JPH0753239A - Superfine particle-carried glass and its production - Google Patents

Abstract

PURPOSE:To surely and relatively easily produce a bulky body of colloid. CONSTITUTION:A colloidal soln. is mixed with a metal alkoxide, stirred, aged and dried to produce the objective superfine particle-carried glass contg. colloidal particles fixed in glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ultrafine particle-supporting glass and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Dispersions of ultrafine particles represented by colloidal solutions, particularly dispersions of ultrafine particles having a particle size of about 10 nm or less, are fine particles having ordinary physical properties such as optical, electromagnetic and thermal properties. Very different from the dispersion. For example, the peculiar property thereof is optical bistability due to the third-order nonlinear optical characteristic, and this property can be applied to the field of optical computer devices and the like. In this case, if the colloid, which is a dispersion solution of ultrafine particles, can be treated as a solid as it is, the above characteristics can be more effectively utilized.

As a conventional technique for solidifying a colloid, there is a method in which a metal ion such as Au or Ag is dissolved in a metal alkoxide and then heated to a temperature of about 300 ° C. or higher to generate a colloid.

However, the above method can only produce a thin film. That is, in order to manufacture a bulk body, it is necessary to perform heating under extremely strict temperature control,
Since it is difficult to control the temperature in the above method, a crack easily occurs in the bulk body. Moreover, the above method has a drawback in that the substance (ultrafine particles) that can be supported is limited to those that generate a colloid by heating.

[0005]

SUMMARY OF THE INVENTION Therefore, the main object of the present invention is to reliably and relatively easily manufacture a bulk body of colloid.

[0006]

As a result of repeated studies to achieve the above object, the present inventor has found that the colloidal particles can be fixed in glass by mixing the colloidal solution with a metal alkoxide. The inventors have also found that a bulk material having such a unique structure exhibits optically excellent characteristics, and completed the present invention.

That is, the present invention relates to the ultrafine particle-supporting glass and the manufacturing method thereof according to the following items 1 and 2. 1. A glass carrying ultrafine particles, characterized in that colloidal particles are fixed in the glass. 2. A method for producing ultrafine particle-supporting glass, which comprises mixing and stirring a colloidal solution and a metal alkoxide, followed by aging and drying.

The present invention will be described in detail below.

First, the colloidal solution used in the present invention is
It can be prepared according to a conventional method, for example, by adding water, acid, alkali, etc. (hereinafter referred to as “additive”) to an aqueous solution containing a desired substance to be fixed in glass, to hydrolyze the substance. It can be obtained by disassembling.

As the above substances, virtually any substance can be used as long as it can form a colloid in an aqueous solution. Further, a water-soluble compound containing the substance can be used as a supply source of the substance. For example, chloride, sulfate, nitrate, carbonate, complex salt of these substances,
Double salts and the like can be used, and specific examples thereof include chloroaurate, silver nitrate, iron nitrate, sodium tungstate, and the like. The concentration of the aqueous solution varies depending on the substance used and the like, but is usually about 0.01 to 0.1 wt%. As the additives, those used for the preparation of ordinary colloidal solutions can be applied as they are, and examples thereof include citric acid, sodium citrate, tannic acid, sodium carbonate, and sodium dodecylbenzenesulfonate. The concentration of the additive is
Usually, it is about 0.1 to 1 wt%. The addition amount may be appropriately determined, and is usually about 1/100 to 1/5 times the amount of the above aqueous solution.

On the other hand, as the metal alkoxide, a known compound used in a general sol-gel method can be applied, and for example, tetramethoxysilane, tetraethoxysilane, zirconium tetraisopropoxide, titanium tetrabutoxide and the like can be used. They can be used, and two or more of these may be used in combination. The addition amount of the metal alkoxide may be appropriately determined, and is usually about 1 to 2 times the colloid solution.

Next, the above colloidal solution and the metal alkoxide are mixed and stirred to hydrolyze the metal alkoxide. Mixing / stirring is performed until a uniform solution is formed, and usually it may be about 1 to 2 hours.

The mixing of the colloidal solution with the metal alkoxide in the present invention also includes a method of first mixing the aqueous solution containing the desired substance with the metal alkoxide, and then adding an additive to the mixture. In this case, the particle size of the colloidal particles can be controlled relatively easily by changing (delaying) the timing of adding the additive.

After stirring, the gel solution is obtained by aging the mixed solution in a container having a desired shape such as a disk or a rod. The aging temperature is usually about 30 to 80 ° C, preferably 3
The temperature may be 5 to 45 ° C. The aging time is usually 1 to 4
Weekly, preferably about 2 to 4 weeks.

After aging, the gel body is dried according to a conventional method. The drying method is not particularly limited, and may be air-dried at room temperature for about 80 to 150 hours.

[0016]

According to the manufacturing method of the present invention, it is possible to obtain ultrafine particle-supporting glass in which colloidal particles are fixed in the glass. Therefore, not only a colloid thin film, but also a colloid bulk body such as a disk and a rod, which cannot be produced conventionally, can be produced.

In the production method of the present invention, the viscosity of the sol is changed by changing the addition timing of the additive.
It is also possible to control the particle size of the colloidal particles in the obtained ultrafine particle-supporting glass. Furthermore, by changing the kind of the metal alkoxide, the glass matrix of the ultrafine particle-supporting glass can be changed to give various optical characteristics.

The ultrafine-particle-supporting glass of the present invention has a unique structure in which colloidal particles are fixed (supported) in the glass as described above, and has characteristics such as third-order nonlinear optical characteristics. Therefore, it is particularly useful for applications such as optical computer devices.

[0019]

EXAMPLES Examples and comparative examples will be shown below to further clarify the features of the present invention.

In the examples, the particle size of the metal fine particles was calculated from the visible spectrum as follows. That is, it was determined by the general formula d = 2 · Vf · ΔW ^-1 (where d is the particle size, Vf is the Fermi velocity, and ΔW is the half width of the waveform centered on the absorption position of the visible spectrum) ( GWArnold, JA
ppl. Phys., 46 (1975) 4466).

Example 1 50 ml of a 0.01 wt% chloroauric acid aqueous solution was boiled, and 0.5 ml of a 1 wt% sodium citrate aqueous solution was added thereto to obtain an aqueous gold colloid solution. 5 ml of this aqueous solution
To the solution was added 6 ml of tetramethoxysilane (TMOS), and the mixture was stirred for 1 hour to form a uniform solution. Then, the sol was aged in a constant temperature bath at 35 ° C. for about 1 week in a rod-shaped container to obtain a gel body. Then, the rod-shaped glass of the present invention carrying gold colloid was obtained by air-drying in a rod-shaped container at room temperature for about 1 week.

The visible spectrum of the above glass is shown in FIG. From this, it is understood that the colloidal gold is in the same dispersed state as that in the aqueous solution in the silica glass. Further, it can be seen from FIG. 1 that the particle size of the gold colloid is 5 to 10 nm. Furthermore, the third-order nonlinear photosensitivity was about 10 ⁻¹¹ esu when measured with the second harmonic of the Nd-YAG laser (wavelength 532 nm, pulse width 8 ns).

Example 2 5 ml of 0.05 wt% chloroauric acid aqueous solution and 6 m of TMOS
and 1 were stirred at 40 ° C. Then 1 hour, 2 hours and 3
After the lapse of time, 0.5 ml of a 1 wt% sodium citrate aqueous solution was added into the system. Then, the disc-shaped glass of the present invention carrying gold colloid was obtained by aging and drying in a disc-shaped container in the same manner as in Example 1.

Each visible spectrum of the above glass is shown in FIG. From this, it can be seen that there is a relation between the addition timing and the position of the visible spectrum, and that the absorption position shifts to the longer wavelength side and the colloidal particles grow as the time until the aqueous solution of sodium citrate is added becomes longer. That is, it is understood that the particle size of the colloidal particles can be controlled by adjusting the viscosity of the sol.

Example 3 An equal amount of 40% citric acid aqueous solution was added to 30% sulfuric acid aqueous solution,
A 50 ml mixture was prepared. After adding 3 to 5 drops of 10% silver nitrate aqueous solution to this mixed solution, a uniform solution was obtained. Then
The sol was aged in a rod-shaped container in a thermostat at 35 ° C. for about 1 week to obtain a dry gel body. Then, the rod-shaped glass of the present invention carrying silver colloid was obtained by air-drying at room temperature for about 1 week.

The visible spectrum of the above glass is 400 n
Since m shows absorption, it was confirmed that silver colloid particles having a particle size of 5 to 10 nm were dispersed and carried.

Example 4 To 6 ml of a solution prepared by adding 2 mol of acetylacetone to 1 mol of zirconium tetraisopropoxide,
5 ml of an aqueous gold colloid solution prepared by the same method as in Example 1 was added. Then, the disc-shaped zirconia glass of the present invention carrying gold colloid particles was obtained by aging and drying in a disc-shaped container in the same manner as in Example 1.

The third-order nonlinear photosensitivity was about 10 ^-10 esu as measured by the second harmonic (wavelength 532 nm, pulse width 8 ns) of the glass Nd-YAG laser. From this, it is understood that the third-order nonlinear photosensitivity can be increased by about 10 times by changing the glass matrix.

Example 5 2 m of diethylene glycol instead of acetylacetone
A zirconia glass of the present invention carrying colloidal gold particles was obtained in the same manner as in Example 4 except that ol was used.

As in Example 4, it was confirmed that the third-order nonlinear photosensitivity can be increased about 10 times by changing the glass matrix.

[Brief description of drawings]

FIG. 1 is a visible spectrum of the glass obtained in Example 1.

2 is each visible spectrum of the glass obtained in Example 2. FIG.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Ryo Sakaguchi, 3-5-8, Higashi Tokiwadai, Toyono-cho, Toyono-gun, Osaka Prefecture

Claims (2)

[Claims] 1. Ultrafine particle-supporting glass, characterized in that colloidal particles are fixed in the glass. 2. A method for producing ultrafine particle-supporting glass, which comprises mixing and stirring a colloidal solution and a metal alkoxide, followed by aging and drying.