Functionalization of multi-walled carbon nanotubes via precipitation polymerization for elevating proton conductivity of Nafion under low humidity
作者：Guangwei He, Jing Zhao, Shen Zhu, Liangqiao Li, Zongyu Li, Yifan Li, Zhen Li, Hong Wu, Xinlin Yang,
關鍵字：Precipitation polymerization; carbon nanotubes; Nafion; composite membranes; proton conductivity under low humidity; mechanical properties
論文來源：期刊
具體來源：ACS Appl Mater Interfaces, 6 (17), 15291-15301 (2014). DOI: 10.1021/am503760u
發表時間：2014年
Covalent grafting of acrylate-modified
multi-walled carbon nanotubes (MWCNTs) with poly(methacrylic
acid-co-ethylene glycol
dimethacrylate), poly(vinylphosphonic acid-co-ethylene glycol
dimethacrylate), and sulfonated poly(styrene-co-divinylbenzene) was achieved via
precipitation polymerization. The formation of
core-shell structures
was evidenced by TEM images, and the thickness of the grafted shell was
well-controlled. The incorporation of the functionalized MWCNTs with
proton-conduction polymers into Nafion matrix afforded the composite membranes
with enhanced water uptake, mechanical stability, and
proton conductivities under reduced relative
humidity (RH). The
composite membrane containing 5 wt% phosphorylated MWCNTs showed the least reliance on humidity and significantly enhanced proton
conductivity under reduced RH. These
enhancements were attributable to the construction of continuous proton transport pathways (lower-energy-barrier) within membrane, excellent
water-retention properties of the cross-linked polymer on MWCNTs and high proton conductivity of –PO3H2 groups under low RH.