A highly luminescent gold-copper nanocluster and its application in preparing luminescent ink
By using gold-copper nanoclusters combined with high molecular polymers to prepare luminescent inks, the synthesis complexity and stability problems of existing luminescent inks are solved, and efficient and waterproof luminescent ink applications are achieved, which are suitable for printing anti-counterfeiting layers and QR codes.
Patent Information
- Application Number
- CN202310317798.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-03-29
- Publication Date
- 2025-09-30
- Estimated Expiration
- 2043-03-29
AI Technical Summary
Existing luminescent ink materials have defects such as complex synthesis, low yield, high toxicity, poor stability, and non-waterproofness, which make it difficult to meet the needs of functional coatings, anti-counterfeiting printing and information encryption.
Gold-copper nanoclusters are used as luminescent materials and combined with high molecular polymers to prepare luminescent inks. The high photoluminescence quantum yield and high stability of gold-copper nanoclusters are utilized to form luminescent inks that are easy to synthesize.
The efficient preparation of luminescent ink has been achieved, which has good printing clarity, luminous intensity and waterproofness. It is suitable for printing anti-counterfeiting layers and QR codes and has good practical application value.
Smart Images
Figure CN116332966B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a nano material and an application thereof, and in particular to a highly luminescent gold-copper nano cluster and an application thereof in preparing luminescent ink. Background Art
[0002] Metal nanoclusters are a new type of metallic nanomaterial, composed of a few to hundreds of metal atoms. Due to their quantum size effects and discrete electronic energy levels, metal nanoclusters possess optical, catalytic, magnetic, and electrochemical properties. Due to the synergistic effects between different metals, alloy nanoclusters often exhibit even better optical properties. In recent years, metal nanoclusters have been developed as fluorescent probes, cell markers, bioimaging, and light-emitting diodes due to their excellent photostability, thermal stability, and low toxicity.
[0003] Luminescent inks are widely used in functional coatings, anti-counterfeiting printing, information encryption, and artistic painting. Current luminescent inks primarily consist of organic dyes, semiconductor quantum dots, inorganic perovskites, rare earth metals, and carbon dots. However, these materials suffer from complex synthesis, low yield, high toxicity, poor stability, and resistance to water resistance.
[0004] Gold-copper nanoclusters exhibit high photoluminescence quantum yields due to ligand-to-metal charge transfer. Furthermore, they exhibit efficient triplet sensitization, enabling phosphorescence emission. Furthermore, their synthesis is simple and yields high yields. Therefore, synthesizing gold-copper nanoclusters and using them in the preparation of luminescent inks is an effective approach to addressing the shortcomings of current luminescent inks. Summary of the Invention
[0005] The present invention provides highly luminescent gold-copper nanoclusters and their use in the preparation of luminescent inks. These gold-copper nanoclusters exhibit fluorescent and phosphorescent emission, high quantum yield, excellent stability, high yield, and ease of synthesis. These gold-copper nanoclusters, when combined with a polymer, form luminescent inks that can be used to print anti-counterfeiting coatings and QR codes. These luminescent inks based on gold-copper nanoclusters offer advantages such as clear printing, strong luminescence, and excellent water resistance, thus possessing excellent practical application value.
[0006] The molecular formula of the highly luminescent gold-copper nanoclusters of the present invention is shown in the following formula (1):
[0007] Au2Cu6(R1)6(R2)2——Formula (1);
[0008] Where R1 is C 10 H 15 S - 、C4H9S - One of the following;
[0009] R2 is (C6H5)2PCH2CH2P(C6H5)2, (C6H5)2PCH2CH2CH2P(C6H5)2,
[0010] (C6H5)2PCH2CH2CH2CH2P(C6H5)2, (C6H5)2PCH2CH2CH2CH2CH2P(C6H5)2,
[0011] One of (C6H5)2PCH2CH2CH2CH2CH2CH2CH2P(C6H5)2, (C6H5)2PCH2CH2CH2CH2CH2CH2CH2CH2CH2P(C6H5)2.
[0012] The gold-copper nanocluster of the present invention has a hexagonal ring pattern consisting of six copper atoms and six thiol ligands at the waist, and a rod-shaped pattern consisting of two gold atoms and two organic phosphine ligands at the head and tail. The gold-copper nanocluster is electrically neutral as a whole. For the specific structure, see Figure 1 .
[0013] The excitation wavelength of the gold-copper nanoclusters of the present invention is 300-650nm.
[0014] The method for preparing the highly luminescent gold-copper nanoclusters of the present invention comprises the following steps:
[0015] Step 1: Dissolve chloroauric acid aqueous solution and tetraoctylammonium bromide in an organic volatile solvent and react at 10-30°C for 10 minutes;
[0016] Step 2: Add copper chloride to the mixture in step 1 and react for 30 minutes;
[0017] Step 3: adding an organic phosphine ligand and a thiol ligand to the system of step 2 in sequence and reacting for 30 minutes;
[0018] Step 4: Add the reducing agent to the system of step 3 and react for 12 hours;
[0019] Step 5: removing the aqueous solution from the reaction solution obtained in step 4, evaporating the organic solvent under reduced pressure, and extracting the obtained product with a mixed solution of dichloromethane and n-hexane and evaporating under reduced pressure;
[0020] Step 6: Use a large amount of organic solvent to wash the product obtained in step 5 to obtain gold-copper nanoclusters Au2Cu6(R1)6(R2)2.
[0021] In step 1, the concentration of the chloroauric acid aqueous solution is 0.1-0.5 g / mL.
[0022] In step 1, the molar ratio of chloroauric acid to tetraoctylammonium bromide is 1:0.5-1.5.
[0023] In step 1, the organic volatile solvent is selected from one or more of dichloromethane, methanol, ethanol, acetone, and tetrahydrofuran.
[0024] In step 2, the molar ratio of the copper chloride to the chloroauric acid is 1:1 to 1.5.
[0025] In step 3, the mass ratio of the organic phosphine ligand to the thiol ligand is 1:1.
[0026] In step 3, the mass ratio of the chloroauric acid to the organophosphine ligand is 1:1-2.
[0027] In step 4, the reducing agent is one or more of sodium borohydride, potassium borohydride, borane-tert-butylamine complex, and sodium cyanoborohydride; and the molar ratio of chloroauric acid to the reducing agent is 1:0.05-0.1.
[0028] In step 5, the volume ratio of dichloromethane to n-hexane is 1:3-5.
[0029] In step 6, the organic solvent is one of methanol, ethanol and ether.
[0030] The organic phosphine ligand is one of 1,2-(bisdiphenylphosphine)ethane, 1,3-(bisdiphenylphosphine)propane, 1,4-(bisdiphenylphosphine)butane, 1,5-(bisdiphenylphosphine)pentane, 1,6-(bisdiphenylphosphine)hexane and 1,8-(bisdiphenylphosphine)octane.
[0031] The application of the highly luminescent gold-copper nanoclusters of the present invention is to combine the gold-copper nanoclusters with a high molecular polymer to form a luminescent ink, which specifically includes the following steps:
[0032] Step 1: dissolving the polymer in an organic volatile solvent;
[0033] Step 2: Dissolve the gold-copper nanoclusters in the solution of step 1 and stir evenly.
[0034] In step 1, the high molecular polymer is selected from one or more of polystyrene, polymethyl phenylene, and polyurethane.
[0035] In step 1, the organic volatile solvent is selected from one or more of dichloromethane, acetone, and tetrahydrofuran.
[0036] In step 2, the mass ratio of the gold-copper nanoclusters to the high molecular polymer is 1:100-500.
[0037] Compared with the prior art, the beneficial effects of the present invention are embodied in:
[0038] 1. Chloroauric acid is used as the gold source and cupric chloride is used as the copper source. The raw materials are easily available. Organic phosphine and thiol are used as ligands, and the raw material cost is low.
[0039] 2. The gold-copper nanoclusters of the present invention have a defined structure, and the purity of the product is easy to monitor.
[0040] 3. The synthesis method is simple and easy to operate, with high yield and suitable for large-scale production.
[0041] 4. Excellent optical properties. From ultraviolet to yellow light, the target product can be excited to produce red light, and the emission wavelength does not change with the change of excitation wavelength.
[0042] 5. The luminescent ink of the present invention has good hydrophobicity, and the anti-counterfeiting layer and QR code prepared therefrom are not affected by water.
[0043] 6. The anti-counterfeiting layer obtained by the luminescent ink of the present invention has good flexibility and is not easily damaged by external forces.
[0044] 7. The two-dimensional code made of the luminescent ink of the present invention has good concealment under visible light and can effectively encrypt information. BRIEF DESCRIPTION OF THE DRAWINGS
[0045] Figure 1 This is a structural diagram of the gold-copper nanoclusters of the present invention. Figure 1 Is Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 After crystallization, single crystal XRD test was performed, and the test results were analyzed and refined. 26 H 24 O)6(SC 10 H 15 )2Structural diagram of nanoclusters.
[0046] Figure 2 The Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 ) Actual picture of 2 nanoclusters. Figure 2 It represents Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2Photographs of nanocluster solution and solid powder under visible and ultraviolet light.
[0047] Figure 3 The Au2Cu6(P2C 26 H 24 O)6(SC10 H 15 )2 nanocluster’s UV (dashed line on the left), photoluminescence excitation spectrum (solid line on the left), and photoluminescence emission spectrum (solid line on the right). Figure 3 It can be seen that Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanoclusters can be excited using light with a wavelength of 300-650nm, and strong luminescence can be obtained within this excitation band.
[0048] Figure 4 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 ) Actual photo of the printed luminescent ink with 2 nanoclusters. Figure 4 It represents the Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )Photographs of prints of the luminescent ink containing 2 nanoclusters under visible and ultraviolet light.
[0049] Figure 5 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanocluster luminescent ink emission spectrum. Figure 3 It can be seen that based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanoclusters and the luminescent ink of Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )The emission spectra of the 2 nanoclusters are the same.
[0050] Figure 6 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 Transmittance graph of a printed strip of luminescent ink containing nanoclusters. Figure 6 It represents the Au2Cu6(P2C 26 H 24 O)6(SC 10 H15 )2 Transmittance of printed tapes of luminescent ink containing nanoclusters.
[0051] Figure 7 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanocluster luminescent ink printed anti-counterfeiting layer photo. Figure 7 It can be seen that the text and pattern on the lower layer can be identified through the anti-counterfeiting layer under visible light, and the anti-counterfeiting layer produces red light emission under ultraviolet light.
[0052] Figure 8 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 The contact angle of the anti-counterfeiting layer printed with the luminescent ink of nanoclusters. Figure 8 It can be seen that based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 ) The anti-counterfeiting layer printed with the luminescent ink of 2 nanoclusters is hydrophobic.
[0053] Figure 9 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanocluster luminescent ink printed anti-counterfeiting layer in dry and wet luminescence photos. Figure 9 It can be seen that water has a great influence on the Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 The luminescence of the anti-counterfeiting layer printed with the luminescent ink of nanoclusters has no effect.
[0054] Figure 10 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2Bending test of the anti-counterfeiting layer printed with luminescent ink of nanoclusters. Figure 10 It can be seen that based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15) The anti-counterfeiting layer printed with luminescent ink containing 2 nanoclusters can return to its original state after being bent to 180°.
[0055] Figure 11 The present invention is based on Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanoclusters and luminescent inks based on [Au 13 Ag 12 (TPP) 10 Photo of a QR code printed with Cl8]Cl nanocluster non-luminescent ink. Figure 11 It can be seen that the QR code is almost indistinguishable under visible light, but can be identified under ultraviolet light, and can be identified more clearly under ultraviolet light through a 550nm filter. DETAILED DESCRIPTION
[0056] The present invention will be further described below with reference to the following examples, but the protection scope of the present invention is not limited thereto.
[0057] Examples 1-4 are methods for preparing Au2Cu6(R1)6(R2)2 nanoclusters, Example 5 is a method for preparing luminescent ink from Au2Cu6(R1)6(R2)2 nanoclusters, and Example 6 is a method for preparing [Au 13 Ag 12 (TPP) 10 Method for preparing non-luminescent ink with Cl8]Cl nanoclusters.
[0058] Example 1:
[0059] First, 8 mL of chloroauric acid aqueous solution (0.2 g / mL), 400 mL of methanol and 2 g of tetraoctylammonium bromide were added to a three-necked flask in sequence, and high-speed stirring was started. After 10 minutes, 750 mg of copper chloride was added. After another 30 minutes, 2 g of 1,2-(bisdiphenylphosphine)ethane and 2 g of adamantane-1-thiol were added in sequence. After 30 minutes, 4 g of borane-tert-butylamine complex was poured into the above flask. After the reaction lasted for 12 hours, stirring was stopped and the aqueous phase was removed. The organic phase was concentrated by evaporation under reduced pressure, and then the product was extracted multiple times with 200 mL of a mixed solution of dichloromethane and n-hexane with a volume ratio of 1:3, and then evaporated under reduced pressure for concentration. Then, it was washed with 20 mL of methanol, and finally the product was dried to obtain the target product Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanoclusters.
[0060] Example 2:
[0061] First, 200 mL of dichloromethane, 1 g of tetraoctylammonium bromide and 4 mL of chloroauric acid aqueous solution (0.2 g / mL) were added to a three-necked flask in sequence and stirring was started. After 10 minutes, 340 mg of copper chloride was added. After another 30 minutes, 1 g of 1,3-(bisdiphenylphosphino)propane and 1 g of adamantane-1-thiol were added in sequence. After 30 minutes, 600 mg of sodium borohydride was poured into the above flask. After the reaction continued for 12 hours, stirring was stopped and the aqueous phase was removed. The organic phase was concentrated by evaporation under reduced pressure. The product was then extracted several times with 100 mL of a mixed solution of dichloromethane and n-hexane with a volume ratio of 1:4, and then evaporated under reduced pressure for concentration. It was then washed with 30 mL of ether and finally dried to obtain the target product Au2Cu6(P2C 27 H 26 O)6(SC 10 H 15 )2 nanoclusters.
[0062] Example 3:
[0063] First, 20 mL of dichloromethane, 0.1 g of tetraoctylammonium bromide and 0.2 mL of chloroauric acid aqueous solution (0.4 g / mL) were added to a three-necked flask in sequence and stirring was started. After 10 minutes, 35 mg of copper chloride was added. After another 30 minutes, 0.1 g of 1,5-(bisdiphenylphosphino)pentane and 0.1 g of adamantane-1-thiol were added in sequence. After 30 minutes, 200 mg of borane-tert-butylamine complex was poured into the above flask. After the reaction continued for 12 hours, stirring was stopped and the aqueous phase was removed. The organic phase was concentrated by evaporation under reduced pressure. The product was then extracted multiple times with 50 mL of a mixed solution of dichloromethane and n-hexane with a volume ratio of 1:5, and then concentrated by evaporation under reduced pressure. It was then washed with 20 mL of ethanol and finally dried to obtain the target product Au2Cu6(P2C 29 H 30 O)6(SC 10 H 15 )2 nanoclusters.
[0064] Example 4:
[0065] First, 1.6 mL of chloroauric acid aqueous solution (0.1 g / mL), 40 mL of methanol and 0.2 g of tetraoctylammonium bromide were added to a three-necked flask in sequence, and high-speed stirring was started. After 10 minutes, 75 mg of copper chloride was added. After another 30 minutes, 0.2 g of 1,2-(bisdiphenylphosphine)ethane and 0.25 mL of tert-butyl mercaptan were added in sequence. After 30 minutes, 0.4 g of borane-tert-butylamine complex was poured into the above flask. After the reaction lasted for 12 hours, stirring was stopped and the aqueous phase was removed. The organic phase was concentrated by evaporation under reduced pressure, and then the product was extracted multiple times with 100 mL of a mixed solution of dichloromethane and n-hexane with a volume ratio of 1:4, and then evaporated under reduced pressure for concentration. It was then washed with 30 mL of ether and finally dried to obtain the target product Au2Cu6(P2C 26 H 24 O)6(SC4H9)2 nanoclusters.
[0066] Example 5:
[0067] Add 1g of polystyrene and 10mL of dichloromethane to a beaker, stir until the solution is dissolved, and then add 2mg of Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanoclusters, and then stir them evenly to obtain Au2Cu6(P2C 26 H 24 O)6(SC 10 H 15 )2 nanoclusters of luminescent ink.
[0068] Example 6:
[0069] The present invention is based on [Au 13 Ag 12 (TPP) 10 Cl8]Cl nanocluster non-luminescent ink as a comparison:
[0070] Add 0.5 g of polyurethane and 5 mL of tetrahydrofuran to a beaker, stir until solution is obtained, and then add 20 mg of [Au 13 Ag 12 (TPP) 10 Cl8]Cl nanoclusters, stirring evenly can obtain the base [Au 13 Ag 12 (TPP) 10 Non-luminescent ink of Cl8]Cl nanoclusters.
Claims
1. A highly luminescent gold-copper nanocluster, characterized in that Its molecular formula is shown in the following formula (1): Au2Cu6(R1)6(R2)2——Formula (1); Where R1 is C 10 H 15 S - 、C4H9S - One of the following; R2 is one of (C6H5)2PCH2CH2P(C6H5)2, (C6H5)2PCH2CH2CH2P(C6H5)2, (C6H5)2PCH2CH2CH2CH2P(C6H5)2; In the gold-copper nanocluster, the waist is a hexagonal ring structure composed of six copper atoms and six thiol ligands, and the head and tail ends are rod-shaped structures formed by two gold atoms and two organic phosphine ligands. The gold-copper nanocluster is electrically neutral as a whole.
2. A method for preparing the highly luminescent gold-copper nanoclusters according to claim 1, characterized in that The steps include: Step 1: Dissolve chloroauric acid aqueous solution and tetraoctylammonium bromide in an organic volatile solvent and react at 10-30°C for 10 minutes; Step 2: Add copper chloride to the mixture in step 1 and react for 30 minutes; Step 3: adding an organic phosphine ligand and a thiol ligand to the system of step 2 in sequence and reacting for 30 minutes; Step 4: Add the reducing agent to the system of step 3 and react for 12 hours; Step 5: removing the aqueous solution from the reaction solution obtained in step 4, evaporating the organic solvent under reduced pressure, and extracting the obtained product with a mixed solution of dichloromethane and n-hexane and evaporating under reduced pressure; Step 6: washing the product obtained in step 5 with a large amount of organic solvent to obtain gold-copper nanoclusters Au2Cu6(R1)6(R2)2; In step 1, the concentration of the chloroauric acid aqueous solution is 0.1-0.5 g / mL, and the molar ratio of the chloroauric acid to tetraoctylammonium bromide is 1:0.5-1.5; In step 2, the molar ratio of copper chloride to chloroauric acid is 1:1-1.5; In step 3, the mass ratio of the organic phosphine ligand to the thiol ligand is 1:1; the mass ratio of the chloroauric acid to the organic phosphine ligand is 1:1-2; In step 4, the reducing agent is one or more of sodium borohydride, potassium borohydride, borane-tert-butylamine complex, and sodium cyanoborohydride; the molar ratio of chloroauric acid to the reducing agent is 1:0.05-0.1; In step 5, the volume ratio of dichloromethane to n-hexane is 1:3-5.
3. A use of the highly luminescent gold-copper nanoclusters according to claim 1, characterized in that: Combining the gold-copper nanoclusters with a high molecular polymer to form a luminescent ink specifically comprises the following steps: Step 1: dissolving a high molecular weight polymer in an organic volatile solvent; the organic volatile solvent is selected from one or more of dichloromethane, acetone, and tetrahydrofuran; Step 2: Dissolve the gold-copper nanoclusters in the solution of step 1 and stir evenly; The high molecular polymer is selected from one or more of polystyrene, polymethyl benzoate, and polyurethane; the mass ratio of the gold-copper nanoclusters to the high molecular polymer is 1:100-500.