The molar segment mass, weight-average molar mass, and molar mass distribution of a poly-(ethylene terephthalate)-poly (tetramethylene ether) multiblock copolymer sample were determined by the methods of proton nuclea...The molar segment mass, weight-average molar mass, and molar mass distribution of a poly-(ethylene terephthalate)-poly (tetramethylene ether) multiblock copolymer sample were determined by the methods of proton nuclear magnetic resonance, low angle laser light scattering, and gel permeation chromatography.展开更多
The compositional homogeneity of a poly (ethylene terephthalate)-poly (tetramethylene ether) multiblock copolymer sample with low content of hard segment was examined by GPC, TLC, and solubility method. The copolymer ...The compositional homogeneity of a poly (ethylene terephthalate)-poly (tetramethylene ether) multiblock copolymer sample with low content of hard segment was examined by GPC, TLC, and solubility method. The copolymer sample was found to have a uniform composition as a function of elution volume over the major portion of sample from GPC method. However within one elution fraction, the copolymer chains, although having the same hydrodynamic volume, may have some difference in composition. Two fractions with different composition were obtained by precipitation in ethanol. Some low molar mass copolymers were also separated by a TLC technique from the copolymer sample.展开更多
A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifie...A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifier(TPE/WBG-2/CaCO_(3)).The effects of differentβ-nucleating agents and ternary compound modifier on the mechanical properties and crystallization behavior of PPR were analyzed.The results show that,compared with pure PPR materials,both WBG-2 and TMB-5 could significantly improve the impact strength of PPR.The crystallization temperature of PPR increased with the addition ofβ-nucleating agent.The modified PPR prepared with ternary compound modifier showed the most excellent comprehensive properties.展开更多
Marine biofouling is an urgent global problem in the process of ocean exploitation and utilization.In our work,a series of zinc-based acrylate copolymers(ACZn-x)were designed and synthesized using benzoic acid,zinc ox...Marine biofouling is an urgent global problem in the process of ocean exploitation and utilization.In our work,a series of zinc-based acrylate copolymers(ACZn-x)were designed and synthesized using benzoic acid,zinc oxide(ZnO)and a random quaternion copolymer consisting of ethyl acrylate(EA),butyl acrylate(BA),acrylic acid(AA)and methacrylic acid(MAA)by free radical polymerization and dehydration condensation.The ACZn-x with a zinc benzoate side chain is able to hydrolyze in natural seawater under static conditions,resulting in the formation of a smooth surface.We investigated and confirmed the antifouling(AF)behavior of ACZn-x in the laboratory and revealed that they have better antibacterial(86%for S.aureus and 72%for E.coli)and anti-algal(≥60.1%for N.closterium and≥67.5%for P.subcordiformis)activities.We also assessed the marine AF properties of ACZn-x and corresponding coatings in Qingdao,China;the ACZn-x exhibited ideal AF properties with little silt and biological mucosa adhered to the ACZn-x surface after 6 months,and corresponding coatings exhibited little biofouling after 16 months in the ocean.Importantly,possible AF mechanisms were further proposed at the cellular level.These results could be helpful for the development and application of effective AF coatings.展开更多
The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives ar...The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives are blended as radical scavengers into the active layer.However,it will induce the intrinsic morphology instability and adversely affect the efficiency and long-term stability.Herein,the antioxidant dibutylhydroxytoluene(BHT)group has been covalently linked onto the side chain of benzothiadiazole(BT)unit,and a series of ternary copolymers D18-Cl-BTBHTx(x=0,0.05,0.1,0.2)with varied ratio of BHT-containing side chains have been synthesized.It was found that the introduction of BHT side chains would have a negligible effect on the photophysical properties and electronic levels,and the D18-Cl-BTBHT0.05:Y6-based OSC achieved the highest power conversion efficiency(PCE)of 17.6%,which is higher than those based active layer blended with BHT additives.More importantly,the unencapsulated device based on D18-Cl-BTBHTx(x=0.05,0.1,0.2)retained approximately 50%of the initial PCE over 30 hours operation under ambient conditions,significantly outperforming the control device based on D18-Cl(90%degradation in PCE after 30 h).This work provides a new structural design strategy of copolymers for OSCs with simultaneously improved efficiency and stability.展开更多
Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the unco...Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the uncontrollable solvents in solid electrolytes usually aggravate poor interfacial contact with lithium metal anode and deteriorate Li^(+) pathways.Here a copolymeric network-structured ion conductor by rationally integrating cellulose nanofibril as a two-in-one functional material is employed to anchor the solvent.Taking advantages of tightly anchoring of cellulose nanofibril to solvent,the asconstructed quasi-solid polymer-based electrolyte offers rapid Li^(+) transport channels and realizes effective Li-dendrite suppression,which enables high ionic conductivity of 1.93 × 10^(-3)S cm^(-1) at room temperature,long-term Li plating/stripping over 1900 h,and high capacity retention of 99%.This work provides a fresh strategy for creating solid electrolytes that meet both high ionic conductivity and interfacial stability requirements for practical solid-state lithium metal battery.展开更多
Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a ...Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain.展开更多
文摘The molar segment mass, weight-average molar mass, and molar mass distribution of a poly-(ethylene terephthalate)-poly (tetramethylene ether) multiblock copolymer sample were determined by the methods of proton nuclear magnetic resonance, low angle laser light scattering, and gel permeation chromatography.
文摘The compositional homogeneity of a poly (ethylene terephthalate)-poly (tetramethylene ether) multiblock copolymer sample with low content of hard segment was examined by GPC, TLC, and solubility method. The copolymer sample was found to have a uniform composition as a function of elution volume over the major portion of sample from GPC method. However within one elution fraction, the copolymer chains, although having the same hydrodynamic volume, may have some difference in composition. Two fractions with different composition were obtained by precipitation in ethanol. Some low molar mass copolymers were also separated by a TLC technique from the copolymer sample.
基金Funded by the Natural Science Foundation of Liaoning Province of China(No.20180550432)Natural Science Foundation for Young Doctoral Research(No.2020-BS-158)Basic Scientific Research Project of Colleges and Universities of Liaoning Provincial Department of Education(No.LJKQZ2021060)。
文摘A novel polypropylene random(PPR)composite materials with optimized properties was developed by addingβ-nucleating compound agents(rare earth complex WBG-2 and aryl amide derivative TMB-5)and ternary compound modifier(TPE/WBG-2/CaCO_(3)).The effects of differentβ-nucleating agents and ternary compound modifier on the mechanical properties and crystallization behavior of PPR were analyzed.The results show that,compared with pure PPR materials,both WBG-2 and TMB-5 could significantly improve the impact strength of PPR.The crystallization temperature of PPR increased with the addition ofβ-nucleating agent.The modified PPR prepared with ternary compound modifier showed the most excellent comprehensive properties.
基金supported by the National Key Research and Development Project(No.2019YFC0312101)the Scientific Research Project of Sanya Yazhou Bay Science and Technology City Administration(No.SKJC2020-01-015)the Hainan Provincial Key Research and Development Project(No.ZDYF2021GXJS029)。
文摘Marine biofouling is an urgent global problem in the process of ocean exploitation and utilization.In our work,a series of zinc-based acrylate copolymers(ACZn-x)were designed and synthesized using benzoic acid,zinc oxide(ZnO)and a random quaternion copolymer consisting of ethyl acrylate(EA),butyl acrylate(BA),acrylic acid(AA)and methacrylic acid(MAA)by free radical polymerization and dehydration condensation.The ACZn-x with a zinc benzoate side chain is able to hydrolyze in natural seawater under static conditions,resulting in the formation of a smooth surface.We investigated and confirmed the antifouling(AF)behavior of ACZn-x in the laboratory and revealed that they have better antibacterial(86%for S.aureus and 72%for E.coli)and anti-algal(≥60.1%for N.closterium and≥67.5%for P.subcordiformis)activities.We also assessed the marine AF properties of ACZn-x and corresponding coatings in Qingdao,China;the ACZn-x exhibited ideal AF properties with little silt and biological mucosa adhered to the ACZn-x surface after 6 months,and corresponding coatings exhibited little biofouling after 16 months in the ocean.Importantly,possible AF mechanisms were further proposed at the cellular level.These results could be helpful for the development and application of effective AF coatings.
基金This work was financially supported by National Key Research and Development Program of China(No.2019YFA0705900)funded by MOSTthe Basic and Applied Basic Research Major Program of Guangdong Province(No.2019B030302007)+1 种基金the National Natural Science Foundation of China(No.U21A6002)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(No.2019B121205002).
文摘The stability of organic solar cells(OSCs)remains a major concern for their ultimate industrialization due to the photo,oxygen,and water susceptibility of organic photoactive materials.Usually,antioxidant additives are blended as radical scavengers into the active layer.However,it will induce the intrinsic morphology instability and adversely affect the efficiency and long-term stability.Herein,the antioxidant dibutylhydroxytoluene(BHT)group has been covalently linked onto the side chain of benzothiadiazole(BT)unit,and a series of ternary copolymers D18-Cl-BTBHTx(x=0,0.05,0.1,0.2)with varied ratio of BHT-containing side chains have been synthesized.It was found that the introduction of BHT side chains would have a negligible effect on the photophysical properties and electronic levels,and the D18-Cl-BTBHT0.05:Y6-based OSC achieved the highest power conversion efficiency(PCE)of 17.6%,which is higher than those based active layer blended with BHT additives.More importantly,the unencapsulated device based on D18-Cl-BTBHTx(x=0.05,0.1,0.2)retained approximately 50%of the initial PCE over 30 hours operation under ambient conditions,significantly outperforming the control device based on D18-Cl(90%degradation in PCE after 30 h).This work provides a new structural design strategy of copolymers for OSCs with simultaneously improved efficiency and stability.
基金financial support from the projects of the National Natural Science Foundation of China (52373074 and 51972121)the Independent Research Project of Maoming Laboratory (2022ZD002)。
文摘Solid-state lithium(Li) metal batteries overwhelm the lithium-ion batteries by harvesting high energy from Li metal anode with ultrahigh capacities and gaining excellent safety from solid electrolytes.However,the uncontrollable solvents in solid electrolytes usually aggravate poor interfacial contact with lithium metal anode and deteriorate Li^(+) pathways.Here a copolymeric network-structured ion conductor by rationally integrating cellulose nanofibril as a two-in-one functional material is employed to anchor the solvent.Taking advantages of tightly anchoring of cellulose nanofibril to solvent,the asconstructed quasi-solid polymer-based electrolyte offers rapid Li^(+) transport channels and realizes effective Li-dendrite suppression,which enables high ionic conductivity of 1.93 × 10^(-3)S cm^(-1) at room temperature,long-term Li plating/stripping over 1900 h,and high capacity retention of 99%.This work provides a fresh strategy for creating solid electrolytes that meet both high ionic conductivity and interfacial stability requirements for practical solid-state lithium metal battery.
文摘Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain.
