Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: Electret filter media comprising a nonwoven web of thermoplastic nonconductive microfibers having trapped charge, said charge provided by (1) subjecting the nonwoven web to a corona treatment, followed by (2) impingement of jets of water or a stream of water droplets on the web at a pressure sufficient to provide the web with filtration enhancing electret charge and (3) drying the web. This electret filter media may be used in a respiratory mask to provide extraordinarily good filtration properties.

Abstract: A method of making electret fibers, which method comprises: extruding a polymeric material to create fibers; and imparting an electric charge to the fibers; wherein the resulting fibers have a level of extractable hydrocarbon material that is less than 3.0 weight percent, based on the weight of the fibers.

Abstract: An approach for beneficially incorporating both a solid organic impregnant and a fluid impregnant into filter media particles without the presence or addition of one unduly affecting the performance of the other. The present invention achieves impregnation by combining sublimation and non-bulk absorption techniques. These techniques may be carried out in sequential, simultaneous, overlapping, and/or alternating fashion, or the like. The invention is especially suitable when the filter media particles already contain or are to contain one or more other impregnants, whose function or presence might be adversely affected when conventional methods are used to add the solid organic and fluid materials.

Abstract: A composition comprising a blend of a thermoplastic resin and at least one compound or oligomer which is ##STR1## wherein R.sub.f is a perfluorinated moiety which may contain one or more catenary ether oxygen atoms, Q is a linking group selected from alkylene groups having 1 or 2 carbon atoms, sulfonamido groups or combinations thereof, R is an alkyl group, R.sup.1 is a perfluoroalkyl group, R.sup.2 is an alkyl group which may be straight chain or branched and n is a number of from 2 to 40.