Nano-SiO2 was modified using silane coupling agent （KH-550） and hyperbranched poly（amine-ester） respectively, and Poly（vinyl chloride） （PVC）/modified nano-SiO2 composites were made by melt-blending. The compos...Nano-SiO2 was modified using silane coupling agent （KH-550） and hyperbranched poly（amine-ester） respectively, and Poly（vinyl chloride） （PVC）/modified nano-SiO2 composites were made by melt-blending. The composites＇ structures andmechanical properties were characterized by transmission electron microscopy（TEM）, sanning electronic microscopy（SEM） and electronic universal testing machine. The results. show that nano-SiO2 grafted by hyperbranched poly （amine-ester） increases obviously in dispersion in PVC matrix, and mechanical properties of PVC are effectively improved. Moreover, it was found that mechanical properties of PVC/nano-SiO2 composites reach the best when weight percent of nano-SiO2 in PVC matrix is 1%. Compared with crude PVC, the tensile strength of hyperbranched poly （amine-ester） grafted nano-SiO2/ PVC composite increases by 24.68 % and its break elongation, flexural strength and impact strength increase by 15.73%, 4.07% and 1 841.84%, respectively. Moreover, the processing of the composites is improved.展开更多
Crosslinked film of hyperbranched poly（amine-ester） （HPAE） was prepared by crosslinking its terminal hydroxyl groups with glutaraldehyde （GA）. Atom force microscope （AFM） and scanning electron microscope （SEM...Crosslinked film of hyperbranched poly（amine-ester） （HPAE） was prepared by crosslinking its terminal hydroxyl groups with glutaraldehyde （GA）. Atom force microscope （AFM） and scanning electron microscope （SEM） reveals that they have smooth surfaces, dense and homogenous matrices. It was found that the water static contact angle is smaller than 41.7°, the tensile strength is higher than 8.9 MPa, the elongation at break is higher than 5.1%, the swelling degree is higher than 42% in water, and the Bovine hemoglobin （Hb） adsorption is relatively low. These results indicate that the crosslinked HPAE films might have some potential applications in many areas.展开更多
Hyperbranched poly(amine-ester) (HBPAE) was synthesized via pseudo-one-step process between trimethylolpropane as a core molecule and N, N-diethylol-3-amine methylpropionate as the AB2 branched monomer. The prepared p...Hyperbranched poly(amine-ester) (HBPAE) was synthesized via pseudo-one-step process between trimethylolpropane as a core molecule and N, N-diethylol-3-amine methylpropionate as the AB2 branched monomer. The prepared polymer was analyzed by IR, GPC, 1H-NMR and thermal analysis (TGA and DSC). The performance of the polymer in cement was tested by measuring the effect of 1, 3 and 5 wt% of HBPAE solutions on the properties of Ordinary Portland Cement. Water of consistency, setting times, bulk density, apparent porosity, compressive strength and combined water content of the polymer/cement pastes were studied. The results showed that water of consistency and apparent porosity decreased while setting times, compressive strength, combined water and bulk density increased with the polymer addition.展开更多
Vaccination with tumor-antigen pulsed, monocyte-derived dendritic cells (DCs) has emerged as a promising strategy in cancer immunotherapy. The standard DC maturation cocktail consists of a combination of tumor necrosi...Vaccination with tumor-antigen pulsed, monocyte-derived dendritic cells (DCs) has emerged as a promising strategy in cancer immunotherapy. The standard DC maturation cocktail consists of a combination of tumor necrosis factor-α (TNF-α)/interleukin (IL)-1β/IL-6 and prostaglandin E2 (PGE2) for generation of standard DCs (sDCs). In order to improve IL-12p70 production and cytotoxic T-lymphocyte (CTL) induction, a novel cocktail composed of TNF-α/IL-1β/ interferon (IFN)-α/IFN-γ and polyinosinic:polycytidylic acid (Poly-I:C) has been introduced to generate so-called α-Type-1 polarized DCs (αDC1s). We and others have previously performed a comprehensive comparison of sDCs and αDC1s. Here we demonstrate that the viability of αDC1s is lowered compared to sDCs and that DC apoptosis is mediated by Poly-I:C. We speculated that activation of protein kinase R (PKR) could mediate the observed apoptosis, but despite significantly higher PKR expression in αDC1s compared to sDCs and induction of active threonine (Thr)446 autophosphorylation of PKR in αDC1s, Poly-I:C did not influence total PKR expression or autophosporylation, indicating PKR-independent Poly-I:C-induced DC apoptosis.展开更多
The leakage of liquid electrolyte and the formation of lithium dendrites pose challenges to safety and stability of lithium metal batteries(LMBs).The appearance of gel polymer electrolyte(GPE)has obviously improved th...The leakage of liquid electrolyte and the formation of lithium dendrites pose challenges to safety and stability of lithium metal batteries(LMBs).The appearance of gel polymer electrolyte(GPE)has obviously improved the safety of traditional LMBs.However,the limited inhibition of GPE on lithium dendrites is detrimental to the safety of LMBs.Herein,a kind of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)/gelatin(GN)GPE with high ionic conductivity,high-temperature resistance,and flame-retardancy,was prepared by electrospinning and soaking method.Utilizing the electrospinning network of PVDF-HFP,its affinity to liquid electrolytes,makes this GPE more beneficial to ions transport and the formation of gel.And,the GN with sol–gel properties,enhances the mechanical property(13.5 MPa)of HFP-GN GPE.Meanwhile,X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT)suggest that the attraction of polar groups of GN to Li+can regulate the distribution of Li+and protect Li anodes.Consequently,the application of HFP-GN GPEs to LMBs with cathodes of LiFePO_(4) and LiCoO_(2) deliver excellent electrochemical performances:after 300 cycles,the LiFePO_(4)/HFP-GN GPE/Li battery keeps a low capacity decay rate of 0.09%at 5 C;after 400 cycles at 2 C,the LiCoO_(2)/HFP-GN GPE/Li cell retains a high capacity retention of 74%.This GPE is demonstrated for the application prospect of safe LMBs.展开更多
A Novel thermosensitive dendritic copolymer based on polyethylene glycol（PEG） and poly（Nisopropylacrylamide）（PNIPAm） with a cloud point（CP） around 36 ？C was successfully synthesized by preparation of a dendri...A Novel thermosensitive dendritic copolymer based on polyethylene glycol（PEG） and poly（Nisopropylacrylamide）（PNIPAm） with a cloud point（CP） around 36 ？C was successfully synthesized by preparation of a dendritic polyol and followed by atom transfer radical polymerization（ATRP） of N-isopropylacrylamide. The dendritic copolymer was characterized using gel-permeation chromatography（GPC）, FTIR and 1H-NMR spectroscopy. The selfassociation behavior of the copolymer in aqueous medium was investigated by dynamic light scattering（DLS） and transmission electron microscopy（TEM）. These investigations confirmed that the dendritic copolymer showed different association behaviors at various temperatures.展开更多
Basing on hydroxyl terminated hyperbranched poly(amine-ester)s(HPAEs),the cross-linking reactions and preparation of ester-crosslinked HPAE films were inves-tigated using succine anhydride(SA)as crosslink reagent.It w...Basing on hydroxyl terminated hyperbranched poly(amine-ester)s(HPAEs),the cross-linking reactions and preparation of ester-crosslinked HPAE films were inves-tigated using succine anhydride(SA)as crosslink reagent.It was proved that the cross-linking reaction between HPAE and SA followed a two-step mechanism.This mechanism provides an efficient route to prepare HPAE/SA cross-linked films,in which,the precursor films were prepared by casting HPAE/SA solution at a lower temperature,and then curing the films at a higher temperature.By varying SA content,the solid HPAE/SA films with different cross-linking degrees were prepared successfully.The highest tensile strength of the cross-linked film could reach 59.60 MPa.With all water contact angle smaller than 74.3°,the crosslinked films demonstrated good hydrophilic properties.展开更多
基金Sponsored by the Ministerial Level Advanced Research Foundation (120701BQ0126)
文摘Nano-SiO2 was modified using silane coupling agent （KH-550） and hyperbranched poly（amine-ester） respectively, and Poly（vinyl chloride） （PVC）/modified nano-SiO2 composites were made by melt-blending. The composites＇ structures andmechanical properties were characterized by transmission electron microscopy（TEM）, sanning electronic microscopy（SEM） and electronic universal testing machine. The results. show that nano-SiO2 grafted by hyperbranched poly （amine-ester） increases obviously in dispersion in PVC matrix, and mechanical properties of PVC are effectively improved. Moreover, it was found that mechanical properties of PVC/nano-SiO2 composites reach the best when weight percent of nano-SiO2 in PVC matrix is 1%. Compared with crude PVC, the tensile strength of hyperbranched poly （amine-ester） grafted nano-SiO2/ PVC composite increases by 24.68 % and its break elongation, flexural strength and impact strength increase by 15.73%, 4.07% and 1 841.84%, respectively. Moreover, the processing of the composites is improved.
基金This work was supported by the National Natural Science Foundation of China (No. 50103010)the "973" Program (No. 2003. CB615705)
文摘Crosslinked film of hyperbranched poly（amine-ester） （HPAE） was prepared by crosslinking its terminal hydroxyl groups with glutaraldehyde （GA）. Atom force microscope （AFM） and scanning electron microscope （SEM） reveals that they have smooth surfaces, dense and homogenous matrices. It was found that the water static contact angle is smaller than 41.7°, the tensile strength is higher than 8.9 MPa, the elongation at break is higher than 5.1%, the swelling degree is higher than 42% in water, and the Bovine hemoglobin （Hb） adsorption is relatively low. These results indicate that the crosslinked HPAE films might have some potential applications in many areas.
文摘Hyperbranched poly(amine-ester) (HBPAE) was synthesized via pseudo-one-step process between trimethylolpropane as a core molecule and N, N-diethylol-3-amine methylpropionate as the AB2 branched monomer. The prepared polymer was analyzed by IR, GPC, 1H-NMR and thermal analysis (TGA and DSC). The performance of the polymer in cement was tested by measuring the effect of 1, 3 and 5 wt% of HBPAE solutions on the properties of Ordinary Portland Cement. Water of consistency, setting times, bulk density, apparent porosity, compressive strength and combined water content of the polymer/cement pastes were studied. The results showed that water of consistency and apparent porosity decreased while setting times, compressive strength, combined water and bulk density increased with the polymer addition.
文摘Vaccination with tumor-antigen pulsed, monocyte-derived dendritic cells (DCs) has emerged as a promising strategy in cancer immunotherapy. The standard DC maturation cocktail consists of a combination of tumor necrosis factor-α (TNF-α)/interleukin (IL)-1β/IL-6 and prostaglandin E2 (PGE2) for generation of standard DCs (sDCs). In order to improve IL-12p70 production and cytotoxic T-lymphocyte (CTL) induction, a novel cocktail composed of TNF-α/IL-1β/ interferon (IFN)-α/IFN-γ and polyinosinic:polycytidylic acid (Poly-I:C) has been introduced to generate so-called α-Type-1 polarized DCs (αDC1s). We and others have previously performed a comprehensive comparison of sDCs and αDC1s. Here we demonstrate that the viability of αDC1s is lowered compared to sDCs and that DC apoptosis is mediated by Poly-I:C. We speculated that activation of protein kinase R (PKR) could mediate the observed apoptosis, but despite significantly higher PKR expression in αDC1s compared to sDCs and induction of active threonine (Thr)446 autophosphorylation of PKR in αDC1s, Poly-I:C did not influence total PKR expression or autophosporylation, indicating PKR-independent Poly-I:C-induced DC apoptosis.
基金supported by the National Natural Science Foundation of China(Nos.51502269,51972287,and U2004172)Natural Science Foundation of Henan Province(Nos.202300410368 and 222301420039)+1 种基金the Foundation for University Key Teachers of Henan Province(No.2020GGJS009)sponsored by Program for Science&Technology Innovation Talents in Universities of Henan Province(No.23HASTIT001).
文摘The leakage of liquid electrolyte and the formation of lithium dendrites pose challenges to safety and stability of lithium metal batteries(LMBs).The appearance of gel polymer electrolyte(GPE)has obviously improved the safety of traditional LMBs.However,the limited inhibition of GPE on lithium dendrites is detrimental to the safety of LMBs.Herein,a kind of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)/gelatin(GN)GPE with high ionic conductivity,high-temperature resistance,and flame-retardancy,was prepared by electrospinning and soaking method.Utilizing the electrospinning network of PVDF-HFP,its affinity to liquid electrolytes,makes this GPE more beneficial to ions transport and the formation of gel.And,the GN with sol–gel properties,enhances the mechanical property(13.5 MPa)of HFP-GN GPE.Meanwhile,X-ray photoelectron spectroscopy(XPS)and density functional theory(DFT)suggest that the attraction of polar groups of GN to Li+can regulate the distribution of Li+and protect Li anodes.Consequently,the application of HFP-GN GPEs to LMBs with cathodes of LiFePO_(4) and LiCoO_(2) deliver excellent electrochemical performances:after 300 cycles,the LiFePO_(4)/HFP-GN GPE/Li battery keeps a low capacity decay rate of 0.09%at 5 C;after 400 cycles at 2 C,the LiCoO_(2)/HFP-GN GPE/Li cell retains a high capacity retention of 74%.This GPE is demonstrated for the application prospect of safe LMBs.
文摘A Novel thermosensitive dendritic copolymer based on polyethylene glycol（PEG） and poly（Nisopropylacrylamide）（PNIPAm） with a cloud point（CP） around 36 ？C was successfully synthesized by preparation of a dendritic polyol and followed by atom transfer radical polymerization（ATRP） of N-isopropylacrylamide. The dendritic copolymer was characterized using gel-permeation chromatography（GPC）, FTIR and 1H-NMR spectroscopy. The selfassociation behavior of the copolymer in aqueous medium was investigated by dynamic light scattering（DLS） and transmission electron microscopy（TEM）. These investigations confirmed that the dendritic copolymer showed different association behaviors at various temperatures.
基金This paper is financially supported by the National Natural Science Foundation of China(Grant No.50103010)China Postdoctoral Science Foundation(No.20060400338)the State Key Development Program for Basic Research of China(Grant No.2003.CB615705).
文摘Basing on hydroxyl terminated hyperbranched poly(amine-ester)s(HPAEs),the cross-linking reactions and preparation of ester-crosslinked HPAE films were inves-tigated using succine anhydride(SA)as crosslink reagent.It was proved that the cross-linking reaction between HPAE and SA followed a two-step mechanism.This mechanism provides an efficient route to prepare HPAE/SA cross-linked films,in which,the precursor films were prepared by casting HPAE/SA solution at a lower temperature,and then curing the films at a higher temperature.By varying SA content,the solid HPAE/SA films with different cross-linking degrees were prepared successfully.The highest tensile strength of the cross-linked film could reach 59.60 MPa.With all water contact angle smaller than 74.3°,the crosslinked films demonstrated good hydrophilic properties.
