TW200538398A - Method of manufacturing metallic nanoparticles - Google Patents

Abstract

This invention provides a method of manufacturing metallic nanoparticles, which uses a chemical compound shown below in formula (I) as a reducing agent to be mixed with a metal salt in a solvent, which is then subject to heating until the reflux of solvent carrying out a reaction; wherein R is selected from a group consisting of C1-6 alkyl, C1-6 alkenyl and C1-6 alkynyl; and n is the integer between 1 to 1,000.

Description

200538398 V. Description of the invention α) [Technical field to which the invention belongs] The present invention relates to a method for manufacturing metal nano particles, particularly a method for manufacturing metal nano particles using a polymer compound as a reducing agent. [Previous technology] Compared with general metal micron-sized particles, metal nano particles have excellent surface properties such as increased surface-to-volume, improved surface energy, high ductility after pressure, high hardness, and high specific heat. As a result, the applicability of metallic nano-particles has attracted much attention in the industrial and scientific circles, which are mainly oriented by materials. For example, today, various types of metal nanoparticle-based catalysts have been used in a variety of catalytic reactions, and have the advantage of high conversion rates for the catalytic reactions of unsaturated hydrocarbons. Depending on the size of the nano-particles, there can be different size-dependent properties of the electronic band, which in turn affects its physical and chemical properties, which is very important for industrial applications. For example, in the electroless nickel reaction, when platinum (Pt) nano-particles are used as the catalytic catalyst, there will be different non-bond reaction rates with different particle sizes. Therefore, how to control the preparation method of synthesizing metallic nano-particles with different particle sizes has become a hot topic in current industrial applications. At present, the procedures for preparing metallic nano particles can be divided into chemical synthesis methods and physical synthesis methods. Among them, the chemical reduction method is most commonly used in industry because of its large output, simple preparation procedure, and low cost. Generally, the chemical reduction method is to dissolve inorganic metal salts in a solution containing a polymer compound or a surfactant, and then use an external reducing agent such as hydrazine, Na B Η 4, ethanol

17790 Industrial Research Institute. Ptd Page 4 200538398 5. Description of the invention (2) or hydrogen, reducing inorganic metal salts to form metal nano particles. For example, U.S. Patent No. 4,5 9 3,0 16 discloses that palladium chloride and stannous gas are separately dissolved in HC 1 aqueous solution, and then the two liquids are mixed to increase the temperature to 1000 ° C, so that Tin ions can reduce palladium ions to form nano colloidal particles of tin-palladium alloy. U.S. Patent No. 5,18,7,209 discloses that ^ 2? 1 :(: 14 is dissolved in 50 ml of an equal proportion of water mixed with 1.1 g of hydrazide functional copolymer. In an ethanol solution, it was irradiated with a 500 w high pressure mercury lamp (hi gh pressure mercury 1 amp) for two hours to reduce the pt solution to synthesize Pt nano particles of about 3 nm. US Patent No. 5, 1 47, 84 1 discloses A solution of NaJtCl4 or NazPdCl4 dissolved in n-octane solution containing cationic surfactant didodecyldifluorenyl ammonium bromide (DDAB), and then adding Pt2 + or Pd2 + in na B Η 4 or hydrazine reduction solution, Pt or Pd Nylen particles having a particle size of 10 to 20 Å are formed. US Patent No. 5,75,9,230 discloses that pdcl 2 or AgN03 is dissolved in an ethanol solution, and ethanol is used as a reducing agent. Heating under reflux at 120 to 200 ° C for 1 to 3 hours to synthesize Pd nano particles at 10 nm and Ag nano particles at 40 ^. The United States No. 5, 3 3 2, 6 4 6 reveals the use of hydrogen to reduce the solvent. Synthesize and effectively disperse Pd and Pt metal nano particles of 2 to 50 nm in organometallic salts of pd and P t in an organic solvent containing a surfactant U.S. Patent No. 5 5 8 4 discloses the use of 690 ml of a 0.1 μM tetraoctyl ammonium bromide τ η F solution as an electrolyte, and two pieces of palladium metal pieces as cathode and anode electrodes, respectively, and anode Electrochemical way to oxidize the cathode to reduce ions to synthesize pd nano particles' in solution and change different current densities to synthesize pd nano particles with different i diameters. US Patent No. 6, 1 0 3, 8 6 8 discloses Dissolve ι50 mM HAuC1 • 3H2 0 in 25 ml of deionized water to form a yellow aqueous solution.

17790 工研院 _ptd Page 5 200538398 V. Description of the invention (3) 0.3 6 5 grams of lye (: 81117) 461 'dissolved in 25 ml of toluene, the aqueous solution was strongly stirred with the toluene solution, and then 0.151 g of NaBH4 was added The gold nano particles are reduced. However, the addition of reducing agents often affects the size of the particles. If they are added too much, the reducing power is strong, and the nucleation rate is too fast, so that the synthesized metal nano particles are too large and uneven in size. If the amount of reducing agent added is too small, the reduction rate is often too slow. It takes several days to synthesize the particles, and even the inorganic metal salts cannot be reduced. Therefore, the selection of the amount of external reducing agent, the stirring method and the type are all critical, increasing the complexity of the process. In summary, how to develop a kind of metal nano particles that can be easily manufactured, and make the obtained metal nano particles have a uniform particle size and stable dispersibility is indeed an urgent need for the relevant research and development field. Topic. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing metal nano particles by directly using a polymer compound as a reducing agent. Another object of the present invention is to provide a method for producing metallic nano particles having a uniform particle size distribution using a polymer compound as a reducing agent. Yet another object of the present invention is to provide a method for manufacturing metal nano particles which can be dispersed in a solution for a long time using a polymer compound as a reducing agent. Another object of the present invention is to provide a method for manufacturing metal nano particles on a large scale using a simple formula. Another object of the present invention is to provide a method for manufacturing metal at a low cost.

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Under the method of dissolving granules in Miruhe Nai, a mixed genus was used to make a gold-based salt to make a genus of gold for the purpose of mentioning the anti-inflammation agent and the original formulation of the anti-inflammatory agent. . Its physical solution method and synthesizer} Fang Huahua (The thermal ξ sub-Dashi plus grains before 4 are combined T rice, T1 S Na C in the French formula, R is selected from C η alkyl, C one of the groups consisting of an η alkenyl group and a C η alkynyl group; and η is an integer ranging from 1 to 1, 0 0. Different from the microbubbles formed by dissolving a polymer compound in a solvent in a conventional method As a protective agent, the method of the present invention directly utilizes the self-reducing ability of a mixture of a polymer compound and a metal salt, and directly uses a compound represented by the formula (I) as a reducing agent without using a reducing agent. Because The method of the present invention does not require other complicated formulas, but has the advantages of simple preparation method, easy large-scale mass production, and low cost. On the other hand, the method of the present invention is suitable for manufacturing nano particles of various metal elements, using specific compounds As a reducing agent, the particle size of the metal nano particles formed is controlled, so that the obtained metal nano particles have the advantages of uniform particle size distribution and long-term dispersion in the solution. [Embodiment] The following is based on special features. Specific examples illustrate embodiments of the present invention,

17790 Industrial Research Institute.ptd Page 7 200538398 V. Description of the invention (5) Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific examples, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention. The present invention provides a method for producing metal nano particles by using a compound represented by the following formula (I) as a reducing agent, mixing it with a metal salt in a solvent, and heating to cause the solvent to reflux, and performing a reaction: In the formula, R is independently selected from one of the group consisting of C-alkyl, C-alkenyl, and C-alkynyl; and η is an integer ranging from 1 to 1,000. The alkyl group may be a linear, branched, or cyclic alkyl group, and examples thereof include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, second butyl, pentyl, hexyl, and Examples of the alkenyl group include, but are not limited to, vinyl, propenyl, and butenyl; examples of the alkynyl group include, but are not limited to, acetylene, propyne, and the like. In a specific example of the present invention, the compound used as the reducing agent is preferably a high molecular compound having a molecular weight between 3,500 and 1,300,000, and an example thereof may have a molecular weight between 3. Polyvinylpyrrolidone (hereinafter referred to as PVP) with a molecular weight of 500 to 1,300,000. Preferably, the high score used as a reducing agent

1779G Institute of Industry and Technology.ptd page 8 200538398 V. Description of the invention (6) The sub-compound is used in the form of an aqueous solution. The method of the present invention is to first mix the polymer compound aqueous solution used as a reducing agent with metal salts; then, 'heating causes the solvent to reflux and the amidine molecular compound reducing agent reacts with the metal salt to form metal nanometers. particle. It can be used to detect whether the 2 reaction is complete by extracting a small amount of the reaction solution. Generally, the reflux time is between 1 and 20 hours, and more preferably between 3 and 10 hours. In a specific embodiment of the present invention, the metal salt is preferably a noble metal salt, such as a salt of Pd, Pt, Ag, or Au. Examples of such precious metal salts include, but are not limited to, Pd (0Ac) 2, PdCl2, H2PtCl6 · II 0, Ag (OAc), Ag (N03), and HAuC14 · 3H2O. The characteristics and effects of the present invention are further detailed below by using specific experimental examples. Among them, the particle size and elemental composition of the synthesized metal nano-particles are identified using a transmission electron microscope (hereinafter referred to as TEM), energy dispersion spectra-EDX, and uV-Visble spectra. Example 1 0.1 g of palladium acetate (? (1 ((^ 〇2)) was dissolved in 50 ml of 0.011 ^ of polyvinylpyrrolidone (PVP, molecular weight 10, 0 0)) aqueous solution, without adding other reducing agents Then, the oil bath is heated under reflux, the temperature of the oil bath is controlled in the range of 110 ° C to 130 ° C, and the reaction time is 16 hours. When the reaction is about 1 hour, the reaction liquid appears clear orange, with Increase in reaction time 'The color of the reaction solution changed from orange to brown, and the reaction solution became black-brown after the reaction time was 16 hours. After the reaction was terminated, the temperature was increased by 15 0 0 r pm 20 minutes.

200538398 V. Description of the invention (7) Centrifugation, the results are divided into a supernatant liquid and a centrifugal precipitate. The supernatant liquid is a clear and light yellow aqueous solution, which is subjected to atomic absorption spectrometer (Atom Absorption)

Spectrum) determined that the yield was 90%. The reaction solution was taken out and measured for TEM. As a result, Pci nano particles having a uniform particle size were shown in Fig. 1. Use PVP to synthesize

The average particle diameter of Pd nano particles is 6 1 γ nm. As shown in FIG. 2, it can be seen from FIG. 2 that the size of the synthesized Pd nano particles is quite uniform. The electron beam of EDX was used to align the particles and the X-ray excited by the electron beam was used to identify the chemical composition as pure Pd. Disperse the prepared P d nanoparticle precipitate in water

in. After a long period of experimental observation, it was found that the prepared metal nano particles can be effectively dispersed in an aqueous solution after 2 years. Example 2 The steps of Example i were repeated, and in the same way, pd (〇Ac 〇5 g of pd Γ 1 & 2 'was synthesized as a dark brown P d nanoparticle solution. After long-term experimental observation, it was found that the produced # κ The metal nano particles prepared by Ba I x τ kg can still be effectively dispersed in an aqueous solution after about 1 to 2 years. Β From the steps of Example 3 n nR. ^ 1, in the same way, Pd (0Ac) jit is As shown in Figure 3 ^), the synthetic black-sweet Pt nanoparticle is not, with an average particle size of 2.36ηπι, as borrowed from Figure 4. Perch 眭 = Shen Dianwu with nano particles, disperse in water again? Experimental observations' found that the prepared metal nanoparticle can be effectively dispersed in an aqueous solution.

Π790 Industrial Research Institute.ptd Page 10 200538398 V. Description of the invention (8) '' '' ~ --- ^^ t Μ Μ This example is to determine the changes of metal salts with different concentrations (the Addition amount) on the preparation of metal nano particles. Change the concentration of metal salts to fix the concentrated reflux reaction temperature of the molecular compound reducing agent. The temperature is controlled in fiber. The reaction conditions are as shown in Table i. The particle size of the prepared metal nano particles is also described in Table J. Table 1 Group PdCl2 concentration (g / 50 ml) P VP concentration (5 g / 50 ml) Average particle size statistics (nm) 4a 0.4 0.01M 6.32 4b 0.08 '0.01M 5.46 4c 0.04 0.01M 6.08 4d 0.01 0.01M 4.62 The experimental results were measured by UV-Vi S spectroscopy and TEM. It was found that nano particles could be synthesized no matter whether the concentration of PdC12 was reduced to 0_01 g / 50 liters or increased to q · 4 g / 50 liters. For Pd nanoparticle solutions synthesized with different concentrations of PdCl 2, pd 2+ is reduced from the polymer in the system, and the reaction is milder than the addition of a reducing agent, so the effect of metal ion concentration on particle size is not significant. —Solid—Top 5 This example is to determine the effect of using different concentrations of high molecular compounds as reducing agents on the synthesis of metallic nano particles. The concentration of the polymer compound reducing agent was changed while the metal salt concentration was fixed. The results are shown in Table 2.

200538398 V. Description of the invention (9) Shown 0 Table 2 Group—PdCl2 concentration ~ (g / 50ml) (g / 50ml) > Statistics of average grain size fnm) 5a 0.4 5 6.32 5b 0.4 4 6.59 5 c 0.4 3 6.47 5d 0.4 2 7.69 5e 0.4 1 4.48

It was found in the experimental results that the experimental results were determined by UV-Vis spectroscopy and TEM. Metal nanoparticle can be prepared with different concentrations of polymer compound reducing agent. Example 6 Is the restoration? (1 ((^ (:) 2 is formed in an aqueous polymer solution? (Is the 1nm particle due to thermal decomposition rather than chemical reduction of Pd (0AC) 2, the following two control experiments were performed: 6a: 1g of Pd ( 0Ac) 2+ 〇 · 〇μ PVP / 5 0ml H20, oil bath temperature ❿ 13 0 ° C, time 16 hours 6b: 0. 0 52 grams of Pd (OAc) 2 / 5ml H20, oil bath 12 ° C for 4 hours

17790 Industrial Research Institute.ptd Page 12 200538398 V. Description of Invention (ίο) In the experiment of entering PVP at 6a, the color of the solution became dark brown, and the spectrum of Pd nano particles appeared; on the other hand, in the case of 6b without PVP, In the experiment, P d (0 AC) 2 had poor solubility in water, and was only partially soluble in water. The oil bath was heated at 120 ° C. After 4 hours, Pd (OAC) 2 was still insoluble in water. From the above results, it can be seen that the nano particles synthesized by this method are not formed by P d nano particles formed by thermal decomposition of Pd (0AC) 2, but are formed by PV P reduction of metal salts.

17790 Institute of Industry and Technology.ptd Page 13 200538398 Brief description of the drawings [Simplified description of the drawings] Figure 1 is a TEM photograph of Pd nano particles produced by the method of the present invention (magnification is 300,000 times, the figure 0.5 cm is 20 nm); Figure 2 is the average particle size distribution of Pd nano particles produced by the method of the present invention; Figure 3 is Pt nano particles produced by the method of the present invention TEM photo (magnification is 300,000 times, 0.5 cm in the figure is 20 nm); and FIG. 4 is the average particle size distribution of Pt nano particles produced by the method of the present invention. (No component symbol in this case)

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Claims (1)

200538398 VI. Scope of patent application 1. A method for manufacturing metal nano particles, the method is to use a compound represented by the following formula (I) as a reducing agent, mix it with a metal salt in a solvent, and heat to cause the solvent to reflux. reaction: In the formula, R is one selected from the group consisting of a C η alkyl group, a C η alkenyl group, and a C η alkynyl group; and η is an integer ranging from 1 to 1,000. · 2. The method according to item 1 of the scope of patent application, wherein the R is a vinyl group. 3. The method according to item 1 of the scope of patent application, wherein the molecular weight of the compound is between 3,500 and 1,300,000. 4. The method according to item 1 of the scope of patent application, wherein the molecular weight of the compound is preferably between 3,500 and 10,0 0. 5. The method according to item 4 of the scope of patent application, wherein the solvent is water. 6. The method according to item 1 of the scope of patent application, wherein the metal salt is one selected from the group consisting of Pd metal salt, Pt metal salt, Ag metal salt, and Au metal ® salt. 7. The method according to item 6 of the scope of patent application, wherein the Pd metal salt is selected from one of Pd (OAc) 2 and PdCl2. 8. The method according to item 6 of the scope of patent application, wherein the Pt metal salt 17790 Industrial Research Institute.ptd Page 15 200538398 6. The scope of patent application is Η 2 P t C 1 6 · Η 2 0. 9. The method according to item 6 of the scope of patent application, wherein the Ag metal salt is one selected from the group consisting of Ag (OAc) and Ag (N03). 10. The method according to item 6 of the scope of patent application, wherein the Au metal salt is HAuCl 4 · 3H2 0. 1 1. The method according to item 1 of the scope of patent application, wherein the reflux time of the solvent caused by heating to reflux is between 1 and 20 hours. 17790 ITRI.ptd Page 16