Porous filters of nanofibrillated cellulose

Abstract

Filters for air purification are predominantly produced of synthetic and non-biodegradable materials. In this work, a range of various air filters have been prepared from 100% pure cellulosic material, with the goal to create alternative air filters which are completely biodegradable. The filters have been prepared by either evaporation of solvents with varying polarity or by freeze drying aqueous cellulose suspensions. The most promising results were obtained by the latter procedure, where an air permeance of ~2000 µm/Pa*s and tensile strength of ~0.20 kN/m was obtained.