Alkali metal sulfide nanocrystalline dispersed glass and preparation method thereof

Abstract

The present invention discloses an alkali metal sulfide nanocrystal dispersed glass and a preparation method thereof. The alkali metal sulfide nanocrystal dispersed glass comprises a glass matrix and alkali metal sulfide nanocrystals within the glass matrix. The glass components, measured in molar percentage, include: SiO2: 40-70; Al2O3: 0-15; B2O3: 0-15; M2O: 0-30; NO: 0-4; and M2S: 15-45, the sum of which is 100, where M represents an alkali metal element and N represents an alkaline earth metal element. The present invention achieves controllable preparation of alkali metal sulfide nanocrystals in glass through composition design and heat treatment process regulation. The preparation process is simple, the nanocrystal size is controllable, and the cost is low.

Description

Technical Field

[0001] The present invention relates to a preparation method of alkali metal sulfide nanocrystals, and in particular to an alkali metal sulfide nanocrystal dispersed glass and a preparation method thereof. Background Art

[0002] Alkali metal sulfides, characterized by low phonon energy, wide band gaps, and high infrared transmittance, are excellent fluorescent matrix materials with enormous potential for applications in bioimaging, information storage, and LEDs. Alkali metal sulfides have also attracted significant attention due to their high ionic conductivity, offering promising applications in solid-state electrolytes.

[0003] However, the inherently poor stability of sulfides has limited their further application. Glass has a dense network structure and excellent chemical and thermal stability. Crystallization of alkali sulfide nanocrystals within glass can significantly improve its stability. However, to date, alkali sulfide nanocrystal dispersed glass is primarily prepared through mechanical grinding, a method that is cumbersome, time-consuming, and requires a high-pressure atmosphere. Summary of the Invention

[0004] The present invention aims to provide an alkali metal sulfide nanocrystalline dispersed glass and a preparation method thereof, wherein the preparation process is simple, the nanocrystalline size is controllable, and the cost is low.

[0005] The solution adopted by the present invention to solve the above technical problems is:

[0006] The invention discloses an alkali metal sulfide nanocrystal dispersed glass, which comprises a glass matrix and alkali metal sulfide nanocrystals in the glass matrix.

[0007] Preferably, the glass components include, in molar percentage, SiO2: 40-70; Al2O3: 0-15; B2O3: 0-15; M2O: 0-30; NO: 0-4; M2S: 15-45, and the sum of the above glass components is 100, where M represents an alkali metal element and N represents an alkaline earth metal element.

[0008] In the embodiment of the present invention, the alkali metal element required to form the alkali metal sulfide nanocrystals is introduced in the form of alkali metal oxide or alkali metal sulfide, and the S element required to form the alkali metal sulfide nanocrystals is introduced in the form of alkali metal sulfide.

[0009] Preferably, in the glass component, M is one of Li and Na or a combination of two of them; N is one of Ca, Sr, and Ba or a combination of any two or more of them.

[0010] Preferably, the M is Na.

[0011] The preparation method of the alkali metal sulfide nanocrystalline dispersed glass comprises the following steps: weighing all raw materials according to the above composition and mixing them uniformly, placing them in a crucible, melting them at 1300°C to 1500°C for 30 minutes to 60 minutes, then shaping and cooling them, and annealing them to obtain red transparent glass; and heat treating them at 400°C to 650°C for 5 to 30 hours to obtain the alkali metal sulfide nanocrystalline dispersed glass.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The present invention adopts a melt quenching-heat treatment method to prepare alkali metal sulfide nanocrystals in glass, which has a simple preparation process and low cost. The present invention embeds the alkali metal sulfide nanocrystals into the glass matrix, which can effectively utilize the excellent thermal stability, chemical stability and mechanical strength of the glass, improve the stability of the alkali metal sulfide nanocrystals, and has important application value in the development of new functional materials and devices based on alkali metal sulfide nanocrystal dispersed glass. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In the following figures, AP represents the original glass sample, that is, the glass sample that has not been heat-treated; in the following figures, in the expression of XXXXX, the first three digits represent the sample heat treatment temperature (°C), and the last two digits represent the sample heat treatment time (hours).

[0015] Figure 1 1 is the X-ray diffraction pattern of AP and heat-treated samples in Example 1.

[0016] Figure 2 2 is the X-ray diffraction pattern of AP and heat-treated samples in Example 2.

[0017] Figure 3 This is the X-ray diffraction pattern of the heat-treated sample in Example 3.

[0018] Figure 4 This is the X-ray diffraction pattern of the heat-treated sample in Example 4.

[0019] Figure 5 This is the X-ray diffraction pattern of the heat-treated sample in Example 5.

[0020] Figure 6 2 is the X-ray diffraction pattern of AP and heat-treated samples in Example 6.

[0021] Figure 7 This is the X-ray diffraction pattern of the heat-treated sample in Example 7.

[0022] Figure 8 This is the X-ray diffraction pattern of the heat-treated sample in Comparative Example 5.

[0023] Figure 9 This is the X-ray diffraction pattern of the heat-treated sample in Comparative Example 6. DETAILED DESCRIPTION

[0024] The present invention is further described below with reference to the accompanying drawings and examples, but the present invention is not limited to the following examples. The glasses described in the following examples and comparative examples were melted at 1350°C for 30 minutes, rapidly cooled, formed, and annealed to produce red, transparent glass. After heat treatment, alkali metal sulfide nanocrystals were precipitated in the glass samples.

[0025] Table 1 Composition (molar percentage) of the alkali metal sulfide nanocrystalline dispersed glass obtained in Examples 1 to 7

[0026]

[0027] Example 1: The glass composition of Example 1 (in molar percentage) is: 40SiO2-10Al2O3-5B2O3-15Na2O-30Na2S. After forming and cooling, a red transparent glass sample is obtained. After the sample is heat-treated at 520°C for 10 hours, Na2S nanocrystals and NaS nanocrystals are precipitated in the glass. The measured XRD pattern is as follows: Figure 1 As shown in the figure, the unheated AP sample only has the glass's mantou peak, while the heat-treated sample shows obvious crystal diffraction peaks. These peaks correspond to the diffraction peaks of Na2S (PDF#65-525) crystals and NaS (PDF#65-1997) crystals, respectively, indicating the precipitation of Na2S nanocrystals and NaS nanocrystals in the glass.

[0028] Example 2: The glass composition of Example 2 (in molar percentage) is: 45SiO2-15Al2O3-10Na2O-28Na2S-2Li2S. After forming and cooling, a red transparent glass sample is obtained. After the sample is heat-treated at 540°C for 10 hours, Na2S nanocrystals and NaS nanocrystals are precipitated in the glass. The measured XRD pattern is as follows: Figure 2 As shown in the figure, the unheated AP sample only has the glass's mantou peak, while the heat-treated sample shows obvious crystal diffraction peaks. These peaks correspond to the diffraction peaks of Na2S (PDF#65-525) crystals and NaS (PDF#65-1997) crystals, respectively, indicating the precipitation of Na2S nanocrystals and NaS nanocrystals in the glass.

[0029] Example 3: The glass composition of Example 3 (in molar percentage) is: 45SiO2-15B2O3-8Na2O-2Li2O-30Na2S. After forming and cooling, a red transparent glass sample is obtained. After the sample is heat-treated at 480°C for 10 hours, Na2S nanocrystals and NaS nanocrystals are precipitated in the glass. The measured XRD pattern is as follows: Figure 3 As shown in the figure, the sample after heat treatment has crystal diffraction peaks, which correspond to the diffraction peaks of Na2S (PDF#65-525) crystals and NaS (PDF#65-1997) crystals, respectively, indicating the precipitation of Na2S nanocrystals and NaS nanocrystals in the glass.

[0030] Example 4: The glass composition of Example 4 (in molar percentage) is: 50SiO2-1B2O3-4BaO-30Na2O-15Na2S. After forming and cooling, a red transparent glass sample is obtained. After the sample is heat-treated at 520°C for 10 hours, NaS nanocrystals are precipitated in the glass. The XRD pattern thereof is shown below. Figure 4 As shown in the figure, it can be seen that the sample after heat treatment has a crystal diffraction peak, which corresponds to the diffraction peak of NaS (PDF#65-1997) crystal, indicating the precipitation of NaS nanocrystals in the glass.

[0031] Example 5: The glass composition of Example 5 (in molar percentage) is: 50SiO2-3B2O3-1CaO-1SrO-45Na2S. After forming and cooling, a red transparent glass sample is obtained. After the sample is heat-treated at 480°C for 10 hours, Na2S nanocrystals and NaS nanocrystals are precipitated in the glass. The measured XRD pattern is as follows: Figure 5 As shown in the figure, it can be seen that after heat treatment, the sample has obvious crystal diffraction peaks, which correspond to the diffraction peaks of Na2S (PDF#65-525) crystals and NaS (PDF#65-1997) crystals, respectively, indicating the precipitation of Na2S nanocrystals and NaS nanocrystals in the glass.

[0032] Example 6: The glass composition of Example 6 (in molar percentage) is: 60SiO2-5Al2O3-5B2O3-30Li2S. After forming and cooling, the glass sample is red and transparent. After the sample is heat-treated at 600°C for 10 hours, Li2S nanocrystals are precipitated in the glass. The measured XRD pattern is as follows: Figure 6 As shown in the figure, it can be seen that the AP sample without heat treatment has only the mantou peak of glass, and the sample after heat treatment has obvious crystal diffraction peaks, which are respectively related to Li2S (PDF#65-2981) crystal and Li x Al x Si 3-xO6 (PDF#31-707) crystal diffraction peaks correspond to the Li2S nanocrystals precipitated in the glass. x Al x Si 3-x O6 crystals precipitated.

[0033] Example 7: The glass composition of Example 7 (in molar percentage) is: 70SiO2-30Na2S. After forming and cooling, a red transparent glass sample is obtained. After the sample is heat-treated at 500°C for 10 hours, Na2S nanocrystals and NaS nanocrystals are precipitated in the glass. The measured XRD pattern is as follows: Figure 7 As shown in the figure, it can be seen that after heat treatment, the sample has obvious crystal diffraction peaks, which correspond to the diffraction peaks of Na2S (PDF#65-525) crystals and NaS (PDF#65-1997) crystals, respectively, indicating the precipitation of Na2S nanocrystals and NaS nanocrystals in the glass.

[0034] Table 2 Glass composition in comparative example 1 (molar percentage)

[0035] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[B2O3]]> <![CDATA[Na2O]]> <![CDATA[Na2S]]> Example 1 40 10 5 15 30 Comparative Example 1 39 10 6 15 30

[0036] Comparative Example 1: The composition (in mole percentage) of Comparative Example 1 was: 39SiO2 - 10Al2O3 - 6B2O3 - 15Na2O - 30Na2S. After forming and cooling, no transparent glass was obtained. Compared with Example 1, the SiO2 content in Comparative Example 1 was reduced, resulting in glass phase separation. The SiO2 content in Comparative Example 1 exceeded the scope of the claims of the present invention. Although alkali metal sulfide nanocrystals were produced, transparent glass could not be obtained due to glass phase separation.

[0037] Table 3 Glass composition in comparative example 2 (molar percentage)

[0038] <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Na2O]]> <![CDATA[Na2S]]> <![CDATA[Li2S]]> Example 2 45 15 10 28 2 Comparative Example 2 44 16 10 28 2

[0039] Comparative Example 2: The composition of Comparative Example 2 (in molar percentage) is 44SiO2-16Al2O3-10Na2O-28Na2S-2Li2S. After forming and cooling, it is a red, transparent glass sample. Compared with Example 2, the Al2O3 content in Comparative Example 2 is increased, and the glass sample does not crystallize after heat treatment. The Al2O3 content in the composition of Comparative Example 2 exceeds the scope of the claims of the present invention and does not have the ability to prepare alkali metal sulfide nanocrystals.

[0040] Table 4 Glass composition in comparative example 3 (molar percentage)

[0041] <![CDATA[SiO2]]> <![CDATA[B2O3]]> <![CDATA[Na2O]]> <![CDATA[Li2O]]> <![CDATA[Na2S]]> Example 3 45 15 8 2 30 Comparative Example 3 44 16 8 2 30

[0042] Comparative Example 3: The composition of Comparative Example 3 (in molar percentage) is 44SiO2-16B2O3-8Na2O-2Li2O-30Na2S. After forming and cooling, it is a red and transparent glass sample. Compared with Example 3, the B2O3 content in Comparative Example 3 is increased, and the glass sample does not crystallize after heat treatment. The B2O3 content in the composition of Comparative Example 3 exceeds the scope of the claims of the present invention and does not have the ability to prepare alkali metal sulfide nanocrystals.

[0043] Table 5 Glass composition in comparative examples 4 and 5 (molar percentage)

[0044] <![CDATA[SiO2]]> <![CDATA[B2O3]]> BaO <![CDATA[Na2O]]> <![CDATA[Na2S]]> Example 4 50 1 4 30 15 Comparative Example 4 50 1 3 31 15 Comparative Example 5 50 2 4 30 14 Comparative Example 6 50 1 5 29 15

[0045] Comparative Example 4: The composition (in mole percentage) of Comparative Example 4 was: 50% SiO₂ - 1% B₂O₃ - 3% BaO - 3% Na₂O - 1% Na₂S. After forming and cooling, no transparent glass was obtained. Compared with Example 4, the increased Na₂O content in Comparative Example 4 resulted in glass phase separation. The Na₂O content in Comparative Example 4 exceeds the scope of the claims of the present invention. Although alkali metal sulfide nanocrystals were produced, transparent glass could not be obtained due to glass phase separation.

[0046] Comparative Example 5: The composition (in molar percentage) of Comparative Example 5 is 50SiO2-2B2O3-4BaO-30Na2O-14Na2S. After forming and cooling, the glass sample is red and transparent. The XRD pattern measured after heat treatment is as follows: Figure 8 Compared to Example 4, the Na2S content in Comparative Example 5 is reduced, resulting in the precipitation of Na2SiO3 crystals after glass heat treatment, without precipitation of alkali metal sulfide nanocrystals. The Na2S content in the composition of Comparative Example 5 exceeds the scope of the claims of the present invention and is not capable of producing alkali metal sulfide nanocrystals.

[0047] Comparative Example 6: The composition (in molar percentage) of Comparative Example 6 is 50SiO2-1B2O3-5BaO-29Na2O-15Na2S. After forming and cooling, the glass sample is red and transparent. The XRD pattern measured after heat treatment is as follows: Figure 9 Compared to Example 4, the increased BaO content in Comparative Example 6 resulted in the preferential precipitation of BaS nanocrystals after glass heat treatment, with no precipitation of alkali metal sulfide nanocrystals. The BaO content in the composition of Comparative Example 6 exceeds the scope of the claims of the present invention and is not capable of producing alkali metal sulfide nanocrystals.

[0048] Table 6 Glass composition in comparative example 7 (molar percentage)

[0049] <![CDATA[SiO2]]> <![CDATA[B2O3]]> CaO SrO <![CDATA[Na2S]]> Example 5 50 3 1 1 45 Comparative Example 7 50 2 1 1 46

[0050] Comparative Example 7: The composition (in mole percentage) of Comparative Example 7 was: 50% SiO₂ - 2% B₂O₃ - 1% CaO - 1% SrO - 46% Na₂S. After forming and cooling, no transparent glass was obtained. Compared with Example 5, the increased Na₂S content in Comparative Example 7 resulted in glass phase separation. The Na₂S content in Comparative Example 7 exceeds the claimed range of the present invention. Although alkali metal sulfide nanocrystals were produced, transparent glass could not be obtained due to glass phase separation.

[0051] Table 7 Glass composition in Comparative Example 8 (molar percentage)

[0052] <![CDATA[SiO2]]> <![CDATA[Na2S]]> Example 7 70 30 Comparative Example 8 71 29

[0053] Comparative Example 8: The composition of Comparative Example 8 (in molar percentage) is 71SiO2-29Na2S, and after forming and cooling, it is a red, transparent glass sample. Compared with Example 7, the SiO2 content in Comparative Example 8 is increased, and the glass sample does not crystallize after heat treatment. The SiO2 content in the composition of Comparative Example 8 exceeds the scope of the claims of the present invention and does not have the ability to prepare alkali metal sulfide nanocrystals.

Claims

1. An alkali metal sulfide nanocrystalline dispersed glass, characterized in that: The alkali metal sulfide nanocrystal dispersed glass includes a glass matrix and alkali metal sulfide nanocrystals in the glass matrix. The glass components, calculated in molar percentage, include: SiO2: 40-70; Al2O3: 0-15; B2O3: 0-15; M2O: 0-30; NO: 0-4; M2S: 15-45, and the sum of the above glass components is 100, wherein M represents an alkali metal element and N represents an alkaline earth metal element. The contents of Al2O3, B2O3, M2O and NO are not all zero at the same time, and the alkali metal sulfide nanocrystals are one or a mixture of Na2S nanocrystals and NaS nanocrystals.

2. The alkali metal sulfide nanocrystalline dispersed glass according to claim 1, characterized in that: In the glass component, M is one of Li and Na or a combination of two of them; N is one of Ca, Sr, and Ba or a combination of any two or more of them.

3. The alkali metal sulfide nanocrystalline dispersed glass according to claim 2, characterized in that: Preferably, the M is Na.

4. A method for preparing the alkali metal sulfide nanocrystalline dispersed glass according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: weighing all raw materials according to the above composition, mixing them uniformly, placing them in a crucible, melting them, shaping them, cooling them, and annealing them to obtain red transparent glass; and heat treating them at 400-650°C for 5-30 hours to obtain alkali metal sulfide nanocrystalline dispersed glass.

5. The preparation method according to claim 4, characterized in that The specific melting steps are: melting at 1300°C to 1500°C for 30 min to 60 min.

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