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X-Ray Diffraction Analysis of Differently Prepared AgI. III.

R. Despotović ; Departments of Physical Chemistry and Solid State, Institute »Rueter Boskovic«, ' Zagreb, Croatia, Yugoslavia
Z. Despotović ; Departments of Physical Chemistry and Solid State, Institute »Rueter Boskovic«, ' Zagreb, Croatia, Yugoslavia
M. Jajetić ; Departments of Physical Chemistry and Solid State, Institute »Rueter Boskovic«, ' Zagreb, Croatia, Yugoslavia
M. Mirnik ; Departments of Physical Chemistry and Solid State, Institute »Rueter Boskovic«, ' Zagreb, Croatia, Yugoslavia
S. Popović ; Departments of Physical Chemistry and Solid State, Institute »Rueter Boskovic«, ' Zagreb, Croatia, Yugoslavia
Ž. Telišman ; Departments of Physical Chemistry and Solid State, Institute »Rueter Boskovic«, ' Zagreb, Croatia, Yugoslavia

Sažetak

The .influence of the concentration ·of the constituent and
coagulatin,g ions, surface active agents, pH, and the rate of pre..,
cipitation on . .the cubic/hexagonal .ratio of Ag! p.nd on the size of
Ag! crystallites formed in statu nascendi sols has been studied. In
the concentration re'gions cKI = 1.0 X 10-5 M to 1.00 M and
cAgNOa = 1.0 X·l0-6 M to 2.00 M different amounts of cubic and
hexagonal Ag! were obtained. The pure hexagonal modification
was found only at 1.00 M KI. At pl 4 220/o of cubic Ag! was
obtained. F.rom aqueous solutions containing AgN03 (1 X 10-6 to
2.00 M) no pure cubic Ag! can be obtained. At pAg 1-2 the
maximum amount (800/o) of cubic Ag! was formed. The aging
process does not change the cubic/hexagonal ratio but influences
the growth of crystallites. The rate at which the precipitation
components are mixed influences the dispersity and the cubic/hexagonal
ratio, which on the other hand also depend on the concentration
of univalent and bivalent coagulating ions. The acidity
of the system (pH = 0.1 - 5.8) does not significantly influence the
dispersity and the cubic/hexagonal ratio of Ag!. Surface active
agents (SAA) in the concentration region from 1.0 X 10-1 M to
1.0 X 10-4 M do not influence the crystal structure; they influence,
however, the dispersity of the particles of sols hindering' their
growth. By dilution of the complex solution of Ag! - KI with
water Ag! sols were formed. At lower initial concentration of KI
the percentage of hexagonal Ag! was higher. In sols formed by
dilution of the complex solution of Ag! - AgN03 with water,
more cubic Ag! was found at lower initial concentration of AgN08•
By cooling a hot complex solution of Ag! - KI (2.0 M KI) from
160° C to room temperature (0.2° C/min) 1000/o of cubic, transparent
Ag! crystals were formed.

Ključne riječi

Hrčak ID:

197535

URI

https://hrcak.srce.hr/197535

Datum izdavanja:

30.10.1970.

Posjeta: 462 *