最新刊期
卷 36 ， 期 1 ， 2023
- 摘要：In this paper, the research progress of polymer gas separation membrane technology is reviewed from the aspects of nanomaterial doping modification and new preparation technology development. The main methods for improving the interfacial compatibility between different nanomaterials (GO, MOFs, and CNTs) and polymer membranes are summarized. The new progress in the preparation of polymer composite membranes with ultrathin selective layers is introduced. The research focus and development direction of polymer gas separation membrane technology are prospected.关键词：Macromolecule;Gas separation membrane;"Trade-off" effect;Nanomaterial doping;Composite membrane
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发布时间：2022-11-18 - 摘要：With the wide application of electroactive polymer (EAP) in bionic robots, flexible sensors, energy and other fields, the research on EAP is also increasing. This paper systematically describes the research progress of EAP intelligent driving materials in modeling, control and application, laying a foundation for the subsequent material application. Firstly, the classification and electro actuation principle of EAP materials are outlined. Then, the modeling and controller design of EAP driving materials are sorted out. Finally, the existing research difficult problems of EAP in material properties, intelligent structure design, system modeling and motion control strategy are summarized, and the future research directions are prospected.关键词：Intelligent driving material;Electroactive polymer;Modeling;Control method
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发布时间：2022-11-18 - 摘要：In recent years, the important application prospect of soft actuator materials in wearable devices, medical and health devices, and soft robots etc. has received much academic and industrial attention. The electroactive polymer (EAP) which is a soft actuator material can change its shape or size by applying an electric field. The EAP materials can be divided into electronic and ionic EAP based on electromechanical mechanism. In contrast with electric EAPs, the ionic electroactive polymer (IEAP) based-actuators have significant advantages for applications in medical machines and wearable devices due to their low driving voltage. In recent years,the shortcomings of traditional IEAP-based actuators such as slow actuation rate, low durability in the atmosphere and low actuation strain and stress are significantly improved by developed electrode materials and ionic liquid based polymer gel electrolyte materials. In this review, we comprehensively summarized the progress of IEAP-based actuators including ionic polymer metal composite (IPMC) actuators, conductive polymer actuators, Bucky gel actuators and ionic gel actuators etc. In addition, we also reviewed the electromechanical coupling mechanisms and the application progresses of IEAP-based actuators, and discussed the challenges and future development trends of IEAP-based actuators.关键词：Soft actuated material;Electroactive polymer;Ionic electroactive polymer;Soft actuator;Electromechanical coupling
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发布时间：2022-11-18 - 摘要：Keratin is a kind of renewable resources with stable structure and great biocompatibility, which has been widely used in biomedical field due to its good biocompatibility, natural abundance, and unique molecular structure. In this review, the structure property and extraction of keratin are introduced. Especially, the biomedical applications of keratin materials in the fields of drug release, wound repair, and tissue engineering are emphasized. Finally, the future development trend is forecasted.关键词：Keratin;Wound repair;Drug release;Tissue engineering
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发布时间：2022-11-18 - 摘要：With magnetic nanoparticles as a pivotal role, the magnetic nanocomposite hydrogel has excellent mechanical properties, good biocompatibility, and rich magnetism. Therefore, the magnetic hydrogels can be used in many fields productively, such as magnetic resonance imaging (MRI), hyperthermia treatment, environmental governance and promotion of stem cell differentiation. Based on the current research progress, the physical and chemical properties of the nanocomposite hydrogel, the characteristics and preparation methods of magnetic nanoparticles as the pivotal component, and the research progress of magnetic hydrogels in application and design strategies were briefly introduced in this review. At the same time, from the perspective of the above applications, future challenges and development were also proposed.关键词：Magnetic;Hydrogel;Nanoparticle;Application;Environmental governance
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发布时间：2022-11-18 - 摘要：The primary consideration in wound treatment is hemostasis and regulating inflammation, so the development of hemostatic and anti-inflammatory dressings is of great significance. In this study, two kinds of hydrogels based on collagen were prepared and their hemostatic and anti-inflammatory effects were tested. Collagen was compounded with chondroitin sulfate A (CSA) and chondroitin sulfate C (CSC), which have anti-inflammatory effects, respectively, and the resulting complex was chemically cross-linked with aldehyde benzoic acid modified polyethylene glycol 6000 (APG6000) to form hydrogels. The hydrogel had a sudden release of chondroitin sulfate A or chondroitin sulfate C, which had the potential of rapid anti-inflammatory when applied to skin wounds. The pores of the hydrogels obversed by the scanning electron microscope (SEM) were compact and uniform. The results of swelling experiment showed favorable water absorption. Both of above properties were beneficial to absorb tissue exudation when applying hydrogels to wound. The results of MTT and living cell staining experiments reflected that the two hydrogels contributed to proliferation of macrophages and fibroblasts. The hemolysis rate of the hydrogels was lower than 1.5%, the blood clotting index (BCI) decreased significantly, and the hemagglutination effect was positive. These results indicated that the two hydrogels have the potential as hemostatic and anti-inflammatory dressings.关键词：Chondroitin sulfate;Collagen;Hemostasis;Anti-inflammatory;Hydrogel
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发布时间：2022-11-18 - 摘要：Controlled release hydrogel was an ideal delivery carrier. In order to achieve controlled release of riboflavin in intestinal tract, in this work, sanxan microcapsules was prepared using an extrusion dripping method based on the pH-responsiveness of sanxan. Physical and in vitro release properties of sanxan microcapsules was measured, where riboflavin was used as loading drug and calcium chloride as regulatory factor. The results showed that stable sanxan hydrogel was prepared by 0.06 mol/L HCl fixed solution and 0.3% sanxan solution, and the toughness of microcapsules increased but the elasticity decreased after calcium chloride was added. There was no significant change in the release rate of sanxan microcapsules in duodenum, and the release rate of jejunum decreased from 42.5% to 24.1%, when the addition of calcium chloride increased from 0% to 10%. Ileum release occurred when calcium chloride supplemental level was 2% or above, and the release rate gradually decreased from 21.6% to 14.9%. The viscosity characteristics and SEM image analysis showed that the viscosity of sanxan solution increased and the porosity of microcapsules was reduced with calcium chloride added, which was the main reason to control the release of riboflavin. Controlled release of riboflavin in intestinal tract was achieved by adjusting the addition amount of calcium chloride in sanxan microcapsules, indicating that controlled release of sanxan microcapsules has broad application prospects for oral delivery.关键词：Sanxan;CaCl2;pH-Responsiveness;Riboflavin;Control release
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发布时间：2022-11-18 - 摘要：Here, cationic nanospheres (NPs) were selected as hydrophobic cross-linked centers to enhance the mechanical strength of hydrogel. The hydrophobic monomer lauryl methacrylate (LMA) adsorbed on the surface of NPs to form hydrophobic association in the presence of surfactants, and then the NPs cross-linked P(AAm-LMA)-NPs hydrogels were obtained by in situ radical polymerization. Under deformation, the dynamic cross-linking centers formed by nanospheres in the hydrogel network could effectively dissipate energy via fracture and recombination, which greatly improved the strength and toughness of hydrogels. As a result, P(AAm-LMA)-NPs hydrogels showed remarkable mechanical properties with an excellent tensile strength of 860 kPa, high stretchability of 1280% and superior toughness of 3.8 MJ/m3. This work constructed tough hydrogels reinforced by polymeric nanospheres and displayed potential applications in biomedical and industrial fields.关键词：Cationic nanospheres;Hydrophobic association;Hydrogel;Mechanical properties
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发布时间：2022-11-18 - 摘要：In contrast to conventional isoprene and butadiene, 1,3-pentadiene monomer can undergo anionic copolymerization to afford special sequence controlled copolymers, such as alternating copolymers. In this paper, a series of binary and ternary copolymers were synthesized using 1,3-pentadiene, styrene and p-tert-butylstyrene comonomers and initiated by n-butyllithium. Focusing on the copolymerization kinetics and microstructure of copolymers, some interesting results were obtained: (1) kinetics analysis indicated that copolymerization conformed to the characteristics of classical primary reactions, and all comonomers can be converted completely; (2) the real-time NMR analysis showed the equal consumption of pentadiene and its comonomer, and 1HNMR/13C-NMR spectra all proved the binary alternating sequence structure; (3) binary and ternary copolymerization had obvious living and controllable polymerization characteristics, the molecular weight was highly consistent with the theoretical value, and the molecular weight distribution D was less than 1.20; (4) the DSC results showed that copolymers were a special class of semi-crystalline polymers, and the glass transition temperature Tg can be fine-tuned by regulating the proportion of comonomers, and Tm is in the range of 100-120 ℃; (5) Based on dual-alternating copolymerization strategy of pentadiene, we proposed the possible alternating polymerization mechanism.关键词：1,3-Pentadiene;Styrene;p-tButyl-styrene;Anionic polymerization;Alternating copolymerization;Living and controlled polymerization
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发布时间：2022-11-18 - 摘要：In this study, we tried to deal with the experimental data of stress relaxation of silicone rubber foam. Based on the second-order Prony series, the nonliner regression analysis method (curve fitting method), the Bayesian method based on the Wiener process and the Bayesian method based on the Gamma process were used to estimate the parameters, and the prediction models are established respectively. By comparing the deviation between the predicted values and experimental values of the three modeling methods, the effects of the three modeling methods are compared. The results showed that the prediction deviation of the model based on the regression analysis was larger than the ones established by the Bayesian method based on the Wiener and Gamma processes, which may indicate that the stochastic process models could better predict the stress relaxation tendency of silicone rubber. The non-negative Gamma process, suitable for the nature of monotone increasing of a stress relaxation process, may contribute to its less deviation than the Wiener process. Our work provided a better way for the parameters estimation of degradation model based on the performance degradation data of polymer materials, contributing to better prediction.关键词：Silicone rubber foam;Stress relaxation;Regression analysis model;Stochastic process model
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发布时间：2022-11-18 - 摘要：Traditional polymer materials, including plastics, rubbers, fibers, coatings, adhesives, and polymer composite materials, etc., have surpassed the metal materials in volume, and taken indispensable roles for daily life and industries, greatly improving the quality of people's life. High performance engineering polymer materials have been applied diversly in the areas of national defense, aerospace, transportation, shipping, oil extraction, and chemical engineering. Therefore, the curriculum of Polymer Materials is becoming a mandatory course for chemistry and materials majors. However, due to the wide variety of polymer materials, scattered knowledge points, boring descriptive contents and lack of applicability, the course teaching process is less attractive for student to concentrate and participate. A measure of research-based learning was thus taken to allow the students to participate actively in the teaching process. In this paper, the process, and pros and cons of researchbased learning are summarized from the students’ perspective. The research-based learning integrated the practical training on learning, testing and presentation of a particular type of polymer materials without any predications, and should be fully performed by a team of 4-5 students. This measure could inspire the subjectivity, knowledge application and open innovation of students. Moreover, the students and teachers would communicate and improve with each other in the research-based learning process. The teachers learned to improve their guidance methods, and the students deepened their understanding of polymer materials and improved their critical thinking. Nonetheless, the research-based learning can be further optimized in terms of more laboratory cooperation, evaluation system, student engagement and teaching strategies.关键词：Polymer materials;Research-based learning;Teaching reform;Practice;Structure analysis
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发布时间：2022-11-18 - 摘要：Taking the example of the designing open of thermal analysis experiments based on common polymer materials, a teaching reform has been introduced opening up large-scale equipment to undergraduates majoring in polymer science. By promoting this teaching reform, the experimental content has been extended, which has also greatly increased the enthusiasm of students to analyze experimental results and fully consider the whole experimental process. This has inspired students to integrate the knowledge from textbooks with the experiments and thus realize the cultivation of scientific research ability towards undergraduates. On the other hand, it has instilled students with the ability for self-exploration, analysis and solving practical problems, and enhancing their skills in operating equipment. This has further realized the cultivation of the capacity for comprehensive practical and engineering thinking.关键词：Polymer physics;Teaching reform;Designing experiment;Practical ability
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发布时间：2022-11-18 - 摘要："Adhesives and additives" course undertakes the task of improving students in "analysis & evaluation" abilities. To develop the abilities in deep-level, the reform ideas and methods from integration perspective of industry-university-academy, teaching cases with high association of industry were designed. They were applied through the teaching process, in terms of course introduction, theory application, problem analysis, performance prediction and technological innovation. Methods of "principle analysis" and "splitting analysis" were proposed in training analysis ability. After multiple rounds of teaching practice, the comprehensive examination results of students' have been improved significantly. The application of teaching cases and analysis methods effectively promots students' analysis & evaluation and practical innovation ability.关键词：Engineering education accreditation;Case-based teaching;Integration of industry-university-academy;Adhesives and additives course
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发布时间：2022-11-18
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