the present invention is directed to improving thermoplastic and cross - linked polymeric networks . the inventive method comprises forming the polymeric network under gravitational conditions comprising from about 10 - 6 to about 10 - 2 g . three modes of energy transfer have been recognized , inter alia , conduction , convection , and radiation . polymeric networks formed under microgravity conditions do not obviate conduction and radiation modes of energy transfer . convection energy transfer , however , is gravity dependent . thus , convection currents can be suppressed in thermoplastic and cross - linked polymeric networks during network formation by forming the network under microgravity conditions . suppression of convection currents reduces the incidences of voids in solvent cast thermoplastic polymeric membranes , which forms yet another aspect of the present invention . particulate - filled thermoplastic and cross - linked polymeric networks will exhibit a more homogeneous distribution of particulates in the network by forming the network under microgravity conditions also , which forms yet a further aspect of the present invention .