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High-performance and robust high-temperature polymer electrolyte membranes with moderate microphase separation by implementation of terphenyl-based polymers
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作者 Jinyuan Li Congrong Yang +3 位作者 Haojiang Lin Jicai Huang Suli Wang Gongquan Sun 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第5期572-578,共7页
Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(te... Acid loss and plasticization of phosphoric acid(PA)-doped high-temperature polymer electrolyte membranes(HT-PEMs)are critical limitations to their practical application in fuel cells.To overcome these barriers,poly(terphenyl piperidinium)s constructed from the m-and p-isomers of terphenyl were synthesized to regulate the microstructure of the membrane.Highly rigid p-terphenyl units prompt the formation of moderate PA aggregates,where the ion-pair interaction between piperidinium and biphosphate is reinforced,leading to a reduction in the plasticizing effect.As a result,there are trade-offs between the proton conductivity,mechanical strength,and PA retention of the membranes with varied m/p-isomer ratios.The designed PA-doped PTP-20m membrane exhibits superior ionic conductivity,good mechanical strength,and excellent PA retention over a wide range of temperature(80–160°C)as well as satisfactory resistance to harsh accelerated aging tests.As a result,the membrane presents a desirable combination of performance(1.462 W cm^(-2) under the H_(2)/O_(2)condition,which is 1.5 times higher than that of PBI-based membrane)and durability(300 h at 160°C and 0.2 A cm^(-2))in the fuel cell.The results of this study provide new insights that will guide molecular design from the perspective of microstructure to improve the performance and robustness of HT-PEMs. 展开更多
关键词 Fuel cell High-temperature polymer electrolyte membranes Microphase separation poly(terphenyl piperidinium)s Phosphoric acid
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High-Performance Quasi-Solid-State Pouch Cells Enabled by in situ Solidification of a Novel Polymer Electrolyte 被引量:3
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作者 Qingwen Lu Changhong Wang +9 位作者 Danni Bao Hui Duan Feipeng Zhao Kieran Doyle-Davis Qiang Zhang Rennian Wang Shangqian Zhao Jiantao Wang Huan Huang Xueliang Sun 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第4期15-21,共7页
Conventional lithium-ion batteries(LIBs)with liquid electrolytes are challenged by their big safety concerns,particularly used in electric vehicles.All-solid-state batteries using solid-state electrolytes have been pr... Conventional lithium-ion batteries(LIBs)with liquid electrolytes are challenged by their big safety concerns,particularly used in electric vehicles.All-solid-state batteries using solid-state electrolytes have been proposed to significantly improve safety yet are impeded by poor interfacial solid–solid contact and fast interface degradation.As a compromising strategy,in situ solidification has been proposed in recent years to fabricate quasi-solid-state batteries,which have great advantages in constructing intimate interfaces and cost-effective mass manufacturing.In this work,quasi-solid-state pouch cells with high loading electrodes(≥3 m Ah cm^(-2))were fabricated via in situ solidification of poly(ethylene glycol)diacrylate-based polymer electrolytes(PEGDA-PEs).Both single-layer and multilayer quasi-solid-state pouch cells(2.0 Ah)have demonstrated stable electrochemical performance over500 cycles.The superb electrochemical stability is closely related to the formation of robust and compatible interphase,which successfully inhibits interfacial side reactions and prevents interfacial structural degradation.This work demonstrates that in situ solidification is a facile and cost-effective approach to fabricate quasi-solid-state pouch cells with both excellent electrochemical performance and safety. 展开更多
关键词 high areal capacity high-energy-density pouch cells in situ solidification poly(ethylene glycol)diacrylate-based polymer electrolyte
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Electrochemical Properties of PP13TFSI-LiTFSI-P(VdF-HFP) Ionic Liquid Gel Polymer Electrolytes 被引量:1
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作者 杨培霞 刘磊 +1 位作者 侯俊 张锦秋 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第4期439-444,J0002,共7页
N-Methyl-N-propylpiperidiniumbis(trifluoromethanesulfonyl)imide (PP13TFSI), bis(triflu- oromethanesulfonyl)imide lithium salt (LiTFSI), and poly(vinylidene difluoride-co- hexafluoropropylene) (P(VdF-HFP)... N-Methyl-N-propylpiperidiniumbis(trifluoromethanesulfonyl)imide (PP13TFSI), bis(triflu- oromethanesulfonyl)imide lithium salt (LiTFSI), and poly(vinylidene difluoride-co- hexafluoropropylene) (P(VdF-HFP)) were mixed and made into ionic liquid gel polymer electrolytes (ILGPEs) by solution casting. The morphology of ILGPEs was observed by scanning electron microscopy. It was found that the ILGPE had a loosened structure with liquid phase uniformly distributed. The ionic conductivity, lithium ion transference num- bet and electrochemical window were measured by electrochemical impedance spectroscopy, chronoamperometric and linear sweep voltammetry. The ionic conductivity and lithium ion transference number of this ILGPE reached 0.79 mS/cm and 0.71 at room temperature, and the electrochemical window was 0 to 5.1 V vs. Li+/Li. Battery tests indicated that the ILGPE is stable when being operated in Li/LiFePO4 batteries. The discharge capacity maintained at about 135, 117, and 100 mAh/g at 30, 75, and 150 mA/g rates, respectively. The capacity retentions were almost 100% after 100 cycles without little capacity fading. 展开更多
关键词 Lithium ion battery Ionic liquid polymer electrolyte N-Methyl-N-propylpiperidiniumbis(trifluoromethanesulfonyl)imide poly(vinylidene difluoride-co-hexafluoropropylene)
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Symmetric Ferroelectric Switching in Ferroelectric Vinylidene Fluoride and Trifluoroethylene Copolymer Films
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作者 朱国栋 罗晓雅 +1 位作者 张吉皓 严学俭 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第4期425-430,I0001,共7页
We report the observation of asymmetric switching dual peaks in ferroelectric copolymer films. These dual peaks occurs when the poling electric field is just below the coercive field and can be removed by continuous a... We report the observation of asymmetric switching dual peaks in ferroelectric copolymer films. These dual peaks occurs when the poling electric field is just below the coercive field and can be removed by continuous application of high enough switching voltage. Our experimental observations can be explained by the injection and the redistribution of space charges in ferroelectric films. 展开更多
关键词 Ferroelectric polymer Ferroelectric switching poly(vinylidene fluoride)
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SEMICONDUCTING AND METALLIC POLYMERS:THE FOURTH GENERATION OF POLYMERIC MATERIALS 被引量:45
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作者 AlanJ.Heeger 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2001年第6期545-572,共28页
INTRODUCTIONIn 1976, Alan MacDiarmid, Hideki Shirakawa and I, together with a talented group of graduate students andpost-doctoral researchers discovered conducting polymers and the ability to dope these polymers over... INTRODUCTIONIn 1976, Alan MacDiarmid, Hideki Shirakawa and I, together with a talented group of graduate students andpost-doctoral researchers discovered conducting polymers and the ability to dope these polymers over the fullrange from insulator to metal. This was particularly exciting because it created a new field of research on theboundary between chemistry and condensed matter physics, and because it created a number of opportunities: 展开更多
关键词 poly SEMICONDUCTING AND METALLIC polymerS
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Thermotolerant and fireproof gel polymer electrolyte toward high-performance and safe lithium-ion battery 被引量:8
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作者 Man-Cheng Long Ting Wang +4 位作者 Ping-Hui Duan You Gao Xiu-Li Wang Gang Wu Yu-Zhong Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第2期9-18,共10页
Poly(ethylene oxide)(PEO)and its derivatives based gel polymer electrolytes(GPEs)are severely limited in advanced and safe lithium-ion batteries(LIBs)owing to the intrinsically high flammability of liquid electrolytes... Poly(ethylene oxide)(PEO)and its derivatives based gel polymer electrolytes(GPEs)are severely limited in advanced and safe lithium-ion batteries(LIBs)owing to the intrinsically high flammability of liquid electrolytes and PEO.Directly adding flame retardants to the GPEs can suppress their flammability and thus improve the safety of LIBs,but results in deteriorative electrochemical performance.Herein,a novel GPE with chemically bonded flame retardant(i.e.diethyl vinylphosphonate)in cross-linked polyethylene glycol diacrylate matrix,featuring both high-safety and high-performance,is designed.This as-prepared GPE storing the commercial 1 mol L^(-1) LiPF6 electrolyte resists high temperature of 200℃and cannot be ignited as well as possesses a high ionic conductivity(0.60 m S cm^(-1))and good compatibility with lithium.Notably,the LiFePO_(4)/Li battery with this GPE delivers a satisfactory capacity of 142.2 m A h g^(-1) and a superior cycling performance with a capacity retention of 96.3%and a coulombic efficiency of close to 100%for 350 cycles at 0.2 C under ambient temperature.Furthermore,the battery can achieve steady charge–discharge for 100 cycles with a coulombic efficiency of 99.5%at 1 C under 80℃and run normally even at a high temperature of 150℃or under the exposure to butane flame.Differential scanning calorimetry manifests significantly improved battery safety compared to commercial battery systems.This work provides a new pathway for developing next-generation advanced LIBs with enhanced performance and high safety. 展开更多
关键词 Gel polymer electrolyte poly(ethylene oxide) Flame retardant Vinylphosphonate Lithium-ion batteries
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Preparation and electrochemical properties of polymer Li-ion battery reinforced by non-woven fabric 被引量:9
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作者 胡拥军 陈白珍 袁艳 《Journal of Central South University of Technology》 EI 2007年第1期47-50,共4页
A polymer electrolyte based on poly(vinylidene) fluoride-hexafluoropropylene was prepared by evaporating the solvent of dimethyl formamide, and non-woven fabric was used to reinforce the mechanical strength of polymer... A polymer electrolyte based on poly(vinylidene) fluoride-hexafluoropropylene was prepared by evaporating the solvent of dimethyl formamide, and non-woven fabric was used to reinforce the mechanical strength of polymer electrolyte and maintain a good interfacial property between the polymer electrolyte and electrodes. Polymer lithium batteries were assembled by using LiCoO2 as cathode material and lithium foil as anode material. Scanning electron microscopy, alternating current impedance, linear sweep voltammetry and charge-discharge tests were used to study the properties of polymer membrane and polymer Li-ion batteries. The results show that the technics of preparing polymer electrolyte by directly evaporating solvent is simple. The polymer membrane has rich micro-porous structure on both sides and exhibits 280% uptake of electrolyte solution. The electrochemical stability window of this polymer electrolyte is about 5.5 V, and its ionic conductivity at room temperature reaches 0.151 S/m. The polymer lithium battery displays an initial discharge capacity of 138 mA·h/g and discharge plateau of about 3.9 V at 0.2 current rate. After 30 cycles, its loss of discharge capacity is only 2%. When the battery discharges at 0.5 current rate, the voltage plateau is still 3.7 V. The discharge capacities of 0.5 and 1.0 current rates are 96% and 93% of that of 0.1 current rate, respectively. 展开更多
关键词 polymer electrolyte Li-ion battery poly(vinylidene) fluoride-hexafluoropropylene ionic conductivity
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Comprehensively-modified polymer electrolyte membranes with multifunctional PMIA for highly-stable all-solid-state lithium-ion batteries 被引量:6
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作者 Lehao Liu Jinshan Mo +6 位作者 Jingru Li Jinxin Liu Hejin Yan Jing Lyu Bing Jiang Lihua Chu Meicheng Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第9期334-343,I0010,共11页
Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion condu... Polyethylene oxide(PEO)-based electrolytes have obvious merits such as strong ability to dissolve salts(e.g.,LiTFSI)and high flexibility,but their applications in solid-state batteries is hindered by the low ion conductance and poor mechanical and thermal properties.Herein,poly(m-phenylene isophthalamide)(PMIA)is employed as a multifunctional additive to improve the overall properties of the PEO-based electrolytes.The hydrogen-bond interactions between PMIA and PEO/TFSI-can effectively prevent the PEO crystallization and meanwhile facilitate the LiTFSI dissociation,and thus greatly improve the ionic conductivity(two times that of the pristine electrolyte at room temperature).With the incorporation of the high-strength PMIA with tough amide-benzene backbones,the PMIA/PEO-LiTFSI composite polymer electrolyte(CPE)membranes also show much higher mechanical strength(2.96 MPa),thermostability(4190℃)and interfacial stability against Li dendrites(468 h at 0.10 mA cm-2)than the pristine electrolyte(0.32 MPa,364℃and short circuit after 246 h).Furthermore,the CPE-based LiFePO4/Li cells exhibit superior cycling stability(137 mAh g^-1 with 93%retention after 100 cycles at 0.5 C)and rate performance(123 mAh g^-1 at 1.0 C).This work provides a novel and effective CPE structure design strategy to achieve comprehensively-upgraded electrolytes for promising solid-state battery applications. 展开更多
关键词 poly(m-phenylene isophthalamide) Composite polymer electrolyte Ion conductance Mechanical strength Solid-state battery
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Synthesis of Comblike Poly(methyl methacrylate) by Atom Transfer Radical Polymerization with Poly(ethyl 2-bromoacrylate) as Macroinitiator 被引量:2
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作者 YanSHI ZhiFengFU +1 位作者 YuDongZHANG ShuKeJIAO 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第12期1289-1292,共4页
Comblike poly(methyl methacrylate) was synthesized by atom transfer radical polymerization of methyl methacrylate with poly(ethyl 2-bromoacrylate) as a macroinitiator, which was prepared by conventional free radical p... Comblike poly(methyl methacrylate) was synthesized by atom transfer radical polymerization of methyl methacrylate with poly(ethyl 2-bromoacrylate) as a macroinitiator, which was prepared by conventional free radical polymerization of ethyl 2-bromoacrylate. The obtained comblike polymers were characterized by GPC and 1H NMR. 展开更多
关键词 Comblike polymer atom transfer radical polymerization (ATRP) MACROINITIATOR poly(methyl methacrylate) ethyl 2-bromoacrylate.
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Composition Dependence of the Thermal Behavior,Morphology and Properties of Biodegradable PBS/PTMO Segment Block Copolymer 被引量:6
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作者 黄勇 LIU Junhong +1 位作者 周涛 张爱民 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第1期219-226,共8页
A series of aliphatic biodegradable poly(ether-ester)s based on poly(butylene succinate)(PBS)as hard segment and poly(tetramethylene oxide)(PTMO,M_n=1 000 g/mol) as soft segment were synthesized.The composit... A series of aliphatic biodegradable poly(ether-ester)s based on poly(butylene succinate)(PBS)as hard segment and poly(tetramethylene oxide)(PTMO,M_n=1 000 g/mol) as soft segment were synthesized.The composition dependence of thermal behavior,morphology and mechanical properties was investigated by differential scanning calorimetry(DSC),atomic force microscopy(AFM),and tensile testing.The crystallization temperature(T_c) and melting temperature(T_m) of the PBS block within poly(ether-ester)s decrease steadily at first,but decrease sharply with PTMO content above 50 wt%.Two crystallization peaks were detected for PTMO in PBSPTMO60 sample,suggesting the occurrence of fractionated crystallization.The crystallization enthalpies(△H_c) and melting enthalpies(△H_m) of PBS block decrease at first,then increase as PTMO content increases further.AFM has demonstrated that phase-separated morphology transforms from a phase of continuous hard matrix to one of continuous soft matrix containing isolated hard domain as PTMO content is increased.Finally,the results of tensile testing show that the poly(ether-ester)s present the behavior of plastics when PTMO content is below 40 wt%,and of thermoplastic elastomers with PTMO content above 50 wt%.By varying the composition of copolymer,the aliphatic poly(ether-ester)s plastics,or especially biodegradable aliphatic poly(ether-ester)s thermoplastic elastomers can be obtained. 展开更多
关键词 poly(ether-ester)s poly(butylene succinate) poly(tetramethylene oxide) thermoplastic elastomers biodegradable polymer
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Redox active polymer metal chelates for use in flexible symmetrical supercapacitors:Cobalt-containing poly(acrylic acid)polymer electrolytes 被引量:3
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作者 Emre Cevik Ayhan Bozkurt 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第4期145-153,共9页
The novel polymer metal chelate electrolytes(polychelates)were prepared by incorporation of cobalt sulfate(Co)into poly(acrylic acid)(PAA)host matrix.Quasi-solid state supercapacitor devices were fabricated using poly... The novel polymer metal chelate electrolytes(polychelates)were prepared by incorporation of cobalt sulfate(Co)into poly(acrylic acid)(PAA)host matrix.Quasi-solid state supercapacitor devices were fabricated using polychelates,PAA-Co X(X:3,5,7,and 10)where X represents the doping fraction(w/w)of Co in PAA.All polymer metal electrolytes were showed excellent bending-stretching properties,thermal stability and electrochemical durability with an optimum ionic conductivity of 3.15×10^(-4) S cm^(-1).Hierarchically porous activated carbon and nano-sized conductive carbon were used to form carbon composite symmetrical device electrodes.The electric double-layer capacitor(EDLC)and redox reactions of Co-incorporated polychelates at the interfaces of porous activated carbon provided an optimum specific capacitance of 341.33 F g^(-1) with a device of PAA-Co7,which is at least 15 times enhancement compared to the device of pristine PAA.The PAA-Co7 device also provided energy density of 21.25 Wh kg^(-1) at a power density of 117.69 W kg^(-1).A prolonged cyclic stability of the device exhibited superior capacitive performance after 10,000 charge-discharge cycles and the maintained 90%of its initial performance.In addition,the supercapacitor with a dimension of 1.5 cm×3 cm containing PAA-Co7 successfully operated the red-blue-green(RGB)LED light. 展开更多
关键词 SUPERCAPACITOR Redox active supercapacitor COBALT poly(acrylic acid) polymer electrolyte
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SYNTHESIS,CHARACTERIZATION AND OPTICAL PROPERTIES OF THE COPOLYMERS OF C_(60) AND 1-PHENYL-1-PROPYNE 被引量:2
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作者 唐本忠 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1999年第4期391-395,共5页
While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are ca... While WCl_6-Ph_4Sn fails to polymerize 1-phenyl-1-propyne (PP) at room temperature, highmolecular weight (M_w up to 410× 10~3) polymers are obtained in high yields (up to 80%) when thepolymerizations of PP are carried out in the presence of C_(60) using the W catalyst under the same conditions.The polymers are soluble in common organic solvents such as THF, chloroform, and toluene. Molecularstructures of the polymers are characterized by FT-IR, UV, NMR, GPC and XRD, and it is found that C_(60) iscopolymerized with PP. Thus C_(60) plays the dual roles of comonomer and cocatalyst in the polymerizationreaction. C_(60) contents of the copolymers can be easily changed by varying the C_(60) amounts in the feedmixtures. The copolymers effectively limit strong 532 nm laser pulses, whose limiting performance issuperior to that of parent C_(60). 展开更多
关键词 Substituted polyacetylenes C_(60) poly[C_(60)-co-(1-phenyl-1-propyne)] Fullerene-functionalized polymers
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Enhanced Electrochemical Performance of Poly(ethylene oxide)Composite Polymer Electrolyte via Incorporating Lithiated Covalent Organic Framework 被引量:3
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作者 Yuan Yao Yu Cao +4 位作者 Gang Li Cheng Liu Zhongyi Jiang Fusheng Pan Jie Sun 《Transactions of Tianjin University》 EI CAS 2022年第1期67-72,共6页
The lithiated covalent organic framework(named TpPa-SO_(3) Li),which was prepared by a mild chemical lithiation strategy,was introduced in poly(ethylene oxide)(PEO)to produce the composite polymer electrolytes(CPEs).L... The lithiated covalent organic framework(named TpPa-SO_(3) Li),which was prepared by a mild chemical lithiation strategy,was introduced in poly(ethylene oxide)(PEO)to produce the composite polymer electrolytes(CPEs).Li-ion can transfer along the PEO chain or across the layer of TpPa-SO_(3) Li within the nanochannels,resulting in a high Li-ion conductivity of3.01×10^(-4)S/cm at 60℃.When the CPE with 0.75 wt.%TpPa-SO_(3) Li was used in the LiFePO_(4)‖Li solid-state battery,the cell delivered a stable capacity of 125 mA·h/g after 250 cycles at 0.5 C,60℃.In comparison,the cell using the CPE without TpPa-SO_(3) Li exhibited a capacity of only 118 mA·h/g. 展开更多
关键词 Lithiated covalent organic framework Composite polymer electrolytes poly(ethylene oxide) Solid-state lithium-ion batteries
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The Effect of Polyvinyl Acetate Polymer on Reducing Dust in Arid and Semiarid Areas 被引量:3
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作者 Gholamreza Tadayonfar Narges Shahmiri Mohammad Hassan Bazoobandi 《Open Journal of Ecology》 2016年第4期176-183,共8页
Because the large areas of Iran are on arid and semiarid belt of the world, it has many problems due to windstorms. Wind storms cause dust and haze due to a mass of fine sand or silt soil elevated in the atmosphere. I... Because the large areas of Iran are on arid and semiarid belt of the world, it has many problems due to windstorms. Wind storms cause dust and haze due to a mass of fine sand or silt soil elevated in the atmosphere. It makes heart disease-cardiovascular and respiratory and so is detrimental for the children. These have plagued the residents and so lives of them are disrupted every so often. In this research, the subject soil stabilization using adherence of poly vinyl acetate polymer as a way to reduce the production of dust is defined for prone area. In this paper, the effect of poly vinyl acetate polymer on silt soil has been studied. In this study the samples were uncompacted particles of soil with different amount of water-solvated polymer (0, 5, 10, 15, 20, 25, 30 grams per meter squared) poured over them. These samples are kept in experimental environment for 7 days. After ensuring complete dryness, their stabilities are tested against wind flow with 20 m/s speed. Results showed that adding more polymers to soil would considerably increase its particles’ stabilities. This stability is due to positive reaction of polymer with soil particles. The effect of this stability is maintained during sample drying time in the lab and the soil maintains its characteristics during testing. The best results are obtained for 20 grams polymer per meter squared, where caused an increase in stability to about 15 times that of the soil without polymer. 展开更多
关键词 HAZE poly Vinyl Acetate polymer Arid and Semi-Arid Area Stability against Wind
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Mathematical modeling of drug release from biodegradable polymeric microneedles 被引量:1
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作者 Sarvenaz Chavoshi Mohammad Rabiee +6 位作者 Mehdi Rafizadeh Navid Rabiee Alireza Shahin Shamsabadi Mojtaba Bagherzadeh Reza Salarian Mohammadreza Tahriri Lobat Tayebi 《Bio-Design and Manufacturing》 SCIE CSCD 2019年第2期96-107,共12页
Transdermal drug delivery systems have overcome many limitations of other drug administration routes,such as injection pain and first-pass metabolism following oral route,although transdermal drug delivery systems are... Transdermal drug delivery systems have overcome many limitations of other drug administration routes,such as injection pain and first-pass metabolism following oral route,although transdermal drug delivery systems are limited to drugs with low molecular weight.Hence,new emerging technology allowing high molecular weight drug delivery across the skin—known as‘microneedles’—has been developed,which creates microchannels that facilitate drug delivery.In this report,drug-loaded degradable conic microneedles are modeled to characterize the degradation rate and drug release profile.Since a lot of data are available for polylactic acid-co-glycolic acid(PLGA)degradation in the literature,PLGA of various molecular weights-as a biodegradable polymer in the polyester family-is used for modeling and verification of the drug delivery in themicroneedles.The main reaction occurring during polyester degradation is hydrolysis of steric bonds,leading to molecular weight reduction.The acid produced in the degradation has a catalytic effect on the reaction.Changes in water,acid and steric bond concentrations over time and for different radii of microneedles are investigated.To solve the partial and ordinary differential equations simultaneously,finite difference and Runge–Kutta methods are employed,respectively,with the aid of MATLAB.Correlation of the polymer degradation rate with its molecular weight and molecular weight changes versus time are illustrated.Also,drug diffusivity is related to matrix molecular weight.The molecular weight reduction and accumulative drug release within the system are predicted.In order to validate and assess the proposed model,data series of the hydrolytic degradation of aspirin(180.16 Da)-and albumin(66,000 Da)-loaded PLGA(1:1 molar ratio)are used for comparison.The proposed model is in good agreement with experimental data from the literature.Considering diffusion as themain phenomena and autocatalytic effects in the reaction,the drug release profile is predicted.Based on our results for a microneedle containing drug,we are able to estimate drug release rates before fabrication. 展开更多
关键词 MATHEMATICAL modeling MICRONEEDLE polymer degradation DRUG release poly(lactic-co-glycolic acid) AUTOCATALYTIC effect
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《CHINESE JOURNAL OF POLYMER SCIENCE》VOLUME CONTENTS 被引量:1
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《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1989年第4期383-386,共4页
关键词 VOLUME CONTENTS CHINESE JOURNAL OF polymer SCIENCE poly
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CONTROLLED ANIONIC SYNTHESIS OF FUNCTIONALIZED AND STAR-BRANCHED POLYMERS 被引量:1
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作者 RODERIC P. QUIRK GABRIEL SUMMERS +1 位作者 KIM Jungahn LAUREL E. SCHOCK 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第2期97-107,共11页
The use of living, alkyllithium-initiated anionic polymerization to prepare chain-end functionalized polymers and heteroarm, star-branched polymers is discussed. The scope and limitations of specific termination react... The use of living, alkyllithium-initiated anionic polymerization to prepare chain-end functionalized polymers and heteroarm, star-branched polymers is discussed. The scope and limitations of specific termination reactions with a variety of electrophilic species are illustrated for carbonation, hydroxyethylation, amination, and sulfonation. The methodology of using substituted 1,1-diphenylethylenes to provide a general, quantitative functionalization procedure is outlined and illustrated with examples of amine and phenol end-functionalization. A methodology is described for the synthesis of functionalized, star-branched copolymers with compositionally heterogeneous arms of controlled molecular weight and narrow molecular weight distribution using 1, 3-bis(1-pbenylethenyl) benzene. 展开更多
关键词 poly CONTROLLED ANIONIC SYNTHESIS OF FUNCTIONALIZED AND STAR-BRANCHED polymerS STAR
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Preparation and properties of composite polymer electrolyte modified with nano-size rare earth oxide 被引量:1
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作者 肖围 李新海 +3 位作者 郭华军 王志兴 杨波 吴贤文 《Journal of Central South University》 SCIE EI CAS 2012年第12期3378-3384,共7页
Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) based composite polymer electrolyte (CPE) modified with CeO2, La2O3 and Y2O3 nano-rare earth oxides was prepared by phase inversion technique. Physical... Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) based composite polymer electrolyte (CPE) modified with CeO2, La2O3 and Y2O3 nano-rare earth oxides was prepared by phase inversion technique. Physical and chemical properties of the modified CPEs were studied by SEM, TG-DSC and electrochemical methods. The results show that the CPE modified with 10% La2O3 (mass fraction) has the best practical applicability, which indicates that the thermal and electrochemical stability can reach over 400 ℃ and 4.5 V, respectively, and temperature dependence of ionic conductivity follows Vogel-Tamman-Fulcher (VTF) relationship and ionic conductivity at room temperature is up to 3.3 mS/cm. The interfacial resistance Ri reaches a stable value about 557 Ω after 6 d storage. 展开更多
关键词 poly(vinylidene fluoride-co-hexafluoropropylene) composite polymer electrolyte nano-rare earth oxide lithium ionpolymer battery
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Fabrication of Microspheres Based on Poly(4-butyltriphenylamine) Blends with Poly(methyl methacrylate) and Block Copolymer by Solvent Evaporation Method 被引量:1
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作者 Hossein Taherzadeh Kenji Ogino 《Open Journal of Organic Polymer Materials》 2015年第2期37-42,共6页
Micron-sized polymer particles from single poly(4-butyltriphenylamine) (PBTPA) homopolymer, binary polymer blend [PBTPA/poly(methyl methacrylate) (PMMA)], and ternary polymer blend (PBTPA/PBTPA-b-PMMA/PMMA) via a solv... Micron-sized polymer particles from single poly(4-butyltriphenylamine) (PBTPA) homopolymer, binary polymer blend [PBTPA/poly(methyl methacrylate) (PMMA)], and ternary polymer blend (PBTPA/PBTPA-b-PMMA/PMMA) via a solvent evaporation method, and the surface morphologies and inside structure of resulting particles were investigated. Spherical homopolymer particles with smooth surface were resulted from PBTPA with low molecular weight. In the case of binary blends (PBTPA/PMMA = 1/1), Janus (low molecular weight) and dumbbell (high molecular weight) type morphologies were observed. The particles based on ternary blends containing PBTPA-b-PMMA showed core-shell type morphologies (PMMA;core, PBTPA;shell). Degree of engulfment of PMMArich domain increased with the content of the block copolymer. The decrease of domain size was not observed although the block copolymer had a suitable structure as a compatibilizer for the blend. It was also found that the initial concentration of polymer solution had an effect on the final morphology. 展开更多
关键词 Microsphere Morphology polymer Blend Block Copolymer poly(4-butyltriphenylamine)
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Phosphate Sorption in Water by Several Cationic Polymer Flocculants 被引量:1
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作者 Timothy S. Goebel Robert J. Lascano Todd A. Davis 《Journal of Agricultural Chemistry and Environment》 2016年第1期45-51,共7页
Although inorganic phosphate is an essential plant nutrient, elevated levels in surface waters lead to adverse effects in the environment. These effects are attributed to runoff from rain or irrigation events that may... Although inorganic phosphate is an essential plant nutrient, elevated levels in surface waters lead to adverse effects in the environment. These effects are attributed to runoff from rain or irrigation events that may cause the sorbed phosphate to be transported from the application sites and to move into neighboring watersheds. Increased phosphate concentration in watersheds may lead to a variety of environmental problems including increased algal blooms, bacterial contamination, and in some cases eutrophication. To overcome these effects, polymer flocculants have been shown to reduce the phosphate concentration in water by removing suspended solids and thereby removing the phosphate sorbed to the solids. The purpose of this study is to determine the amount, if any, of phosphate removed by several commercial polymers. The polymers chosen include the polyacrylamides Magnifloc 494C, Magnifloc 985N and Poly (diallyldimethyl ammonium chloride) (Poly (DADMAC)). Using these polymers, it is discovered that the positive charge density of the polymers affects the amount of phosphate removed from solution with Poly (DADMAC) (having 100% positive charge density) removing 40% of the phosphate from a solution containing 10 ppm phosphate. 展开更多
关键词 polymer Flocculants PHOSPHATE SORPTION polyACRYLAMIDES poly (DADMAC) SMECTITE
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