Modified siloxane ligand, CaF2: Tb < 3 + > nanoparticles, CaF2: Tb < 3 + > nanoparticle sol-gel hybrid material and preparation method and application thereof

Abstract

The invention belongs to the field of photoluminescent materials, and particularly relates to a modified siloxane ligand, CaF2: Tb < 3 + > nanoparticles, a CaF2: Tb < 3 + > nanoparticle sol-gel hybrid material as well as a preparation method and application of the modified siloxane ligand, the CaF2: Tb < 3 + > nanoparticles and the CaF2: Tb < 3 + > nanoparticle sol-gel hybrid material. The modified siloxane ligand has a structure as shown in a formula I in the specification. CaF2: Tb < 3 + > nanoparticles are prepared by using the modified siloxane ligand, and a CaF2: Tb < 3 + > nanoparticle sol-gel hybrid material has excellent luminescence performance; # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of photoluminescent materials, and specifically relates to a modified siloxane ligand, CaF2:Tb 3+ Nanoparticles, CaF2:Tb 3+ Nanoparticle sol-gel hybrid materials and preparation methods and applications. Background Art

[0002] The atoms of rare earth elements have an unfilled, shielded 4f5d electronic configuration. This unique electronic structure gives rare earth elements excellent optical properties in photoluminescent materials. Rare earth organic-inorganic hybrid materials have attracted great attention in the field of luminescence as rare earth functional materials. At present, the research on them mainly introduces the lanthanide luminescence center into sol-gel matrix, mesoporous matrix and mesoporous organosilicon. The sol-gel method uses hydrolysis reaction to form sol, waits for the sol to gel, and dries the gel to form an inorganic hybrid material with a spatial network structure. The preparation of rare earth sol-gel hybrid luminescent materials by sol-gel method has the advantages of simple process and equipment, low reaction temperature, high purity and luminescence efficiency. The research on this type of hybrid materials is relatively early and in-depth, and mainly focuses on introducing rare earth organic complexes into sol-gel matrix by chemical doping. Although great breakthroughs have been made in the preparation of rare earth complex sol-gel hybrid luminescent materials by chemical doping methods, there are still problems that need to be solved in this research, such as the need to further improve the optical properties and stability of hybrid materials.

[0003] Compared with rare earth organic complexes, rare earth doped nanoparticles have advantages such as larger Stokes shift, sharper emission spectrum, longer life, higher chemical / optical stability, etc., and have broad application prospects in the fields of light-emitting devices, solar cells, laser materials, chemical analysis, biomedicine, etc. However, rare earth doped nanoparticles have high surface energy and are easy to agglomerate. Directly doping them into the sol-gel matrix is ​​prone to problems such as uneven doping, wide particle size distribution, and even phase separation. Therefore, it is of great significance to seek a substance that can solve this problem and connect rare earth doped nanoparticles with the sol-gel matrix. Summary of the invention

[0004] Based on the above technical problems, the present invention provides a modified siloxane ligand as a multifunctional linker, which can coordinate with rare earth doped nanoparticles to sensitize the central rare earth ions to emit light, and at the same time hydrolyze and condense it with orthosilicate compounds to obtain a hybrid material with CaF2:Tb 3+ The nanoparticles are integrated with the matrix, the nanoparticles are evenly distributed, and have excellent luminescence properties.

[0005] The specific technical solutions provided by the present invention are as follows:

[0006] In a first aspect, the present invention provides a modified siloxane ligand having a structure as shown in Formula I:

[0007]

[0008] in, Selected from R1 is selected from methyl or ethyl, and R2 is selected from -CH2CH2- or -CH2CH(CH3)-.

[0009] In a second aspect of the present invention, a method for preparing the modified siloxane ligand is provided, comprising the following steps:

[0010] Mercaptobenzoic acid is mixed with 3-(methacryloyloxy)propyltrimethoxysilane or 3-(methacryloyloxy)propyltriethoxysilane or 3-(acryloyloxy)propyltrimethoxysilane or 3-(acryloyloxy)propyltriethoxysilane to carry out nucleophilic addition reaction, and the obtained product is the modified siloxane ligand.

[0011] As a preferred embodiment of the present invention, the molar ratio of mercaptobenzoic acid to 3-(methacryloyloxy)propyltrimethoxysilane or 3-(methacryloyloxy)propyltriethoxysilane or 3-(acryloyloxy)propyltrimethoxysilane or 3-(acryloyloxy)propyltriethoxysilane is 1 to 1.05:1.

[0012] As a preferred embodiment of the present invention, the nucleophilic addition reaction is carried out using triethylamine as a catalyst, under the protection of an inert gas, at 60-65° C., and the termination of the reaction is monitored by thin layer chromatography.

[0013] In a third aspect, the present invention provides a modified siloxane ligand for preparing CaF2:Tb 3+ Applications of nanoparticles.

[0014] In a fourth aspect, the present invention provides a CaF2:Tb 3+ The nanoparticles are prepared according to the following steps:

[0015] The modified siloxane ligand, calcium salt, terbium salt and fluoride salt are mixed for coprecipitation reaction to obtain the CaF2:Tb 3+ Nanoparticles.

[0016] In a fifth aspect, the present invention provides a CaF2:Tb 3+ Nanoparticles in the preparation of CaF2:Tb 3+ Applications of Nanoparticle Sol-Gel Hybrid Materials.

[0017] In a sixth aspect of the present invention, there is provided a CaF2:Tb 3+ The nanoparticle sol-gel hybrid material is prepared according to the following steps:

[0018] The CaF2:Tb 3+ The nanoparticles are mixed with the gel precursor solution and then undergo hydrolysis and condensation reactions to form a sol. The reaction product continues to gel and age to obtain the CaF2:Tb 3+ Nanoparticle sol-gel hybrid materials.

[0019] As a preferred embodiment of the present invention, the gel precursor solution is formed by mixing an aqueous solution of polyvinyl alcohol (PVA) with an anhydrous ethanol solution of an orthosilicate compound; the mass volume ratio of the PVA to the orthosilicate compound is 1g:0.8-2mL.

[0020] More preferably, the orthosilicate compound is ethyl orthosilicate or methyl orthosilicate.

[0021] Further preferably, the CaF2:Tb 3+ After the nanoparticles are mixed with the gel precursor solution, acid is added to promote hydrolysis, and then hexamethylenetetramine is added to adjust the pH to about 5. After a single phase is formed, the mixture is sealed and placed at 55°C for 4 days to obtain the CaF2:Tb 3+ Nanoparticle sol-gel hybrid materials.

[0022] In a seventh aspect, the present invention provides a CaF2:Tb 3+ Nanoparticles or the CaF2:Tb 3+ Application of nanoparticle sol-gel hybrid materials as photoluminescent materials.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] The present invention uses aromatic carboxylic acid modified siloxane as a multifunctional bonding ligand, which can be bonded with CaF2:Tb 3+ Nanoparticle coordination, sensitizing center Tb 3+ Ion luminescence, as a precursor of sol-gel reaction, in the presence of orthosilicate compounds and PVA, rare earth doped nanoparticles were chemically grafted onto the skeleton of the sol-gel matrix through hydrolysis and condensation reactions, successfully synthesizing CaF2:Tb 3+ Nanoparticle sol-gel hybrid material. The CaF2:Tb 3+ The nanoparticles are integrated with the matrix, the nanoparticles are evenly distributed, the active components are stable, and the doping concentration is high, which overcomes the shortcomings of uneven doping and phase separation, and makes the hybrid material have excellent luminescence properties and certain toughness.

[0025] PVA has good water solubility, flexibility and ductility. The present invention improves the cracking problem of the gel hybrid material by introducing PVA. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a physical picture of sample B;

[0027] Figure 2 It is CaF2:Tb 3+ Nanoparticle sol-gel hybrid materials;

[0028] Figure 3 is the infrared spectrum of modified siloxane;

[0029] Figure 4 It is CaF2:Tb 3+ Infrared spectra of nanoparticles;

[0030] Figure 5 It is CaF2:Tb 3+ Infrared spectra of nanoparticle sol-gel hybrid materials;

[0031] Figure 6 It is CaF2:Tb 3+ XRD pattern of nanoparticles;

[0032] Figure 7 It is CaF2:Tb 3+ TEM images of nanoparticles;

[0033] Figure 8 It is CaF2:Tb 3+ SEM images of nanoparticle sol-gel hybrid materials;

[0034] Fig. 9 It is CaF2:Tb 3+ Excitation spectrum of nanoparticles (λ em =490nm);

[0035] Fig.10 It is CaF2:Tb 3+ The emission spectrum of nanoparticles (λ ex =265nm);

[0036] Fig.11 It is CaF2:Tb 3+ Excitation spectra of nanoparticle sol-gel hybrid materials (λ em =543nm);

[0037] Fig.12 It is CaF2:Tb 3+ Emission spectra of nanoparticle sol-gel hybrid materials (λ ex=322nm). DETAILED DESCRIPTION

[0038] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below, and preferred embodiments of the present invention are provided. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0040] The atoms of rare earth elements have an unfilled and shielded 4f5d electron configuration. This unique electronic structure gives rare earth elements excellent optical properties in photoluminescent materials. Rare earth organic-inorganic hybrid materials have attracted great attention in the field of luminescence as rare earth functional materials. At present, the research on it mainly introduces the lanthanide luminescence center into sol-gel matrix, mesoporous matrix and mesoporous organosilicon. Although the research on the preparation of rare earth complex sol-gel hybrid luminescent materials by chemical doping has made great breakthroughs, there are still problems that need to be solved in this research, such as the optical properties and stability of hybrid materials need to be further improved.

[0041] Compared with rare earth organic complexes, rare earth-doped nanoparticles have the advantages of larger Stokes shift, sharper emission spectrum, longer lifetime, higher chemical / optical stability, etc. However, rare earth-doped nanoparticles have high surface energy and are easy to agglomerate. Directly doping them into the sol-gel matrix is ​​prone to problems such as uneven doping, wide particle size distribution, and even phase separation.

[0042] Based on this, the present invention provides a modified siloxane ligand having a structure as shown in Formula I:

[0043]

[0044] in, Selected from R1 is selected from methyl or ethyl, and R2 is selected from -CH2CH2- or -CH2CH(CH3)-.

[0045] The modified siloxane ligand is a multifunctional linker that can coordinate with rare earth-doped nanoparticles to sensitize the central rare earth ions to emit light, and at the same time react with orthosilicate compounds to hydrolyze and condense to obtain CaF2:Tb in the hybrid material. 3+ The nanoparticles are integrated with the matrix, the nanoparticles are evenly distributed, and have excellent luminescence properties.

[0046] Example 1

[0047] 1. Synthesis of modified siloxane ligands

[0048] Weigh 0.925g (6.0mmol) of o-mercaptobenzoic acid (thiosalicylic acid) into a three-necked flask, dissolve 15mL of toluene dried with 4A molecular sieves, and then add 1.490g (6mmol) of 3-(methacryloyloxy)propyltrimethoxysilane, add dropwise to the reaction system, add triethylamine as a catalyst, and introduce nitrogen as a reaction protective gas. The mixed solution reacts at 60°C for 5h. After the reaction is completed by monitoring with thin layer chromatography, the solvent is evaporated at 65°C for about 1h using a rotary evaporator, and the modified siloxane ligand is obtained after purification and separation. The NMR data are: 1 H-NMR (CDCl3, 400MHz): 0.68(s,2H), 1.22(t,3H), 1.71(m,2H), 2.61(m,1H), 3.17(t ,2H), 3.58(s,9H), 4.02(t,2H), 7.17(q,1H), 7.34(d,1H), 7.46(q,1H), 8.10(d,1H).

[0049] The specific synthesis route of the modified siloxane ligand is as follows:

[0050]

[0051] 2. CaF2:Tb 3+ Synthesis of nanoparticles

[0052] 1mmol modified siloxane ligand reagent, 4.5mmol Ca(NO3)2·4H2O and 0.024mmol TbCl3·6H2O and 15mL ethylene glycol were added to a three-necked flask and mixed evenly under magnetic stirring. The mixture was heated to 120℃ and stirred for 30min. 8.5mmol NH4F was dissolved in 15mL ethylene glycol and added dropwise to the above mixture. After the reaction was carried out at 120℃ for 6h, the mixture dispersion was naturally cooled to room temperature, separated and purified, and placed in an electric heating blast drying oven to dry and remove moisture to prepare CaF2:Tb 3+ Nanoparticles.

[0053] 3. Research on sol-gel hybrid materials

[0054] 1g of polyvinyl alcohol (PVA) was added to 6mL of deionized water and heated to dissolve, then cooled to room temperature to form an aqueous solution (liquid a), 0.8mL of tetraethyl orthosilicate was measured and dissolved in 9mL of anhydrous ethanol (liquid b), and liquid b was poured into liquid a under magnetic stirring to form a clear solution and stirred for 30 minutes. Then dilute hydrochloric acid (1mol / L) was dripped into the mixed solution to promote hydrolysis (pH=2-3), and after stirring for about 2h, an appropriate amount of hexamethylenetetramine was added to adjust the pH value to about 5, and the mixture was stirred for about 1h. Finally, a single phase was formed and sealed in an oven, and kept at 55°C for about 4 days. During this period, the gel gelled and aged, and the sample solidified into a whole, which was recorded as sample A.

[0055] Similarly, the amount of tetraethyl orthosilicate was adjusted to 1.25 mL, 1.5 mL, and 2 mL respectively dissolved in 9 mL of anhydrous ethanol, and the other conditions were kept the same to prepare the sol, which was then sealed and placed in an oven to gel and age. The samples were solidified into a whole and recorded as sample B, sample C, and sample D. Sample B was the best and could be used for the subsequent formulation selection of sol-gel hybrid materials, see Table 1 and Figure 1 .

[0056] Table 1 Sol-gel hybrid materials prepared under different conditions

[0057]

[0058] 4. CaF2:Tb 3+ Synthesis of Nanoparticle Sol-Gel Hybrid Materials

[0059] 1g of polyvinyl alcohol (PVA) was added to 6mL of deionized water and heated to dissolve, then cooled to room temperature to form an aqueous solution (liquid a). 1.25mL of tetraethyl orthosilicate was measured and dissolved in 9mL of anhydrous ethanol (liquid b). Under magnetic stirring, liquid b was poured into liquid a to form a clear solution, and 50mg of CaF2:Tb was added. 3+ Nanoparticles, and then stirred for 30 minutes. Then dilute hydrochloric acid (1 mol / L) was added to the mixture to promote hydrolysis (pH = 2-3). After stirring for about 2 hours, an appropriate amount of hexamethylenetetramine was added to adjust the pH value to about 5. The mixture was stirred for about 1 hour. Finally, a single phase was formed and sealed and placed in an oven, and kept at 55°C for about 4 days. During this period, the gel gelled and aged, and CaF2:Tb was prepared. 3+ Nanoparticle hybrid xerogel materials, see Figure 2 .

[0060] Example 2

[0061] The difference from Example 1 is that the modified siloxane ligand is different. The specific synthesis process is:

[0062] Weigh 0.925g (6.0mmol) of p-mercaptobenzoic acid and add it to a three-necked flask, measure 15mL of toluene dried with 4A molecular sieves to dissolve, then add 1.490g (6mmol) of 3-(methacryloyloxy)propyltrimethoxysilane, add it dropwise to the reaction system, add triethylamine as a catalyst, and introduce nitrogen as a reaction protective gas. The mixed solution is reacted at 60°C for 5h. After the reaction is completed by monitoring by thin layer chromatography, the solvent is evaporated at 65°C for about 1h using a rotary evaporator, and the modified siloxane ligand is obtained after purification and separation.

[0063] Example 3

[0064] The difference from Example 1 is that the modified siloxane ligand is different. The specific synthesis process is:

[0065] Weigh 0.925g (6.0mmol) of o-mercaptobenzoic acid and add it to a three-necked flask, measure 15mL of toluene dried with 4A molecular sieves to dissolve, then add 1.658g (6mmol) of 3-(acryloyloxy)propyltriethoxysilane, add it dropwise to the reaction system, add triethylamine as a catalyst, and introduce nitrogen as a reaction protection gas. The mixed solution is reacted at 60°C for 5h. After the reaction is completed by monitoring by thin layer chromatography, the solvent is evaporated at 65°C for about 1h using a rotary evaporator, and the modified siloxane ligand is obtained after purification and separation.

[0066] Example 4

[0067] The difference from Example 1 is that the synthesis process of the modified siloxane ligand is different, specifically:

[0068] Weigh 0.971g (6.3mmol) of o-mercaptobenzoic acid (thiosalicylic acid) into a three-necked flask, dissolve 15mL of toluene dried with 4A molecular sieves, and then add 1.490g (6mmol) of 3-(methacryloyloxy)propyltrimethoxysilane, dropwise add to the reaction system, add triethylamine as a catalyst, and introduce nitrogen as a reaction protection gas. The mixed solution is reacted at 65°C for 5h. After the reaction is completed by monitoring by thin layer chromatography, the solvent is evaporated at 65°C for about 1h using a rotary evaporator, and the modified siloxane ligand is obtained after purification and separation.

[0069] Example 5

[0070] The difference from Example 1 is that the synthesis process of the sol-gel hybrid material is different, specifically:

[0071] 1g of polyvinyl alcohol (PVA) was added to 6mL of deionized water and heated to dissolve, then cooled to room temperature to form an aqueous solution (liquid a). 1.25mL of methyl orthosilicate was measured and dissolved in 9mL of anhydrous ethanol (liquid b). Under magnetic stirring, liquid b was poured into liquid a to form a clear solution, and 50mg of CaF2:Tb was added. 3+ Nanoparticles, and then stirred for 30 minutes. Then dilute hydrochloric acid (1 mol / L) was dripped into the mixture to promote hydrolysis (pH = 2-3). After stirring for about 2 hours, an appropriate amount of hexamethylenetetramine was added to adjust the pH value to about 5. The mixture was stirred for about 1 hour. Finally, after a single phase was formed, it was sealed and placed in an oven and kept at 55°C for about 4 days. During this period, the gel gelled and aged, and the hybrid dry gel material was prepared.

[0072] Example 6

[0073] The difference from Example 1 is that the synthesis process of the sol-gel hybrid material is different, specifically:

[0074] 1g of polyvinyl alcohol (PVA) was added to 6mL of deionized water and heated to dissolve, then cooled to room temperature to form an aqueous solution (liquid a). 1.5mL of tetraethyl orthosilicate was measured and dissolved in 9mL of anhydrous ethanol (liquid b). Under magnetic stirring, liquid b was poured into liquid a to form a clear solution, and 50mg of CaF2:Tb was added. 3+ Nanoparticles, and then stirred for 30 minutes. Then dilute hydrochloric acid (1 mol / L) was dripped into the mixture to promote hydrolysis (pH = 2-3). After stirring for about 2 hours, an appropriate amount of hexamethylenetetramine was added to adjust the pH value to about 5. The mixture was stirred for about 1 hour. Finally, after a single phase was formed, it was sealed and placed in an oven and kept at 55°C for about 4 days. During this period, the gel gelled and aged, and the hybrid dry gel material was prepared.

[0075] Since Examples 1 to 6 all prepared the modified siloxane ligands, CaF2:Tb 3+ Nanoparticles and CaF2:Tb 3+ The preparation effects of the nanoparticle sol-gel hybrid material in each embodiment are basically similar, so the present invention below only takes the product prepared in embodiment 1 as an example to illustrate the performance and effects.

[0076] 1. Infrared absorption spectrum analysis

[0077] 1.1 Modified siloxane and CaF2:Tb 3+ Infrared spectroscopy analysis of nanoparticles

[0078] Figure 3 The infrared spectrum of modified siloxane is shown at 2980 and 2884 cm -1The absorption peaks at 2944 cm-1 are the asymmetric and symmetric stretching vibrations of -CH3. -1 The absorption peak is -CH2 asymmetric stretching vibration, 1724cm -1 The absorption peak at 1247 cm -1 The absorption peak at 1118 cm is Si-C stretching vibration. -1 The absorption peak at 800 cm-1 is attributed to the Si-O-Si antisymmetric stretching vibration. -1 The absorption peak at 1038cm is the Si-O-Si symmetric stretching vibration. -1 CSC stretching vibration appeared at , and this characteristic absorption peak indicated that the modified siloxane was successfully synthesized through the addition reaction of o-mercaptobenzoic acid and 3-(methacryloyloxy)propyltrimethoxysilane.

[0079] Figure 4 Shown is CaF2:Tb 3+ Infrared spectrum of nanoparticles, 3430 cm -1 The absorption peak at 1730 cm is the stretching vibration of hydroxyl group. -1 The absorption peak at 1590 cm is the stretching vibration of the ester carbonyl (C=O). -1 The absorption peak at 1380cm is the skeleton vibration of the benzene ring. -1 The absorption peak at 1260 cm is the -CH3 symmetric deformation vibration. -1 The absorption peak at 1090 cm is Si-C stretching vibration. -1 The absorption peak at 1030 cm is the Si-O-Si antisymmetric stretching vibration. -1 The absorption peak at 805 cm is attributed to CSC stretching vibration. -1 The absorption peak at is the Si-O-Si symmetric stretching vibration.

[0080] 1.2 CaF2:Tb 3+ Infrared Spectral Analysis of Nanoparticle Sol-Gel Hybrid Materials

[0081] like Figure 5 As shown, located at 2947cm -1 The absorption peak at 1450cm belongs to the antisymmetric stretching vibration of CH -1 The absorption peak at 1388 cm belongs to the asymmetric deformation vibration of CH. -1 The absorption peak at 1724cm belongs to CH symmetric deformation vibration. -1 The absorption peak at 1098 cm is the stretching vibration of the ester carbonyl (C=O). -1 The absorption peak at 812 cm is the Si-O-Si antisymmetric stretching vibration. -1The absorption peak at is attributed to the Si-O-Si symmetric stretching vibration.

[0082] 2. XRD analysis

[0083] Figure 6 CaF2:Tb 3+ The XRD pattern of the nanoparticles showed five obvious diffraction peaks in the range of 10° to 85°. The diffraction peaks were consistent with the CaF2 standard card (PDF#35-0816), and no other impurity peaks were found, indicating that Tb 3+ When ions enter the CaF2 lattice, the unit cell does not expand or contract, and it is a single-phase crystal with a CaF2 cubic phase structure.

[0084] 3. Transmission electron microscopy analysis (TEM)

[0085] Figure 7 Shows CaF2:Tb 3+ The microstructure of the nanoparticles. 3+ The nanoparticles are approximately elliptical in shape, and CaF2:Tb 3+ The size distribution of the nanoparticles is narrow, and CaF2:Tb can be observed at higher resolution. 3+ Lattice fringes of nanoparticles, observed for CaF2:Tb 3+ The particle size of the nanoparticles is mainly distributed between 15 and 20 nm. 3+ The nanoparticles are well dispersed and have no obvious agglomeration.

[0086] 4. Scanning Electron Microscope (SEM)

[0087] Figure 8 CaF2:Tb 3+ Scanning electron microscopy (SEM) images of nanoparticle sol-gel hybrid materials. From the low-magnification image, it can be seen that the prepared CaF2:Tb 3+ The surface of the nanoparticle sol-gel hybrid material is uneven, forming a cross-linked network structure. CaF2:Tb can be observed in the high-magnification image. 3+ The nanoparticles are evenly distributed in the sol-gel matrix, CaF2:Tb 3+ The nanoparticles are combined with the sol-gel matrix through chemical bonds to effectively avoid phase separation and achieve hybridization at the molecular level.

[0088] 5. Fluorescence performance analysis

[0089] 5.1 CaF2:Tb 3+ Fluorescence properties of nanoparticles

[0090] Fig. 9CaF2:Tb at room temperature 3+ Excitation spectrum of nanoparticles (λ em =490nm). As shown in the figure, the excitation spectrum wavelength range of the nanoparticles is 260-290nm, and the central wavelength of the broadband peak is 279nm, which is the absorption of the modified siloxane, indicating that the modified siloxane can effectively sensitize Tb 3+ Glow.

[0091] Fig.10 CaF2:Tb at room temperature 3+ Nanoparticles at the excitation wavelength λ ex = The emission spectrum at 265nm will exceed the measurement range if measured at the maximum excitation wavelength (279nm). Fig.10 It can be seen that the strongest emission peak is at 543nm, corresponding to Tb 3+ of 5 D4- 7 F5 transition is a magnetic dipole transition, and the other three peaks are located at 490nm ( 5 D4- 7 F6), 588nm( 5 D4- 7 F4), 623nm( 5 D4- 7 F3).

[0092] 5.2 CaF2:Tb 3+ Fluorescence properties of nanoparticle sol-gel hybrid materials

[0093] Fig.11 Demonstrated room temperature CaF2:Tb 3+ Excitation spectra of nanoparticle sol-gel hybrid materials (λ em =543nm). Fig.11 As shown, CaF2:Tb 3+ The excitation spectrum wavelength range of the nanoparticle sol-gel hybrid material is 275-400 nm, and the central wavelength of the broadband excitation peak is 322 nm.

[0094] Fig.12 CaF2:Tb at room temperature 3+ Nanoparticle sol-gel hybrid materials at the excitation wavelength λ ex =Emission spectrum at 322nm, such as Fig.12 As shown, CaF2:Tb 3+ Nanoparticle sol-gel hybrid materials show Tb 3+ The characteristic emission peak of the quartz crystal is located at 544nm ( 5 D4- 7 F5), the other three peaks are at 490nm (5 D4- 7 F6), 587nm( 5 D4- 7 F4), 623nm( 5 D4- 7 F3), which is basically consistent with the fluorescence emission peak of the nanoparticles.

[0095] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A modified siloxane ligand, characterized in that: It has a structure as shown in Formula I: in, Selected from R1 is selected from methyl or ethyl, and R2 is selected from -CH2CH2- or -CH2CH(CH3)-.

2. A method for preparing the modified siloxane ligand according to claim 1, characterized in that: The following steps are involved: Mercaptobenzoic acid is mixed with 3-(methacryloyloxy)propyltrimethoxysilane or 3-(methacryloyloxy)propyltriethoxysilane or 3-(acryloyloxy)propyltrimethoxysilane or 3-(acryloyloxy)propyltriethoxysilane to carry out nucleophilic addition reaction, and the obtained product is the modified siloxane ligand.

3. The method for preparing the modified siloxane ligand according to claim 2, characterized in that: The molar ratio of the mercaptobenzoic acid to 3-(methacryloyloxy)propyltrimethoxysilane or 3-(methacryloyloxy)propyltriethoxysilane or 3-(acryloyloxy)propyltrimethoxysilane or 3-(acryloyloxy)propyltriethoxysilane is 1-1.05:

1.

4. The method for preparing a modified siloxane ligand according to claim 2, characterized in that: The free radical addition reaction uses triethylamine as a catalyst, reacts at 60-65° C. under the protection of an inert gas, and terminates the reaction by monitoring the reaction using thin layer chromatography.

5. A modified siloxane ligand according to claim 1 in the preparation of CaF2:Tb 3+ Applications of nanoparticles.

6. A CaF2:Tb 3+ Nanoparticles, characterized in that It is prepared according to the following steps: The modified siloxane ligand of claim 1, calcium salt, terbium salt and fluoride salt are mixed for coprecipitation reaction to obtain the CaF2:Tb 3+ Nanoparticles.

7. A CaF2:Tb as claimed in claim 6 3+ Nanoparticles in the preparation of CaF2:Tb 3+ Applications of Nanoparticle Sol-Gel Hybrid Materials.

8. A CaF2:Tb 3+ Nanoparticle sol-gel hybrid material, characterized in that It is prepared according to the following steps: The CaF2:Tb 3+ The nanoparticles are mixed with the gel precursor solution to undergo hydrolysis and condensation to form a sol, which is then gelled and aged to obtain the CaF2:Tb 3+ Nanoparticle sol-gel hybrid materials.

9. CaF2:Tb according to claim 8 3+ Nanoparticle sol-gel hybrid material, characterized in that The gel precursor solution is prepared by mixing a polyvinyl alcohol aqueous solution with an anhydrous ethanol solution of an orthosilicate compound; the mass volume ratio of the polyvinyl alcohol to the orthosilicate compound is 1 g: 0.8-2 mL.

10. A CaF2:Tb as claimed in claim 6 3+ Nanoparticles or CaF2:Tb as claimed in claim 8 3+ Application of nanoparticle sol-gel hybrid materials as photoluminescent materials.

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