Enhanced water retention and proton conductivity of the proton exchange membranes by incorporating hollow polymer microspheres grafted with sulfonated polystyrene brushes
作者：Wei Zhang, Bei Zhang, Guangwei He, Bin Liu, Zhongyi Jiang, Xinlin Yang*, Chenxi Li
關鍵字：Hollow polymer microspheres, Sulfonated polystyrene brush, Surface-initiated atom transfer radical polymerization, Sulfonated poly(ether ether ketone), Hybrid membrane
論文來源：期刊
具體來源：RSC Adv., 5 (7), 5343-5356 (2015). DOI: 10.1039/C4RA13582B
發表時間：2015年
Hollow polymer microspheres grafted with sulfonated polystyrene brushes
(HPSS) were synthesized via combination of surface-initiated atom transfer
radical polymerization (SI-ATRP) of styrene from SiO2@P(MAA-co-DVB-co-CMSt)
core-shell microspheres, sulfonation of the polystyrene brushes, and finally
removal of the silica core. These HPSSs were then incorporated into the
sulfonated poly(ether ether ketone) (SPEEK) matrix to fabricate hybrid
membranes. As a comparison, the SPEEK/HPS hybrid membranes were prepared by
incorporation of sulfonated hollow polymer microspheres (HPS) into the SPEEK
matrix. The water retention, methanol resistant property and proton
conductivity were increased by doping with both kinds of hollow polymer
microspheres. The SPEEK/HPSS hybrid membranes exhibited much higher proton
conductivity than SPEEK/HPS hybrid membranes with the same filler contents
ranging from 2.5 to 15 wt%. The highest conductivity was obtained as 0.33 S cm-1 for SPEEK/HPSS under 75 oC and 100% relative humidity (RH), which was 83.3% higher than that (0.18 S cm-1) for SPEEK
control membrane under the same conditions. The increment of proton
conductivity was mainly contributed to the large cavity of HPSS as water reservoirs
and excellent flexibility and high accessibility of the sulfate groups (-SO3H)
pendent on the surface grafted polymer brushes to provide proton hopping sites
as proton-conducting pathways. Moreover, the hybrid membranes exhibited good
thermal and mechanical stability.