▎ 摘　　要

NOVELTY - A filter material comprises a laminate of a permeable covering layer, a pre-trapping layer, a main trapping comprising porous polylactic acid micro-nano fiber film doped with reduced graphene oxide-grafted polylactic acid. USE - Material for gas filter unit (claimed). ADVANTAGE - The filter material has simple preparation, increased softness of the particle surface, and can easily swell and modify the particles. The micro-nano fiber film has small fiber diameter, large specific surface area, large pore volume, excellent mechanical property, antibacterial property and high temperature resistance. The filter material is manufactured in high yield. The filter unit has excellent PM2.5 particulate matter collecting property, low pressure resistance, and improved performance due to the reduced thickness of trapping layer. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for gas filter unit.