when we heat up sample power or gel up-to (710-900) degree Celsius, results performed by FTIR, result shows water molecules vibrations v(O-H) and sigma(OH) etc. this is very surprising for me. why water molecules are still present at 900 C
Hello Haider,
There is possibility that the sample adsorbed water just after removed from the heat source e.g. furnace. If you made a pellet for FTIR it is very likely that water adsorbed during the pelleting. in Case of ATR also water could get involved.
Regards
Amin
After cooling down from 900C to 120C and below- water molecules occupy the surface very rapidly - and you can observe the kinetics of sorption:
a) for single water molecules.... followed by
b) formation of water dimers... and then
b) formation of poly-molecular layer of H-bonded molecules of water.
The band position of O-H stretching is changing during this process (towards lower vawenumbers) - so all the 3 states of sorbed water are discernible.
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