Conductive polymers as one of the candidate materials with pseudocapacitor behavior have inspired wide attentions,because of their high conductivity,fexibility,low cost and excellent processability.However,the intrins...Conductive polymers as one of the candidate materials with pseudocapacitor behavior have inspired wide attentions,because of their high conductivity,fexibility,low cost and excellent processability.However,the intrinsically poor cycling stability induced by the volume change over the doping/dedoping redox process limits their practical applications.Herein,we report the exploration of electrodes with robust cycling capacity for supercapacitors(SCs),which are rationally designed by coating conductive poly(3,4-ethylenedioxythiophene)(PEDOT)around free-standing SiC nanowires using an all-dry oxidative chemical vaper deposition(oCVD)method.The as-constructed SiC@PEDOT nanowire architecture enables a specific capacitance of 26.53 m F/cm^(2)at 0.2 m A/cm^(2),which is~370%to that of SiC nanowire counterpart(7.04 m F/cm^(2)).Moreover,their aqueous-based SCs exhibit robust cycling stability with104%capacity retention after 10000 cycles,which is among the highest values achieved for PEDOTbased SCs.展开更多
The gel-spun ultra-high molecular weight polyethylene （UHMWPE） fibers were prepared at the industrial production line with different gel solution concentrations of 15 wt%, 18 wt% and 24 wt%. The difference in ultima...The gel-spun ultra-high molecular weight polyethylene （UHMWPE） fibers were prepared at the industrial production line with different gel solution concentrations of 15 wt%, 18 wt% and 24 wt%. The difference in ultimate structure and mechanical properties of UHMWPE fibers for different gel solution concentrations were analyzed by tensile testing, differential scanning calorimetry （DSC）, wide angle X-ray diffraction （WAXD） and small angle X-ray scattering （SAXS）. With the increase of gel solution concentration, the ultimate mechanical properties of UHMWPE fibers were decreased and the crystallization and orientation of UHMWPE fibers became inferior. Besides, both the average shish length （ （Lshsh） ） and shish misorientation （B0） of UHMWPE fibers were decreased with the increase of gel solution concentration. In addition, the appropriate increase of spinning temperature led to the further optimization of the ultimate structure and mechanical properties of UHMWPE fibers.展开更多
The open-cell structure foams of linear low-density polyethylene（LLDPE） and linear low-density polyethylene（LLDPE）/multi-wall carbon nanotubes（MWCNTs） composites are prepared by using supercritical carbon dioxid...The open-cell structure foams of linear low-density polyethylene（LLDPE） and linear low-density polyethylene（LLDPE）/multi-wall carbon nanotubes（MWCNTs） composites are prepared by using supercritical carbon dioxide（sc-CO2）as a foaming agent. The effects of processing parameters（foaming temperature, saturation pressure, and depressurization rate） and the addition of MWCNTs on the evolution of cell opening are studied systematically. For LLDPE foaming, the foaming temperature and saturation pressure are two key factors for preparing open-cell foams. An increase in temperature and pressure promotes both the cell wall thinning and cell rupture, because a high temperature results in a decrease in the viscosity of the polymer, and a high pressure leads to a larger amount of cell nucleation. Moreover, for the given temperature and pressure, the high pressurization rate results in a high pressure gradient, favoring cell rupture. For LLDPE/MWCNTs foaming, the addition of MWCNTs not only promotes the cell heterogeneous nucleation, but also prevents the cell collapse during cell opening, which is critical to achieve the open-cell structures with small cell size and high cell density.展开更多
The interaction between the aggregation-induced emissive(AIE) luminogens(AIEgen) and the polymer is the key scientific question in the design of functional AIE hydrogels. In this study, we report the AIE behavior of a...The interaction between the aggregation-induced emissive(AIE) luminogens(AIEgen) and the polymer is the key scientific question in the design of functional AIE hydrogels. In this study, we report the AIE behavior of a poly(acrylic acid)(PAAc) and poly(acrylamide)(PAAm) interpenetrating network(IPN) hydrogel doped with tetra-cationic tetraphenylethene(TCTPE). The cationic AIEgen can bind with PAAc through ionic interaction, while PAAc and PAAm chains can associate with each other through hydrogen-bonds(H-bonds). These two interactions can restrict the intramolecular rotation and thus activate the luminescence of the AIEgen. The PAAc-PAAm H-bonds can be broken by increasing temperature or p H, restoring the intramolecular rotation of the AIEgen and quenching the fluorescence of the hydrogel. Therefore, the TCTPE-doped IPN hydrogel is designed as temperature-and p H-sensitive displayers which can record information imprinted by photo-printing or iono-printing with good switchability and reversibility. Another application of this TCTPE-doped hydrogel is demonstrated as a luminescent soft actuator, which has fast shape deformation and editable fluorescence pattern. The above results reveal a pathway to tune the emission behavior through tuning polymer-polymer and polymer-AIEgen interactions, which may inspire new design strategies of aggregation-induced emissive polymers and broaden their applications.展开更多
Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was investigated.In situ small-angle X-ray scattering(SAXS)and ...Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was investigated.In situ small-angle X-ray scattering(SAXS)and wide-angle X-ray diffraction(WAXD)techniques were used to monitor the formation and evolution of shish-kebab structure sheared at low temperature in simple shear mode and low rate.Only the bimodal PE with no branch formed shish-kebab crystals at the shear temperature of 129℃,and the shish length increased with the crystallization time,while bimodal PE with branch has no observable shish under the same conditions.The degree of crystallization for bimodal PE with no branch increased with time up to above 7%,while those with ethyl branch increased continually up to above 23%.Furthermore,bimodal PE's Hermans orientation factor with no branch increased to 0.60,while those with ethyl branch only increased to a value below 0.15.This study indicated that the shish-kebab crystal formed at the low temperature of 129℃is due to the stretch of entangled chains under shear for the bimodal PE with no branch.Only partly oriented lamellar crystals were formed for the bimodal PE with ethyl branch.All the results at the shear temperatures higher,closed to,and lower than the melting point,the modulation of shish crystals formation owing to different mechanisms of the coil-stretch transition and the stretched network by changing shear temperature was achieved in the bimodal PE samples.展开更多
Ultra-high molecular weight polyethylene（UHMWPE）/chitin nanocrystal（CNC） fibers were prepared. Compared with the pure UHMWPE fibers, the ultimate tensile strength and Young＇s modulus of UHMWPE/CNC fibers are impr...Ultra-high molecular weight polyethylene（UHMWPE）/chitin nanocrystal（CNC） fibers were prepared. Compared with the pure UHMWPE fibers, the ultimate tensile strength and Young＇s modulus of UHMWPE/CNC fibers are improved by 15.7% and 49.6%, respectively, with the addition of chitin nanocrystals（CNCs） of 1 wt%. The melting temperature（Tm） of UHMWPE/CNC fibers was higher than that of pure UHMWPE fibers. Pure UHMWPE fibers and UHMWPE/CNC fibers were characterized with respect to crystallinity, orientation and kebab structure by wide-angle X-ray diffraction（WAXD）, small-angle X-ray scattering（SAXS） and scanning electron microscopy（SEM）. It is found that the CNCs act as the shish structure in UHMWPE/CNC fibers and the kebab crystals are grown around the CNCs. There was almost no difference between pure UHMWPE fibers and UHMWPE/CNC fibers in orientation. But the degree of crystallinity of various stages of UHMWPE/CNC fibers was respectively higher than the corresponding stage of pure UHMWPE fibers. Moreover, the addition of 1 wt% CNCs improved the thickness of kebab crystals and accelerated the transformation of kebab to shish.展开更多
Microbeam wide-angle X-ray diffraction（WAXD） experiments were carried out at different structural knot positions of SIOC and M4 fibers of ultra-high molecular weight polyethylene（UHMWPE）. The optical microscope im...Microbeam wide-angle X-ray diffraction（WAXD） experiments were carried out at different structural knot positions of SIOC and M4 fibers of ultra-high molecular weight polyethylene（UHMWPE）. The optical microscope images revealed that SIOC fiber had bamboo-like structural knots, and M4 fiber had chaotic distribution of structural knots. WAXD patterns showed the monoclinic unit cell in the whole M4 fiber, but different lamellar orientations in the bamboo joint of SIOC fiber. In addition, small-angle X-ray scattering（SAXS） patterns confirmed that the SIOC fiber contained uniform distribution of shish structures, and differential scanning calorimetry（DSC） measurements showed that its less branched and short chains benefited the orthorhombic-hexagonal phase transformation.展开更多
The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)[P(HB-co-HV)]with the middle HV content of 19.4 mol%and 28.7 mol%were confirmed...The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)[P(HB-co-HV)]with the middle HV content of 19.4 mol%and 28.7 mol%were confirmed by differential scanning calorimetry(DSC),and the evolutions of crystal structure and lamellar morphology in the heating and melting process were tracked by in situ synchrotron wide angle X-ray diffraction(WAXD)and small angle X-ray scattering(SAXS)techniques.The emergence of asymmetric features of both the diffraction peaks and scattering curves indicates the coexistence of different lamellar crystals with varied unit cell parameters.Based on the in situ WAXD and SAXS measurements,we calculated the evolutions of the unit cell parameters a and b as well as the long period and lamellar thickness upon heating.The comparative analysis of WAXD and SAXS data confirms that the multiple endothermic peaks of P(HB-co-19.4%HV)and P(HB-co-28.7%HV)result from the melting of different lamellae rather than the melting/recrystallization.The thinner,unstable uniform lamellae with HV counits total inclusion melt first and the thicker,stable sandwich lamellae with HV counits partial inclusion melt last.In addition,the large second melting peak in P(H B-co-19.4%HV),differing from that of samples with HV content of 28.7 mol%and 36.2 mol%,is due to the unique state of HV content leading to a transition of sandwich lamellae to uniform lamellae.The present study establishes the relationship between the different lamellae structure and multiple melting behaviors of isomorphous copolymer.展开更多
Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we pr...Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we present a unique poly(acrylic acid)/calcium acetate shape memory hydrogel with cold-induced shape recovery performances as ultrastrong artificial muscles.Since the acetate groups could form aggregate at high temperatures and thus induce the association of the hydrogel network,the hydrogel can be fixed into a temporary shape upon heating and recover to its original shape in a cold environment.Moreover,a programmable shape recovery process is realized by adjusting the shape fixing time.In addition,the unique shape memory process enables the application demonstration as bio-inspired artificial muscles with an ultrahigh work density of45.2 kJ m^(-3),higher than that of biological muscles(~8 kJ m^(-3)).展开更多
Smart materials with a combination of tough solid-like properties,fast self-healing and optical responsiveness are of interests for the development of new soft machines and wearable electronics.In this work,tough phys...Smart materials with a combination of tough solid-like properties,fast self-healing and optical responsiveness are of interests for the development of new soft machines and wearable electronics.In this work,tough physically cross-linked elastomers that show high mechanical strength,intriguing temperature-adaptable self-healing and fluorochromic response properties are designed using aluminum(Al)and fluorescent europium(Eu)ions as cross-linkers.The ionic Al-COOH binding is incorporated to construct the strong polymer network which mainly contributes to the mechanical robustness of the elastomer consisting of two interpenetrated networks.The Eu-iminodiacetate(IDA)coordination is mainly used to build the weaker but more dynamic network which dominate the elasticity,self-healing and luminescence of the elastomer.Moderate Eu^(3+) and Al^(3+) contents give these supramolecular elastomers high toughness.The temperature-sensitive Eu-IDA coordination enables tunable self-healing rate and efficiency along with fast Eu-centered"ON/OFF"switchable red emission.The mechanical,self-healing and luminescence properties of these elastomers can be adjusted by tuning the ratio of the two types of metal ions.This elastomer is potentially applicable for biosensors,wearable optoelectronics and anticounterfeiting materials.展开更多
The multiple endothermic peaks of poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （P（HB-co-HV）） in differential scanning calorimetry （DSC） results, as one representative phenomenon of polymer with unique cocrysta...The multiple endothermic peaks of poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （P（HB-co-HV）） in differential scanning calorimetry （DSC） results, as one representative phenomenon of polymer with unique cocrystallization behavior, were generally considered as the results of melting/recrystallization. In this study, wide angle X-ray diffraction （WAXD） and small angle X-ray scattering （SAXS） experiments were conducted to analyze the phenomena of multiple endothermic peaks in DSC results. The results of these analyses indicated that the multiple endotherms were mainly caused by different lamellae structures. For P（HB-co-HV） with lower HV content, it was comprised of two structures of HV total exclusion and HV partial inclusion in the crystal lamellae. For P（HB-co-HV） with higher HV content, it was also comprised of two structures of HV total inclusion and HV partial inclusion in the crystal lamellae. However, only structure with HV partial inclusion in the crystal lamellae remained existing after first melting peak for all samples.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,51972178 and 52072041)the Natural Science Foundation of Zhejiang Province(ZJNSF,LY20E030003)+2 种基金the Science and Technology Project of Jiangsu Province(BE2020111)the National Key R&D Project from Minister of Science and Technology in China(2016YFA0202701)the University of Chinese Academy of Sciences(Y8540XX2D2)。
文摘Conductive polymers as one of the candidate materials with pseudocapacitor behavior have inspired wide attentions,because of their high conductivity,fexibility,low cost and excellent processability.However,the intrinsically poor cycling stability induced by the volume change over the doping/dedoping redox process limits their practical applications.Herein,we report the exploration of electrodes with robust cycling capacity for supercapacitors(SCs),which are rationally designed by coating conductive poly(3,4-ethylenedioxythiophene)(PEDOT)around free-standing SiC nanowires using an all-dry oxidative chemical vaper deposition(oCVD)method.The as-constructed SiC@PEDOT nanowire architecture enables a specific capacitance of 26.53 m F/cm^(2)at 0.2 m A/cm^(2),which is~370%to that of SiC nanowire counterpart(7.04 m F/cm^(2)).Moreover,their aqueous-based SCs exhibit robust cycling stability with104%capacity retention after 10000 cycles,which is among the highest values achieved for PEDOTbased SCs.
基金financially supported by the National Natural Science Foundation of China(No.51273210)Natural Science Foundation of Ningbo Municipal(No.2015A610021)K.C.Wong Magna Fund in Ningbo University
文摘The gel-spun ultra-high molecular weight polyethylene （UHMWPE） fibers were prepared at the industrial production line with different gel solution concentrations of 15 wt%, 18 wt% and 24 wt%. The difference in ultimate structure and mechanical properties of UHMWPE fibers for different gel solution concentrations were analyzed by tensile testing, differential scanning calorimetry （DSC）, wide angle X-ray diffraction （WAXD） and small angle X-ray scattering （SAXS）. With the increase of gel solution concentration, the ultimate mechanical properties of UHMWPE fibers were decreased and the crystallization and orientation of UHMWPE fibers became inferior. Besides, both the average shish length （ （Lshsh） ） and shish misorientation （B0） of UHMWPE fibers were decreased with the increase of gel solution concentration. In addition, the appropriate increase of spinning temperature led to the further optimization of the ultimate structure and mechanical properties of UHMWPE fibers.
基金financially supported by the National Natural Science Foundation of China(Nos.21306090 and 51403110)Scientific Research Fund of Zhejiang Provincial Education Department(Nos.Y201430774 and Y201327472)K.C.Wong Magna Fund in Ningbo University
文摘The open-cell structure foams of linear low-density polyethylene（LLDPE） and linear low-density polyethylene（LLDPE）/multi-wall carbon nanotubes（MWCNTs） composites are prepared by using supercritical carbon dioxide（sc-CO2）as a foaming agent. The effects of processing parameters（foaming temperature, saturation pressure, and depressurization rate） and the addition of MWCNTs on the evolution of cell opening are studied systematically. For LLDPE foaming, the foaming temperature and saturation pressure are two key factors for preparing open-cell foams. An increase in temperature and pressure promotes both the cell wall thinning and cell rupture, because a high temperature results in a decrease in the viscosity of the polymer, and a high pressure leads to a larger amount of cell nucleation. Moreover, for the given temperature and pressure, the high pressurization rate results in a high pressure gradient, favoring cell rupture. For LLDPE/MWCNTs foaming, the addition of MWCNTs not only promotes the cell heterogeneous nucleation, but also prevents the cell collapse during cell opening, which is critical to achieve the open-cell structures with small cell size and high cell density.
基金the National Natural Science Foundation of China(22075154,21604044)Natural Science Foundation of Zhejiang Province(LY19B040001)Ningbo Public Welfare Science and Technology Project(2019C50072)。
文摘The interaction between the aggregation-induced emissive(AIE) luminogens(AIEgen) and the polymer is the key scientific question in the design of functional AIE hydrogels. In this study, we report the AIE behavior of a poly(acrylic acid)(PAAc) and poly(acrylamide)(PAAm) interpenetrating network(IPN) hydrogel doped with tetra-cationic tetraphenylethene(TCTPE). The cationic AIEgen can bind with PAAc through ionic interaction, while PAAc and PAAm chains can associate with each other through hydrogen-bonds(H-bonds). These two interactions can restrict the intramolecular rotation and thus activate the luminescence of the AIEgen. The PAAc-PAAm H-bonds can be broken by increasing temperature or p H, restoring the intramolecular rotation of the AIEgen and quenching the fluorescence of the hydrogel. Therefore, the TCTPE-doped IPN hydrogel is designed as temperature-and p H-sensitive displayers which can record information imprinted by photo-printing or iono-printing with good switchability and reversibility. Another application of this TCTPE-doped hydrogel is demonstrated as a luminescent soft actuator, which has fast shape deformation and editable fluorescence pattern. The above results reveal a pathway to tune the emission behavior through tuning polymer-polymer and polymer-AIEgen interactions, which may inspire new design strategies of aggregation-induced emissive polymers and broaden their applications.
基金the National Natural Science Foundation of China(Nos.51773101 and 51973097).
文摘Formation of shish-kebab crystals using a bimodal polyethylene system containing high molecular weight(HMW)component with different ethyl branch contents was investigated.In situ small-angle X-ray scattering(SAXS)and wide-angle X-ray diffraction(WAXD)techniques were used to monitor the formation and evolution of shish-kebab structure sheared at low temperature in simple shear mode and low rate.Only the bimodal PE with no branch formed shish-kebab crystals at the shear temperature of 129℃,and the shish length increased with the crystallization time,while bimodal PE with branch has no observable shish under the same conditions.The degree of crystallization for bimodal PE with no branch increased with time up to above 7%,while those with ethyl branch increased continually up to above 23%.Furthermore,bimodal PE's Hermans orientation factor with no branch increased to 0.60,while those with ethyl branch only increased to a value below 0.15.This study indicated that the shish-kebab crystal formed at the low temperature of 129℃is due to the stretch of entangled chains under shear for the bimodal PE with no branch.Only partly oriented lamellar crystals were formed for the bimodal PE with ethyl branch.All the results at the shear temperatures higher,closed to,and lower than the melting point,the modulation of shish crystals formation owing to different mechanisms of the coil-stretch transition and the stretched network by changing shear temperature was achieved in the bimodal PE samples.
基金financially supported by the National Natural Science Foundation of China(Nos.51273210,51003117 and 5140030545)Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of SciencesK.C.Wong Magna Fund in Ningbo University
文摘Ultra-high molecular weight polyethylene（UHMWPE）/chitin nanocrystal（CNC） fibers were prepared. Compared with the pure UHMWPE fibers, the ultimate tensile strength and Young＇s modulus of UHMWPE/CNC fibers are improved by 15.7% and 49.6%, respectively, with the addition of chitin nanocrystals（CNCs） of 1 wt%. The melting temperature（Tm） of UHMWPE/CNC fibers was higher than that of pure UHMWPE fibers. Pure UHMWPE fibers and UHMWPE/CNC fibers were characterized with respect to crystallinity, orientation and kebab structure by wide-angle X-ray diffraction（WAXD）, small-angle X-ray scattering（SAXS） and scanning electron microscopy（SEM）. It is found that the CNCs act as the shish structure in UHMWPE/CNC fibers and the kebab crystals are grown around the CNCs. There was almost no difference between pure UHMWPE fibers and UHMWPE/CNC fibers in orientation. But the degree of crystallinity of various stages of UHMWPE/CNC fibers was respectively higher than the corresponding stage of pure UHMWPE fibers. Moreover, the addition of 1 wt% CNCs improved the thickness of kebab crystals and accelerated the transformation of kebab to shish.
基金supported by the National Natural Science Foundation of China(No.51273210)the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied ChemistryChinese Academy of Sciences and the K.C.Wong Magna Fund in Ningbo University
文摘Microbeam wide-angle X-ray diffraction（WAXD） experiments were carried out at different structural knot positions of SIOC and M4 fibers of ultra-high molecular weight polyethylene（UHMWPE）. The optical microscope images revealed that SIOC fiber had bamboo-like structural knots, and M4 fiber had chaotic distribution of structural knots. WAXD patterns showed the monoclinic unit cell in the whole M4 fiber, but different lamellar orientations in the bamboo joint of SIOC fiber. In addition, small-angle X-ray scattering（SAXS） patterns confirmed that the SIOC fiber contained uniform distribution of shish structures, and differential scanning calorimetry（DSC） measurements showed that its less branched and short chains benefited the orthorhombic-hexagonal phase transformation.
基金the National Natural Science Foundation of China(Nos.51973097 and 51773101).
文摘The multiple endothermic peaks without observable recrystallization phenomenon of isomorphous poly(3-hydroxybutyrate-co-3-hydroxyvalerate)[P(HB-co-HV)]with the middle HV content of 19.4 mol%and 28.7 mol%were confirmed by differential scanning calorimetry(DSC),and the evolutions of crystal structure and lamellar morphology in the heating and melting process were tracked by in situ synchrotron wide angle X-ray diffraction(WAXD)and small angle X-ray scattering(SAXS)techniques.The emergence of asymmetric features of both the diffraction peaks and scattering curves indicates the coexistence of different lamellar crystals with varied unit cell parameters.Based on the in situ WAXD and SAXS measurements,we calculated the evolutions of the unit cell parameters a and b as well as the long period and lamellar thickness upon heating.The comparative analysis of WAXD and SAXS data confirms that the multiple endothermic peaks of P(HB-co-19.4%HV)and P(HB-co-28.7%HV)result from the melting of different lamellae rather than the melting/recrystallization.The thinner,unstable uniform lamellae with HV counits total inclusion melt first and the thicker,stable sandwich lamellae with HV counits partial inclusion melt last.In addition,the large second melting peak in P(H B-co-19.4%HV),differing from that of samples with HV content of 28.7 mol%and 36.2 mol%,is due to the unique state of HV content leading to a transition of sandwich lamellae to uniform lamellae.The present study establishes the relationship between the different lamellae structure and multiple melting behaviors of isomorphous copolymer.
基金supported by the National Natural Science Foundation of China(51873223 and 22075154)the Natural Science Foundation of Zhejiang Province(LY19B040001)。
文摘Thermo-responsive shape memory hydrogels generally achieve shape fixation at low temperatures,and shape recovery at high temperatures.However,these hydrogels usually suffer from poor mechanical properties.Herein,we present a unique poly(acrylic acid)/calcium acetate shape memory hydrogel with cold-induced shape recovery performances as ultrastrong artificial muscles.Since the acetate groups could form aggregate at high temperatures and thus induce the association of the hydrogel network,the hydrogel can be fixed into a temporary shape upon heating and recover to its original shape in a cold environment.Moreover,a programmable shape recovery process is realized by adjusting the shape fixing time.In addition,the unique shape memory process enables the application demonstration as bio-inspired artificial muscles with an ultrahigh work density of45.2 kJ m^(-3),higher than that of biological muscles(~8 kJ m^(-3)).
基金support of Natural Sclenee Foundation of Zhejiang Province(No.LY19E030002)Ningbo Municipal Science and Technology Bureau(No.2019A610133)K.C.Wong Magna Fund in Ningbo University.
文摘Smart materials with a combination of tough solid-like properties,fast self-healing and optical responsiveness are of interests for the development of new soft machines and wearable electronics.In this work,tough physically cross-linked elastomers that show high mechanical strength,intriguing temperature-adaptable self-healing and fluorochromic response properties are designed using aluminum(Al)and fluorescent europium(Eu)ions as cross-linkers.The ionic Al-COOH binding is incorporated to construct the strong polymer network which mainly contributes to the mechanical robustness of the elastomer consisting of two interpenetrated networks.The Eu-iminodiacetate(IDA)coordination is mainly used to build the weaker but more dynamic network which dominate the elasticity,self-healing and luminescence of the elastomer.Moderate Eu^(3+) and Al^(3+) contents give these supramolecular elastomers high toughness.The temperature-sensitive Eu-IDA coordination enables tunable self-healing rate and efficiency along with fast Eu-centered"ON/OFF"switchable red emission.The mechanical,self-healing and luminescence properties of these elastomers can be adjusted by tuning the ratio of the two types of metal ions.This elastomer is potentially applicable for biosensors,wearable optoelectronics and anticounterfeiting materials.
基金financially supported by Natural Science Foundation of Zhejiang Province(No.LY15B040003)K.C.Wong Magna Fund in Ningbo University
文摘The multiple endothermic peaks of poly（3-hydroxybutyrate-co-3-hydroxyvalerate） （P（HB-co-HV）） in differential scanning calorimetry （DSC） results, as one representative phenomenon of polymer with unique cocrystallization behavior, were generally considered as the results of melting/recrystallization. In this study, wide angle X-ray diffraction （WAXD） and small angle X-ray scattering （SAXS） experiments were conducted to analyze the phenomena of multiple endothermic peaks in DSC results. The results of these analyses indicated that the multiple endotherms were mainly caused by different lamellae structures. For P（HB-co-HV） with lower HV content, it was comprised of two structures of HV total exclusion and HV partial inclusion in the crystal lamellae. For P（HB-co-HV） with higher HV content, it was also comprised of two structures of HV total inclusion and HV partial inclusion in the crystal lamellae. However, only structure with HV partial inclusion in the crystal lamellae remained existing after first melting peak for all samples.
