Photocatalytic Degradation of Secondary Alcohol Ethoxylate: Spectroscopic, Chromatographic, and Mass Spectrometry Studies

Secondary alcohol ethoxylate (SAE) was photocataiytically degraded using a suspension of TiO₂ particles irradiated with long wavelength ultraviolet light. High starting concentrations of SAE were used (ca. 2000 mg/L), and changes in both SAE oligomer distribution and production of intermediates were monitored by using GC, GC/MS, NMR, and ESMS. Initial preferential cleavage of the ethoxyl groups over HO* reactions with the aliphatic portions of the molecule is followed by cleavage at the secondary carbon. Relatively hydrophilic intermediates remained in solution, while the hydrophobic products adhered to the TiO₂, causing agglomeration of the particles.