Lamellar silica samples were synthesized by a neutral amine process and str
uctural modifications were induced by copper nitrate or sulfate addition. T
he lamellar silica showed three diffraction peaks at 2 theta values of 3.8,
7.3 and 11.5 degrees, due to the 001, 002 and 003 diffraction planes. Addi
tion of copper nitrate or sulfate affected the structure of the starting ma
trices as demonstrated by X-ray diffraction patterns. Both metal-doped lame
llar silicas were mechanically induced to react in the solid state with pot
assium bromide, to give products which exhibited significant structural mod
ifications. The thermal stability of the lamellar silica samples increased
by addition of copper salts. Thus, the precursor lamellar silica and the co
rresponding nitrate and sulfate metal-doped samples started to degrade at 1
05 degrees C, 130 degrees C and 230 degrees C, respectively. Structural and
thermal measurements on these samples exhibited an increased resistance to
decomposition, however, the nitrate and sulfate anions caused remarkable s
tructural modifications in the synthesized matrices. (C) 2000 Elsevier Scie
nce B.V. All rights reserved.