Two novel fluorine-containing cyclophanes 1 and 2 incorporating a 1,4-bismethylfluorophenylene subunits have been synthesized via the template-directed clipping methodology and their structure was characterized by ~1H...Two novel fluorine-containing cyclophanes 1 and 2 incorporating a 1,4-bismethylfluorophenylene subunits have been synthesized via the template-directed clipping methodology and their structure was characterized by ~1H NMR,^(13)C NMR, MALDI-TOF-MS and elemental analysis.X-ray diffraction analysis of the solid state molecular structure showed that the complex units are linked by non-classical C-H…F hydrogen bonding.展开更多
Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks...Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.展开更多
基金support from the National Natural Science Foundation of China(No.20872051)
文摘Two novel fluorine-containing cyclophanes 1 and 2 incorporating a 1,4-bismethylfluorophenylene subunits have been synthesized via the template-directed clipping methodology and their structure was characterized by ~1H NMR,^(13)C NMR, MALDI-TOF-MS and elemental analysis.X-ray diffraction analysis of the solid state molecular structure showed that the complex units are linked by non-classical C-H…F hydrogen bonding.
基金support of the National Natural Science Foundation of China(Nos. 21603197, 21703212,21233006 and 21473164)Natural Science Foundation of Hubei Province of China(No.2016CFB181)+1 种基金Fundamental Research Funds for the Central University, China University of Geosciences (Wuhan)(No. CUGL180403)China University of Geosciences (Wuhan) for the program of Center for Advanced Energy Research and Technologies
文摘Low methanol permeability of proton exchange membranes (PEMs) is greatly important for direct methanol fuel cells (DMFCs). Here, sulfonated poly (ether ether ketone) (SPEEK) based semiinterpenetrating polymer networks (semi-IPNs) are successfully prepared by interpenetrating SPEEK into the in-situ synthesized crosslinking networks. The polymeric networks are formed by the covalent bonds between bromobenzyl groups of bro mo methylated poly (phenylene oxide) and amine groups of diamine linkers as well as the ionic bonds between amine species and sulfonated groups. Two linkers without and with sulfonated groups are applied to fabricate the semi-IPNs. The core properties of the membranes, like phase separation, water uptake, proton conductivity and methanol permeability, are systematically studied and compared. The DMFCs assembled by using the semi-IPN membranes display better performance than Nafion 117 in high concentration methanol solutions. The present work provides a facile way to prepare PEMs with enhanced DMFC performance.
