The inelastic behavior of thermoplastic polymers may involve shearing and crazing,and both depend on temperature and strain rate.Traditional constitutive models account for temperature and strain rate through phenomen...The inelastic behavior of thermoplastic polymers may involve shearing and crazing,and both depend on temperature and strain rate.Traditional constitutive models account for temperature and strain rate through phenomenological or empirical formulas.In this study,we present a physics-guided machine learning(ML)framework to model shear and craze in polymeric materials.The effects of all three principal stresses for the craze initiation are considered other than the maximum tensile principal stress solely in previous works.We implemented a finite element framework through a user-defined material subroutine and applied the constitutive model to the deformation in three polymers(PLA 4060D,PLA 3051D,and HIPS).The result shows that our ML-based model can predict the stress-strain and volume-strain responses at different strain rates with high accuracy.Notably,the ML-based approach needs no assumptions about yield criteria or hardening laws.This work highlights the potential of hybrid physics-ML paradigms to overcome the trade-offs between model complexity and accuracy in polymer mechanics,paving the way for computationally efficient and generalizable constitutive models for thermoplastic materials.展开更多
To address the challenges of poor surface quality and high energy consumption in marble cutting,this study introduces an auxiliary abrasive jet cutting technology enhanced by the use of polyacrylamide(PAM)as a dragred...To address the challenges of poor surface quality and high energy consumption in marble cutting,this study introduces an auxiliary abrasive jet cutting technology enhanced by the use of polyacrylamide(PAM)as a dragreducing additive.The effects of feed rate(50-300 mm/min),polymer concentration(0-0.5 g/L),and nozzle spacing(4-12 mm)on kerf width and surface roughness are systematically investigated through an orthogonal experimental design.Results reveal that feed rate emerges as themost significant factor(p<0.01),followed by PAM concentration and nozzle spacing.The optimal set of parameters,comprising a 200 mm/min feed rate,0.3 g/L PAM concentration,and 6mmnozzle spacing,achieves the narrowest kerf width(0.867 mm)and the lowest surface roughness(10.220μm).Analysis of the underlying mechanisms demonstrates that PAMenhances the energy efficiency of the jet by suppressing turbulent pulsations and increasing fluid viscoelasticity,thereby minimizing energy loss during the cutting process.展开更多
Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a ...Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a sealant,coupled with an air seepage evaluation model that incorporates Knudsen diffusion.Moreover,the initial coating application methods were outlined,and the advantages of using NOSP compared to other sealing materials,particularly regarding cost and construction techniques,were also examined and discussed.Experimental results indicated a significant reduction in permeability of rock specimens coated with a 7–10μm thick NOSP layer.Specifically,under a 0.5 MPa pulse pressure,the permeability decreased to less than 1 n D,and under a 4 MPa pulse pressure,it ranged between4.5×10^(-6)–5.5×10^(-6)m D,marking a 75%–80%decrease in granite permeability.The sealing efficacy of NOSP surpasses concrete and is comparable to rubber materials.The optimal viscosity for application lies between 95 and 105 KU,and the coating thickness should ideally range from 7 to 10μm,applied to substrates with less than 3%porosity.This study provides new insights into air transport and sealing mechanisms at the pore level,proposing NOSP as a cost-effective and simplified solution for CAES applications.展开更多
Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinica...Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinical practice.However, esophageal stents of different types and parameters have varying adaptability and effectiveness forpatients, and they need to be individually selected according to the patient’s specific situation. The purposeof this study was to provide a reference for clinical doctors to choose suitable esophageal stents. We used 3Dprinting technology to fabricate esophageal stents with different ratios of thermoplastic polyurethane (TPU)/(Poly-ε-caprolactone) PCL polymer, and established an artificial neural network model that could predict the radial forceof esophageal stents based on the content of TPU, PCL and print parameter. We selected three optimal ratios formechanical performance tests and evaluated the biomechanical effects of different ratios of stents on esophagealimplantation, swallowing, and stent migration processes through finite element numerical simulation and in vitrosimulation tests. The results showed that different ratios of polymer stents had different mechanical properties,affecting the effectiveness of stent expansion treatment and the possibility of postoperative complications of stentimplantation.展开更多
This paper describes the sodium storage mechanism of hard carbon,including the insertion-adsorption model,adsorption-insertion model,adsorption-filling model,and adsorption-insertion-filling model.The research progres...This paper describes the sodium storage mechanism of hard carbon,including the insertion-adsorption model,adsorption-insertion model,adsorption-filling model,and adsorption-insertion-filling model.The research progress of hard carbon prepared by synthetic polymers in recent years is reviewed.The modification strategies of morphology and structure regulation,surface engineering,defect engineering,heteroatom doping,and pretreatment are proposed to improve the electrochemical performance of hard carbon materials and promote the research and development of hard carbon as anode materials for sodium-ion batteries.展开更多
The conduct mechanism of the doped polymer is considered. In an asymmetrysystem composed of high polymer and doping conductive matte, chain or congeries framework will beformed between the conductive particles to impr...The conduct mechanism of the doped polymer is considered. In an asymmetrysystem composed of high polymer and doping conductive matte, chain or congeries framework will beformed between the conductive particles to improve the conductance characteristic. In thisprocession, the conductive particles interact to each other. In this paper, we describe theconductance of the doped polymer by Monte Carlo method. The results accord with the experimentsquite well. It can be concluded that there is an evident change of doped polymer from nonconductorto metal.展开更多
The polymer translocation through a nanopore from a donor space(or named cis side) to a receiver space(trans side) in the chaperone-induced crowded environment has attracted increasing attention in recent years due to...The polymer translocation through a nanopore from a donor space(or named cis side) to a receiver space(trans side) in the chaperone-induced crowded environment has attracted increasing attention in recent years due to its significance in biological systems and technological applications. In this work, we mainly focus on the effects of chaperone concentration and chaperone-polymer interaction on the polymer translocation. By assuming the polymer translocation to be a quasi-equilibrium process, the free energy F of the polymer can be estimated by Rosenbluth-Rosenbluth method and then the translocation time τ can be calculated by Fokker-Plank equation based on the obtained free energy landscape. Our calculation results show that the translocation time can be controlled by independently tuning the chaperone concentration and chaperone-polymer interaction at the cis side or the trans side. There exists a critical chaperone-polymer attraction ε~*=-0.2 at which the volume exclusion and interaction effects of the chaperone can balance each other. Additionally, we also find that at large chaperone-polymer attraction, the translocation time is mainly governed by the diffusion coefficient of the polymer.展开更多
Zinc-based batteries(ZBs)have been deemed as a potential substitute for lithium-ion batteries due to its unique advantages of abundant resources,low cost and acceptable energy density.Despite great progress in designi...Zinc-based batteries(ZBs)have been deemed as a potential substitute for lithium-ion batteries due to its unique advantages of abundant resources,low cost and acceptable energy density.Despite great progress in designing electrode materials has been made,the development of high-performance ZBs still remain challenges,such as the dendrite growth of zinc anode,hydrogen evolution reaction,limited electrochemical stability window,water evaporation and liquid leakage.Gel polymer electrolytes(GPEs),including hydrous GPEs with low content of active water and anhydrous GPEs without the presence of water,are proposed to avoid these problems.Furthermore,employing GPEs is conductive to fabricate flexible devices owing to the good mechanical strength.To date,most of researches focus on discovering new GPEs and exploring its application on flexible or wearable devices.Recent reviews also have outlined the polymer matrixes and advances of GPEs in various battery systems.Given this,herein,we seek to summarize the gelation mechanisms of GPEs,involving physical gel of polymer,chemical crosslinking of polymer and chemical polymerization of monomers.Peculiarly,the preparation methods are also classified.In addition,not only the features and central conundrum of GPEs are analyzed but also the corresponding strategies are discussed,contributing to design GPEs with ideal properties for high-performance ZBs.展开更多
Polymer electrolyte fuel cells(PEFCs)being employed in fuel cell electric vehicles(FCEVs)are promising power generators producing electric power from fuel stream via porous electrodes.Structure of carbon paper gas dif...Polymer electrolyte fuel cells(PEFCs)being employed in fuel cell electric vehicles(FCEVs)are promising power generators producing electric power from fuel stream via porous electrodes.Structure of carbon paper gas diffusion layers(GDLs)applying in the porous electrodes can greatly affect the PEFC performance,especially at the cathode side where electrochemical reaction is more sluggish.To discover the role of carbon paper GDL structure on the mass transfer properties,different cathode electrodes with dissimilar structural parameters are simulated via lattice Boltzmann method(LBM).3D contours of oxygen and water vapor concentration through the GDL as well as the 2D contours of current density on the catalyst layer are illustrated and examined.The results indicate that the carbon fiber diameter has a negligible impact on the current density while the impact of carbon paper thickness and porosity is significant.In fact,increasing of carbon paper thickness or porosity leads to lack of cell performance.展开更多
Several methods for investigating the thickness uniformity of polymer thin films are presented as well as their measurement principles. A comparison of these experimental methods is given.The cylindrical lightwave ref...Several methods for investigating the thickness uniformity of polymer thin films are presented as well as their measurement principles. A comparison of these experimental methods is given.The cylindrical lightwave reflection method is found to can obtain the thickness distribution along a certain direction.It is a simple and suitable method to evaluate the film thickness uniformity.展开更多
It is found that there is a linear relationship between log P-w, and the parameter term V-f/0.5 E(coh) [1+(delta(w) - delta(p))(2)/delta(p)(2), from the water permeability (P-w) data of 21 polymers covering 4 orders o...It is found that there is a linear relationship between log P-w, and the parameter term V-f/0.5 E(coh) [1+(delta(w) - delta(p))(2)/delta(p)(2), from the water permeability (P-w) data of 21 polymers covering 4 orders of magnitude. This correlation may be useful in choosing membrane materials for dehumidification of gases.展开更多
Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC...Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail.展开更多
During the course of study, we found that both poly (N-isopropylacrylamide ) (PNIP) and PNIP-Ab (enzyme-labelled antibody)could be adhere tightly to a cellulose acetale-nitrate membrane, and that the retention of PNI...During the course of study, we found that both poly (N-isopropylacrylamide ) (PNIP) and PNIP-Ab (enzyme-labelled antibody)could be adhere tightly to a cellulose acetale-nitrate membrane, and that the retention of PNIP-Ab on the membrane increased over 30-fold when compared with the unconjugated Ab.Thus we used this characteristic to develop a novel immunoassay method-polymer enzyme linked immunoassay method: homogeneous antigen-antibody reaction and heterogeneous separation process. When applied for detection of human serum HBsAg, this immunoassay system can detect as little as 1 ng/ml of human serum HBsAg.展开更多
To develop the green polymeric membrane electrolyte,-Polycaprolactone(PCL)was used as a host and the Ionic liquid(IL)(1-Ethyl-3-methylimidazolium tosylate)as a dopant.The IL is a source of mobile charges in the polyme...To develop the green polymeric membrane electrolyte,-Polycaprolactone(PCL)was used as a host and the Ionic liquid(IL)(1-Ethyl-3-methylimidazolium tosylate)as a dopant.The IL is a source of mobile charges in the polymer electrolyte system.The composite membrane has been prepared by Hot Press method and then we characterised this membrane for ionic transportation.Formation of nanocomposite system has been ascertained from their XRD pattern.Interaction phenomenon was studied by ATR based FTIR and Laser Raman spectroscopic technique.Variation of conductivity with composition and temperature was studied with the aid of impedance spectroscopy data.展开更多
In today's education and teaching reform,the traditional teaching method in the teaching of polymer materials has been gradually replaced with various new teaching methods.Among them,the case analysis method is a ...In today's education and teaching reform,the traditional teaching method in the teaching of polymer materials has been gradually replaced with various new teaching methods.Among them,the case analysis method is a very efective teaching method,which has been applied to the teaching of polymer materials.Through example-based teaching,students 125 participation can be effectively improved,and their theoretical knowledge can be fully utilized.This would have a positive role in promoting the improvement of students'knowledge system and their learning ability.In regard to this,this article analyzes the application of case analysis in the teaching of polymer materials so as to improve its efficiency and quality.展开更多
The irrationality of existing phase field model is analyzed and a modified phase-field model is proposed for polymer crystal growth, in which the parameters are obtained from real materials and very simple to use, and...The irrationality of existing phase field model is analyzed and a modified phase-field model is proposed for polymer crystal growth, in which the parameters are obtained from real materials and very simple to use, and most importantly, no paradoxical parameters appeared in the model. Moreover, it can simulate different microstructure patterns owing to the use of a new different free energy function for the simulation of morphologies of polymer. The new free energy function considers both the cases of T〈Tm and T≥Tm, which is more reasonable than that in published literatures that all ignored the T≥Tm case. In order to show the validity of the modified model, the finite difference method is used to solve the model and different crystallization morphologies during the solidification process of isotactic polystyrene are obtained under different conditions. Numerical results show that the growth rate of the initial secondary arms is obviously increased as the anisotropy strength increases. But the anisotropy strength seems to have no apparent effect on the global growth rate. The whole growth process of the dendrite depends mainly upon the latent heat and the latent heat has a direct effect on the tip radius and tip velocity of side branches.展开更多
The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographer...The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency.展开更多
Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural div...Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes,a number of 3DGCP composites with novel structures and attractive performance have been developed.Particularly,the hierarchical porosity,the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods,which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites.In this short review,we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance.The challenges and future opportunities are also discussed for promotion of further study.展开更多
Recently, polymers with aggregation-induced emission(AIE) effects have attracted significant attention due to their broad applications in luminescence sensors, stimuli responsive materials, electroluminescence devices...Recently, polymers with aggregation-induced emission(AIE) effects have attracted significant attention due to their broad applications in luminescence sensors, stimuli responsive materials, electroluminescence devices, etc. In this review, we summarize recent advances concerning AIE polymers. Four types of AIE polymers including end-functionalized polymers, side-chain polymers, main-chain polymers, and other polymers according to the location of AIEgens, are described. Their synthetic preparation, optical property, AIE effects, and applications are also illustrated in this review.展开更多
With the rapid development of electronic information technology,antenna systems in the fields of aviation,aerospace,transportation,and 5 G communication services are becoming more and more intensive and accurate.Polym...With the rapid development of electronic information technology,antenna systems in the fields of aviation,aerospace,transportation,and 5 G communication services are becoming more and more intensive and accurate.Polymer matrix wave-transparent composites with lightweight,low dielectric constant(∈)and dielectric loss tangent(tanδ),high temperature resistance,and excellent mechanical properties are urgently needed in order to ensure high-fidelity transmission of electromagnetic wave and protect antenna systems from external interference.This review introduces the wave transmission mechanism,key compositions(polymer matrix&reinforced fibers),and several typical testing methods for dielectric properties of polymer matrix wave-transparent composites,mainly elaborates the latest research progress and achievements of polymer matrix wave-transparent composites from polymer matrix,reinforced fibers and their surface functionalization methods,and presents the key scientific and technical problems that need to be solved urgently in the application of polymer matrix wave-transparent composites in the antenna systems.Finally,the future development trends and application prospects of the polymer matrix wave-transparent composites are also proposed.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)Excellent Research Group Program for“Multiscale Problems in Nonlinear Mechanics”(Grant No.12588201)。
文摘The inelastic behavior of thermoplastic polymers may involve shearing and crazing,and both depend on temperature and strain rate.Traditional constitutive models account for temperature and strain rate through phenomenological or empirical formulas.In this study,we present a physics-guided machine learning(ML)framework to model shear and craze in polymeric materials.The effects of all three principal stresses for the craze initiation are considered other than the maximum tensile principal stress solely in previous works.We implemented a finite element framework through a user-defined material subroutine and applied the constitutive model to the deformation in three polymers(PLA 4060D,PLA 3051D,and HIPS).The result shows that our ML-based model can predict the stress-strain and volume-strain responses at different strain rates with high accuracy.Notably,the ML-based approach needs no assumptions about yield criteria or hardening laws.This work highlights the potential of hybrid physics-ML paradigms to overcome the trade-offs between model complexity and accuracy in polymer mechanics,paving the way for computationally efficient and generalizable constitutive models for thermoplastic materials.
基金supported by the National Natural Science Foundation of China(grant number:52006061)the Key R&D Program of Hunan Province(grant number:2024AQ2001)+2 种基金Scientific Research Program of Hunan Provincial Department of Education(grant number:22B0840)Natural Science Foundation of Hunan Province(grant number:2023JJ50483)Hunan University of Humanities,Science and Technology Graduate Student Research and Innovation Program(ZSCX2024Y06,ZSCX2024Y01).
文摘To address the challenges of poor surface quality and high energy consumption in marble cutting,this study introduces an auxiliary abrasive jet cutting technology enhanced by the use of polyacrylamide(PAM)as a dragreducing additive.The effects of feed rate(50-300 mm/min),polymer concentration(0-0.5 g/L),and nozzle spacing(4-12 mm)on kerf width and surface roughness are systematically investigated through an orthogonal experimental design.Results reveal that feed rate emerges as themost significant factor(p<0.01),followed by PAM concentration and nozzle spacing.The optimal set of parameters,comprising a 200 mm/min feed rate,0.3 g/L PAM concentration,and 6mmnozzle spacing,achieves the narrowest kerf width(0.867 mm)and the lowest surface roughness(10.220μm).Analysis of the underlying mechanisms demonstrates that PAMenhances the energy efficiency of the jet by suppressing turbulent pulsations and increasing fluid viscoelasticity,thereby minimizing energy loss during the cutting process.
基金supported by the National Natural Science Foundation of China(No.42272321)Hubei Provincial Key Research Projects(Nos.2022BAA093 and 2022BAD163)+1 种基金Major Scientific and Technological Special Project of Jiangxi Province(No.2023ACG01004)WSGRI Engineering&Surveying Incorporation Limited(No.6120230256)。
文摘Enhancing cavern sealing is crucial for improving the efficiency of compressed air energy storage(CAES)in hard rock formations.This study introduced a novel approach using a nano-grade organosilicon polymer(NOSP)as a sealant,coupled with an air seepage evaluation model that incorporates Knudsen diffusion.Moreover,the initial coating application methods were outlined,and the advantages of using NOSP compared to other sealing materials,particularly regarding cost and construction techniques,were also examined and discussed.Experimental results indicated a significant reduction in permeability of rock specimens coated with a 7–10μm thick NOSP layer.Specifically,under a 0.5 MPa pulse pressure,the permeability decreased to less than 1 n D,and under a 4 MPa pulse pressure,it ranged between4.5×10^(-6)–5.5×10^(-6)m D,marking a 75%–80%decrease in granite permeability.The sealing efficacy of NOSP surpasses concrete and is comparable to rubber materials.The optimal viscosity for application lies between 95 and 105 KU,and the coating thickness should ideally range from 7 to 10μm,applied to substrates with less than 3%porosity.This study provides new insights into air transport and sealing mechanisms at the pore level,proposing NOSP as a cost-effective and simplified solution for CAES applications.
基金Nanning Technology and Innovation Special Program(20204122)and Research Grant for 100 Talents of Guangxi Plan.
文摘Esophageal disease is a common disorder of the digestive system that can severely affect the quality of life andprognosis of patients. Esophageal stenting is an effective treatment that has been widely used in clinical practice.However, esophageal stents of different types and parameters have varying adaptability and effectiveness forpatients, and they need to be individually selected according to the patient’s specific situation. The purposeof this study was to provide a reference for clinical doctors to choose suitable esophageal stents. We used 3Dprinting technology to fabricate esophageal stents with different ratios of thermoplastic polyurethane (TPU)/(Poly-ε-caprolactone) PCL polymer, and established an artificial neural network model that could predict the radial forceof esophageal stents based on the content of TPU, PCL and print parameter. We selected three optimal ratios formechanical performance tests and evaluated the biomechanical effects of different ratios of stents on esophagealimplantation, swallowing, and stent migration processes through finite element numerical simulation and in vitrosimulation tests. The results showed that different ratios of polymer stents had different mechanical properties,affecting the effectiveness of stent expansion treatment and the possibility of postoperative complications of stentimplantation.
基金supported by the Guangdong University of Technology Hundred Talents Program(220418136).
文摘This paper describes the sodium storage mechanism of hard carbon,including the insertion-adsorption model,adsorption-insertion model,adsorption-filling model,and adsorption-insertion-filling model.The research progress of hard carbon prepared by synthetic polymers in recent years is reviewed.The modification strategies of morphology and structure regulation,surface engineering,defect engineering,heteroatom doping,and pretreatment are proposed to improve the electrochemical performance of hard carbon materials and promote the research and development of hard carbon as anode materials for sodium-ion batteries.
文摘The conduct mechanism of the doped polymer is considered. In an asymmetrysystem composed of high polymer and doping conductive matte, chain or congeries framework will beformed between the conductive particles to improve the conductance characteristic. In thisprocession, the conductive particles interact to each other. In this paper, we describe theconductance of the doped polymer by Monte Carlo method. The results accord with the experimentsquite well. It can be concluded that there is an evident change of doped polymer from nonconductorto metal.
基金financially supported by the National Natural Science Foundation of China (Nos.11704333 and 20904047)the Natural Science Foundation of Zhejiang Province (Nos.LY17A040001 and LY19F030004)。
文摘The polymer translocation through a nanopore from a donor space(or named cis side) to a receiver space(trans side) in the chaperone-induced crowded environment has attracted increasing attention in recent years due to its significance in biological systems and technological applications. In this work, we mainly focus on the effects of chaperone concentration and chaperone-polymer interaction on the polymer translocation. By assuming the polymer translocation to be a quasi-equilibrium process, the free energy F of the polymer can be estimated by Rosenbluth-Rosenbluth method and then the translocation time τ can be calculated by Fokker-Plank equation based on the obtained free energy landscape. Our calculation results show that the translocation time can be controlled by independently tuning the chaperone concentration and chaperone-polymer interaction at the cis side or the trans side. There exists a critical chaperone-polymer attraction ε~*=-0.2 at which the volume exclusion and interaction effects of the chaperone can balance each other. Additionally, we also find that at large chaperone-polymer attraction, the translocation time is mainly governed by the diffusion coefficient of the polymer.
基金supported by the Natural Science Foundation of Henan Province(No.222300420511)Science and Technology Research Project of Henan Province(No.212102210462).
文摘Zinc-based batteries(ZBs)have been deemed as a potential substitute for lithium-ion batteries due to its unique advantages of abundant resources,low cost and acceptable energy density.Despite great progress in designing electrode materials has been made,the development of high-performance ZBs still remain challenges,such as the dendrite growth of zinc anode,hydrogen evolution reaction,limited electrochemical stability window,water evaporation and liquid leakage.Gel polymer electrolytes(GPEs),including hydrous GPEs with low content of active water and anhydrous GPEs without the presence of water,are proposed to avoid these problems.Furthermore,employing GPEs is conductive to fabricate flexible devices owing to the good mechanical strength.To date,most of researches focus on discovering new GPEs and exploring its application on flexible or wearable devices.Recent reviews also have outlined the polymer matrixes and advances of GPEs in various battery systems.Given this,herein,we seek to summarize the gelation mechanisms of GPEs,involving physical gel of polymer,chemical crosslinking of polymer and chemical polymerization of monomers.Peculiarly,the preparation methods are also classified.In addition,not only the features and central conundrum of GPEs are analyzed but also the corresponding strategies are discussed,contributing to design GPEs with ideal properties for high-performance ZBs.
文摘Polymer electrolyte fuel cells(PEFCs)being employed in fuel cell electric vehicles(FCEVs)are promising power generators producing electric power from fuel stream via porous electrodes.Structure of carbon paper gas diffusion layers(GDLs)applying in the porous electrodes can greatly affect the PEFC performance,especially at the cathode side where electrochemical reaction is more sluggish.To discover the role of carbon paper GDL structure on the mass transfer properties,different cathode electrodes with dissimilar structural parameters are simulated via lattice Boltzmann method(LBM).3D contours of oxygen and water vapor concentration through the GDL as well as the 2D contours of current density on the catalyst layer are illustrated and examined.The results indicate that the carbon fiber diameter has a negligible impact on the current density while the impact of carbon paper thickness and porosity is significant.In fact,increasing of carbon paper thickness or porosity leads to lack of cell performance.
文摘Several methods for investigating the thickness uniformity of polymer thin films are presented as well as their measurement principles. A comparison of these experimental methods is given.The cylindrical lightwave reflection method is found to can obtain the thickness distribution along a certain direction.It is a simple and suitable method to evaluate the film thickness uniformity.
基金This work was supported by the National Natural Science Foundation of China
文摘It is found that there is a linear relationship between log P-w, and the parameter term V-f/0.5 E(coh) [1+(delta(w) - delta(p))(2)/delta(p)(2), from the water permeability (P-w) data of 21 polymers covering 4 orders of magnitude. This correlation may be useful in choosing membrane materials for dehumidification of gases.
文摘Method of VSC (Voltage Shorted Compaction)can be used to determine the intrinsic temperature dependence ofconductivity ofpolycrystalline compaction. The experimental conditions and technical key for preparation of VSC device and its physical model as well as its applications in conducting polymers are discussed in detail.
文摘During the course of study, we found that both poly (N-isopropylacrylamide ) (PNIP) and PNIP-Ab (enzyme-labelled antibody)could be adhere tightly to a cellulose acetale-nitrate membrane, and that the retention of PNIP-Ab on the membrane increased over 30-fold when compared with the unconjugated Ab.Thus we used this characteristic to develop a novel immunoassay method-polymer enzyme linked immunoassay method: homogeneous antigen-antibody reaction and heterogeneous separation process. When applied for detection of human serum HBsAg, this immunoassay system can detect as little as 1 ng/ml of human serum HBsAg.
文摘To develop the green polymeric membrane electrolyte,-Polycaprolactone(PCL)was used as a host and the Ionic liquid(IL)(1-Ethyl-3-methylimidazolium tosylate)as a dopant.The IL is a source of mobile charges in the polymer electrolyte system.The composite membrane has been prepared by Hot Press method and then we characterised this membrane for ionic transportation.Formation of nanocomposite system has been ascertained from their XRD pattern.Interaction phenomenon was studied by ATR based FTIR and Laser Raman spectroscopic technique.Variation of conductivity with composition and temperature was studied with the aid of impedance spectroscopy data.
文摘In today's education and teaching reform,the traditional teaching method in the teaching of polymer materials has been gradually replaced with various new teaching methods.Among them,the case analysis method is a very efective teaching method,which has been applied to the teaching of polymer materials.Through example-based teaching,students 125 participation can be effectively improved,and their theoretical knowledge can be fully utilized.This would have a positive role in promoting the improvement of students'knowledge system and their learning ability.In regard to this,this article analyzes the application of case analysis in the teaching of polymer materials so as to improve its efficiency and quality.
基金This work is supported by the National Natural Science Foundation of China （No.11402210）, the Natural Science Foundation of Shanxi Province （No.2012011019-2）, and the Doctoral Fund of Taiyuan University of Science and Technology （No.20152024）.
文摘The irrationality of existing phase field model is analyzed and a modified phase-field model is proposed for polymer crystal growth, in which the parameters are obtained from real materials and very simple to use, and most importantly, no paradoxical parameters appeared in the model. Moreover, it can simulate different microstructure patterns owing to the use of a new different free energy function for the simulation of morphologies of polymer. The new free energy function considers both the cases of T〈Tm and T≥Tm, which is more reasonable than that in published literatures that all ignored the T≥Tm case. In order to show the validity of the modified model, the finite difference method is used to solve the model and different crystallization morphologies during the solidification process of isotactic polystyrene are obtained under different conditions. Numerical results show that the growth rate of the initial secondary arms is obviously increased as the anisotropy strength increases. But the anisotropy strength seems to have no apparent effect on the global growth rate. The whole growth process of the dendrite depends mainly upon the latent heat and the latent heat has a direct effect on the tip radius and tip velocity of side branches.
文摘The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency.
基金supported by The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(No.TP2015002)the National Natural Science Foundation of China(No.51403099)
文摘Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes,a number of 3DGCP composites with novel structures and attractive performance have been developed.Particularly,the hierarchical porosity,the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods,which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites.In this short review,we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance.The challenges and future opportunities are also discussed for promotion of further study.
基金financially supported by the National Natural Science Foundation of China (Nos. 21776190, 21336005, and 51773144)PAPD in Jiangsu Province
文摘Recently, polymers with aggregation-induced emission(AIE) effects have attracted significant attention due to their broad applications in luminescence sensors, stimuli responsive materials, electroluminescence devices, etc. In this review, we summarize recent advances concerning AIE polymers. Four types of AIE polymers including end-functionalized polymers, side-chain polymers, main-chain polymers, and other polymers according to the location of AIEgens, are described. Their synthetic preparation, optical property, AIE effects, and applications are also illustrated in this review.
基金the support and funding from National Scientific Research Project(Basis Strengthening Plan)Space Supporting Fund from China Aerospace Science and Industry Corporation(2020-HT-XG)+4 种基金Fundamental Research Funds for the Central Universities(310201911qd003)China Postdoctoral Science Foundation(2019M653735)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials from Donghua University(KF2001)Open Fund from Henan University of Science and Technology(2020-RSC02)financially supported by Polymer Electromagnetic Functional Materials Innovation Team of Shaanxi Sanqin Scholars.
文摘With the rapid development of electronic information technology,antenna systems in the fields of aviation,aerospace,transportation,and 5 G communication services are becoming more and more intensive and accurate.Polymer matrix wave-transparent composites with lightweight,low dielectric constant(∈)and dielectric loss tangent(tanδ),high temperature resistance,and excellent mechanical properties are urgently needed in order to ensure high-fidelity transmission of electromagnetic wave and protect antenna systems from external interference.This review introduces the wave transmission mechanism,key compositions(polymer matrix&reinforced fibers),and several typical testing methods for dielectric properties of polymer matrix wave-transparent composites,mainly elaborates the latest research progress and achievements of polymer matrix wave-transparent composites from polymer matrix,reinforced fibers and their surface functionalization methods,and presents the key scientific and technical problems that need to be solved urgently in the application of polymer matrix wave-transparent composites in the antenna systems.Finally,the future development trends and application prospects of the polymer matrix wave-transparent composites are also proposed.
