writer：Guangwei He, Yifan Lia, Zongyu Li, Lingli Nie, Hong Wu, Xinlin Yang ,Yuning Zhao, Zhongyi Jiang*
keywords：Controllable hydrophilicityehydrophobicity; Polymer microcapsules; Water retention; Proton conductivity
source：期刊
specific source：J. Power Sources, 248 (1), 951-961 (2014). DOI: 10.1016/j.jpowsour.2013.10.017
Issue time：2014年
Four kinds of polymer microcapsules (PMCs) with different hydrophilicityehydrophobicity are synthesized via distillationeprecipitation polymerization (polymer microcapsules form by self-crosslinking of monomers/crosslinkers in this process) and incorporated into sulfonated poly(ether ether ketone) (SPEEK) matrix to prepare composite membranes. To improve the water retention of the PMCs, the hydrophilicityehydrophobicity of the PMCs is manipulated by regulating the proportion of hydrophilic ethylene glycol dimethacrylate (EGDMA) and hydrophobic divinylbenzene (DVB) crosslinkers in the synthesis formula. The hydrophilicity of the PMCs decreases with increasing the content of polyDVB in
the PMCs. The four kinds of PMCs exhibit different water retention properties. The PMCs with appropriate hydrophilic/hydrophobic balance (EGDMA: DVB ? 1:1) possess the best water retention properties. Incorporation of PMCs into SPEEK matrix enhances the water-retention properties, and consequently increases proton conductivity to 0.0132 S cm1 under 20% relative humidity, about thirteen times higher than that of the SPEEK control membrane. Moreover, the incorporation of PMCs reduces the activation energy for proton conduction and the methanol permeability of the membranes. This study may be helpful to rational design of excellent water-retention materials.