Co-reporter:Ye Li, Yuan Liang, Xitao Wang, Min Xie, Xincai Liu, Ce Wang
International Journal of Hydrogen Energy 2014 Volume 39(Issue 13) pp:7060-7068
Publication Date(Web):24 April 2014
DOI:10.1016/j.ijhydene.2014.02.116
•Branched sulfonated poly(ether ether ketone)s containing intermolecular ionic cross-linkable groups were synthesized.•Benzoxazole groups were grafted onto the polymer backbone via thiol-ene click reaction.•The membranes exhibited low swelling, low methanol permeability and improved chemical stability.A series of novel branched sulfonated poly(ether ether ketone)s containing intermolecular ionic cross-linkable groups, benzoxazole groups, have been prepared for direct methanol fuel cells. The benzoxazole groups are grafted onto the polymer chain via a thiol-ene click chemistry reaction. The expected structures of the copolymers are confirmed by 1H NMR and Fourier transform infrared spectroscopy. Compared with the unmodified polymer membrane, the ionic cross-linked membranes show enhanced thermal and mechanical properties. We also investigate the changes in water uptake, proton conductivity and chemical stability. The dense membrane structures formed by branching and the interactions between sulfonic acid and benzoxazole groups make a great contribution to the improvements of dimensional stability and methanol resistance property. Although the proton conductivities of the ionic cross-linked membranes are lower than the pristine membrane, the selectivities are much higher. The results show that the novel copolymers in this study are possible potential candidate materials for proton electrolyte membrane.
Co-reporter:Ye Li, Min Xie, Xitao Wang, Danming Chao, Xincai Liu, Ce Wang
International Journal of Hydrogen Energy 2013 Volume 38(Issue 27) pp:12051-12059
Publication Date(Web):10 September 2013
DOI:10.1016/j.ijhydene.2013.06.090
•Br-SPEEK were obtained via two-step polymerization.•The polymer exhibited higher degree of branching values.•The membrane showed improved mechanical strength, excellent dimensional stability.In this article, novel branched sulfonated poly(ether ether ketone)s (Br-SPEEK) containing various amounts of 1,3,5-tris(4-fluorobenzoyl)benzene as the branching agent have been successfully prepared. Compared with the traditional linear polymer membranes, the membranes prepared by Br-SPEEK showed improved mechanical strength, excellent dimensional stability and superior oxidative stability with similar proton conductivity. Notably, the Br-SPEEK-10 membrane began to break after 267 min in Fenton's reagent at 80 °C, which was 4 times longer than that of the L-SPEEK. Although the proton conductivity decreased with the addition of the branching agent, satisfying methanol permeability value was observed (down to 6.3 × 10−7 cm2 s−1), which was much lower than Nafion 117 (15.5 × 10−7 cm2 s−1). All the results indicated that the novel branched sulfonated poly(ether ether ketone)s membrane was potential candidate as proton conductive membranes for application in fuel cells.
Co-reporter:Ye Li, Xitao Wang, Min Xie, Xincai Liu, Ce Wang
International Journal of Hydrogen Energy 2013 Volume 38(Issue 36) pp:16276-16285
Publication Date(Web):13 December 2013
DOI:10.1016/j.ijhydene.2013.10.036
•A series of BSPEEK containing propenyl groups were synthesized.•Benzimidazole sulfonic acid groups have been grafted onto the polymer backbone via thiol-ene click reaction.•The membranes exhibited enhanced proton conductivity, relative lower water uptake and methanol permeability.A series of novel branched sulfonated poly(ether ether ketone)s containing propenyl groups have been synthesized using a nucleophilic polycondensation reaction. Subsequently, a thiol-ene click chemistry reaction between propenyl and thiol groups results in a new series of copolymers containing benzimidazole sulfonic acid groups. The expected structures of the copolymers are confirmed by 1H NMR and Fourier transform infrared spectroscopy. The introduction of benzimidazole sulfonic acid groups into the copolymer improves proton conductivity obviously. Compared with the linear sulfonated poly(ether ether ketone)s with the same sulfonation degree (DS), the BSPEEK-BIS membranes show lower water uptake and methanol permeability. The branching structure and the interaction between sulfonic acid and benzimidazole groups make the contribution to the improvement of the membrane's properties. Therefore, the high proton conduction, low methanol permeation, and low water uptake property of the as-prepared membranes are of significant interest for DMFCs.
Co-reporter:Lirong Kong, Xincai Liu, Xiujie Bian and Ce Wang
RSC Advances 2012 vol. 2(Issue 7) pp:2887-2894
Publication Date(Web):10 Feb 2012
DOI:10.1039/C2RA00657J
In this work, a simple hydrothermal method is presented for fabricating hierarchically porous silica nanocubes using a surfactant-polyelectrolyte template. The formed silica nanocubes possess Pmn symmetry, which are patterned after organic template and their shape can be easily transformed from solid nanocubes to hollow cubes by controlling the composition of the surfactant-polyelectrolyte template. We have studied the fabrication conditions of silica nanocubes as a function of reaction temperature, reaction time, and the amount of reactants, and proposed a nanoparticle formation mechanism. For drug delivery, the calcined solid and hollow silica nanocubes show high loading capacities of ibuprofen, 362 mg g−1 and 509 mg g−1, respectively. These properties make the hierarchically porous silica nanocubes a promising material for drug delivery.
Co-reporter:Ye Li;Jian Chen;DeCai Yang
Science China Chemistry 2012 Volume 55( Issue 4) pp:612-617
Publication Date(Web):2012 April
DOI:10.1007/s11426-011-4397-5
Thermal behavior and phase behavior in blends of liquid crystalline poly(aryl ether ketone) with lateral methoxy groups (M-PAEK) and poly(aryl ether ether ketone) containing thioether units (S-PEEK) have been investigated by differential scanning calorimetry (DSC) and polarized light microscopy (PLM) techniques. The results indicate that the composition of the blends has great effect on the phase behavior and morphology. Thin films of pure M-PAEK and S-PEEK crystallized from the melts exhibit typical mosaic and spherulitic structures, respectively. For the blends with higher M-PAEK contents (> 50%), an unusual ring-banded spherulite with structural discontinuity is formed. The bright core and rings of the ring-banded spherulites under PLM are composed of M-PAEK phase, while the dark rings consist mainly of S-PEEK phase. For the 50:50 M-PAEK/S-PEEK blend, the ring-banded spherulites and S-PEEK spherulites coexist, which implies that a partial phase separation between the two components takes place in the melting state. In S-PEEK-rich blends, a volume-filled spherulite is produced. In addition, the effect of isothermal crystallization temperature on the phase behavior, especially the ring-banded spherulite formation in the blends, is discussed.
Co-reporter:Libing He;Danming Chao;Xitao Wang;Xiaoteng Jia;Ce Wang
Journal of Polymer Research 2012 Volume 19( Issue 12) pp:
Publication Date(Web):2012 December
DOI:10.1007/s10965-012-9999-x
A novel hyperbranched electroactive azo copolymer with different oligoaniline segments was synthesized by an oxidative coupling polymerization approach, exhibiting an exciting molecular structure. The detailed characteristics of the obtained copolymer were systematically studied by Fourier-transform infrared (FTIR) spectra, nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC) and X-ray powder diffraction (XRD). The thermal resistance of the copolymer was investigated by thermogravimetric analysis (TGA). Through cyclic voltammogram (CV), we explored the electrochemical behavior of the copolymer. Moreover, photoisomerization process and doping process of the copolymer were monitored with UV–vis spectra. Dielectric properties of the as-synthesized copolymer were investigated in detail, and gratifying results have been reported. Firstly, a large enhancement in the dielectric constant was achieved utilizing HCl-doping of the conjugated oligoaniline segments. Secondly, the copolymer in HCl-doped form possessed much higher dielectric constants compared with the similar linear polymer, mainly due to the branched molecular architecture.
Co-reporter:Libing He, Danming Chao, Xiaoteng Jia, Hongtao Liu, Lei Yao, Xincai Liu and Ce Wang
Journal of Materials Chemistry A 2011 vol. 21(Issue 6) pp:1852-1858
Publication Date(Web):03 Dec 2010
DOI:10.1039/C0JM02960B
By an oxidative coupling polymerization approach, we have synthesized a novel electroactive polymer with good solubility containing alternating phenyl-capped aniline tetramer in the main chain and azo chromophores in the side chain. Dielectric properties of the as-synthesized polymer were investigated in detail and gratifying results have been observed. Firstly, a large enhancement in the dielectric constant was achieved utilizing the method of doping the conjugated oligoaniline segments with hydrochloric acid. Secondly, the adjustment of dielectric constant was implemented primarily by means of exposing the samples to UV and visible irradiation, mainly owing to the photoisomerization derived from azo chromophores in the side chain. The detailed characteristics of the as-synthesized polymer were systematically studied by Fourier-transform infrared (FTIR) spectra, nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). UV-vis spectra were used to monitor the photoisomerization and doping process of the polymer. The thermal characteristics of the polyamide were evaluated by thermogravimetric analysis (TGA). Moreover, the electrochemical activity of the polymer was explored by cyclic voltammogram (CV) measurement, showing that the intrinsic electroactivity of the oligoaniline was maintained in the polymer.
Co-reporter:Hui Mao, Yongxin Li, Xincai Liu, Wanjin Zhang, Ce Wang, Salem S. Al-Deyab, Mohamed El-Newehy
Journal of Colloid and Interface Science 2011 Volume 356(Issue 2) pp:757-762
Publication Date(Web):15 April 2011
DOI:10.1016/j.jcis.2011.01.004
Novel spindle-like polypyrrole hollow nanocapsules containing Pt nanoparticles (Pt NPs/PPy composite hollow nanospindles) were successfully prepared by using beta-akaganeite (β-Fe3+O(OH,Cl)) nanospindles as templates and methanoic acid as a reducing agent. The β-Fe3+O(OH,Cl) templates can be easily obtained in ethanol/water mixing solution in the presence of thiophene and FeCl3·6H2O, and after coating by PPy shell, they can be gradually and completely etched during the reduction of H2PtCl6 into Pt nanoparticles (Pt NPs) with the average size of 3.6 nm on spindle-like polypyrrole hollow nanocapsules, which could still keep their integrality of morphologies with the thickness of PPy shell of 18–20 nm. The investigation of Pt NPs/PPy composite hollow nanospindles modified glassy carbon electrode (GCE) for the application to detect nicotinamide adenine dinucleotide (NADH) with cyclic voltammetry (CV) and amperometry indicated good linearity and sensitivity of responses in the certain range of NADH concentration. The influence of Pt NPs content to the NADH oxidation current was also studied. This new kind of unique spindle-like noble metal/conducting polymer hollow nanostructured complex can be acted as a good steady electrode material for electrocatalytic oxidation of NADH.Graphical abstractNovel spindle-like polypyrrole hollow nanocapsules containing Pt nanoparticles can be successfully prepared and acted as a good steady electrode material for electrocatalytic oxidation of NADH.Research highlights► A novel Pt NPs/PPy composite hollow nanospindles were fabricated. ► The chemical structure of the Pt NPs/PPy composite hollow nanospindles was studied. ► The composite hollow nanospindles showed good electrocatalysis oxidation of NADH.
Co-reporter:Ye Li, Zhiliang Li, Xiaofeng Lu, Chengcheng Zhang, Zhaojie Wang, Lirong Kong, Ce Wang, Xincai Liu
International Journal of Hydrogen Energy 2011 Volume 36(Issue 22) pp:14622-14631
Publication Date(Web):November 2011
DOI:10.1016/j.ijhydene.2011.08.045
Composite membranes based on sulfonated poly(aryl ether ketone)s containing the hexafluoroisopropylidene diphenyl moiety and poly(amic acid) with oligoaniline in the main chain have been prepared and immersed in H3PO4 to obtain acid-doped composite films. As expected, the water uptake values and methanol permeability of the composite membranes decrease with the increase of the weight fraction of PAA in the membrane matrix. Notably, the SPEEK-6F/PAA-15 shows a water uptake of 13.2% and a methanol permeability of 0.9 × 10−7 cm2 s−1, which are much lower than those of the Nafion (28.6% and 15.5 × 10−7 cm2 s−1, respectively). Although the proton conductivities decrease after the addition of PAA, higher selectivity values are obtained with the composite membranes. Therefore, the SPEEK-6F/PAA blend membranes, with the improved proton conductivity, methanol resistance and good thermal stability, can be used as a good alternative for proton conductive membranes with potential application in proton exchange membrane fuel cells (PEMFCs).Highlights► The sulfonated PAEK with hexafluoroisopropylidene diphenyl moiety was synthesized. ► Poly(amic acid) with oligoaniline in the main chain is blended with the SPEEK-6F. ► The composite membranes are immersed in H3PO4 to obtain acid-doped composite films. ► The membranes show improved proton conductivity and methanol resistance.
Co-reporter:Hongtao Liu;Danming Chao;Xiaoteng Jia;Libing He;Lili Cui;Lei Yao ;Ce Wang
Polymer International 2011 Volume 60( Issue 5) pp:725-729
Publication Date(Web):
DOI:10.1002/pi.2990
Abstract
A type of self-doped polyaniline derivative was successfully synthesized using an oxidative coupling polymerization approach. The structure of the electroactive polymer was investigated using Fourier transform infrared and 1H NMR spectroscopy and gel permeation chromatography. Its thermal and spectral properties were characterized using thermogravimetric analysis and UV-visible spectroscopy. The electrochemical activity of the polymer was studied using cyclic voltammetry (CV) in 1.0 mol L−1 H2SO4 solution with various scan rates. The peak current increases linearly with scan rate from 10 to 120 mV s−1, which indicates that the electrode reaction is controlled by a surface process. In addition, the self-doped characteristic was investigated using CV in 1.0 mol L−1 KCl solution with pH value changing from 1 to 12, and the results indicate that the polymer has excellent electrochemical activity even in neutral and alkaline environments. Copyright © 2010 Society of Chemical Industry
Co-reporter:Hui Mao, Xincai Liu, Danming Chao, Lili Cui, Yongxin Li, Wanjin Zhang and Ce Wang
Journal of Materials Chemistry A 2010 vol. 20(Issue 45) pp:10277-10284
Publication Date(Web):04 Oct 2010
DOI:10.1039/C0JM01745K
By using Ce(SO4)2·4H2O as an oxidant and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as a surfactant, unique poly(3,4-ethylenedioxythiophene) (PEDOT) nanorods with a couple of cuspate tips were successfully prepared by reverse interfacial polymerization. The morphology of these PEDOT nanorods was very regular and well-dispersed with widths and lengths from one tip to another tip mostly in the range 40–60 nm and 370–460 nm, respectively. The chemical structure and formation mechanism of PEDOT nanorods are discussed in detail by several analysis methods. AOT played an important role during the formation of PEDOT nanorods. It could be combined with Ce4+ to form a unique template for the polymerization of 3,4-ethylenedioxythiophene (EDOT) in the cylindrical micelles formed by n-hexane, H2O and AOT. Furthermore, the application of PEDOT nanorod-modified glassy carbon electrode (GCE) as an electrochemical sensor for detecting nitrite was also investigated. Due to their good dispersibility and large surface area, PEDOT nanorods exhibited good linearity and sensitivity of cyclic voltammetry (CV) responses as well as amperometric responses for electrocatalytic oxidation of nitrite. It resulted in PEDOT nanorods acting as a good steady and sensitive electrode material for detecting nitrite.
Co-reporter:Zhiliang Li;Danming Chao;Xiaofeng Lu;Libing He;Yang Yang ;Wanjin Zhang
Journal of Applied Polymer Science 2010 Volume 118( Issue 6) pp:3318-3323
Publication Date(Web):
DOI:10.1002/app.32439
Abstract
Novel proton exchange membranes are solvent-cast from N,N-dimethylacetamide (DMAc) solutions of the crosslinked poly(arylene ether ketone) copolymer with pendant carboxylic acid group (C-SPAEK) via poly(ethylene glycol) (PEG) with different amounts. These membranes are formed as a result of physical and chemical crosslinking. In this study, 1H-NMR and FTIR have been used to confirm the chemical structures of the copolymers. Mechanical and thermal properties, swelling and proton conductivity are affected by the crosslinker (PEG) content in the copolymers. Compared to the noncrosslinked C-SPAEK membrane, the crosslinked membranes become more flexible and greatly reduced water uptake and swelling ratio with only slight sacrifice in proton conductivities. And the crosslinked membranes keep higher proton conductivities without a sharply decrease at higher temperature. These results show that the crosslinked membranes have potential applications as proton exchange membranes for fuel cell. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Co-reporter:Libing He, Danming Chao, Xiaoteng Jia, Hongtao Liu, Lei Yao, Xincai Liu and Ce Wang
Journal of Materials Chemistry A 2011 - vol. 21(Issue 6) pp:NaN1858-1858
Publication Date(Web):2010/12/03
DOI:10.1039/C0JM02960B
By an oxidative coupling polymerization approach, we have synthesized a novel electroactive polymer with good solubility containing alternating phenyl-capped aniline tetramer in the main chain and azo chromophores in the side chain. Dielectric properties of the as-synthesized polymer were investigated in detail and gratifying results have been observed. Firstly, a large enhancement in the dielectric constant was achieved utilizing the method of doping the conjugated oligoaniline segments with hydrochloric acid. Secondly, the adjustment of dielectric constant was implemented primarily by means of exposing the samples to UV and visible irradiation, mainly owing to the photoisomerization derived from azo chromophores in the side chain. The detailed characteristics of the as-synthesized polymer were systematically studied by Fourier-transform infrared (FTIR) spectra, nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC). UV-vis spectra were used to monitor the photoisomerization and doping process of the polymer. The thermal characteristics of the polyamide were evaluated by thermogravimetric analysis (TGA). Moreover, the electrochemical activity of the polymer was explored by cyclic voltammogram (CV) measurement, showing that the intrinsic electroactivity of the oligoaniline was maintained in the polymer.
Co-reporter:Hui Mao, Xincai Liu, Danming Chao, Lili Cui, Yongxin Li, Wanjin Zhang and Ce Wang
Journal of Materials Chemistry A 2010 - vol. 20(Issue 45) pp:NaN10284-10284
Publication Date(Web):2010/10/04
DOI:10.1039/C0JM01745K
By using Ce(SO4)2·4H2O as an oxidant and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as a surfactant, unique poly(3,4-ethylenedioxythiophene) (PEDOT) nanorods with a couple of cuspate tips were successfully prepared by reverse interfacial polymerization. The morphology of these PEDOT nanorods was very regular and well-dispersed with widths and lengths from one tip to another tip mostly in the range 40–60 nm and 370–460 nm, respectively. The chemical structure and formation mechanism of PEDOT nanorods are discussed in detail by several analysis methods. AOT played an important role during the formation of PEDOT nanorods. It could be combined with Ce4+ to form a unique template for the polymerization of 3,4-ethylenedioxythiophene (EDOT) in the cylindrical micelles formed by n-hexane, H2O and AOT. Furthermore, the application of PEDOT nanorod-modified glassy carbon electrode (GCE) as an electrochemical sensor for detecting nitrite was also investigated. Due to their good dispersibility and large surface area, PEDOT nanorods exhibited good linearity and sensitivity of cyclic voltammetry (CV) responses as well as amperometric responses for electrocatalytic oxidation of nitrite. It resulted in PEDOT nanorods acting as a good steady and sensitive electrode material for detecting nitrite.
![Benzamide, 2,6-difluoro-N-[4-[[4-[[4-(phenylamino)phenyl]amino]phenyl]amino]phenyl]-](/data/chemimg/161600/1269633-71-7.png)
![Benzamide, 2,6-difluoro-N-[4-[[4-[[4-(phenylamino)phenyl]amino]phenyl]amino]phenyl]-](/data/chemimg/161600/1269633-71-7_b.png)
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![Benzamide, 2,6-bis(4-aminophenoxy)-N-[4-[[4-[[4-(phenylamino)phenyl]amino]phenyl]amino]phenyl]-](/data/chemimg/161600/1323950-13-5_b.png)
![1,4-Benzenediamine, N-(4-aminophenyl)-N'-[4-(phenylamino)phenyl]-](http://img.cochemist.com/ccimg/80500/80471-61-0.png)
![1,4-Benzenediamine, N-(4-aminophenyl)-N'-[4-(phenylamino)phenyl]-](http://img.cochemist.com/ccimg/80500/80471-61-0_b.png)