JP2004283924A - Organic-inorganic nano complex and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide, in a very simple process, a zinc hydroxide-interfacial active agent layered organic-inorganic nano complex constituted only of zinc hyrdoxide and an interfacial active agent, which is conventionally difficult to manufacture, and also to provide its manufacturing method. <P>SOLUTION: This organic-inorganic nano complex is furnished with a structure in which zinc hydroxide and an organic layer are alternately laminated in a nano meter order. The manufacturing method of the organic-inorganic nano complex forms the structure in which zinc hydroxide and the organic layer are alternately laminated in the nano meter order by discharging zinc in an aqueous solution as an atom, ion and a cluster by applying strong energy on a metallic zinc surface in the interfacial active agent aqueous solution. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is applicable to a photofunctional material, a sensor material, a catalyst carrier, an adsorbent or a host material of an inclusion compound, etc., wherein a zinc hydroxide layer and an organic layer, particularly a surfactant layer, are on the order of nanometers. And a method for producing the same.
[0002]
[Prior art]
In recent years, organic-inorganic composite materials have attracted attention because they can improve the properties of organic materials that are relatively weak to heat, or can impart the functions of organic molecules to inorganic compounds. Among them, organic-inorganic nanocomposites with a composite structure in the nanometer order are composed of molecules and nanometer-sized clusters and fine particles, and the molecular and quantum size effects present in the nanocomposite It is expected to exhibit new physical properties due to, and is a very promising substance as an optical functional material or sensor material.
Furthermore, if a layered structure can be introduced into these nanocomposites, new molecules can be intercalated between layers on the order of nanometers, making them very useful as catalyst supports, adsorbents or host materials for inclusion compounds. It is a promising substance.
[0003]
Heretofore, as a method for producing a layered material having zinc hydroxide as a basic skeleton, a method utilizing a reaction between amorphous zinc hydroxide and an organic oxychloride or an organic carboxylic acid is known (for example, Non-Patent Documents) 1).
Further, as a method for producing a layered substance having a basic skeleton of a double hydroxide containing zinc and a surfactant, a micellar organic anionic surfactant and an uncharged organic compound are provided between layers having a basic skeleton layer of a layered double hydroxide. A method of intercalating a substance has also been reported (for example, see Patent Document 1).
However, in the case of these production methods, a step of mixing and reacting a hydroxide such as zinc hydroxide or a layered double hydroxide, which is a basic skeleton of the layered substance, with an organic molecule such as a carboxylic acid or an anionic surfactant. Prior to this, a step of synthesizing these hydroxides is also required, which has a drawback that the operation becomes extremely complicated. Until now, it has not been possible to produce a layered organic-inorganic nanocomposite consisting only of zinc hydroxide and a surfactant.
[0004]
On the other hand, there is a report of a technique for performing laser ablation using a surfactant aqueous solution. However, in this case, all methods are methods for adjusting the size of the noble metal nano-particles or obtaining manganese nanowires, and are merely methods for preparing particles of a single metal (see Non-Patent Documents 2 and 3 and Patent Document 2).
[0005]
[Non-patent document 1]
Functional Materials, “Control of Layer Space and Morphology of Layered Structure by Reaction of Zinc Hydroxide and Organic Carboxylic Acid”, Vol. 12, No. 10, pp. 45-52, 2001 [Non-Patent Document 2]
"Full physical preparation of size-selected gold nanoparticles in solution: Laser ablation and laser-induced size control", Mafune F, Kohno JY, Takeda Y, Kondow T, JOURNAL OF PHYSICAL CHEMISTRY B, 106 (31): 7575-7577 AUG 8 2002.
[Non-Patent Document 3]
"Growth of gold clusters into nanoparticles in a solution following laser-induced fragmentation", Mafune F, Kohno JY, Takeda Y, Kondow T, JOURNAL OF PHYSICAL CHEMISTRY B, 106 (34): 8555-8561 AUG 29 2002.
[Patent Document 1]
JP-A-6-48742 [Patent Document 2]
JP-A-2003-2651
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to use a very simple process, and a zinc hydroxide-surfactant composed only of a zinc hydroxide and a surfactant which has heretofore been difficult to produce. It is to provide a layered organic-inorganic nanocomposite and a method for producing the same.
[0007]
[Means for Solving the Problems]
After extensive research to achieve the object of the present invention, by applying strong energy to the metal zinc surface in an anionic surfactant aqueous solution, the zinc is released into the aqueous solution as atoms, ions or clusters. It has been found that a nanocomposite crystal of zinc hydroxide-organic layer can be obtained in a very simple process.
The present invention is based on this finding,
1. 1. An organic-inorganic nanocomposite having a structure in which zinc hydroxide and an organic layer are alternately stacked in a nanometer order. 2. The organic-inorganic nanocomposite as described in 1 above, wherein the organic layer is a surfactant. 3. The organic-inorganic nanocomposite according to the above item 2, wherein the organic layer is an anionic surfactant. 4. The organic-inorganic nanocomposite according to any one of the above items 1 to 3, wherein the single layer has a laminated structure of 1 nm to 6 nm. 5. The organic-inorganic nanocomposite according to any one of the above items 1 to 4, wherein the organic-inorganic nanocomposite has a structure in which organic anions are lamellarly arranged between layers of zinc hydroxide.
[0008]
Further, the present invention further provides:
6. A structure in which zinc hydroxide and an organic layer are alternately laminated on the order of nanometers by applying strong energy to the surface of metallic zinc in a surfactant aqueous solution and releasing zinc as atoms, ions, and clusters in the aqueous solution 6. A method for producing an organic-inorganic nanocomposite, A structure in which zinc hydroxide and an organic layer are alternately laminated on the order of nanometers by applying strong energy to the surface of metallic zinc in a surfactant aqueous solution and releasing zinc as atoms, ions or clusters in the aqueous solution 7. The method for producing an organic-inorganic nanocomposite according to any one of the above 2 to 5, wherein The method for producing an organic-inorganic nanocomposite according to the above item 6 or 7, wherein pulsed laser ablation is performed by applying condensing irradiation energy of a pulsed laser beam. 9. Applying a pulsed energy of 9.50 mJ / pulse or more. 9. The method for producing an organic-inorganic nanocomposite according to any one of the above items 6 to 8, wherein 10. The method for producing an organic-inorganic nanocomposite according to any one of the above items 6 to 9, wherein a laser light energy density of 1 J / cm ² or more is applied to the surface of the metal zinc target. 11. The method for producing an organic-inorganic nanocomposite according to any one of the above items 6 to 9, wherein a laser light energy density of ² J / cm ² or more is applied to the surface of the metal zinc target. 12. The method for producing an organic-inorganic nanocomposite according to any one of the above items 6 to 11, wherein an alkyl sulfate is used as a surfactant. 13. The method for producing an organic-inorganic nanocomposite according to any one of the above items 6 to 11, wherein sodium dodecyl sulfate is used as a surfactant. 14. The method for producing an organic-inorganic nanocomposite according to any one of the above items 6 to 13, wherein the concentration of the surfactant in the aqueous solution is 0.0001 mol / L or more. 14. The method for producing an organic-inorganic nanocomposite according to any one of 6 to 13 above, wherein the concentration of the surfactant in the aqueous solution is 0.001 mol / L or more and a saturation concentration or less.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
As described above, the present invention applies strong energy to the surface of metallic zinc in an aqueous solution of an anionic surfactant to release zinc as an atom, an ion or a cluster in the aqueous solution, and the presence of an anionic surfactant and water. The reaction is performed under the following conditions to produce a zinc hydroxide-layered organic-inorganic nanocomposite crystal in a very simple process. When pulsed laser ablation is performed by applying energy according to the method, a zinc hydroxide-surfactant layered organic-inorganic nanocomposite crystal can be obtained with high efficiency.
In the practice of the present invention, pulsed laser ablation is particularly effective.However, as long as strong energy capable of releasing zinc as atoms, ions or clusters can be applied, for example, a method such as pulse discharge may be applied. it can.
[0010]
FIG. 1 shows a zinc hydroxide-surfactant layered organic-inorganic nanocomposite manufacturing apparatus (vertical cell system manufacturing apparatus 1-1 and horizontal cell system manufacturing apparatus 1-2). The laser is irradiated from the laser device 2 to the zinc metal plate target 7 loaded in the quartz glass cell 5 via the laser light reflecting mirror 3 and the condenser lens 4.
A zinc metal plate having a purity of 98% or more is used as the zinc metal plate target 7. The zinc metal plate target 7 is fixed to the bottom of the quartz glass cell 5 or to a shaft 10 on a table 9. A suitable amount of an aqueous solution of a surfactant, for example, an aqueous solution of an anionic surfactant is added to the quartz glass cell 5. Reference numeral 11 denotes a gear box, and reference numeral 12 denotes a target rotation driving motor.
Any usable surfactant can be used as long as there is no strong light absorption for the wavelength of the laser beam to be used. For example, alkyl _{sulfates: C n H 2n + 1 O} 4 SNa (n = 10~18) such can be used.
[0011]
The concentration of the surfactant, for example, the concentration of the anionic surfactant may be 0.0001 mol / L or more, preferably 0.001 mol / L or more and the saturation concentration of the surfactant or less.
The laser beam wavelength of the laser device 2 that can be used only needs to have no strong absorption for the anionic surfactant to be used. For example, a fundamental wave (wavelength: 1064 nm) of a pulsed Nd: YAG laser, a second harmonic (wavelength) : 532 nm), the third harmonic (wavelength: 355 nm), and the like.
The energy of the laser beam may be energy at which the target zinc metal is released as atoms, ions or clusters in an aqueous solution.If a pulsed laser is used as the energy source, the zinc metal laser ablation phenomenon may occur. All you need is enough energy.
It is sufficient that the energy per pulse is 50 mJ / pulse or more. The energy density of the laser beam on the target surface may be 1 J / cm ² or more, preferably ² J / cm ² .
[0012]
Next, actual experimental results will be described. FIG. 2 shows the preparation and analysis procedure. This aqueous solution was prepared using sodium dodecyl sulfate, which is a cationic surfactant, as a surfactant. In an aqueous solution, sodium dodecyl sulfate is ionized into sodium ions (Na ⁺ ) and dodecyl sulfate cations (C ₁₂ H ₂₅ OSO ₃ ⁻ ). The concentration of sodium dodecyl sulfate was changed in the range of 0.0001 mol / L to 0.1 mol / L.
A zinc plate having a purity of 99.9% (size: 20 mm × 20 mm, thickness: 5 mm) was mounted on the apparatus shown in FIG. 1, and a repetition frequency of 10 Hz was used as the third harmonic (wavelength: 355 nm) of a pulsed Nd: YAG laser. .
[0013]
After adjusting the position of the lens so that the laser beam spot size on the target has a diameter of 1.5 mm with a pulse energy of 100 mJ / pulse, the target is rotated in a sodium dodecyl sulfate aqueous solution via a target rotation driving motor. Irradiated with pulsed laser light for 1 hour.
As a result, zinc was released into the aqueous solution as atoms, ions, and clusters, and immediately reacted with the dodecyl sulfate cation in the presence of water to form a zinc hydroxide-surfactant layered organic-inorganic nanocomposite.
[0014]
The obtained solid was washed after centrifugation. Washing and centrifugation were repeated several times to recover a white solid product. The obtained solid product is dried at room temperature in dry air, and then subjected to X-ray diffraction analysis, structural analysis by transmission electron microscope observation and transmission electron diffraction, energy dispersive X-ray analysis, Fourier transform infrared absorption spectrum measurement and heat The zinc hydroxide-surfactant layered organic-inorganic nanocomposite was characterized by analysis and the like.
[0015]
FIG. 3 shows an X-ray diffraction pattern of the zinc hydroxide-surfactant layered organic-inorganic nanocomposite. A diffraction peak corresponding to the (00l) plane is observed, indicating that the product has a layered structure.
From the peak position of the diffraction peak, it was found that the layer interval was 26.52 °. The distance between the layers can be controlled by the type of anionic surfactant used.
[0016]
In general, an anionic surfactant consists of an ionized head group and a hydrophobic hydrocarbon chain bonded to the head group. The longer the hydrocarbon chain, the more zinc hydroxide-surfactant is obtained. The layer interval of the layered organic-inorganic nanocomposite tends to increase.
FIG. 4 shows a transmission electron micrograph and a transmission electron beam diffraction pattern of the zinc hydroxide-surfactant layered organic-inorganic nanocomposite. The product is an octagonal plate-like crystal, and the transmission electron beam diffraction pattern shows that the zinc hydroxide layer, which is the inorganic layer skeleton, has a β-Zn (OH) ₃ structure having a hexagonal crystal structure.
[0017]
From the Fourier transform infrared absorption spectrum measurement shown in FIG. 5, it was found that the product clearly contained a hydroxyl group and water of hydration, and that a dodecyl sulfate group was inserted between the layers.
Energy dispersive X-ray analysis showed that the product did not contain sodium contained in the anionic surfactant at all and had a Zn to S ratio of 1: 0.35 and a Zn to C ratio of 1: 0.3. It turned out that it was 4.23.
The thermogravimetric measurement results shown in FIG. 5 also showed that the ratio of hydroxyl (OH) to H ₂ O was 1: 0.13. From these results, the following formula shows the chemical formula of the zinc hydroxide-surfactant layered organic-inorganic nanocomposite formed by laser ablation of zinc in the aqueous solution of sodium dodecyl sulfate.
Zn (OH) _1.66 (C ₁₂ H ₂₅ SO ₄ ) _0.34 · 0.22N ₂ O
[0018]
Furthermore, when the length of the dodecyl sulfate anion molecule is calculated by molecular model simulation and the arrangement structure of the dodecyl sulfate anion in the layered organic-inorganic nanocomposite is analyzed, the arrangement structure of the dodecyl sulfate anion between the zinc hydroxide layers is: It is considered that a lamellar structure is formed between the zinc hydroxide layers as shown in FIG.
Further, the length of the octadecyl sulfate cation (C ₁₈ H ₃₇ OSO ₃ ⁻ ) is calculated by molecular model simulation, and the layer interval of the obtained layered organic-inorganic nanocomposite is estimated to be up to 6 nm depending on the inclination of the cation molecule. It was observed that zinc hydroxide-surfactant layered organic-inorganic nanocomposites were also present.
As described above, when pulsed laser light is condensed and irradiated on the surface of metallic zinc in an aqueous solution of anionic surfactant to release zinc as atoms, ions, and clusters in the aqueous solution, organic anions are formed between the layers of zinc hydroxide. A zinc hydroxide-surfactant layered organic-inorganic nanocomposite crystal having a structure inserted with a lamellar arrangement can be obtained by a very simple process.
[0019]
【The invention's effect】
According to the present invention, zinc hydroxide and an organic layer are alternately laminated in the order of nanometers by applying strong energy to the metal zinc surface in a surfactant aqueous solution to release zinc as atoms, ions or clusters in the aqueous solution. Hydroxide-surfactant layered organic-inorganic nanocomposite consisting only of zinc hydroxide and surfactant, which has been considered to be difficult to produce in a very simple process, which forms a structured structure And an excellent effect of being able to provide a production method thereof.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view of an apparatus for producing a zinc hydroxide-surfactant layered organic-inorganic nanocomposite.
FIG. 2 is a diagram showing the steps of preparing and analyzing a zinc hydroxide-surfactant layered organic-inorganic nanocomposite.
FIG. 3 is a view showing an X-ray diffraction pattern of a zinc hydroxide-surfactant layered organic-inorganic nanocomposite.
FIG. 4 shows a transmission electron micrograph and a transmission electron diffraction pattern of a zinc hydroxide-surfactant layered organic-inorganic nanocomposite.
FIG. 5 is a diagram showing a Fourier transform infrared absorption spectrum of a zinc hydroxide-surfactant layered organic-inorganic nanocomposite.
FIG. 6 is a schematic diagram in which a dodecyl sulfate anion forms a lamellar structure between zinc hydroxide layers.
[Explanation of symbols]
1-1 Vertical type cell type manufacturing apparatus 1-2 Horizontal type cell type manufacturing apparatus 2 Laser apparatus 3 Laser beam reflecting mirror 4 Condensing lens 5 Quartz glass cell 6 Laser beam 7 Zinc metal plate target 8 Surfactant aqueous solution 9 units 10 axis 11 Gearbox 12 Target rotation drive motor

Claims (15)

An organic-inorganic nanocomposite having a structure in which zinc hydroxide and an organic layer are alternately stacked on the order of nanometers. The organic-inorganic nanocomposite according to claim 1, wherein the organic layer is a surfactant. The organic-inorganic nanocomposite according to claim 2, wherein the organic layer is an anionic surfactant. The organic-inorganic nanocomposite according to any one of claims 1 to 3, wherein the monolayer has a laminated structure of 1 nm to 6 nm. The organic-inorganic nanocomposite according to any one of claims 1 to 4, having a structure in which organic anions are lamella arranged between layers of zinc hydroxide. A structure in which zinc hydroxide and organic layers are alternately laminated in the order of nanometers by applying strong energy to the surface of metallic zinc in a surfactant aqueous solution and releasing zinc as atoms, ions, and clusters in the aqueous solution A method for producing an organic-inorganic nanocomposite, comprising: A structure in which zinc hydroxide and organic layers are alternately laminated on the order of nanometers by applying strong energy to the metal zinc surface in a surfactant aqueous solution and releasing zinc as atoms, ions or clusters in the aqueous solution The method for producing an organic-inorganic nanocomposite according to any one of claims 2 to 5, wherein The method for producing an organic-inorganic nanocomposite according to claim 6 or 7, wherein pulsed laser ablation is performed by applying condensing irradiation energy of pulsed laser light. The method for producing an organic-inorganic nanocomposite according to any one of claims 6 to 8, wherein a pulse energy of 50 mJ / pulse or more is applied. Organic according to any one of claims 6-9, characterized in that impart 1 J / cm ² or more laser light energy density metallic zinc target surface - method of producing an inorganic nanocomposite. The method for producing an organic-inorganic nanocomposite according to any one of claims 6 to 9, wherein a laser light energy density of ² J / cm2 or more is applied to the surface of the metal zinc target. The method for producing an organic-inorganic nanocomposite according to any one of claims 6 to 11, wherein an alkyl sulfate is used as the surfactant. The method for producing an organic-inorganic nanocomposite according to any one of claims 6 to 11, wherein sodium dodecyl sulfate is used as a surfactant. The method for producing an organic-inorganic nanocomposite according to any one of claims 6 to 13, wherein the concentration of the surfactant in the aqueous solution is 0.0001 mol / L or more. The method for producing an organic-inorganic nanocomposite according to any one of claims 6 to 13, wherein the concentration of the surfactant in the aqueous solution is 0.001 mol / L or more and a saturation concentration or less.

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