TiO_2光催化降解聚乙烯薄膜

Photodegradation of Polyethylene Films Catalyzed by TiO_2

以快速溶胶法制备了纳米TiO2光催化剂,用于室温下固相光催化降解聚乙烯(PE)包装薄膜的研究。对催化剂和薄膜进行了X射线衍射分析,傅立叶红外光谱分析,扫描电子显微镜形貌观察。结果表明,15W紫外光辐射240h后,PE质量损失为7.66%,金红石型纳米TiO2光催化剂使PE质量损失14.93%,锐钛矿型纳米TiO2光催化剂使PE质量损失23.97%;TiO2加速了高分子碳链的断裂和光氧化,在薄膜表面形成大量的凹坑,降解产物中小分子量的石蜡含量明显增高,锐钛矿型纳米TiO2光催化降解PE的活性高于金红石型纳米TiO2。

A nano-size TiO_(2) photocatalyst was prepared readily by the Sol-gel method, and was used to (catalyze) the degradation of PE films under UV(15 W intensity) irradiation for 240 h in air. The properties of the catalyst and the degraded PE films were characterized by XRD, FT-IR and SEM. The results show that PE films lose only 7.66% of its mass under UV irradiation for 240 h, while Rutile style TiO_(2) and Anatase TiO_(2) photocatalysts can increase the mass loss to 14.93%, and 23.97%, respectively, indicating that TiO_(2) speeds up the breaking and photo oxidation of PE chains. The SEM micrograph of the PE film after photodegradation shows a large number of pits on the film surface. The XRD patterns indicate there was more wax in the degradation products in the presence of TiO_2. Anatase style TiO_(2) exhibited a higher activity than Rutile style TiO_(2) for the photodegradation of PE films.