CN102886527A - Method for preparing cubic crystal form nano-silver material by using oleic acid silver as raw material based on oil-water interface method - Google Patents

Abstract

The present invention relates to a method for preparing cubic nano-silver material by oil-water interface method using silver oleate as raw material, comprising: (1) dissolving silver oleate in cyclohexane at 80°C, adding a surfactant, Stir until the solution is clear and transparent to obtain a silver precursor; dissolve sodium borohydride in deionized water at room temperature, and stir evenly to obtain a borohydride precursor; (2) add the above borohydride precursor to the above silver precursor, Under 80°C, the upper layer oil phase was stirred electrically and the lower layer water phase was stirred magnetically for 2~3 hours, the obtained product was separated and washed, and finally the product was dried. The invention has simple operation and mild reaction conditions, and the obtained cubic crystal nano-silver particles are evenly dispersed and stable, and have good application prospects.

Description

A method for preparing cubic crystal nano-silver material by oil-water interface method using silver oleate as raw material

technical field

The invention belongs to the field of preparation of nano silver materials, in particular to a method for preparing cubic crystal nano silver materials by an oil-water interface method using silver oleate as a raw material.

Background technique

Recently, researchers not only have a strong interest in the preparation of monodisperse, well-uniform, and size-controllable nano-silver particles, but they have also raised the application field of nano-silver to a higher level. Oil-soluble nano-silver particles have a wide range of uses. For example, oil-soluble nano-silver particles can be used as laboratory raw materials for universities and research institutes; for reaction catalysts in non-polar and weakly polar solutions; for Weak polarity plastic masterbatch extruded antibacterial additive; used for nano-silver conductive ink, conductive adhesive, coating, stealth material, etc. At the same time, the application range of water-soluble nano-silver particles is also very wide. Professor Zhu Meifang from the School of Materials Science and Technology of Donghua University and other colleges have independently developed nano-silver antibacterial socks, which can effectively treat athlete's foot, and have reached industrialization, with an annual profit of more than 9 million. We can connect biological small molecules on the surface of surfactant-coated silver nanoparticles for biomarking, biomonitoring, drug delivery and catalytic reactions in aqueous solutions. The future research direction will be to synthesize some composite nanoparticles, such as Ag-TiO ₂ , Ag-Fe ₃ O ₄ , Ag-ZnS, Ag-NaYF ₄ and so on. Combining the unique properties of silver nanoparticles with the properties of other nanoparticles aims to take advantage of the common advantages of the two, for example, Ag-TiO ₂ not only has a double bactericidal effect, but also can be used as a catalyst and degrade polymer pollutants; Ag-TiO 2 -Fe ₃ O ₄ not only has the function of magnetic positioning, it can be applied to drug delivery, and at the same time it can be used for sterilization at the site of drug action.

At present, the commonly used methods for preparing nano-silver materials mainly include hydrothermal method and microemulsion method. The hydrothermal method is inconvenient to operate, the prepared particles have low purity and are easy to agglomerate, the particle size is not easy to control, the particle size is large, the product loss is large, and the yield is low. The nanomaterials synthesized by the microemulsion method have many excellent properties, but the synthesis yield is relatively low and the crystallinity is poor. The oil-water interface method means that the raw materials of the reactants are in the oil phase and the water phase respectively, and lipophilic nanoparticles with small particle size and excellent uniformity are formed at the oil-water interface at a lower temperature; then the nanoparticles are coated with surfactants. After coating, under the action of three surface tensions (γ oil-solid, γ oil-water and γ water-solid) and concentration diffusion (due to the small effect of particle gravity, it can be ignored), it is dragged into the upper oil phase, and in the oil phase Good dispersion and long-term stable storage. The oil-water interface method has the advantages of mild reaction conditions, simple operation, controllable particle size, high product purity, high yield, good crystallinity, good dispersibility, small particle size, low cost and high efficiency. In 2008, Zhou Xingping used the oil-water interface method [Zhou Xingping, Donghua University Journal: Natural Science Edition, 2008, 35(4): 441-444] to successfully synthesize CdS quantum dots, and the prepared CdS quantum dots High quantum efficiency, narrow particle size distribution, good monodispersity, simple synthesis method, low temperature requirement, mass production and low cost. In 2010, Zhou Xingping used the oil-water interface method [Zhou Xingping, Nanotechnology; 2010, December: Vol7, No.6] to successfully synthesize ZnS quantum dots, doped with some rare metals, and have good fluorescence properties. A good semiconductor material.

Silver oleate is used as the precursor. Compared with silver stearate, silver oleate is easier to dissolve in the organic phase, and the dissolution rate is fast and the reaction temperature is low, which can effectively increase the reaction rate.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing cubic crystal nano-silver material by the oil-water interface method using silver oleate as raw material. , stable and has a good application prospect.

A kind of method that the oil-water interface method of the present invention uses silver oleate as raw material to prepare cubic crystal nano-silver material comprises:

(1) Dissolve silver oleate in cyclohexane at 80°C, add surfactant, and stir until the solution is clear and transparent to obtain an oil phase containing silver oleate and cyclohexane; dissolve sodium borohydride in In deionized water, stir evenly to obtain the aqueous phase of sodium borohydride;

(2) Add the aqueous phase of sodium borohydride to the oil phase containing silver oleate and cyclohexane, stir the upper oil phase electrically and the lower aqueous phase magnetically for 2~3 hours at 80°C, and separate and wash the obtained product , and finally dry the product to obtain cubic crystal nano-silver material.

The concentration of the silver cyclohexane oleate solution in the step (1) is 0.025-0.0375M.

The surfactant in the step (1) is dodecylamine, hexadecylamine or zinc oleate.

The ratio of surfactant to silver oleate in the step (1) is 1:1.88.

The concentration of the sodium borohydride aqueous solution in the step (2) is 0.075-0.1M.

The volume ratio of the oil phase containing silver oleate and cyclohexane to the aqueous phase of sodium borohydride in the step (2) is 1:1.

The rate at which sodium borohydride in the step (2) is added to the oil phase containing silver oleate and cyclohexane is 160ml/h.

The separation and washing in the step (2) is specifically followed by washing with absolute ethanol and deionized water in sequence. After the solution is clearly separated and the lower aqueous phase is clarified, the upper oil phase solution is separated and centrifuged at 11000rmp for 15min.

The drying in the step (2) is at 65-70° C. for 2-4 hours.

The average diameter of the cubic nano-silver particles in the step (2) is 8.5-9.5 nm.

Beneficial effect

(1) The present invention has simple operation, mild reaction conditions, low price of experimental raw materials, and good economy;

(2) The obtained cubic crystal nano-silver particles have a size of about 8.5-9.5nm, are uniformly dispersed and stable, and have good application prospects.

Description of drawings

Fig. 1 is the process flow diagram of embodiment 1;

Fig. 2 is the transmission electron microscope figure of embodiment 1 gained product;

Fig. 3 is the transmission electron microscope figure of embodiment 2 gained product;

Fig. 4 is the transmission electron microscope figure of embodiment 3 gained product;

Detailed ways

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

(1) Weigh 0.99g (0.00253mol) of silver oleate, completely dissolve it in 85ml of cyclohexane at 80°C, add 0.25g (1.345×10 ^-3 mol) of dodecylamine, stir magnetically until the solution is transparent, and store spare;

(2) Weigh 0.3g (0.00792mol) of sodium borohydride, dissolve it in 80ml of deionized water at room temperature, stir it evenly with magnetic force, and store it for later use;

(3) Add the sodium borohydride prepared in step 2 to the silver cyclohexane oleate solution prepared in step 1 within 30 minutes, stir the upper oil phase under electric stirring at 80°C, and magnetically stir the lower water phase for 2 hours (oil phase and water phase The volume ratio is 1:1), add 100ml of absolute ethanol, so that the produced nano-silver is evenly dispersed in the upper oil phase, then remove the lower water phase, and then rinse with 100ml deionized water to separate the upper oil phase solution. Take out 1ml of the oil phase, dilute it with 25ml of cyclohexane, sonicate it, and do TEM test. The remaining oil phase was centrifuged at 11000rmp for 15min, the precipitated substance was cleaned twice with absolute ethanol, and then centrifuged at 11000rmp for 15min, and finally the precipitated substance was dried in a vacuum drying oven at 65°C for 2h, and the final product with high purity nano silver material. The TEM image shows that the average particle size of the product is about 10.25nm, the dispersion is relatively uniform, and there is almost no agglomeration phenomenon.

Example 2

(1) Weigh 0.99g (0.00253mol) of silver oleate, completely dissolve it in 85ml of cyclohexane at 80°C, add 0.5g (1.345×10 ^-3 mol) of cetylamine, stir magnetically until the solution is transparent, and store spare;

(2) Weigh 0.3g (0.00792mol) of sodium borohydride, dissolve it in 80ml of deionized water at room temperature, stir it evenly with magnetic force, and store it for later use;

(3) Add the sodium borohydride prepared in step 2 to the silver cyclohexane oleate solution prepared in step 1 within 30 minutes, stir the upper oil phase at 80°C electrically, and magnetically stir the lower water phase for 3 hours (oil phase and water phase The volume ratio is 1:1), add 100ml of absolute ethanol, so that the produced nano-silver is evenly dispersed in the upper oil phase, then remove the lower water phase, and then rinse with 100ml deionized water to separate the upper oil phase solution. Take out 1ml of the oil phase, dilute it with 25ml of cyclohexane, sonicate it, and do TEM test. The remaining oil phase was centrifuged at 11000rmp for 15min, and the precipitated substance was cleaned twice with absolute ethanol, and then centrifuged at 11000rmp for 15min, and finally the precipitated substance was dried in a vacuum drying oven at 70°C for 4h, and the final product with a high purity nano silver material. The TEM image shows that the average particle size of the product is about 8.76nm, the dispersion is relatively uniform, and there is almost no agglomeration phenomenon.

Example 3

(1) Weigh 0.99g (0.00253mol) of silver oleate, completely dissolve it in 85ml of cyclohexane at 80°C, add 0.5252g (1.345×10 ^-3 mol) of zinc oleate, stir magnetically until the solution is transparent, and store spare;

(2) Weigh 0.3g (0.00792mol) of sodium borohydride, dissolve it in 80ml of deionized water at room temperature, stir it evenly with magnetic force, and store it for later use;

(3) Add the sodium borohydride prepared in step 2 to the silver cyclohexane oleate solution prepared in step 1 within 30 minutes, stir the upper oil phase at 80°C electrically, and magnetically stir the lower water phase for 3 hours (oil phase and water phase The volume ratio is 1:1), add 100ml of absolute ethanol, so that the produced nano-silver is evenly dispersed in the upper oil phase, then remove the lower water phase, and then rinse with 100ml deionized water to separate the upper oil phase solution. Take out 1ml of the oil phase, dilute it with 25ml of cyclohexane, sonicate it, and do TEM test. The remaining oil phase was centrifuged at 11000rmp for 15min, and the precipitated substance was cleaned twice with absolute ethanol, and then centrifuged at 11000rmp for 15min, and finally the precipitated substance was dried in a vacuum drying oven at 70°C for 4h, and the final product with a high purity nano silver material. The TEM image shows that the average particle size of the product is about 9.04nm, the dispersion is relatively uniform, and there is almost no agglomeration phenomenon.

Claims (10)

1. the method for the preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material comprises:

(1) oleic acid silver is dissolved in the cyclohexane under 80 ℃, adds surfactant, be stirred to the oil phase that the solution clear must contain oleic acid silver and cyclohexane; Sodium borohydride is dissolved in the deionized water at normal temperatures, and the water of sodium borohydride stirs to get;

(2) water with sodium borohydride joins in the oil phase that contains oleic acid silver and cyclohexane, at 80 ℃ of lower upper oil phase electric stirrings, the water magnetic agitation 2 ~ 3h of lower floor, the product that obtains is carried out separating, washing, at last product is drying to obtain the cubic crystal type nano ag material.

2. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1 is characterized in that: the oleic acid silver cyclohexane solution concentration in the described step (1) is 0.025-0.0375M.

3. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1, it is characterized in that: the surfactant in the described step (1) is lauryl amine, cetylamine or zinc oleate.

4. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1, it is characterized in that: the surfactant in the described step (1) and the proportioning of oleic acid silver are 1:1.88.

5. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1, it is characterized in that: the sodium borohydride aqueous solution concentration in the described step (2) is 0.075-0.1M.

6. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1 is characterized in that: in the described step (2) to contain oleic acid silver and the oil phase of cyclohexane and the water volume ratio of sodium borohydride be 1:1.

7. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1 is characterized in that: the speed that the sodium borohydride in the described step (2) adds in the oil phase that contains oleic acid silver and cyclohexane is 160ml/h.

8. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1, it is characterized in that: the separating, washing in the described step (2) is specially successively with behind the absolute ethyl alcohol and deionized water rinsing, the solution layering is obviously and after lower floor's water clarification, isolate upper oil phase solution, centrifugation 15min under 11000rmp.

9. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1 is characterized in that: the drying in the described step (2) is in 65 ~ 70 ℃ of drying 2 ~ 4h.

10. the method for a kind of preparing cubic crystal nano silver material by oil-water interface take oleic acid silver as raw material according to claim 1 is characterized in that: the average diameter in the cubic crystal type nano silver granuel footpath in the described step (2) is 8.5-9.5nm.

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