Poly(vinylidene fluoride), PVDF, membranes have attracted considerable attention as polymer electrolytes for fuel cells. This study explores the effect of solvent on the spherulite size and the crystallinity of the po...Poly(vinylidene fluoride), PVDF, membranes have attracted considerable attention as polymer electrolytes for fuel cells. This study explores the effect of solvent on the spherulite size and the crystallinity of the polymeric membranes. Based on Hansen solubility parameters theory, the mixture of DMC and DMSO was selected among a dozen of solvents for the preparation of PVDF membranes by thermally induced phase separation. The addition of two protic ionic liquids(PILs), bis(2-ethyl hexyl) ammonium hydrogen phosphate [EHNH_2][H_2PO_4], and imidazolium hexanoate [Im][Hex] to PVDF membranes at concentrations(10% < wP IL< 50%) has been investigated by SEM, FTIR, DSC, TGA, EIS, and DMA. The inclusion of ionic liquids into the polymer matrix influences structural parameters(degree of crystallinity and electroactive phases), thermal stability, proton conductivity and mechanical properties of the membranes. The membranes become transparent regardless type of ionic liquid employed. A small amount of ionic liquids increases the degree of crystallinity and facilitates the production of polar β and γ crystals. The proton conductivity mechanism(Grotthuss) is dependent on the ionic liquid structure(due to its selforganization in water) and the content in the PVDF membrane, as well as the membrane water uptake.Different behavior has been observed for the two ionic liquids, which stresses the challenge on selecting an appropriate cation and anion combination. The obtained composite membranes exhibited excellent mechanical performance and reduced elastic modulus, with respect to the pure polymer matrix. These results indicate that PVDF/IL composite membranes have a high potential for PEMFC applications.展开更多
Objective:Plant hormones act as chemical messengers in the regulation of plant development and metabolism.The production of ginsenosides in Panax hybrid is promoted by auxins that are transported and accumulated by PI...Objective:Plant hormones act as chemical messengers in the regulation of plant development and metabolism.The production of ginsenosides in Panax hybrid is promoted by auxins that are transported and accumulated by PIN-FORMED(PIN)and PIN-LIKES(PILS)auxin transporters.However,genome-wide studies of PIN/PILS of ginseng are still scarce.In current study,identification and transcriptional profiling of PIN/PILS gene families,as well as their potential relationship with ginsenoside biosynthesis in Panax ginseng were investigated.Methods:PIN/PILS genes in P.ginseng was identified via in silico genome-wide analysis,followed by phylogenetic relationships,gene structure,and protein profiles investigation.Moreover,previously reported RNA-sequence data from various tissues and roots after infection were utilized for PIN/PILS genes expression pattern analysis.The Pearson’s correlation analysis of specific PIN/PILS genes expression level and main ginsenoside contents were taken to reveal the potential relationship between auxin transports and ginsenoside biosynthesis in P.ginseng.Results:A genome-wide search of P.ginseng genome for homologous auxin transporter genes identified a total of 17 PIN and 11 PILS genes.Sequence alignment,putative motif organization,and sub-cellular localization indicated redundant and complementary biological functions of these PIN/PILS genes.Most PIN/PILS genes were differentially expressed in a tissue-specific manner,and showed significant correlations with ginsenoside content correspondingly.Eight auxin transporter genes,including both PIN and PILS subfamily members,were positively correlated with ginsenoside content(cor>0.60;P-value<0.05).The expression levels of eleven auxin transporter genes were increased dramatically in the early stage(0–0.5 DPI)after Cylindrocarpon destructans infection,accompanied with various overall expression patterns,implying the dynamic auxin transport in response to biotic stress.Conclusion:Based on the results,we speculate that the accumulation or depletion in te展开更多
Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis.In this work,a series of metal-based PIL with different ionic ratios wer...Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis.In this work,a series of metal-based PIL with different ionic ratios were prepared for the selective oxidation of cyclohexane.Characterization analysis reveals that different degrees of ionization could adjust the Co-N sites of the catalysts efficiently,leading to significant changes in their electronic structure,which strongly relate to catalytic performance in oxidation.20.07%cyclohexane conversion and 13.06%cyclohexanone and cyclohexanol(KA oil)yield can be achieved by metal-based PILs that are better than other commercial catalysts.Compared with CoCl_(2),metal-based PILs perform well,with superior conversion and KA oil yield.More interestingly,the catalyst created in this study features a malleable Co-N site,which may potentially have an impact on how oxygen species adsorb and desorb from the catalyst.Therefore,the catalyst studied in this work is used as molecular oxygen for the selective oxidation of cyclohexane to produce KA oil,and its application prospect is promising.展开更多
An efficient extraction-free oxidative desulfurization(ODS)process using a series of cross-linked polyionic liquid phosphotungstate(CLPIL-PW)catalysts is reported.The cross-linked PILs were prepared with DVB and 1-n-a...An efficient extraction-free oxidative desulfurization(ODS)process using a series of cross-linked polyionic liquid phosphotungstate(CLPIL-PW)catalysts is reported.The cross-linked PILs were prepared with DVB and 1-n-alkyl-3-vinyl imidazole hydrobromide(alkyl=ethyl,butyl,octyl,dodecyl),and were then assembled with phosphotungstic acid(H_(3)PW_(12)O_(40))to form the catalysts.The CLPIL-PWs have been applied to the oxidative removal of dibenzothiophene(DBT)from model oil with H_(2)O_(2) as an oxidant.The effects of ionic liquid(IL)cationic species,varying the DVB/IL molar ratio in the polymerization process,and varying operating conditions were investigated.The CLPIL-PWs were characterized by inductively coupled plasma(ICP)mass spectrometry,elemental analysis,scanning electron microscopy(SEM),Fourier transform infra-red(FTIR)spectroscopy,X-ray diffraction(XRD),^(13)C and^(31)P nuclear magnetic resonance(NMR)spectroscopy.The polydivinylbenzene-co-1-n-octyl-3-vinyl imidazole phosphotungstate(P(DVB-OVIm)PW)exhibited the highest DBT removal efficiency(99.9%)and remarkable recyclability,and could be reused eight times without reducing its activity.Finally,an extraction-free ODS mechanism is proposed.展开更多
基金“La region Centre Val de Loire” for financial support to the researchers involved in this study under “Lavoisier II” regional program。
文摘Poly(vinylidene fluoride), PVDF, membranes have attracted considerable attention as polymer electrolytes for fuel cells. This study explores the effect of solvent on the spherulite size and the crystallinity of the polymeric membranes. Based on Hansen solubility parameters theory, the mixture of DMC and DMSO was selected among a dozen of solvents for the preparation of PVDF membranes by thermally induced phase separation. The addition of two protic ionic liquids(PILs), bis(2-ethyl hexyl) ammonium hydrogen phosphate [EHNH_2][H_2PO_4], and imidazolium hexanoate [Im][Hex] to PVDF membranes at concentrations(10% < wP IL< 50%) has been investigated by SEM, FTIR, DSC, TGA, EIS, and DMA. The inclusion of ionic liquids into the polymer matrix influences structural parameters(degree of crystallinity and electroactive phases), thermal stability, proton conductivity and mechanical properties of the membranes. The membranes become transparent regardless type of ionic liquid employed. A small amount of ionic liquids increases the degree of crystallinity and facilitates the production of polar β and γ crystals. The proton conductivity mechanism(Grotthuss) is dependent on the ionic liquid structure(due to its selforganization in water) and the content in the PVDF membrane, as well as the membrane water uptake.Different behavior has been observed for the two ionic liquids, which stresses the challenge on selecting an appropriate cation and anion combination. The obtained composite membranes exhibited excellent mechanical performance and reduced elastic modulus, with respect to the pure polymer matrix. These results indicate that PVDF/IL composite membranes have a high potential for PEMFC applications.
基金supported by grants from the National Science and Technology Major Project (No.2018ZX09201-011,2017ZX09301060-012)the Fundamental Research Funds for the Central Public Welfare Research Institutes (ZXKT17027,ZXKT19027)+1 种基金the National Nature Science Foundation of China(81803672)the National Key Research and Development Program of China (2017YFC1702100)
文摘Objective:Plant hormones act as chemical messengers in the regulation of plant development and metabolism.The production of ginsenosides in Panax hybrid is promoted by auxins that are transported and accumulated by PIN-FORMED(PIN)and PIN-LIKES(PILS)auxin transporters.However,genome-wide studies of PIN/PILS of ginseng are still scarce.In current study,identification and transcriptional profiling of PIN/PILS gene families,as well as their potential relationship with ginsenoside biosynthesis in Panax ginseng were investigated.Methods:PIN/PILS genes in P.ginseng was identified via in silico genome-wide analysis,followed by phylogenetic relationships,gene structure,and protein profiles investigation.Moreover,previously reported RNA-sequence data from various tissues and roots after infection were utilized for PIN/PILS genes expression pattern analysis.The Pearson’s correlation analysis of specific PIN/PILS genes expression level and main ginsenoside contents were taken to reveal the potential relationship between auxin transports and ginsenoside biosynthesis in P.ginseng.Results:A genome-wide search of P.ginseng genome for homologous auxin transporter genes identified a total of 17 PIN and 11 PILS genes.Sequence alignment,putative motif organization,and sub-cellular localization indicated redundant and complementary biological functions of these PIN/PILS genes.Most PIN/PILS genes were differentially expressed in a tissue-specific manner,and showed significant correlations with ginsenoside content correspondingly.Eight auxin transporter genes,including both PIN and PILS subfamily members,were positively correlated with ginsenoside content(cor>0.60;P-value<0.05).The expression levels of eleven auxin transporter genes were increased dramatically in the early stage(0–0.5 DPI)after Cylindrocarpon destructans infection,accompanied with various overall expression patterns,implying the dynamic auxin transport in response to biotic stress.Conclusion:Based on the results,we speculate that the accumulation or depletion in te
基金supported by the National Science Fund for Excellent Young Scholars(22222813)Key Scientific and Technological Projects in Huizhou(2021JBZ5.1)the Joint Fund of Yulin University,and the Dalian National Laboratory for Clean Energy(Grant No.YLU-DNL Fund 2021016)
文摘Poly(ionic liquids)(PILs)combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis.In this work,a series of metal-based PIL with different ionic ratios were prepared for the selective oxidation of cyclohexane.Characterization analysis reveals that different degrees of ionization could adjust the Co-N sites of the catalysts efficiently,leading to significant changes in their electronic structure,which strongly relate to catalytic performance in oxidation.20.07%cyclohexane conversion and 13.06%cyclohexanone and cyclohexanol(KA oil)yield can be achieved by metal-based PILs that are better than other commercial catalysts.Compared with CoCl_(2),metal-based PILs perform well,with superior conversion and KA oil yield.More interestingly,the catalyst created in this study features a malleable Co-N site,which may potentially have an impact on how oxygen species adsorb and desorb from the catalyst.Therefore,the catalyst studied in this work is used as molecular oxygen for the selective oxidation of cyclohexane to produce KA oil,and its application prospect is promising.
基金supported by the Natural Science Foundation of Heilongjiang Province of China (Grant No. LH2019B025)
文摘An efficient extraction-free oxidative desulfurization(ODS)process using a series of cross-linked polyionic liquid phosphotungstate(CLPIL-PW)catalysts is reported.The cross-linked PILs were prepared with DVB and 1-n-alkyl-3-vinyl imidazole hydrobromide(alkyl=ethyl,butyl,octyl,dodecyl),and were then assembled with phosphotungstic acid(H_(3)PW_(12)O_(40))to form the catalysts.The CLPIL-PWs have been applied to the oxidative removal of dibenzothiophene(DBT)from model oil with H_(2)O_(2) as an oxidant.The effects of ionic liquid(IL)cationic species,varying the DVB/IL molar ratio in the polymerization process,and varying operating conditions were investigated.The CLPIL-PWs were characterized by inductively coupled plasma(ICP)mass spectrometry,elemental analysis,scanning electron microscopy(SEM),Fourier transform infra-red(FTIR)spectroscopy,X-ray diffraction(XRD),^(13)C and^(31)P nuclear magnetic resonance(NMR)spectroscopy.The polydivinylbenzene-co-1-n-octyl-3-vinyl imidazole phosphotungstate(P(DVB-OVIm)PW)exhibited the highest DBT removal efficiency(99.9%)and remarkable recyclability,and could be reused eight times without reducing its activity.Finally,an extraction-free ODS mechanism is proposed.
