Study of glass materials containing CuO with a deodorizing function

Abstract

In this study, focusing on the oxidation reactivity of glass containing CuO, the authors investigated the deodorizing function of the glass to malodorous substances sulfur-based compounds and lower fatty acids, particularly methyl mercaptan. It was confirmed the glass removes hydrogen sulfide, mercaptans and lower fatty acids by the deodorization test with the gas detection tube. Dimethyl disulfide which is an oxidation product of methyl mercaptan was identified by gas chromatography in the gas which methyl mercaptan was removed. The hydroxyl radicals generated from the glass was observed by the radical detection test using the spin-trapping method. Therefore, it is considered this radical dimerized methyl mercaptan and it lead to dimethyl disulfide formation. To compare with CuO showing the same oxidation mechanism as glass, a repeated deodorization test of methyl mercaptan was carried out and the surfaces of the glass and CuO were analyzed by X-ray photoelectron spectroscopy before and after deodorization. As a result, the glass showed higher deodorizing function durability of methyl mercaptan. Sulfur is hardly immobilized on the glass surface, however is immobilized on CuO surface, therefore it is presumed that the glass deodorizing function is more persistent than that of CuO. This study suggested that the glass containing CuO has a function of deodorizing sulfur-based compounds and lower fatty acids and that oxidation mechanism of methyl mercaptan to dimethyl disulfide is a radical reaction.