Polymer filters treated by plasma-assisted graft polymerization (PG), nonthermal plasma (NTP) and PG followed by NIP treatment are developed for use as multifunctional filters that can simultaneously remove odor and particulate. A NTP-treated filter can adsorb a large amount of a typical odor component, ammonia (NH(3)). However, the performance of the NTP-treated filter deteriorates significantly after one month whereas that of a PG followed by NTP-treated filter deteriorates only slightly. The particulate collection efficiency of a both-side PG-treated filter is higher than that of an untreated filter whereas that of the NTP-treated filter is slightly lower. (C) 2011 Elsevier B.V. All rights reserved.