Sample preparation
Prior to use cobalt driers were dissolved or diluted with acetone in
volumetric flasks to a final concentration of 27.2 mM. Linseed oil (1
mL) was added to a vial and stirred under air for 15 minutes. An aliquot
of catalyst solution (0.050, 0.075, or 0.100 mL; 1.36, 2.04 or 2.72
μmol) was added to the aerated oil for a final catalyst concentration of
1.36 mM, 2.04 mM, or 2.72 mM. The oil and drier mixture was stirred for
a further 30 seconds before being applied to the IR window via pipette.
A uniform film thickness was obtained by running a razorblade over the
IR window depression.