Surface characterization of IM7/5260 composites by x-ray photoelectron spectroscopy

Surfaces of high-performance carbon fiber/bismeleimide (BMI) composites (IM 7/5260) have been characterized by x-ray photoelectron spectroscopy. An exp erimental technique to separately examine the chemical natures of the carbo n fibers and BMI resin in the composite form was developed. This technique uses a flood gun to establish differential charging conditions on the BMI r esin. The binding energies from the BMI resin were shifted by an amount of voltage applied to the flood gun, whereas those from the carbon fibers were uniquely determined due to their electrically conducting nature. By adding external bias voltage to the sample, the binding energies for conducting f ibers were further shifted from those of the BMI resin, thereby separating the IM7 phase completely from the BMI phase in the binding energy scale, al lowing independent measurement of the chemical changes associated with thos e peaks. Using this technique, the effects of thermal aging and surface pla sma treatment on the IM7/5260 composite were studied. (C) 2001 American Vac uum Society.