Owing to the potential ability of metal nanoparticles to enhance the performance of energy storage devices,their catalytic performance has been studied by many researchers.However,a limited number of suitable characte...Owing to the potential ability of metal nanoparticles to enhance the performance of energy storage devices,their catalytic performance has been studied by many researchers.However,a limited number of suitable characterization techniques does not allow fully elucidating their catalytic mechanism.Herein,high‐accuracy operando magnetometry is employed to investigate the catalytic properties of a cobalt oxide electrode for lithium‐ion batteries fabricated by magnetron sputtering.Using this technique,the magnetic responses generated by the Co‐catalyzed reversible formation and decomposition of a polymer/gel‐like film are successfully detected.A series of CoO/Co films are prepared by magnetron sputtering in different environments at various sputtering times to study the influence of Co content and film thickness on their catalytic properties.It is clearly demonstrated that increasing the Co content enhances the magnetic signal associated with the catalysis process.Furthermore,decreasing the electrode thickness increases the area affected by the catalytic reactions,which in turn enhances the corresponding magnetic responses.The obtained results experimentally confirm the catalytic activity of Co metal nanoparticles and provide a scientific guidance for designing advanced energy storage devices.This work also shows that operando magnetometry is a versatile technique for studying the catalytic effects of transition metals.展开更多
In order to further improve the driving performance of ionic polymer metal composites(IPMCs),Nafion/graphene quantum dots(GQDs)hybrid membranes incorporating GQDs with various contents of 0,0.1 wt.%,0.5 wt.%,1.0 wt.%,...In order to further improve the driving performance of ionic polymer metal composites(IPMCs),Nafion/graphene quantum dots(GQDs)hybrid membranes incorporating GQDs with various contents of 0,0.1 wt.%,0.5 wt.%,1.0 wt.%,2.0 wt.%and 4.0 wt.%were fabricated by solution casting,and then IPMCs were manufactured by electroless plating.The water contents and elastic moduli of the hybrid membranes were tested.The morphology characteristics of the hybrid membranes and the IPMCs were observed,and the current,AC impedance,blocking force and displacement of the IPMCs were measured.The results show that the elastic modulus of the hybrid membranes decreases,the water content increases,and the actuation performance of the IPMCs improves significantly after the addition of GQDs.IPMC with 1.0 wt.%GQDs exhibits the best driving property.Compared with the IPMC without GQDs,the working current,ion conductivity,blocking force,and tip displacement increase by 94.67%,311.11%,53.66%,and 66.07%,respectively.These results lay a solid foundation for the preparation of IPMCs with high performance,and further broaden their applications in biomedical devices and bionic robots.展开更多
Fifteen new polyester ligands were prepared by copolymerndion Of EDTA(ethylenediaminetetraacetic acid ) dianhydride or DTPA (dikthylenetriaminepenlaacetic acid) dianhydrtde and dihydric alcohol or dihydric phenol. The...Fifteen new polyester ligands were prepared by copolymerndion Of EDTA(ethylenediaminetetraacetic acid ) dianhydride or DTPA (dikthylenetriaminepenlaacetic acid) dianhydrtde and dihydric alcohol or dihydric phenol. Theirparanzagnetic metal complexes were also synthesized. All polyester ligands andmetal complexes were characterized by IHNMR, IR spectra and elemental analyses. Preliminary study showed that the polyester .metal complexes had higher relaxation effectiveness as compared to corresponding small molecular metal complexes.展开更多
Toxic Zn(II) ion imprinted interpenetrating polymer networks were synthesized for the selective sorption of Zn(ll) from aqueous solutions using a biopolymer alginic acid. The polymeric biosorbant was prepared usin...Toxic Zn(II) ion imprinted interpenetrating polymer networks were synthesized for the selective sorption of Zn(ll) from aqueous solutions using a biopolymer alginic acid. The polymeric biosorbant was prepared using Zn(II) ion as template, acrylamide as functional monomer, cross linker NNMBA (N,N' Methylene-bis-acrylamide) and potassium persulphate as an initiator. The non-imprinted polymer networks were also prepared without use of the Zn(II) ion. The synthesized interpenetrating networks were characterized by various spectral techniques. Metal ion binding studies were carried out and the factors affecting binding were also optimized. Competitive sorption studies were investigated to determine the selectivity of Zn(II) ion imprinted interpenetrating polymer network. Zinc ion imprinted polymer networks showed good selectivity for the target ion.展开更多
During the last two decades,porous coordination polymers(PCPs),usually called as metal-organic frameworks(MOFs),have been developed rapidly due to their versatile structural diversities and potential physical and chem...During the last two decades,porous coordination polymers(PCPs),usually called as metal-organic frameworks(MOFs),have been developed rapidly due to their versatile structural diversities and potential physical and chemical functions.This article provides a short review of recent advances in the design and constructions of porous coordination polymers based on three planar rigid ligands,including imidazole-4,5-dicarboxlate(H3IDC),1H-tetrazole(HTz),as well as 1H-tetrazole-5-carboxylate(H2Tzc).Their preparations,crystal structures,and desirable properties have been reviewed.展开更多
Regioseletive 1,3-dipolar polycycloadditions of 4,4'-isopropylidenediphenyl dipropiolate (1) and tetraphenylethene (TPE)-containing diazides (2) are carried out in polar solvents such as DMF/toluene at a moderate ...Regioseletive 1,3-dipolar polycycloadditions of 4,4'-isopropylidenediphenyl dipropiolate (1) and tetraphenylethene (TPE)-containing diazides (2) are carried out in polar solvents such as DMF/toluene at a moderate temperature of 100℃ for 6 h,producing poly(aroxycarbonyltriazole)s (PACTs) P3 with high molecular weights (Mw up to 23900) and regioregularities (F1,4 up to ~90%) in high yields (up to ~99%).These metal-free click polymerizations can propagate smoothly in an open atmosphere without protection from oxygen and moisture.The obtained polymers are soluble in common organic solvents and thermally stable at temperatures up to 375℃.Thanks to their contained TPE moieties,the PACTs show aggregation-induced emission and can serve as fluorescent chemosensors for superamplified detection of explosives.展开更多
We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10^(-4) mol/L, two orders of magnitud...We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10^(-4) mol/L, two orders of magnitude higher than that reported in the literature. The p H value of the solution was 3.9, and the hydrogen bonds between the intrinsic and ionized carboxylic acid groups formed dynamic networks, which captured aggregation-induced emission-active molecules(a tetra-quaternary ammonium modified tetraphenylethene derivative) inside the polymer coils and induced fluorescence emission. The hydrogen bonds can be classified as intra- or intermolecular; both can be probed based on the emission change of the tetra-quaternary ammonium modified tetraphenylethene probes. The effects of different external stimuli on the polymer chain dynamics were investigated using different metal cations(including Na^+, Li^+, Zn^(2+), Ni^(2+), Ca^(2+), and Co^(2+)), different cation concentrations(1×10^(-6) to 4×10^(-4) mol/L), different poly(acrylic acid) molecular weights(5, 240, and 450 k Da), and different copolymers. The experimental results indicate that the long poly(acrylic acid) chains(high molecular weight) tend to form dense globular coils and exclude the probe molecules outside, which are robust and unsusceptible to water-soluble metal cations. However, the shorter poly(acrylic acid) chains tend to form intermolecular hydrogen bonds, which are helpful in capturing more probe molecules inside the networks, thus inducing stronger emission. Because of the dual functions of forming hydrogen bonds with carboxylic groups and acting as an acceptor of protons from the carboxylic acid group to form cationic species, copolymerization with acrylate amide [poly(acrylic acid)-co-poly(acrylamide)] can greatly affect the chain dynamics of poly(acrylic acid) segments, which is reflected by the drastically decreased emission intensity from the fluorescent probes.展开更多
文摘Owing to the potential ability of metal nanoparticles to enhance the performance of energy storage devices,their catalytic performance has been studied by many researchers.However,a limited number of suitable characterization techniques does not allow fully elucidating their catalytic mechanism.Herein,high‐accuracy operando magnetometry is employed to investigate the catalytic properties of a cobalt oxide electrode for lithium‐ion batteries fabricated by magnetron sputtering.Using this technique,the magnetic responses generated by the Co‐catalyzed reversible formation and decomposition of a polymer/gel‐like film are successfully detected.A series of CoO/Co films are prepared by magnetron sputtering in different environments at various sputtering times to study the influence of Co content and film thickness on their catalytic properties.It is clearly demonstrated that increasing the Co content enhances the magnetic signal associated with the catalysis process.Furthermore,decreasing the electrode thickness increases the area affected by the catalytic reactions,which in turn enhances the corresponding magnetic responses.The obtained results experimentally confirm the catalytic activity of Co metal nanoparticles and provide a scientific guidance for designing advanced energy storage devices.This work also shows that operando magnetometry is a versatile technique for studying the catalytic effects of transition metals.
基金Projects(51605220,U1637101)supported by the National Natural Science Foundation of ChinaProject(BK20160793)supported by the Jiangsu Provincial Natural Science Foundation,ChinaProject(NS2020029)supported by the Fundamental Research Funds for the Central Universities,China。
文摘In order to further improve the driving performance of ionic polymer metal composites(IPMCs),Nafion/graphene quantum dots(GQDs)hybrid membranes incorporating GQDs with various contents of 0,0.1 wt.%,0.5 wt.%,1.0 wt.%,2.0 wt.%and 4.0 wt.%were fabricated by solution casting,and then IPMCs were manufactured by electroless plating.The water contents and elastic moduli of the hybrid membranes were tested.The morphology characteristics of the hybrid membranes and the IPMCs were observed,and the current,AC impedance,blocking force and displacement of the IPMCs were measured.The results show that the elastic modulus of the hybrid membranes decreases,the water content increases,and the actuation performance of the IPMCs improves significantly after the addition of GQDs.IPMC with 1.0 wt.%GQDs exhibits the best driving property.Compared with the IPMC without GQDs,the working current,ion conductivity,blocking force,and tip displacement increase by 94.67%,311.11%,53.66%,and 66.07%,respectively.These results lay a solid foundation for the preparation of IPMCs with high performance,and further broaden their applications in biomedical devices and bionic robots.
文摘Fifteen new polyester ligands were prepared by copolymerndion Of EDTA(ethylenediaminetetraacetic acid ) dianhydride or DTPA (dikthylenetriaminepenlaacetic acid) dianhydrtde and dihydric alcohol or dihydric phenol. Theirparanzagnetic metal complexes were also synthesized. All polyester ligands andmetal complexes were characterized by IHNMR, IR spectra and elemental analyses. Preliminary study showed that the polyester .metal complexes had higher relaxation effectiveness as compared to corresponding small molecular metal complexes.
文摘Toxic Zn(II) ion imprinted interpenetrating polymer networks were synthesized for the selective sorption of Zn(ll) from aqueous solutions using a biopolymer alginic acid. The polymeric biosorbant was prepared using Zn(II) ion as template, acrylamide as functional monomer, cross linker NNMBA (N,N' Methylene-bis-acrylamide) and potassium persulphate as an initiator. The non-imprinted polymer networks were also prepared without use of the Zn(II) ion. The synthesized interpenetrating networks were characterized by various spectral techniques. Metal ion binding studies were carried out and the factors affecting binding were also optimized. Competitive sorption studies were investigated to determine the selectivity of Zn(II) ion imprinted interpenetrating polymer network. Zinc ion imprinted polymer networks showed good selectivity for the target ion.
文摘During the last two decades,porous coordination polymers(PCPs),usually called as metal-organic frameworks(MOFs),have been developed rapidly due to their versatile structural diversities and potential physical and chemical functions.This article provides a short review of recent advances in the design and constructions of porous coordination polymers based on three planar rigid ligands,including imidazole-4,5-dicarboxlate(H3IDC),1H-tetrazole(HTz),as well as 1H-tetrazole-5-carboxylate(H2Tzc).Their preparations,crystal structures,and desirable properties have been reviewed.
基金supported by the National Natural Science Foundation of China (20634020,50703033,20974098 and 20974028)the Ministry of Science and Technology of China (2009CB623605)+4 种基金the University Grants Committee of Hong Kong ( AoE/P-03/08)the Research Grants Council of Hong Kong (603509,601608 and 602707)the Innovation and Technology Fund of Hong Kong (ITS/168/09). A.J.Q. and B.Z.T acknowledge the supports from the Postdoctoral Research Foundation of China (20081461)the Fundamental Research Funds for the Central Universities (2010KYJD005)the CAO GuangBiao Foundation of Zhejiang University,respectively
文摘Regioseletive 1,3-dipolar polycycloadditions of 4,4'-isopropylidenediphenyl dipropiolate (1) and tetraphenylethene (TPE)-containing diazides (2) are carried out in polar solvents such as DMF/toluene at a moderate temperature of 100℃ for 6 h,producing poly(aroxycarbonyltriazole)s (PACTs) P3 with high molecular weights (Mw up to 23900) and regioregularities (F1,4 up to ~90%) in high yields (up to ~99%).These metal-free click polymerizations can propagate smoothly in an open atmosphere without protection from oxygen and moisture.The obtained polymers are soluble in common organic solvents and thermally stable at temperatures up to 375℃.Thanks to their contained TPE moieties,the PACTs show aggregation-induced emission and can serve as fluorescent chemosensors for superamplified detection of explosives.
基金supported by the Natural Science Foundation of Zhejiang Province(2012C32007Z4110056)the National Basic Research Program of China(2013CB834704)
文摘We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10^(-4) mol/L, two orders of magnitude higher than that reported in the literature. The p H value of the solution was 3.9, and the hydrogen bonds between the intrinsic and ionized carboxylic acid groups formed dynamic networks, which captured aggregation-induced emission-active molecules(a tetra-quaternary ammonium modified tetraphenylethene derivative) inside the polymer coils and induced fluorescence emission. The hydrogen bonds can be classified as intra- or intermolecular; both can be probed based on the emission change of the tetra-quaternary ammonium modified tetraphenylethene probes. The effects of different external stimuli on the polymer chain dynamics were investigated using different metal cations(including Na^+, Li^+, Zn^(2+), Ni^(2+), Ca^(2+), and Co^(2+)), different cation concentrations(1×10^(-6) to 4×10^(-4) mol/L), different poly(acrylic acid) molecular weights(5, 240, and 450 k Da), and different copolymers. The experimental results indicate that the long poly(acrylic acid) chains(high molecular weight) tend to form dense globular coils and exclude the probe molecules outside, which are robust and unsusceptible to water-soluble metal cations. However, the shorter poly(acrylic acid) chains tend to form intermolecular hydrogen bonds, which are helpful in capturing more probe molecules inside the networks, thus inducing stronger emission. Because of the dual functions of forming hydrogen bonds with carboxylic groups and acting as an acceptor of protons from the carboxylic acid group to form cationic species, copolymerization with acrylate amide [poly(acrylic acid)-co-poly(acrylamide)] can greatly affect the chain dynamics of poly(acrylic acid) segments, which is reflected by the drastically decreased emission intensity from the fluorescent probes.