Preparation and cas permeation of immobilized fullerene membranes

Fullerene-dispersed membranes were homogeneously prepared under the conditi ons in which a 10 wt % polystyrene solution containing 1 wt % fullerene was dried under a reduced pressure of 50 cmHg at room temperature. The fullere ne membranes prepared with 1,2-dichlorobenzene were found to have the darke st color, and showed no evidence of fullerene crystals in their photomicrog raphs. UV-visible and infrared absorption spectra of the fullerene membrane s showed fullerene bands, which indicated that the fullerene was homogeneou sly dispersed in the membranes. The permeability coefficients of pure nitro gen, oxygen, carbon dioxide, ethane, and ethylene were found to increase si gnificantly in the fullerene membranes compared to those in the polystyrene membranes, although the ideal separation factors for oxygen/nitrogen and e thylene/ethane in the fullerene membranes (i.e., 4.3 and 1.7, respectively) were slightly less than the separation factors in the polystyrene membrane s. The permeability increase originated from the increase in diffusion coef ficients in the fullerene membranes. (C) 2000 John Wiley & Sons, Inc.