CN1718670A - Method of preparing ultrafine long afterglow luminous material - Google Patents

Abstract

A process for preparing superfine long-afterglow luminescent material by sol-gel method is prepared from citric acid, inorganic Al salt, Sr or Ca, Ba salt, europium oxide, dysprosium oxide and soluble boric acid or boron oxide through preparing precursor by so-gel method, and synthesizing aluminate-system long-afterglow luminescent material at 1200-1250 deg.C in weak reducing atmosphere. Its advantages are high brightness of afterglow and long afterglow.

Description

A kind of method for preparing ultrafine long afterglow luminous material

Technical field

The invention belongs to ultra-fine strontium aluminate phase long after glow luminous material preparing technical field, a kind of method for preparing ultrafine long afterglow luminous material is provided especially.

Background technology

The aluminate-series luminescent material is a kind of efficient long after glow luminous material that wavelength is the 400-520nm visible light that can send after illumination.Its luminosity and time of persistence are than traditional ZnS type luminescent material more than high ten times.Utilize its accumulation of energy on daytime, night emitting characteristics, this embedded photoluminescent material shows at dial plates such as clock and watch, instrument, road indication, buildings sign, aspects such as low illumination at the night in billboard and room have a wide range of applications, and are a kind of ideal environmental protection and energy saving materials.

On the other hand, the fluorescent probe that uses in the biotechnology all is a luminescent material just luminous under light source activation at present, uses this fluorescent probe to be difficult to avoid the fluorescence by excitation light generation to carry on the back end problem.And the long-afterglow fluorescent probe can survey after cutting out excitation light source, can not produce fluorescence back of the body end problem.But as the fluorescent probe that is applied to biotechnology, owing to biokinetic requirement, luminescent material must have enough thin granularity on the one hand; On the other hand, detect in order to be detected device, luminescent material must have enough brightness.Long after glow luminous material is used for biotechnology also is in development at present.

The method for preparing at present the aluminate series long afterglow luminescent material has high temperature solid-state method, sol-gel method, coprecipitation method and combustion method etc.Wherein high temperature solid-state method is technology maturation, realizes the in batches method of suitability for industrialized production.Its product has been widely used in dial plate and has shown, road indication, buildings sign, aspects such as low illumination at the night in billboard and room.But the product particle degree that high temperature solid-state method is produced is big, can not satisfy the kinetics requirement of biotechnology with fluorescent probe.

Combustion method, coprecipitation method and sol-gel method all are the methods that might synthesize fine particle materials, but use combustion method synthetic aluminate-series luminescent material particle still relatively large at present, and be lower with such material brightness of coprecipitation method synthetic.The present invention adopts sol-gel method.

Sol-gel method can realize the uniform mixing and the reaction of atom or molecularity when the preparation presoma, be the method for preparing ultra-fine grain easily.The method of having reported for preparing the aluminate series long afterglow luminescent material with sol-gel method can be divided into two classes, and a class is that fertile material selects organism; Another kind of fertile material inorganics.Select for use the method for organism fertile material that the shortcoming that raw materials cost is higher and toxicity is bigger is arranged.It is the method for inorganics that the present invention adopts fertile material.

The method that adopts the inorganics fertile material to prepare the aluminate series long afterglow luminescent material mainly can be divided into two kinds at present, and a kind of is not add boron in preparation strontium aluminate phase long after glow luminous material process.But do not add boron, the luminescent material brightness of preparation is lower; Another kind method is after making colloid, is that sintering agent adds boron-containing compounds such as boric acid at the roasting previous crops.Though a kind of method in back has improved the luminosity of product, granularity easily produces glassy phase than boric acid big and that add.This glassy phase impurity that is present in the luminescent material, influence is little in the occasion of using in batches (as sign board etc.), but the occasion of using separately at each light-emitting particles (as fluorescent probe) is totally unfavorable.

Summary of the invention

The object of the present invention is to provide a kind of method for preparing ultrafine long afterglow luminous material.Solved that " not adding boron, to prepare the luminosity of product low; It is big and have not that fluorescent glass exists mutually to add preparation product granularity behind the boric acid " problem.

It is sequestrant that the present invention adopts citric acid, inorganic aluminate and strontium or calcium, barium salt, inorganicss such as rare earth oxide europium sesquioxide and dysprosium oxide and solubility boron-containing compound boric acid, boron oxide are raw material, adopt sol-gel method to prepare presoma earlier, and in the process of preparation presoma, add synchronously the solubility boron-containing compound, make behind the colloid on temperature control furnace 150-250 ℃ of oven dry 20～40 minutes, again presoma 800～900 ℃ of pre-burnings, under 1200～1250 ℃ and weakly reducing atmosphere, handle then, obtain superfine aluminate system long after glow luminous material.Special feature of the present invention is: use inorganic raw material and solubility boron-containing compound boric acid or boron oxide etc. are added in the process of preparation presoma synchronously, and the drying of selecting for use and pretreatment technology have shortened preparation time greatly.Concrete technology is:

A, mineral acid concentrated nitric acid or concentrated hydrochloric acid dissolving rare earth oxide europium sesquioxide and dysprosium oxide, acid amount and europium sesquioxide ratio are 2.5 * 10 ^-5/ ml, europium sesquioxide and dysprosium oxide ratio are 1: 2.Wherein rare earth oxide and strontium nitrate ratio are respectively 2.0～2.5mol% and 4.0～5.0mol%;

B, be 2: 1 inorganic aluminate and strontium or calcium, barium salt with mol ratio, aluminum nitrate and strontium nitrate or aluminum chloride and calcium chloride, and with the matrix mol ratio be 5%～25% boric acid, be dissolved in water into the aqueous solution;

C, will be dissolved inorganic salt of rare earth and the b aqueous solution in step, and to add mole number be the citric acid of 2.0～2.5 times of all metal ions mole number sums, fully stirring makes its whole dissolvings;

D, when keep stirring, add ammoniacal liquor adjust pH to 5.5～6.5.Optimal ph is 6;

E, with the aqueous solution heating in water bath that mixes up, temperature remains between 75-85 ℃.Optimum temps is 80 ℃;

F, the colloid that obtains is taken out, and 150-250 ℃ of oven dry 20～40 minutes on temperature control furnace;

G, dry thing is taken out, under air conditions, in 800～950 ℃ of pre-burnings 80～120 minutes;

H, be under 1/8 the atmosphere,, to obtain superfine aluminate series long afterglow luminescent material with the pre-burning thing again in 1200-1250 ℃ of following calcination 50～70 minutes in hydrogen and nitrogen ratios;

The invention has the advantages that:

1, selecting parent stock for use is inorganics, prepared product, brightness will be a little more than the product that adds the preparation of boric acid method usually before calcination, and granularity size and the product basically identical that does not add the preparation of boron method, be 100nm～5 μ m, and be difficult for reuniting the requirement of fluorescent probe of over-all properties basic symbols symphysis thing technology.

2, preparation raw material and sequestrant selected inorganics and citric acid for use, compares as raw material with other sequestrants with selecting organism, can significantly reduce the cost of raw material, and preparation technology is not simply, produce toxic gas in the preparation process substantially.

3, by in the process of preparation presoma, adding the method for B element, avoided not adding the brightness of boron product low and after add the problem that boride product particle produces glassy phase more greatly and easily.

4, reported with sol-gel method and adopt inorganic raw material to prepare the experiment of steady persistence, when the preparation xerogel all is to adopt the technology of just carrying out pre-burning in tens hours at 120 ℃ of left and right sides freeze-day with constant temperature, technology is compared therewith, the present invention directly promptly carries out pre-burning in oven dry under 150-250 ℃ after 20-40 minute after making colloid, preparation time shortens greatly.

Embodiment

Embodiment 1:

1) according to table 1 preparation desired raw material.

Table 1 composition of raw materials

2) europium sesquioxide and dysprosium oxide are dissolved in the concentrated nitric acid of 5ml.

3) water 30ml dissolving strontium nitrate, aluminum nitrate and boric acid; Use 30ml water dissolution citric acid again.

4) nitrate of europium, dysprosium is sneaked in the aqueous solution of strontium nitrate, aluminum nitrate and boric acid, pour the lemon aqueous acid again into, stirred 1 hour.

5) under condition of stirring, add proper ammonia and regulate pH value to 5.5.

6) evaporate to dryness solution under the condition of 75 ℃ of water-baths makes it form colloid.

7) the gained colloid was dried 40 minutes down in 150 ℃.

8) with dry thing air atmosphere, 800 ℃ of following pre-burnings 120 minutes.

9) again with the pre-burning thing hydrogen and nitrogen ratio be under 1/8 the atmosphere, promptly got strontium aluminate phase long after glow luminous material in 70 minutes in 1200 ℃ of following calcinations.

Embodiment 2:

1, according to table 2 preparation desired raw material.

Table 2 composition of raw materials

2, europium sesquioxide and dysprosium oxide are dissolved in the concentrated nitric acid of 5ml.

3, water 30ml dissolving strontium nitrate, aluminum nitrate and boric acid; Use 30ml water dissolution citric acid again.

4, the nitrate of europium, dysprosium is sneaked in the aqueous solution of strontium nitrate, aluminum nitrate and boric acid, pour the lemon aqueous acid again into, stirred 1 hour.

5, under condition of stirring, add proper ammonia and regulate pH value to 6.0.

6, evaporate to dryness solution under the condition of 80 ℃ of water-baths makes it form colloid.

7, the gained colloid was dried 30 minutes down in 200 ℃.

8, with dry thing air atmosphere, 900 ℃ of following pre-burnings 100 minutes.

9, be under 1/8 the atmosphere, promptly to get strontium aluminate phase long after glow luminous material in 60 minutes again with the pre-burning thing in 1225 ℃ of following calcinations in the ratio of hydrogen and nitrogen.

Embodiment 3:

1, according to table 3 preparation desired raw material.

Table 3 composition of raw materials

2, europium sesquioxide and dysprosium oxide are dissolved in the concentrated hydrochloric acid of 4ml.

3, water 30ml dissolving calcium chloride, aluminum chloride and boric acid; Use 30ml water dissolution citric acid again.

4, the oxymuriate of europium, dysprosium is sneaked in the aqueous solution of calcium chloride, aluminum chloride and boric acid, pour the lemon aqueous acid again into, stirred 1 hour.

5, under condition of stirring, add proper ammonia and regulate pH value to 6.5.

Evaporate to dryness solution under the condition of 85 ℃ of water-baths makes it form colloid.

6, the gained colloid was dried 20 minutes down in 250 ℃.

7, with dry thing air atmosphere, 950 ℃ of following pre-burnings 80 minutes.

8, again with the pre-burning thing hydrogen and nitrogen ratio be under 1/8 the atmosphere, promptly got strontium aluminate phase long after glow luminous material in 50 minutes in 1250 ℃ of following calcinations.

Claims (2)

1, a kind of method for preparing ultrafine long afterglow luminous material, it is characterized in that: the employing citric acid is a sequestrant, the oxide compound europium sesquioxide of inorganic aluminate, strontium or calcium, barium salt, rare earth, dysprosium oxide and solubility boron-containing compound boric acid, boron oxide etc. are raw material, adopt sol-gel method to prepare presoma earlier, and in the process of preparation presoma, add synchronously the solubility boron-containing compound, on temperature control furnace, dry after making colloid, again the presoma pre-burning, under weakly reducing atmosphere, handle synthesizing superfine aluminates system long after glow luminous material then.

2, in accordance with the method for claim 1, it is characterized in that: concrete technology is:

A, mineral acid concentrated nitric acid or concentrated hydrochloric acid dissolving rare earth oxide europium sesquioxide and dysprosium oxide, acid amount and europium sesquioxide ratio are 2.5 * 10 ^-5/ ml, europium sesquioxide and dysprosium oxide ratio are 1: 2; Wherein rare earth oxide and strontium nitrate ratio are respectively 2.0～2.5mol% and 4.0～5.0mol%;

B, be 2: 1 inorganic aluminate and strontium or calcium, barium salt with mol ratio, aluminum nitrate and strontium nitrate or aluminum chloride and bariumchloride, and with strontium or calcium, barium salt mol ratio be 5%～25% boric acid, be dissolved in water into the aqueous solution;

C, will be dissolved inorganic salt of rare earth and the b aqueous solution in step, and to add mole number be the citric acid of 2.0～2.5 times of all metal ions mole number sums, fully stirring makes its whole dissolvings;

D, when keep stirring, add ammoniacal liquor adjust pH to 5.5～6.5;

E, with the aqueous solution heating in water bath that mixes up, temperature remains between 75-85 ℃;

F, the colloid that obtains is taken out, and 150-250 ℃ of oven dry 20～40 minutes on temperature control furnace;

G, dry thing is taken out, under air conditions, in 800～950 ℃ of pre-burnings 80～120 minutes;

H, be under 1/8 the atmosphere with the pre-burning thing again in hydrogen and nitrogen ratios, in 1200～1250 ℃ of following calcinations 50～70 minutes, superfine aluminate series long afterglow luminescent material.