Adsorption of ZDDP on alpha-phase iron oxide

Abstract: Two different ZDDP solutions were prepared, one with ZDDP in hexadecane,
the other one with ZDDP in Diethylene glycol dibutyl ether (DGDE). The
concentration of them was increased from 0.1 weight percent to 5 weight
percent of ZDDP. Alpha-phase Iron(‡V) Oxide is used for ZDDP adsorption.
The scope of the exam work was to first measure the molar absorption
coefficient for ZDDP in DGDE as well as in hexadecane by recording ATR
spectra of ZDDP in the two solvents as a function of concentration.
Subsequently, the absorption coefficients would be used in batch
experiments where ZDDP was adsorbed on alpha-phase Iron(III) oxide in order
to construct adsorption isotherms at various temperatures. In the latter
part of the experiments, the temperature and time stability of ZDDP should
also be examined. Finally, the aim was to study the adsorption of ZDDP on
alpha-phase iron(III) oxide in-situ, using the ATR method. However, the
final part of the experiments was not meaningful, since it eventually
turned out that the ZDDP chemical, as received from SKF, was not pure
enough as confirmed at our laboratories by means of NMR analysis.