聚乙烯醇对碳纳米管负载氧化铁影响的研究

Effect of PVA on Ferric Oxide Coated on Carbon Nanotubes

采用液相化学沉积法制备了碳纳米管负载的Fe2O3.TEM观察发现,添加聚乙烯醇作为表面活性剂可以实现碳纳米管对Fe2O3的有效负载,未添加聚乙烯醇两者出现物相分离.聚乙烯醇均匀吸附在碳纳米管表面,增强碳纳米管在水溶液中的分散,其疏水基团与碳纳米管以范德华力结合,其亲水基团与Fe2O3.nH2O结合,对碳纳米管有效负载Fe2O3起到了桥梁作用.在样品煅烧过程中,聚乙烯醇熔融后均匀地包裹在碳纳米管表面上,进一步阻止了两者在煅烧过程中的物相分离.

Fe2O3 coated on CNTs were prepared by adding CNTs in liquid-disposition process. The TEM images show that CNTs and Fe2O3 would be separated from each other without the PVA and be connected well when the PVA was absorbed on the surface of CNTs. The PVA could help CNTs weltering the aquatic phase and enhance the stability of their dispersion. The PVA had bi-functional bridges, with hydrophilic groups jointed with the Fe2O3 film, and hydrophobic chains adhered to the surface of the carbon nanotubes, so the Fe2O3 were supported on the surface of the carbon nanotubes through the surfactant. When the sample was calcined at 350 ℃, the PVA melted and coated on the external suface of CNTs to prevent the Fe2O3 from seperating from the CNTs＇ external suface. The XRD patterns of the Fe2O3 film coated on CNTs reveal that the coating was α-Fe2O3 and γ-Fe2O3.