Optical limiting in fullerene materials

Fullerene chemistry is booming, but how the chemical reactions affect fullerene's materials properties has seldom been studied. We have investigated optical limiting behavior of a series of fullerene derivatives, polymers, and glasses and have observed the following structure-property relationships for optical limiting in the fullerene materials: (i) The fullerene polymers with aromatic and chlorine moieties, i.e., C-60-containing polycarbonate (C-60-PC), polystyrene (C-60-PS), and poly(vinyl chloride) (C-60-PVC), limit the 8-ns pulses of 532-nm laser light more effectively than does the parent C-60; (ii) the fullerene polymers with carbonyl groups, i.e., C-60-containing CR-39 (C-60-CR-39) and poly(methyl methacrylate), (C-60-PMMA), do not enhance C-60's limiting power; and (iii) the aminated fullerene derivatives, i.e., HxC60(NBR), [R = -(CH2CH2O)(2)H (1), x = 11; -(CH2)(6)OH (2), x = 7; -cyclo-C6H11 (3), x = 11; -(CH2)(3)Si(OC2H5)(3) (4), x = 4], and their sol-gel glasses, i.e., 1-3/SiO2 (physical blending) and 4-SiO2 (chemical bonding), show complex limiting responses, with 4(-SiO2) performing consistently better than 1-3(/SiO2). The fullerene glasses are optically stable and their optical limiting properties remain unchanged after being subjected to continuous attack by the strong laser pulses for ca. 1 h