CN108359115B - Nafion polymer matrix Er3+/Yb3+Codope calcirm-fluoride nanocrystalline composite material and preparation method thereof - Google Patents

Abstract

The invention discloses a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystal composite material and a preparation method thereof, which comprises the following steps: preparing Nafion concentrated solution; preparing Er ³⁺ /Yb ³⁺ Co-doped calcium fluoride nanocrystals; preparation of Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystal composites. The present invention uses a two-step method to synthesize a composite material of Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystals and Nafion with strong near-infrared luminescence, and the prepared composite film is uniform and transparent, and the nanocrystals in the composite material The crystal phase structure is a cubic crystal phase, which is a single-phase crystal, and the nanocrystal grain size is uniform, the dispersion is good, and there is no obvious agglomeration phenomenon. The preparation method of the invention is simple, easy to scale up, good in controllability, excellent in product performance and has broad market prospects.

Description

Nafion polymer-based Er3+/Yb3+ co-doped calcium fluoride nanocrystalline composites and their applications Preparation

technical field

The invention belongs to the technical field of composite material preparation, and in particular relates to a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystal composite material and a preparation method thereof.

Background technique

In recent years, Er ³⁺ doped materials have attracted extensive research and application in near-infrared amplifier integrated planar optical circuits and optical communication materials. However, the CH and OH bonds contained in ligands and solvent molecules can quench the emission of Er ³⁺ , which reduces the emission intensity of Er ³⁺ and shortens the excited state lifetime. In addition, the luminous efficiency will be affected by the distance between adjacent activated ions and the absorption cross section of activated ions. When the proportion of rare earth doping is large, the ion distance will be reduced, which will lead to cross-resistance phenomenon between adjacent activated ions, resulting in concentration quenching effect. In order to reduce the concentration quenching effect, the absorption cross section of the active ion can be changed by adding a sensitizer, and its luminous efficiency will be improved.

Yb ³⁺ is a very effective sensitizing ion, because the absorption cross section of Er ³⁺ is much smaller than the absorption cross section of Yb ³⁺ , and the absorption energy of the first excited state of Er ³⁺ just coincides with the excitation spectrum of Yb ³⁺ ( 980nm), Yb ³⁺ can effectively transfer energy to Er ³⁺ after absorbing energy. Therefore, in the case of adding Yb ³⁺ , the luminous intensity of Er ³⁺ can be significantly improved. Fluoride has good optical uniformity and thermal stability, high optical transparency, and easy doping of various valence ions, so co-doping Er ³⁺ and Yb ^{3+ ions} into fluoride nanomaterials can be easily achieved. Optimize the luminescence performance of Er ³⁺ to a great extent. In order to enhance the mechanical strength of the synthesized nanomaterials and reduce the quenching of Er3 ⁺ luminescence by CH and OH bonds, it can be doped into perfluoropolymers. Nafion is a perfluorosulfonic acid ion exchange polymer. Since the polymer is composed of a hydrophobic fluorocarbon polymer main chain and a hydrophilic alkyl sulfonate side chain, the hydrophobicity of the main chain in aqueous solution makes the polymer The long chain is far away from the aqueous solution, while the hydrophilicity of the sulfonate group makes the side chain extend into the aqueous solution. In addition, Nafion membrane also has strong thermal stability and chemical mechanical strength. The present invention uses Nafion as the coating agent and matrix, and realizes the compounding of nanoparticles and Nafion polymer through the coordination and modification of nanoparticles by sulfonic acid groups and metal ions, and prepares a uniform near-infrared luminescent composite membrane material, which is expected to Used in erbium-doped optical waveguide amplifiers.

Contents of the invention

The invention provides a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystal composite material and its preparation method, which solves the compatibility problem between nanocrystals and perfluoropolymers in the prior art , and the CH and OH bonds contained in the ligand and solvent molecules in the Er ³⁺ doped polymer material will quench the luminescence of Er ³⁺ , which will reduce the luminescence intensity of Er ³⁺ and shorten the lifetime of the excited state, It also solves the problem that Er ³⁺ easily leads to the concentration quenching effect when the 980nm absorption cross section is small and the doping ratio is large.

The first object of the present invention is to provide a kind of Nafion polymer-based Er ³⁺ /Yb ³⁺ preparation method of co-doped calcium fluoride nanocrystalline composite material, comprising the following steps:

Add N,N-dimethylformamide and Nafion solution with a mass concentration of 5% into the reaction vessel according to the ratio of 1mL: 13.3g, mix well, concentrate until the volume is 1/4 of the original volume, and then add Nafion solution with The N, N-dimethylformamide equal volume of N, N-dimethylformamide, the mixed solution after mixing uniformly, continues to concentrate until the volume is 1/5 of the mixed solution, to obtain the Nafion concentrated solution;

Step 2, preparation of Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystals

Step 2.1, dissolving ErCl ₃ 6H ₂ O and YbCl ₃ 6H ₂ O in distilled water to obtain a salt solution;

The ratio of ErCl ₃ ·6H ₂ O, YbCl ₃ ·6H ₂ O and distilled water in the salt solution is 0.2692-0.6395mmoL: 0.1795-0.2692mmoL: 5mL;

Step 2.2, dissolving NH ₄ F in distilled water to obtain NH ₄ F aqueous solution;

Among them, the ratio of NH ₄ F to distilled water is 5.35-22.45mmoL: 6mL;

Step 2.3, mixing the salt solution in step 2.1, Ca(NO ₃ ) ₂ ·4H ₂ O, Nafion solution with a mass concentration of 5%, and distilled water, and then stirring until the solid raw materials are completely dissolved to obtain a mixed reaction solution;

Among them, the ratio of Ca(NO ₃ ) ₂ ·4H ₂ O, ErCl ₃ ·6H ₂ O in step 2.1, Nafion solution with a mass concentration of 5%, and distilled water is 2.1536-12.1588mmoL:0.2692-0.6395mmoL:10g:2mL;

Step 2.4: Slowly add the NH ₄ F solution in step 2.2 to the mixed reaction solution in step 2.3. After the dropwise addition, stir the reaction at 70°C for 3 hours. After the reaction, cool the reaction solution to room temperature, and then concentrate to a viscous shape to obtain a concentrated reactant, the concentrated reactant was washed twice with water, and centrifuged after washing to obtain nanocrystals;

Wherein, the molar ratio of NH ₄ F to ErCl ₃ ·6H ₂ O in step 2.1 is 5.35-22.45:0.2692-0.6395;

Step 3, preparation of Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites

Mix the nanocrystals in step 2 with the Nafion concentrate in step 1 according to the ratio of 1g: 4mL to obtain a mixed solution;

Evenly drop the mixed solution onto the glass slide, dry the glass slide at 60°C for 1 hour after the dropwise addition, and then dry at 100-200°C for 5 hours, and obtain the composite material in film form after drying.

Preferably, the composite material has a thickness of 70-150 μm.

The second object of the present invention is to provide a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystal composite material prepared by the above method.

Compared with prior art, the beneficial effect of the present invention is:

The present invention uses a two-step method to synthesize a composite material with strong near-infrared luminescence. The crystal phase structure of the nanocrystal in the composite material is a cubic crystal phase, which is a single-phase crystal, and Nafion is well coated on Er ³⁺ /Yb ^{3 +} Co-doped calcium fluoride nanocrystals, in addition, the composite material film prepared by the present invention is uniform and transparent, and the nanocrystal particles in the composite material have uniform shape and size, good dispersion, and no obvious agglomeration phenomenon. The preparation method of the invention is simple, easy to scale up, good in controllability, excellent in product performance and has broad market prospects.

Description of drawings

Figure 1 is the infrared spectrum of Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites in the preparation process of step 3 under different drying temperatures and different Er ³⁺ and Yb ³⁺ doping amounts picture;

Figure 2 shows the X-rays of Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites at different drying temperatures and different Er ³⁺ and Yb ³⁺ doping amounts in the preparation process of step 3 Diffraction spectrum;

Figure 3 shows the Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites with different Er ³⁺ and Yb ³⁺ doping amounts when the drying temperature in the preparation process of step 3 is 100°C The SEM thickness test picture below;

Among them, Fig. 3 (a) is the SEM thickness test picture when Er ³⁺ doping amount is 5%, Fig. 3 (b) is Er ³⁺ doping amount is 10%, Yb ³⁺ doping amount is 5% SEM thickness test chart;

Figure 4 shows the Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites with different Er ³⁺ and Yb ³⁺ doping amounts when the drying temperature in the preparation process of step 3 is 150°C The SEM topography test chart below;

Among them, Figure 4(a) is the SEM morphology test chart when the Er ³⁺ doping amount is 5%, and Figure 4(b) is the Er ³⁺ doping amount is 5%, and the Yb ³⁺ doping amount is 5% SEM topography test chart;

Figure 5 shows the Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites with different Er ³⁺ and Yb ³⁺ doping amounts when the drying temperature in the preparation process of step 3 is 150°C The following emission spectrum (λ _ex =980 nm);

Figure 6 shows the emission spectra of Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites at different drying temperatures and the same Er ³⁺ and Yb ³⁺ doping amounts in the preparation process of step 3 Figure (λ _ex = 980 nm).

Detailed ways

In order to enable those skilled in the art to better understand that the technical solutions of the present invention can be implemented, the present invention will be further described below in conjunction with specific examples and accompanying drawings, but the given examples are not intended to limit the present invention.

The experimental methods and detection methods described in the following examples, unless otherwise specified, are conventional methods; the reagents and materials, unless otherwise specified, can be purchased in the market.

Example 1

A method for preparing a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composite material, comprising the following steps:

Step 1, take 20g of Nafion solution with a mass concentration of 5%, and 1.5mL of N,N-dimethylformamide (DMF) and add them to a 100mL flask. After mixing evenly, use a rotary evaporator to evaporate part of the solvent to make the flask Concentrate the volume of the mixture to 1/4 of its original volume, then add 1.5mL of DMF to the flask, evaporate most of the solvent, and finally stop the remaining liquid in the flask at about 4mL to obtain Nafion concentrate;

Step 2, add 0.2692mmoL of ErCl ₃ 6H ₂ O and 0.2692mmoL of YbCl ₃ 6H ₂ O to a 25mL beaker, then add 5mL of distilled water to dissolve ErCl ₃ 6H ₂ O and YbCl ₃ 6H ₂ O in distilled water to obtain a saline solution;

Add 10 g of Nafion solution with a mass concentration of 5% to the salt solution, add 4.8456 mmoL of Ca(NO ₃ ) ₂ 4H ₂ O at the same time, and add a small amount of distilled water to dissolve all the solids to obtain a mixed reaction solution. Add it to a 50mL round bottom flask, and stir it magnetically for 10min;

Dissolve 10.5mmoL of NH ₄ F in 6mL of distilled water to make NH ₄ F aqueous solution, slowly add the NH ₄ F aqueous solution to the mixed reaction solution using a constant pressure dropping funnel, and stir and react at 70°C after the addition is complete 3h, with the magnetic stirring, a white precipitate gradually formed;

After the reaction, cool the reaction solution to room temperature, then evaporate the reaction solution to a viscous state with a rotary evaporator to obtain a concentrated reaction product, wash the concentrated reaction product twice with water, centrifuge with a centrifuge, and pour off the supernatant , to obtain nanocrystals;

Step 3, take 1g of the nanocrystals in step 2 and 4mL of the Nafion concentrate in step 1 to make a mixed solution;

Evenly drop the mixed solution onto the glass slide. After the dropwise addition, dry the glass slide at 60°C for 1 hour, and then dry at 100°C for 5 hours. After drying, a film with 5% Er ³⁺ and Yb ³⁺ content can be obtained. shape composite material.

Example 2

The preparation method is the same as that in Example 1, except that in step 3, drying at 60°C for 1 hour and then drying at 150°C for 5 hours, after drying, a film-like composite material with Er ³⁺ and Yb ³⁺ contents of 5% is obtained.

Example 3

The preparation method is the same as in Example 1, except that in step 3, drying at 60°C for 1 hour and then drying at 200°C for 5 hours, after drying, a film-like composite material with Er ³⁺ and Yb ³⁺ contents of 5% is obtained.

Example 4

A method for preparing a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composite material, comprising the following steps:

Step 1, take 20g of Nafion solution with a mass concentration of 5% and 1.5mL of DMF into a 100 mL flask, mix well and use a rotary evaporator to evaporate part of the solvent, so that the volume of the mixture in the flask is concentrated to 1/4 of its original volume , then take 1.5mL of DMF and add it to the flask, evaporate most of the solvent, and finally stop the remaining liquid in the flask at about 4mL to obtain Nafion concentrated solution;

Step 2, add 0.3589mmoL of ErCl ₃ 6H ₂ O and 0.1795mmoL of YbCl ₃ 6H ₂ O into a 25mL beaker, then add 5mL of distilled water to dissolve ErCl ₃ 6H ₂ O and YbCl ₃ 6H ₂ O in distilled water to obtain a saline solution;

Add 10 g of Nafion solution with a mass concentration of 5% to the salt solution, add 3.0501 mmoL of Ca(NO ₃ ) ₂ 4H ₂ O at the same time, and add a small amount of distilled water to dissolve all the solids to obtain a mixed reaction solution. Add it to a 50mL round bottom flask, and stir it magnetically for 10min;

Dissolve 7.1mmoL of NH ₄ F in 6mL of distilled water to make NH ₄ F aqueous solution, slowly add the NH ₄ F aqueous solution to the mixed reaction solution using a constant pressure dropping funnel, and stir and react at 70°C after the addition is complete 3h, with the magnetic stirring, a white precipitate gradually formed;

After the reaction is completed, the reaction solution is evaporated to a viscous state with a rotary evaporator to obtain a concentrated reactant, the concentrated reactant is washed twice with water, centrifuged with a centrifuge, and the supernatant is poured off to obtain nanocrystals;

Step 3, take 1g of the nanocrystals in step 2 and 4mL of the Nafion concentrate in step 1 to make a mixed solution;

Evenly drop the mixed solution onto the glass slide. After the dropwise addition, dry the glass slide at 60°C for 1 hour, and then dry at 100°C for 5 hours. After drying, the content of Er ³⁺ is 10%, and the content of Yb ³⁺ is 5%. % of film-like composites.

Example 5

The preparation method is the same as in Example 4, except that in step 3, drying at 60°C for 1 hour and then drying at 150°C for 5 hours, after drying, a film-like composite material with an Er ³⁺ content of 10% and a Yb ³⁺ content of 5% is obtained .

Example 6

The preparation method is the same as in Example 4, except that in step 3, drying at 60°C for 1 hour and then drying at 200°C for 5 hours, after drying, a film-like composite material with an Er ³⁺ content of 10% and a Yb ³⁺ content of 5% is obtained .

Example 7

A method for preparing a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composite material, comprising the following steps:

Step 1, take 20g of Nafion solution with a mass concentration of 5% and 1.5mL of DMF, add them to a 100mL flask, mix well and use a rotary evaporator to evaporate part of the solvent, so that the volume of the mixture in the flask is concentrated to 1/4 of its original volume , then take 1.5mL of DMF and add it to the flask, evaporate most of the solvent, and finally stop the remaining liquid in the flask at about 4mL to obtain Nafion concentrated solution;

Step 2, add 0.2692mmoL of ErCl ₃ 6H ₂ O and 0.2692mmoL of YbCl ₃ 6H ₂ O to a 25mL beaker, then add 5mL of distilled water to dissolve ErCl ₃ 6H ₂ O and YbCl ₃ 6H ₂ O in distilled water to obtain a saline solution;

Add 10 g of Nafion solution with a mass concentration of 5% to the salt solution, add 2.1536 mmoL of Ca(NO ₃ ) ₂ 4H ₂ O at the same time, and add a small amount of distilled water to dissolve all the solids to obtain a mixed reaction solution. Add it to a 50mL round bottom flask, and stir it magnetically for 10min;

Dissolve 5.35mmoL of NH ₄ F in 6mL of distilled water to make NH ₄ F aqueous solution, and slowly add the NH ₄ F aqueous solution to the reaction solution using a constant pressure dropping funnel, and then stir and react at 70°C for 3h , with the magnetic stirring, a white precipitate gradually formed;

After the reaction is completed, the reaction solution is evaporated to a viscous state with a rotary evaporator to obtain a concentrated reactant, the concentrated reactant is washed twice with water, centrifuged with a centrifuge, and the supernatant is poured off to obtain nanocrystals;

Step 3, take 1g of the nanocrystals in step 2 and 4mL of the Nafion concentrate in step 1 to make a mixed solution;

Evenly drop the mixed solution onto the glass slide. After the dropwise addition, dry the glass slide at 60°C for 1 hour, and then dry at 100°C for 5 hours. After drying, the Er ³⁺ content is 10%, and the Yb ³⁺ content is 10%. % of film-like composites.

Example 8

The preparation method is the same as in Example 7, except that in step 3, drying at 60°C for 1 hour and then drying at 150°C for 5 hours, after drying, a film-like composite material with an Er ³⁺ content of 10% and a Yb ³⁺ content of 10% is obtained .

Example 9

The preparation method is the same as in Example 7, except that in step 3, drying at 60°C for 1 hour and then drying at 200°C for 5 hours, after drying, a film-like composite material with an Er ³⁺ content of 10% and a Yb ³⁺ content of 10% is obtained .

Comparative example 1

A method for preparing a Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composite material, comprising the following steps:

Step 1, take 20g of Nafion solution with a mass concentration of 5%, and add 1.5mL of DMF into a 100mL flask. After mixing evenly, use a rotary evaporator to evaporate part of the solvent, so that the volume of the mixture in the flask is concentrated to 1/4 of its original volume. Add 1.5mL of DMF to the flask, evaporate most of the solvent, and finally stop the remaining liquid in the flask at about 4mL to obtain Nafion concentrate;

Step 2, add 0.6369mmoL of ErCl ₃ 6H ₂ O into a 25mL beaker, and then add 5mL of distilled water to dissolve ErCl ₃ 6H ₂ O in distilled water to obtain an ErCl ₃ 6H ₂ O aqueous solution;

Add 10 g of Nafion solution with a concentration of 5% to the ErCl ₃ 6H ₂ O aqueous solution, add 12.1588 mmoL of Ca(NO ₃ ) ₂ 4H ₂ O at the same time, and add a small amount of distilled water to dissolve all the solids to obtain a mixed reaction solution. Add the mixed reaction solution into a 50mL round bottom flask, and stir it magnetically for 10min;

Dissolve 22.45mmoL of NH ₄ F in 6mL of distilled water to make an aqueous NH _{4 F solution. Slowly add the NH 4 F} aqueous solution to the mixed reaction solution using a constant pressure dropping funnel. After the addition is complete, stir and react at 70°C for 3h , with the magnetic stirring, a white precipitate gradually formed;

After the reaction, cool the reaction solution to room temperature, then evaporate the reaction solution to a viscous state with a rotary evaporator to obtain a concentrated reaction product, wash the concentrated reaction product twice with water, centrifuge with a centrifuge, and pour off the supernatant , to obtain nanocrystals;

Step 3, take 1g of the nanocrystals in step 2 and 4mL of the Nafion concentrate in step 1 to make a mixed solution;

The mixed solution was evenly added dropwise onto the glass slide, and after the dropwise addition, the glass slide was dried at 60° C. for 1 hour, and then dried at 100° C. for 5 hours. After drying, a film-like composite material with an Er ³⁺ content of 5% was obtained.

Comparative example 2

The preparation method is the same as that of Comparative Example 1, except that in step 3, it is dried at 60°C for 1 hour and then dried at 150°C for 5 hours. After drying, a film-like composite material with an Er ³⁺ content of 5% is obtained.

Comparative example 3

The preparation method is the same as that of Comparative Example 1, except that in step 3, it is dried at 60°C for 1 hour and then dried at 200°C for 5 hours. After drying, a film-like composite material with an Er ³⁺ content of 5% is obtained.

The performance of Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composite material prepared by Examples 1-9 and Comparative Examples 1-3 is detected, to illustrate the effect of the present invention, specific results See Figure 1-6.

Figure 1 is the infrared spectrum of the Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composite material at different drying temperatures and different Er ³⁺ and Yb ³⁺ doping amounts in the preparation process of step 3 It can be seen from Figure 1 that Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystals are indeed recombined with Nafion polymer, and part of the -SO ₃ H groups of Nafion are bonded to the surface of nanocrystals , indicating that part of Nafion is coated on the surface of nanocrystals through chemical bonds.

Figure 2 shows the X-rays of Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites at different drying temperatures and different Er ³⁺ and Yb ³⁺ doping amounts in the preparation process of step 3 Diffraction spectrum, it can be seen from the figure that the nanocrystals are well crystallized, which is consistent with the XRD standard spectrum of cubic CaF ₂ , indicating that Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystals in the composite material Belonging to the cubic phase crystal system, the crystal phase structure of CaF ₂ has not been changed during the synthesis process.

Figure 3 shows the Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites with different Er ³⁺ and Yb ³⁺ doping amounts when the drying temperature in the preparation process of step 3 is 100°C The SEM thickness test picture below;

Among them, Fig. 3 (a) is the SEM thickness test picture when Er ³⁺ doping amount is 5%, Fig. 3 (b) is Er ³⁺ doping amount is 10%, Yb ³⁺ doping amount is 5% It can be seen from Figure 3(a) and Figure 3(b) that the thickness of the synthesized film material is uniform, and the thickness is about 145 μm.

Figure 4 shows the Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites with different Er ³⁺ and Yb ³⁺ doping amounts when the drying temperature in the preparation process of step 3 is 150°C The SEM topography test chart below;

Among them, Figure 4(a) is the SEM morphology test chart when the Er ³⁺ doping amount is 5%, and Figure 4(b) is the Er ³⁺ doping amount is 5%, and the Yb ³⁺ doping amount is 5% It can be seen from Figure 4(a) and Figure 4(b) that the shape of nanocrystalline particles is similar to spherical, with uniform particle size and good dispersion, and there is no obvious agglomeration phenomenon. It can also be seen from the figure that doping with different Er ³⁺ , Yb ^{3 +} ions, and different ratios does not change the morphology of the sample much.

Figure 5 shows the Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystalline composites with different Er ³⁺ and Yb ³⁺ doping amounts when the drying temperature in the preparation process of step 3 is 150°C The following emission spectrum (λ _ex =980nm); Fig. 6 is Nafion polymer-based Er ³⁺ /Yb ³⁺ co-doped calcium fluoride nanocrystal composite material in the preparation process of step 3 with different drying temperatures and the same Er ³ Emission spectra (λ _ex =980nm) at ⁺ and Yb ³⁺ doping levels. It can be seen from Figure 5 that when the drying temperature is the same, the luminescence intensity of Er ³⁺ is significantly increased when Yb ³⁺ is added, and the fluorescence intensity is the highest when the doping ratios of Er ³⁺ and Yb ³⁺ are 10% and 5% respectively. Strong, the fluorescence intensity is the weakest when the doping ratio Er ³⁺ is 5%. It can be concluded from Figure 6 that when the Er ³⁺ and Yb ³⁺ doping ratios are the same, the luminous intensity reaches the strongest when the drying temperature is 200°C.

It should be noted that when a numerical range is involved in the claims of the present invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected, because the steps and methods adopted are the same as those in Embodiment 1- 9 Likewise, to avoid redundancy, the present invention describes preferred embodiments, but those skilled in the art can make additional changes and modifications to these embodiments once the basic inventive concept is known. Therefore, it is intended that the appended claims be construed to cover the preferred embodiment as well as all changes and modifications which fall within the scope of the invention.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. In this way, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, it is also intended to include these modifications and variations.

Claims (3)

1. a kind of Nafion polymer matrix Er³⁺/Yb³⁺The preparation method of codope calcirm-fluoride nanocrystalline composite material, feature exist In sequentially including the following steps:

Step 1, Nafion concentrate is prepared

The Nafion solution that n,N-Dimethylformamide and mass concentration are 5% is added to instead according to the ratio of 1mL:13.3g Answer in container, be concentrated into volume is original 1/4 after mixing, then be charged with the n,N-Dimethylformamide etc. The n,N-Dimethylformamide of volume, mixed liquor after mixing continue to be concentrated, until volume is the 1/5 of mixed liquor, obtain Nafion concentrate；

Step 2, Er is prepared³⁺/Yb³⁺Codope calcirm-fluoride is nanocrystalline

Step 2.1, by ErCl₃·6H₂O、YbCl₃·6H₂O is dissolved in distilled water, obtains salting liquid；

ErCl in the salting liquid₃·6H₂O、YbCl₃·6H₂The ratio of O and distilled water is 0.2692-0.6395mmoL: 0.1795-0.2692mmoL:5mL；

Step 2.2, by NH₄F is dissolved in distilled water, obtains NH₄F aqueous solution；

Wherein, NH₄The ratio of F and distilled water is 5.35-22.45mmoL:6mL；

Step 2.3, by salting liquid, Ca (NO in step 2.1₃)₂·4H₂O, Nafion solution and distilled water that mass concentration is 5% Stirring is completely dissolved to solid material after mixing, obtains mixed reaction solution；

Wherein, Ca (NO₃)₂·4H₂O, ErCl in step 2.1₃·6H₂O, the Nafion solution and distillation that mass concentration is 5% The ratio of water is 2.1536-12.1588mmoL:0.2692-0.6395mmoL:10g:2mL；

Step 2.4, by NH in step 2.2₄F solution is slowly dropped in the mixed reaction solution of step 2.3, in 70 after being added dropwise Be stirred to react 3h at DEG C, be after reaction cooled to room temperature reaction solution, be then concentrated into it is thick, obtain concentration reactant, Concentration reactant is washed twice with water, is centrifuged, obtains nanocrystalline after washing；

Wherein, NH₄F and ErCl in step 2.1₃·6H₂The molar ratio of O is 5.35-22.45:0.2692-0.6395；

Step 3, Nafion polymer matrix Er is prepared³⁺/Yb³⁺Codope calcirm-fluoride nanocrystalline composite material

Nafion concentrate with step 1 nanocrystalline in step 2 is uniformly mixed according to the ratio of 1g:4mL, obtains mixing molten Liquid；

Mixed solution is dropped evenly on glass slide, by glass slide in 60 DEG C of dry 1h after being added dropwise, then at 100-200 DEG C Dry 5h, drying finish the composite material for obtaining film-form.

2. Nafion polymer matrix Er according to claim 1³⁺/Yb³⁺The system of codope calcirm-fluoride nanocrystalline composite material Preparation Method, which is characterized in that the composite material with a thickness of 70-150 μm.

3. Nafion polymer matrix Er made of -2 described in any item preparation methods according to claim 1³⁺/Yb³⁺Codope fluorine Change calcium nanocrystalline composite material.