high porosity polyethylene aerogels

monolithic aerogels of high molecular weight polyethylene (mw= 3x106- 6x106 g/mol) have been prepared by solvent extraction with supercritical carbon dioxide from thermoreversible gels prepared in decalin. these low density and highly porous aerogels present an apparent porosity up to 90%. the aerogel morphology observed by scanning electron microscopy (sem) is characterized by spherulitic structures being interconnected by fibers. x-ray diffraction experiments show that pe aerogels are highly crystalline with a degree of crystallinity of c.a. 80% and pe chains being packed into the typical orthorombic unit cell. combined sem and n2 sorption investigations show that pe aerogels are essentially macroporous with a small amount of mesopores. the oil-sorption performance of polyethylene aerogels has been also evaluated in this study in order to assess a possible use of these materials for oil spillage recovery and results show that aerogel macropores allow a very fast sorption kinetics with a 100% oil weight uptake obtained in less than 1 minute.