Materialism is just human instinct, we strive to become more technicologically adept. Whether we reach a limit of ultimate materialism depends on whether the universe is infinite or whether it has boundaries (the big crunch theory). With infinite knowledge (materialistic), there would be no way of discovering everything as it is limitless. If the universe was not infinite than we can expect to discover "everything" materialistic within a certain amount of time (if we dont blow ourselves up in the meantime).