Anion Exchange membrane with High hydroxide ion conductivity and robust tensile strength fabricated from quaternary ammonia functionalized Pinus contorta, Dougl. Chip

Abstract The Pinus contorta, Dougl. chip was ammonianized by 3-chloro-2-hydroxypropyltrimethyl ammonium chloride. Subsequently, the functionalized chip was thermally compressed under 30 MPa at 100 °C for 72 h to form the quaternary ammonia functionalized membrane (QAFW). The results revealed that the hydroxide ion conductivity and ion exchange capacity (IEC) of the as-fabricated membrane were up to 15.2 mS cm−1 and 1.86 mmolg−1 at 25 °C under 100 % relative humidity respectively, which is higher than most of the quaternary ammonia-functionalized aromatic polymer membranes. The ratio of hydroxide ion conductivity to methanol permeability of the optimized QAFW membrane is up to 3.86 × 103 S s cm−3. The decomposition temperature of QAFW membrane is ∼252 °C. The tensile strength of the wet QAFW membrane is as high as 60.02 MPa, which is significantly higher than that of the aromatic polymer membranes. Conclusively, a novel method herein characterized with environmentally friendly and economically attractive for the anion exchange membranes fabrication was presented.