最新刊期
卷 35 ， 期 9 ， 2022
- 摘要：Electrospun nano-medical dressing is an advanced wound dressing. Compared with traditional dressings, it has a loose and porous structure that is highly similar to the human body’s natural extracellular matrix (ECM), which can effectively regulate cell proliferation and accelerate wound closure. It shows great advantages in promoting skin growth and healing. Not only that, studies have shown that loading drugs and biologically active substances in electrospun nanofibers can achieve sustained release. This feature can provide convenient conditions for the growth of damaged tissues within an effective time. The electrospun fiber membrane can significantly improve the healing speed, and can be promoted to clinical applications as a medical dressing with superior performance. Based on the current research, this article briefly introduces the basic principles of electrospinning technology and the characteristics of electrospinning medical dressings. Subsequently, according to the types of electrospun substrates, they were classified into natural electrospun dressings, synthetic electrospun dressings and composite electrospun dressings. The characteristics and antibacterial capabilities of various dressings were discussed in detail. Finally, some problems in the electrospinning process and antibacterial experiments of electrospinning medical dressings at this stage, and prospects for the research of optimized electrospinning dressings for bionic skin are put forward.关键词：Electrospinning;Bioactive material;Dressing;Antibacterial;Wound healing
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发布时间：2022-09-09 - 摘要：Polymer binders as one of the key auxiliary components in lithium batteries have gradually developed from providing bonding function to maintaining the mechanical stability of electrodes to environmentally friendly and efficient multifunctional binders. Acrylic polymers exhibit excellent electrochemical properties due to their adequate polar functional groups, insolubility in organic electrolyte and high chemical and mechanical stability. It can be widely used in different structural parts of lithium batteries. In this review, the recent development and application of acrylic polymer binders in lithium batteries silicon anodes, sulfur cathodes, transition metal salt and oxide anodes, polymer electrolyte and separators modification are introduced, in order to provide references for the research of advanced binders for high performance batteries.关键词：Lithium batteries;Acrylic acid;Binders
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发布时间：2022-09-09 - 摘要：In recent years, with the rapid development of wearable electronic products, flexible sensors have also received more and more attention. Two-dimensional transition metal carbonitrides (MXene) has been widely applied in electromagnetic shielding, biomedical, energy conversion and storage, sensors and other fields because of its good mechanical properties, excellent conductivity and hydrophilicity and other advantages. The structural characteristics and producing methods of MXene and its applications are introduced firstly. Furthermore, the application progress of MXene in the flexible sensors, such as flexible stress/strain sensors, flexible temperature sensors, flexible humidity sensors, and flexible gas sensors, is highlighted and summarized. And the application progress of MXene in the field of flexible sensors is also summarized. Last, that MXene-based flexible sensors will have greater development potential in the future are predicted.关键词：MXene;Two-dimensional materials;Flexible sensors
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发布时间：2022-09-09 - 摘要：In this paper, the cleaning, separation and purification processes of the three waste plastics mixtures for medical non-prohibited, PET bottle and mulching film were studied, and the properties of the purified waste plastics were compared with those of the pure waste plastics. It was found that after sorting, crushing, friction cleaning, water rinsing, drying, rubber separator and air separator, polypropylene (PP) crushing material and polyethylene/polypropylene (PE/ PP) composite material obtained from disposable infusion bottle/bag waste plastic have almost the same performance as the corresponding pure crushing material. The purity of PET crushing material was very high after destandard, crushing, scrubbing, rinsing, detergent hot washing and air separation process. The impurities content of PE broken film was very low after shredding, sand removal, crushing, friction cleaning and other processes.关键词：Infusion bottle/bag;PET bottle;Mulching film;Separation and purification;Flow separation
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发布时间：2022-09-09 - 摘要：It is an important problem that fabricating nano-filter materials with good adsorption and antibacterial properties in the application of nano-fiber membranes in the field of filtration. Among the preparation methods of various fiber and film materials, the electrospinning method has the characteristics of large specific surface area and high porosity, which provides an effective idea for preparing nano-filter materials with adsorption and antibacterial properties. In this study, the nano-silver particles-activated carbon (AgNPs-AC) composite nanofiber membrane was prepared by the electrostatic spinning method, and nano-silver particles were deposited on the activated carbon carrier so that a highperformance filter electrospun composite fiber membrane with good antibacterial adsorption can be prepared. The morphology and structure of the composite nanofibers were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and other equipments. Besides, the adsorption performance and antibacterial properties of the composite fiber membrane were investigated. The results show that the fiber diameter distribution of the prepared AgNPs-AC composite nanofiber membrane gradually tends to be uniform with the increase of activated carbon and silver concentration. Moreover, when the EVOH mass fraction is 10% and the silver nitrate/activated carbon concentration ratio is 0.05/0.085 (g/mL), the composite fiber membrane possesses the best adsorption performance. In addition, the AgNPs-AC composite nanofiber membrane shows good antibacterial properties against Staphylococcus aureus.关键词：Electrospinning;Nanofiber;Adsorptive property;Antimicrobial property;Functional materials
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发布时间：2022-09-09 - 摘要：Using the double replacement reaction, lanthanum nitrate, 6-methyluracil (MUA), and ammonia water were used as raw materials to prepare 6-methyluracil lanthanum (LMUA). The product was characterized by infrared spectroscopy, thermal analysis and elemental analysis. The molecular formula is determined to be La(C5H4N2O2)NO3· 1.5H2O. Through the Congo red experiment, high temperature aging experiment and electrical conductivity experiment, the effect of LMUA on the thermal stability of PVC was studied. The results showed that when LMUA alone was used as a heat stabilizer for PVC, its thermal stability and discoloration resistance performed excellent, the static thermal stability time reached 73min, and the dynamic thermal stability time reached 88min. Combining LMUA and other heat stabilizers for binary, ternary and quaternary compounding, not only the synergy of the product was good, but also the stability was improved. When the composite stabilizer is compounded according to the mass ratio of LMUA∶CaSt2∶pentaerythritol= 3∶1∶1, the static thermal stability interval reaches 88min, and the discoloration resistance and thermal stability are the best. The light stability was analyzed by ultraviolet absorption spectrophotometry, which preliminarily verified that LMUA has light stabilization effect. LMUA can react with the HCl generated during the degradation of PVC to generate LaCl3, which reduces the catalytic effect of HCl on the degradation of PVC, thereby achieving the purpose of enhancing the thermal stability of PVC.关键词：Rare earth;Polyvinyl chloride;Thermal stability;6-Methyluracil lanthanum;Compound
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发布时间：2022-09-09 - 摘要：Cellulase pretreatment has attracted much attention in the preparation of microfibrillated cellulose due to its environmental friendliness. In this study, different concentrations of cellulase and high pressure jet treatment were used to prepare microfibrillated cellulose. The results show that the diameter of cellulose fibrils was decreased from several or tens of microns to tens or hundreds of nanometers and crystal structure was not changed after cellulase pretreatment and high pressure jet treatment. The particle size analysis shows that the cellulose micronizing level based on 1% (w/w ) cellulase pretreatment and high pressure jet treatment is higher. With the increase of enzyme concentration from 0.1% to 0.5%, the viscosity of cellulose aqueous dispersion increased, and the thermal stability and the tensile properties of cellulose films were enhanced. The average tensile strength of the films treated with 0.5% enzyme and high pressure jet treatment is 18.74MPa. The tensile properties of the films treated with 1% cellulase pretreatment and high pressure jet treatment had little change. And the average tensile strength is 18.99MPa, the average elongation at break is 8.74%, and the average elastic modulus is 293.8MPa.关键词：Microfibrillated cellulose;Enzyme pretreatment;High pressure jet;Micronization
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发布时间：2022-09-09 - 摘要：This experiment starts with the preparation of temperature-sensitive hydrogel poly-N-isopropylacrylamide. The content of the experiment not only includes the synthesis process of radical polymerization, but also demonstrates the phase transition of the temperature-sensitive hydrogel through simple and precise temperature control in the laboratory. The process of volume phase change will stimulates students’ interest in experiments. At the same time, nuclear magnetic resonance spectrometer is introduced to characterize the structural changes during the phase change process of the hydrogel at variable temperatures, allowing students to further understand the structural changes behind the volume phase change of the hydrogel, and comprehend the dialectical relationship between its performance and structure. In addition, the latest applications of temperature-sensitive hydrogels in the fields of oil-water separation and sewage treatment are introduced into the experiment, reflecting new ideas and new achievements in the development of hydrogels. Ultimately the fundamental purpose of improving the quality of undergraduate experimental teaching and cultivating high-quality comprehensive talents is achieved.关键词：Temperature-sensitive hydrogel;Poly (N-isopropylacrylamide);Radical polymerization;Phase transition
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发布时间：2022-09-09 - 摘要：The isothermal crystallization experiment of polypropylene is an important item in the teaching of Polymer Physics Experiment. In view of the students' misunderstanding of the experimental results in the course of "observing the growth process of polypropylene spherulites by polarized light microscopy method" , the authors further help students fully understand the differences of crystallization rate in different stages of spherulite growth and the underlying causes by guiding the students to compare the isothermal crystallization process of polypropylene obtained by differential scanning calorimetry with the results of polarized light microscopy experiments. The aim is to enable students to have a more comprehensive and profound understanding of the polymer crystallization process, and to achieve the organic combination of theory and experiment.关键词：Polymer crystallization;Experimental teaching;Polarized light microscopy;Differential scanning calorimetry
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发布时间：2022-09-09 - 摘要：Based on the research work of teachers and the concept of green chemistry, an improved comprehensive chemical experiment project was designed: using microelement method, phytic acid as gel and dopant, ammonium persulfate as oxidant, polyaniline (PANI) electroconductive hydrogel with three-dimensional network structure was prepared, and it had good electrochemical performance. As an undergraduate comprehensive experimental project, the experiment is simple and the product is environment-friendly. While giving students perceptual knowledge, it enhances students' understanding of the preparation, material structure and electrochemical performance characterization of conductive hydrogel materials. The teaching practice shows that it can provide opportunities for undergraduates to contact the frontier of science, improve their ability to comprehensively use professional knowledge, and cultivate their ability to analyze and solve problems.关键词：Polyaniline;Hydrogel;Comprehensive experiment;Electrochemistry
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发布时间：2022-09-09 - 摘要：Differential scanning calorimetry (DSC) is a classical project in the course of polymer physics experiments. The traditional DSC teaching experiment is only to determine the melting point or glass transition temperature of polymer separately. The experiment content is single and lacks systematicness. In this paper, several sets of comprehensive experimental projects, including thermal transition, physical aging, crystallinity measurement and compatibility characterization experiments are designed through the design and expansion of the original experiment content based on the application of DSC in the polymer physics experiments. The setting of the experiments can help students to understand the principle and method of DSC analysis, learn to apply the method to systematically study the molecular movement and transition of polymer, stimulate their enthusiasm for learning, and develop the ability to use relevant knowledge to analyze and solve practical problems.关键词：Differential scanning calorimetry method;Molecular movement and phase transition;Polymer physics experiments
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发布时间：2022-09-09 - 摘要："Microlecture" can transform the knowledge points into lively videos for students, which is conducive to students' in-depth thinking based on rich perceptual knowledge. Anionic living polymerization is an important issue in the teaching of polymer chemistry, and its importance also lies in its close relationship with multiple practical applications. In this paper, a vivid and interesting microlecture is described, in which an interesting course introduction, the adoption of appropriate teaching skills and the thinking of humanity are included. The microlecture can be used to help students to prepare for their forthcoming lessons, to learn and to review the content of the lessons. Such a microlecture not only helps to teach students the essential contents but also helps to enhance the teaching quality, stimulate students’ interest in learning, and improve the traditional teaching techniques.关键词：Microlecture;Anionic living polymerization;Polymer chemistry;Teaching effect
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发布时间：2022-09-09 - 摘要：Based on research projects and school characteristics, a teaching experiment was designed for the fabrication and application of high-performance conductive hydrogels. The experiment includes preparation, mechanical properties, structure-property relationship, and application of the conductive hydrogel. Owing to the synergy of hydrophobic associations and ionic interactions, the obtained hydrogel displayed outstanding mechanical properties, that is, the tensile strain and toughness were 30mm/mm and 10.34MJ/m3, which were 19 and 225 times of the traditional polyacrylamide hydrogel, respectively. In addition, it exhibited gauge factor of 3.4, and could reliably monitor finger bending. This experiment captured the students’ attention and promoted their involvements. The experiment not only consolidated basic concepts in the field of organic chemistry, analytical chemistry, polymer chemistry and material engineering, but also improved their skills in conducting experiments, analyzing data and conveying information accurately.关键词：Experiment design;Teaching reform;Conductive hydrogel
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发布时间：2022-09-09 - 摘要：Due to the unique flexibility and entropy elasticity of molecular chain, rubber shows great deformability and obvious caloric effect. In recent years, the research of elastocaloric refrigeration based on rubber stretch-removal endothermic mechanism has attracted more and more attention, which opens up a new direction for the research of polymer physics. Based on the thermodynamic analysis of high elastic deformation and elastocaloric effect in the course of "Polymer Physics", this paper introduces the principle and research progress of rubber elastocaloric refrigeration effect, and designs the teaching objectives and teaching process of "refrigeration effect of rubber entropy elasticity". It not only helps to transform the abstract basic theory of polymer physics into practical application examples, improving the learning quality of polymer physics, but also exercises the consciousness and ability of college students to track the frontier of disciplines and carry out innovative training.关键词：Rubber;Entropy elasticity;Elastocaloric refrigeration;Teaching design
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发布时间：2022-09-09 - 摘要：Based on the requirements of new engineering construction for training talents, the paper discusses the reform orientation of polymer specialty experiments teaching, taking the material failure analysis comprehensive experiment as an example. By introducing teachers' crosswise scientific research subjects, relying on the national and provincial virtual simulation experiment teaching project sharing platform and carrying out the experiment teaching modes of flipped classroom, teacher guide students to consult literature, design experimental methods,analyze data diagrams and give reasonable analysis conclusions for failed products. Meanwhile,two teaching cases of karting car seat screw column fracture failure analysis and washer for noise deadening failure analysis are presented to show students'practical operation process. The experiment not only stimulates the students' learning initiative, but also effectively promotes students to master multidisciplinary theoretical knowledge,and enhances their ability to solve practical engineering problems.关键词：New engineering;Polymer materials;Experiment teaching;Failure analysis
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发布时间：2022-09-09 - 摘要：Engineering education accreditation (EEA)is an international quality assurance system for engineering education, and it is also an important basis for international mutual recognition of engineering education and engineer qualification. In this paper, the course "Polymer Science Experiment" of Zhejiang University of Technology was taken as an example to illustrate how to put forward its curriculum reform to fulfill the requirements of EEA. The existing problems in the experimental course of polymer science are analyzed first. then the specific curriculum reform measures and practices were elaborated from four aspects: making new teaching outline, optimizing experiment item and experiment content, reforming teaching mode, perfecting experiment examination method. On the basis of the above work, preliminary results have been achieved in integrating the teaching content, enriching the teaching methods, improving the utilization of large instruments equipment, and increasing the process evaluation of students' experiments. An experimental course that meets the requirements of EEA has been created.关键词：Engineering education accreditation;Polymer science experiment;Curriculum reform
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发布时间：2022-09-09 - 摘要：Based on the training goal to cultivate innovative and entrepreneurial talents and the student-centered outcome-based education, aiming at the key points and difficult problems in the teaching and the weaknesses in the learning of polymer chemistry, a series of innovative teaching practices are carried out, including mind mapping, knowledge transfer, information-based teaching, formula tracing, and strengthening practice, which stimulate students' interest in learning, enhance the engineering consciousness and cultivate students' innovation ability.关键词：Polymer chemistry;Applied talents;Teaching method
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发布时间：2022-09-09 - 摘要：An important content of the new engineering construction is to enable students to obtain three-dimensional, extensive and comprehensive abilities, in order to achieve their high-quality development. Large instruments and equipment, as one of the important basic conditions for stimulating students' innovative consciousness and improving students' comprehensive quality, play an important role in the structural analysis and performance characterization of polymer materials, and penetrate into all aspects of polymer experimental and practical teaching. Regarding to the current status and drawbacks of large instruments and equipment applied in the instructional system of polymer experiments, a progressive teaching content system has been established and practiced by our teaching team. In the teaching process, the project-based learning method based on online and offline learning resources is adopted. In order to guide students to analyze and solve problems independently in practical instruction and improve their operating capabilities of large-scale polymer characterization equipment and instruments effectively, open-ended equipment management and modularized classification instruction are applied step by step, including problem and project as the orientation, students as the main body, teachers offering the guidance. It can cultivate students' good practical and innovative ability, which will help further achieve the main goal of improving students' comprehensive quality.关键词：New engineering;Large instruments and equipment;Progressive teaching;Project-based learning;Openended equipment management
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发布时间：2022-09-09 - 摘要：Henan University of Urban Construction, together with Pingdingshan Municipal Government and China Pingmei Shenma Group, established Nylon Industrial College (NIC) to meet the needs of the construction of "China Nylon City" and industrial transformation and upgrading. NIC explores a new mode of training applied talent characterized by school-enterprise cooperation and industry-education integration. The engineering practice ability and innovation consciousness of college students were enhanced through effective connection of education chain, talent chain, industrial chain and innovation chain. NIC provides talent support and intellectual guarantee for improving the core competitiveness of nylon industry and gathering new drivers of local economic development. This paper introduces the explorations made by NIC in the aspects of multi-body co-construction and co-management, the main role of enterprises, the improvement of social service ability and the construction of scientific research platform.关键词：Industrial college;Applied talent;Integration of production and education;Training mode
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发布时间：2022-09-09 - 摘要：Polymer chemistry experiment is the practical teaching content of polymer chemistry, which plays an irreplaceable role in deepening students' understanding of theoretical knowledge and improving their experimental operation ability. The experimental current situations in some universities are investigated, and the results show that polymer chemistry experiment are set independently in few universities, the number of experiment projects is limited, and the courses are still based on the traditional verification content. On this basis, some suggestions on curriculum reform are proposed, such as paying attention to the application and interest of experiment content, popularizing the teaching form of virtual simulation, increasing the proportion of integrated and designed experiments, and changing from cultivating experiment skills to improving scientific research ability, and detailed implementation measures are provided.关键词：Polymer chemistry experiment;Current situation;Experiment reform
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发布时间：2022-09-09 - 摘要：In view of the complexity and abstractness of the course content of Polymer Physics, this paper discusses the proper combination of visualized means such as object, video and engineering application examples in the teaching of polymer physics. Advocating the combination of abstract theory and real objects in life, the combination of abstract process and experiment or video, and the combination of unfamiliar materials and engineering practice cases. Teaching examples, such as the stress-strain curve, viscoelasticity etc., were put forward. This visual teaching method can not only activate the teaching atmosphere, improve students' interest in learning and deepen their understanding of knowledge, but also stimulate students' inquiry spirit and achieve good teaching results.关键词：Polymer physics;Visualized teaching;Teaching effect
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发布时间：2022-09-09 - 摘要：In order to cultivate innovative talents suitable for economic development, new engineering and Made in China 2025 put forward new requirements for higher education. Based on the establishment of the "craftsmanship spirit" core thought, the Polymer Physics is taken as an example in the paper. Integrating 'craftsmanship spirit’ into professional course under the background of new engineering is boldly tried by revising the syllabus, enhancing teachers' craftsman quality, reforming teaching methods, and reforming examination and assessment methods, etc., and a new teaching mode of Polymer Physics is established with the 'craftsmanship spirit’ cultivation. The beneficial results are obtained.关键词：Craftsmanship spirit;Teaching methods;Examination and assessment method;Teaching mode
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发布时间：2022-09-09
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