Study of fullerene-containing epoxy membranes with tunable ultraviolet light-filtering properties

Fullerene-containing epoxy membranes with tunable ultraviolet (UV) optical properties were prepared by adding various amounts of aminated-fullerene derivatives into an epoxy resin/ethylenediamine system. The influences of content and chemical structure (e.g., amine kind and addition degree) of aminated-fullerene on the mechanical, optical and thermal properties of the cured epoxy membranes were investigated systematically. Dynamic mechanical analysis (DMA) indicates that the aminated-fullerene participates in the epoxy curing process and that a star-like crosslinking structure is formed. A higher cross-link density results in a higher glass transition temperature and storage module. The UV-Vis absorbance spectra reveal that the cutoff wavelength λc of the aminated-fullerene/epoxy membranes can be changed over almost the entire UV region simply by varying the fullerene derivative content. The charge-transfer complexes formed between the fullerene derivatives and the epoxy-amine complex may be responsible for the UV light-filtering behaviors. The result of thermogravimertic analyses (TGA) reveals that a higher amount (0.48 wt%) of fullerene derivative obviously leads to the better thermal stability of the cured epoxy membrane.