SOL-GEL SYNTHESIS OF ORTHOSILICATES

(1)

666.92 + 620.193

ɇ

.

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.

Ɇɚɥɹɜɫɤɢɣ

,

Ȼ

.

ȼ

.

ɉɨɤɢɞɶɤɨ

*

ɎȽȻɈɍ

ȼɉɈ

«

ɆȽɋɍ

», *

ɎȽȻɈɍ

ȼɉɈ

«

ɆɂɌɏɌ

»

ɁɈɅɖ

-

ȽȿɅɖ

ɋɂɇɌȿɁ

ɈɊɌɈɋɂɅɂɄȺɌɈȼ

Ɋɚɫɫɦɨɬɪɟɧɵɩɪɨɛɥɟɦɵɡɨɥɶ-ɝɟɥɶɫɢɧɬɟɡɚɜɵɫɨɤɨɨɫɧɨɜɧɵɯ ɫɢɥɢɤɚɬɨɜ, ɜɱɚɫɬɧɨɫɬɢ —

ɨɪɬɨɫɢɥɢɤɚɬɨɜɩɟɪɟɯɨɞɧɵɯɦɟɬɚɥɥɨɜ. ɉɪɟɞɥɨɠɟɧɧɨɜɵɣɦɟɬɨɞɢɯɡɨɥɶ-ɝɟɥɶɫɢɧɬɟɡɚɧɚɨɫɧɨɜɟ

ɢɫɩɨɥɶɡɨɜɚɧɢɹɱɟɬɵɪɟɯɤɨɦɩɨɧɟɧɬɧɵɯɜɨɞɨɪɚɫɬɜɨɪɢɦɵɯɩɪɟɤɭɪɫɨɪɨɜ. ɉɨɤɚɡɚɧɚɜɨɡɦɨɠɧɨɫɬɶ

ɩɨɥɭɱɟɧɢɹɬɚɤɢɦɫɩɨɫɨɛɨɦɚɦɨɪɮɧɨɝɨɨɪɬɨɫɢɥɢɤɚɬɚɦɟɞɢ.

Ʉɥɸɱɟɜɵɟɫɥɨɜɚ: ɡɨɥɶ-ɝɟɥɶɫɢɧɬɟɡ, ɨɪɬɨɫɢɥɢɤɚɬɵ, ɜɨɞɧɵɟɪɚɫɬɜɨɪɵ, ɨɪɬɨɫɢɥɢɤɚɬɦɟɞɢ.

,

.

[1],

--

,

[2, 3]

[4, 5]

(

) SiO

₂

[2]

[3—7]

.

-

MO/SiO

₂

,

-,

.

SiO

₄4–

-,

(

)

.

-

-,

—

,

-,

.

—

(II) —

-.

(II)

-,

,

Cu

2+

_.

_,

100…400 ° ,

(

)

,

CuO.

800 °

Cu

₂

O. (II)

-.

. 1

-

(

)

-

.

-,

,

:

1)

M(NO

₃

)

₂

(M = Cu, Mg, Zn, Cd) —

.

(

)

,

(2)

-8

/20

12 —

Mg

₂

SiO

₄

c

,

Zn

₂

SiO

₄

c

Cd

₂

SiO

₄

;

. 1.

-2)

— 3-

NH

₂

(CH

₂

)

₃

Si(OH)

₃

—

-,

,

.

3-

:

H

₂

N(CH

₂

)

₃

Si(OC

₂

H

₅

)

₃

+ 3 H

₂

O ® H

₂

N(CH

₂

)

₃

Si(OH)

₃

+ 3 C

₂

H

₅

OH

.

--

(

. 2).

-

15 [6], . .

[6, 7];

C

H

₂

CH

₂

C

H

₂

NH

₂

Si

O

H

OH

Si

C

H

₂

C

H

₂

C

H

₂

O

H

OH

NH

₃

+

. 2.

M(NO

₃

)

₂

H

₂

O

H

₂

O

(3)

3) T

—

(HOC

₂

H

₄

)

₃

N,

-,

.

—

[7];

4) MT

—

[CH

₃

(C

₂

H

₅

)

₃

N]OH,

-,

.

(

,

)

.

,

-,

( u,Mg)

₂

SiO

₄

, ( u,Zn)

₂

SiO

₄

, ( u,Cd)

₂

SiO

₄

1:1.

10 ° /

300, 500, 700 900 ° .

200…400

.

,

-

(

- ),

(

)

(

)

-.

(

)

-4-13 (

CuK

_a

-

)

RAPID POWTOOL.

-

-2000

320…850

.

-

--

400…4000

–1

Perkin-Elmer 2000.

-LHS-10

MgK



( = 1253,6

)

10

–4

_.

_,

-, . .

-

(l =

410 )

HCl [1].

(

,

)

x

500 ° .

x

MO/SiO

₂

.

,

x

= 2

(

),

x

= 1,5

,

x

= 1

,

x

= 0

.

-n

:

x

= 1 + 1/

n

.

(

X = 2g

₁

+ 1,5

g

₂

+

x

₃

g

₃

+

x

₄

g

₄

).

500 °

Cu CuMg Mg CuZn Zn CuCd Cd

g₁ 0,925 0,268 0,737 0,709 0,971 0,523 0,611

g₂ 0,075 0,400 — — 0,029 — 0,072

g₃ — 0,331 0,186 0,213 — 0,242 0,076

x₃ — 1,180 1,276 1,237 — 1,275 1,144

g₄ — — 0,077 0,078 — 0,235 0,240

x₄ — — 0,947 1,006 — 0,883 0,890

X 1,96 1,53 1,78 1,76 1,99 1,56 1,63

,

500 °

(4)

8 /20

12 -

,

-

.

,

-,

500 °

(54 %),

[1].

,

.

-

(71 %

), «

»,

, 21 %

(

,

-) 8 %

(

,

).

-,

-

300 500 ° .

500…900 °

.

. 3

-

,

-,

(

).

CuO,

.

. 3. - 2CuO∙SiO₂

500 . : 1 — Cu(NO₃)₂ + + + + H₂O; 2 — Cu(NO₃)₂ + +

+ NH4OH + + H2O; 3 — Cu(NO3)2 + Ludox + + + H2O; 4 — Cu(NO3)2 +

+ + + + H2O; 5 — Cu(NO3)2 + + + H2O; 6 — Cu(NO3)2 +

+ + NH₄OH + H₂O; 7 — Cu(NO₃)₂ + + HNO₃ + H₂O; 8 — Cu(NO₃)₂ + + H₂O

340...350

(3,5

) [7],

, . .

CuO,

.

8 (

CuO,

)

100 %,

(

1)

15 %.

,

CuO

85 %.

,

. 3,

-1

2

3

4

5

6

7

8

300 350 400 450 ,

,

.

(5)

.

,

(

3 ,

4 ),

(

2 ),

(

5 ,

6 ),

,

(

7 )

,

.

-

--

500…600 ° .

—

Si-O-Si (n

_as

).

,

n

_as

.

4-

n

_as

(

–1

_{): 1010 (300 ° ), 990 (500 ° ), 1070 (700}

_{° ) 1080 (900 ° ).}

-,

500 °

-.

CuO

,

.

(

. 4).

(300, 500 700 ° )

,

(

)

900 ° .

:

700 °

CuO

-,

900 ° ,

.

. 4. 2CuO∙SiO₂

4- : 1 — SiO2; 2 — CuO

,

500 °

-10 20 30 40 50 60 70 80 2Θ, .

,

.

900 °

700 °

500 °

300 ° 1

1 1

1 1 1

1

(6)

8 /20

12 .

. 5

-

2p-.

2p

_3/2

(935,3

)

(943

)

Cu

2+

_{( . .}

_).

Cu

2+

_(933,7

₎

,

CuO,

.

. 5. ( LHS-10)

2CuO∙SiO₂ 550 °C ( Cu-2p)

,

-,

:

100 ° —

;

300 ° —

,

-;

500 ° —

,

Cu

₂

SiO

₄

CuO;

700 ° —

CuO

;

900 ° —

-

,

.

-

-.

Cu

₂

SiO

₄

,

500…600 ° ,

,

-.

Ȼɢɛɥɢɨɝɪɚɮɢɱɟɫɤɢɣɫɩɢɫɨɤ

1. ɋɢɞɨɪɨɜ ȼ.ɂ., Ɇɚɥɹɜɫɤɢɣ ɇ.ɂ., ɉɨɤɢɞɶɤɨ Ȼ.ȼ.

// . 2007. № 1. . 163—166. 2. Tsai M.T. Preparation and crystallization of forsterite ﬁ brous gels // J. Eur. Ceram. Soc., 2003, vol. 23, pp. 1283—1291.

3. Stoia M., Stefanescu M., Dippong T., Stefanescu O. and Barvinschi P. Low temperature synthesis of Co₂SiO₄/SiO₂ nanocomposite using a modiﬁ ed sol–gel method // J. Sol-Gel Sci. and Technol., 2010, vol. 54, pp. 49—56.

955 950 945 940 935 930 925

,

1/2 3/2

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4. Saberi A., Negahdari Z., Alinejad B. and Golestani-Fard F. Synthesis and characterization of nanocrystalline forsterite through citrate–nitrate route // Ceramics Int., 2009, vol. 35, pp. 1705—1708.

5. Douy A. Aqueous syntheses of forsterite (Mg₂SiO₄) and enstatite (MgSiO₃) // J. Sol-Gel Sci. and Technol., 2002, vol. 24, pp. 221—228.

6. Maliavski N.I., Dushkin O.V., Tchekounova E.V., Markina J.V. and Scarinci G. An organic-inorganic silica precursor suitable for the sol-gel synthesis in aqueous media // J. Sol-Gel Sci. and Technol., 1997, vol. 8. pp. 571—575.

7. Maliavski N.I., Dushkin O.V. and Scarinci G. Low-temperature synthesis of some orthosilicates // Ceramics – Silikaty, 2001, vol. 45, pp. 48—54.

ɉɨɫɬɭɩɢɥɚɜɪɟɞɚɤɰɢɸɜɦɚɟ 2012 ɝ.

: Ɇɚɥɹɜɫɤɢɣ ɇɢɤɨɥɚɣ ɂɜɚɧɨɜɢɱ — , , , ɎȽȻɈɍ ȼɉɈ «Ɇɨɫɤɨɜɫɤɢɣ ɝɨɫɭɞɚɪɫɬɜɟɧɧɵɣ

ɫɬɪɨɢɬɟɥɶɧɵɣɭɧɢɜɟɪɫɢɬɟɬ» (ɎȽȻɈɍȼɉɈ «ɆȽɋɍ»), 129337, . , , . 26, (492) 183-32-92, nikmal08@yandex.ru;

ɉɨɤɢɞɶɤɨȻɨɪɢɫȼɥɚɞɢɦɢɪɨɜɢɱ — , ,

, ɎȽȻɈɍ ȼɉɈ «Ɇɨɫɤɨɜɫɤɢɣ ɝɨɫɭɞɚɪɫɬɜɟɧɧɵɣ ɭɧɢɜɟɪɫɢɬɟɬ ɬɨɧɤɢɯ

ɯɢɦɢɱɟɫɤɢɯɬɟɯɧɨɥɨɝɢɣɢɦ. Ɇ.ȼ. Ʌɨɦɨɧɨɫɨɜɚ» (ɎȽȻɈɍȼɉɈ «ɆɂɌɏɌ»),119571, . , , . 86, (495) 936-88-58, pokidko2000@mail.ru.

: Ɇɚɥɹɜɫɤɢɣ ɇ.ɂ., ɉɨɤɢɞɶɤɨ Ȼ.ȼ. - //

. 2012. № 8. . 131—138.

N.I. Malyavskiy, B.V. Pokid’ko

SOL-GEL SYNTHESIS OF ORTHOSILICATES

The objective of the research is the sol-gel preparation of the crystalline or amorphous or-thosilicates of some bivalent metals, namely, copper orthosilicate (Cu₂SiO₄), which seems to be a quite efﬁ cient catalyst, although it has not been synthesized yet. The main obstacles that prevent the sol-gel synthesis of orthosilicates include high metal/silica molar ratios in precursor mixtures. They cause (i) formation of the crystalline of metal oxides at intermediate stages of synthesis and (ii) a substantial difference between intermediate and ﬁ nal anion structures because of the polycon-densation of silicate anions at the stages of gelation and drying. This can result in a double-stage character of synthesis, involving formation of metal polysilicates and a metal oxide as intermediates.

The synthesis pattern employed by the authors was based on a combination of “anti-polycon-densation” actions that had three components involved: a) 3-aminopropylsilanetriol, a water-soluble silica precursor that demonstrates low polymerizability and high stability in any ambience; b) trietha-nolamine, a high-boiling chemically active agent that prevents metal hydroxide precipitation and inhibits polycondensation at initial stages of heat treatment; c) methyl triethylammonium hydroxide, a strong component that inhibits polycondensation processes at the stage of the solution drying.

Metal nitrates M(NO₃)₂ (M=Cu, Mg, Zn, Cd) were employed as metal oxide precursors, while water was the solvent. Coating solutions were applied to glass, silica glass or silicon substrates and heated to 300, 500, 700 and 900 °C. The resulting silicate ﬁ lms were studied using UV-VIS spec-troscopy, FTIR, XPS and XRD methods. Molecular mass distribution of silicate anions in the ﬁ lms was measured using the molybdate method.

As a result, the synthesis pattern proved effi cient in the synthesis of orthosilicates of bivalent metals. Amorphous copper silicates with the anion structures close to the orthosilicate (basicities up to 1.96), were prepared in the form of thin fi lms after heating up to 500°C. At 700…900 °C, they decomposed with the formation of CuO. Only in the case of CuZnSiO₄ the polymerization grade of silicate anions was suffi ciently low, if the ternary samples are taken into consideration (the anion basicity was about 1.7).

Key words: sol-gel synthesis, orthosilicates, aqueous solutions, copper orthosilicate.

References

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8 /20

12

2. Tsai M.T. Preparation and Crystallization of Forsterite Fibrous Gels. J. Eur. Ceram. Soc., 2003, vol. 23, pp. 1283—1291.

3. Stoia M., Stefanescu M., Dippong T., Stefanescu O. and Barvinschi P. Low Temperature Synthe-sis of Co2SiO4/SiO2 Nanocomposite Using a Modiﬁ ed Sol–Gel Method. J. Sol-Gel Sci. and Technol., 2010, vol. 54, pp. 49—56.

4. Saberi A., Negahdari Z., Alinejad B. and Golestani-Fard F. Synthesis and Characterization of Nanocrystalline Forsterite through Citrate–Nitrate Route. Ceramics Int., 2009, vol. 35, pp. 1705—1708.

5. Douy A. Aqueous Syntheses of Forsterite (Mg2SiO4) and Enstatite (MgSiO3). J. Sol-Gel Sci. and Technol. 2002, vol. 24, pp. 221—228.

6. Malyavskiy N.I., Dushkin O.V., Tchekounova E.V., Markina J.V. and Scarinci G. An Organic-Inor-ganic Silica Precursor Suitable for the Sol-Gel Synthesis in Aqueous Media. J. Sol-Gel Sci. and Technol. 1997, vol. 8. pp. 571—575.

7. Malyavskiy N.I., Dushkin O.V. and Scarinci G. Low-Temperature Synthesis of Some Orthosili-cates. Ceramics – Silikaty, 2001, vol. 45, pp. 48—54.

A b o u t t h e a u t h o r s: Malyavskiy Nikolay Ivanovich — Candidate of Chemical Sciences, Profes-sor, Department of General Chemistry, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; nikmal08@yandex.ru; +7 (499) 183-32-92;

Pokid’ko Boris Vladimirovich — Candidate of Chemical Sciences, Associated Professor, Depart-ment of Colloid Chemistry, LomonosovMoscow University of Fine Chemical Technology (MITHT), 86 Prospekt Vernadskogo, Moscow, 119571, Russian Federation, pokidko2000@mail.ru; +7 (495) 936-88-58.