol monomethyl ether quality is 1～15 times of raw materials quality, makes uniform solution;

(2) be benchmark with the amount that adds nitrocalcite in the step (1), with analytically pure butyl(tetra)titanate, with Ca: the Ti mol ratio is 1: 4 batching, is dissolved in methyl alcohol or the ethanol, and methyl alcohol or ethanol volume are 1～15 times of butyl(tetra)titanate volume, make the solution of homogeneous;

(3) solution that step (1) is made joins in the solution of step (2), and adding speed is per second 1-5～30 milliliter, and stir on impouring limit, limit, and stirring velocity is 30～180 rev/mins, and restir was 0.1～2 hour after impouring finished, and obtained uniform sol;

(4) in the colloidal sol of step (3) gained, drip the water-reducible ethanol of de-ionized; Wherein the deionized water volume is 0.2～2.0 times of ethanol volume; The volume that drips is 1～20% of a sol volume, stirs while dripping, and stirring velocity is 20～120 rev/mins; Churning time is 0.2～5 hour, obtains gel;

(5) O.3-10 step (4) gained gel is left standstill hour, thermal treatment is 1～3 hour under 500～1100 ℃ of temperature, obtains the CaCu of cube phase ₃Ti ₄O ₁₂Powder;

Step (1), (2), (3) and (4) are in air or be full of in the glove box of drying nitrogen or dry inert gas and carry out.

The invention has the beneficial effects as follows: substituted the calcium acetate of expensive with cheap nitrocalcite, reduced production cost; Need not to use catalyzer in the preparation engineering, reduced the pressure of production technique environment; Soaking time in the calcination process significantly reduces, and has reduced energy consumption effectively.The present invention simplified the Prepared by Sol Gel Method calcium copper titanium oxide powder preparation technology, greatly reduce cost and reduced pollution environment, successful preparation uniform component, good dispersivity, thing compare pure CaCu ₃Ti ₄O ₁₂Powder.

Description of drawings

Fig. 1 is embodiment of the invention 1CaCu ₃Ti ₄O ₁₂The X ray collection of illustrative plates of powder.

Fig. 2 is embodiment of the invention 2CaCu ₃Ti ₄O ₁₂The ESEM picture of body.

Embodiment

Embodiment 1:

Nitrocalcite, the cupric nitrate that uses the analytical pure level is to carry out weigh batching at 1: 3 in molar ratio, is dissolved in the ethylene glycol monomethyl ether, and the ethylene glycol monomethyl ether quality is 3 times of raw materials quality, makes uniform solution (A solution).Nitrocalcite with top adding is benchmark; By Ca: the Ti mol ratio is that the tetrabutyl titanate that 1: 4 usefulness graduated cylinder is measured respective amount is dissolved in the absolute ethyl alcohol, and the ethanol volume is 3 times of tetrabutyl titanate volume, fully stirs; Tetrabutyl titanate is solved homogeneously in the absolute ethyl alcohol, form B liquid.The A drop is gone in the B liquid, and adding speed is 4 milliliters of per seconds, stirs while splashing into, and stirring velocity is 100 rev/mins, drip off A liquid after, restir 0.2 hour obtains colloidal sol; Add the water-reducible ethanol of de-ionized, wherein the deionized water volume is 1.0 times of ethanol volume, and the volume of dropping is 5% of a sol volume, stirs while add, and stirring velocity is 40 rev/mins, and churning time is 0.3 hour, obtains gel.This gel was left standstill after 4 hours under 600 ℃ of temperature thermal treatment 2 hours, and porphyrize obtains the CaCu of cube phase in agate mortar then ₃Ti ₄0 ₁₂Powder.Fig. 1 is the X ray collection of illustrative plates of the embodiment of the invention 1 calcium copper titanium oxide powder.

Embodiment 2:

Nitrocalcite, the cupric nitrate that uses the analytical pure level is to carry out weigh batching at 1: 3 in molar ratio, is dissolved in the ethylene glycol monomethyl ether, and the ethylene glycol monomethyl ether quality is 8 times of raw materials quality, makes uniform solution (A solution).Nitrocalcite with top adding is benchmark; By Ca: the Ti mol ratio is that the tetrabutyl titanate that 1: 4 usefulness graduated cylinder is measured respective amount is dissolved in the absolute ethyl alcohol, and the ethanol volume is 12 times of tetrabutyl titanate volume, fully stirs; Tetrabutyl titanate is solved homogeneously in the absolute ethyl alcohol, form B liquid.The A drop is gone in the B liquid, and adding speed is 10 milliliters of per seconds, stirs while splashing into, and stirring velocity is 40 rev/mins, drip off A liquid after, restir 0.5 hour obtains colloidal sol; Add the water-reducible ethanol of de-ionized, wherein the deionized water volume is 2.0 times of ethanol volume, and the volume of dropping is 16% of a sol volume, stirs while add, and stirring velocity is 110 rev/mins, and churning time is 1.1 o'clock, obtains gel.This gel was left standstill after 5 hours under 1100 ℃ of temperature thermal treatment 0.8 hour, and porphyrize obtains the CaCu of cube phase in agate mortar then ₃Ti ₄O ₁₂Powder.Fig. 2 is the ESEM picture of the embodiment of the invention 2 calcium copper titanium oxide powders.

Embodiment 3:

Nitrocalcite, the cupric nitrate that uses the analytical pure level is to carry out weigh batching at 1: 3 in molar ratio, is dissolved in the ethylene glycol monomethyl ether, and the ethylene glycol monomethyl ether quality is 12 times of raw materials quality, makes uniform solution (A solution).Nitrocalcite with top adding is benchmark; By Ca: the Ti mol ratio is that the tetrabutyl titanate that 1: 4 usefulness graduated cylinder is measured respective amount is dissolved in the absolute ethyl alcohol, and the ethanol volume is 6 times of tetrabutyl titanate volume, fully stirs; Tetrabutyl titanate is solved homogeneously in the absolute ethyl alcohol, form B liquid.The A drop is gone in the B liquid, and adding speed is 25 milliliters of per seconds, stirs while splashing into, and stirring velocity is 160 rev/mins, drip off A liquid after, restir 1.8 hours obtains colloidal sol; Add the water-reducible ethanol of de-ionized, wherein the deionized water volume is 0.5 times of ethanol volume, and the volume of dropping is 8% of a sol volume, stirs while add, and stirring velocity is 60 rev/mins, and churning time is 4.2 hours, obtains gel.This gel was left standstill after 9 hours under 800 ℃ of temperature thermal treatment 2 hours, and porphyrize obtains the CaCu of cube phase in agate mortar then ₃Ti ₄O ₁₂Powder.

Claims

1. a preparation method of calcium copper titanium oxide compound powder, is characterized in that concrete steps are:

(1) Dissolve analytically pure calcium nitrate and analytically pure copper nitrate in a molar ratio of 1:3, dissolve them in ethylene glycol monomethyl ether, and the quality of ethylene glycol monomethyl ether is 1 to 15 times that of the raw material, to prepare to obtain a homogeneous solution;

(2) Taking the amount of calcium nitrate added in step (1) as a benchmark, the analytically pure butyl titanate is dissolved in methanol or ethanol with a Ca:Ti molar ratio of 1:4, and the volume of methanol or ethanol is 1 to 15 times the volume of butyl titanate to obtain a uniform solution;

(3) Add the solution prepared in step (1) to the solution in step (2) at a speed of 1.5 to 30 ml per second, stirring while pouring in at a stirring speed of 30 to 180 rpm, pouring in After completion, stir for another 0.1 to 2 hours to obtain a uniform sol;

(4) Add dropwise the ethanol diluted with deionized water in the sol obtained in step (3), wherein the volume of deionized water is 0.2～2.0 times of the volume of ethanol, and the volume added is 1～20% of the volume of the sol, while dripping Stir while adding, the stirring speed is 20-120 rpm, and the stirring time is 0.2-5 hours to obtain a gel;

(5) Let the gel obtained in step (4) stand for 0.3-10 hours, heat-treat at a temperature of 500-1100° C. for 1-3 hours, and obtain cubic phase CaCu ₃ Ti ₄ O ₁₂ powder;

Steps (1), (2), (3) and (4) are carried out in air or in a glove box filled with dry nitrogen or dry inert gas.