最新刊期
卷 53 ， 期 2 ， 2022
- 摘要：The contradiction between the extensive usage of traditional thermosetting resin and the depletion of petrochemical resources as well as environmental pollution and deterioration has attracted more and more attention, which makes the sustainable development of high-performance thermosets face severe challenges. Taking renewable resources as feedstocks to replace traditional petrochemical products for the synthesis of bio-based thermosetting resin is one of the feasible and significant methods to achieve its green production. Besides, how to endow the bio-based thermosets with satisfied service performance and multi-functionality under different applicated environment as well as high-efficient and high-quality recyclability are also important research topics for increasing sustainability. As early as ten years ago, our team started to design and synthesize sustainable thermosetting resin, of which the high-performance and functionality were successfully realized. Aiming to further achieve the sustainable development of thermosets in the total lifecycle, we dedicated our research focus to the comprehensive improvement of the resins including renewable material selection, green manufacturing process, versatile application, and high value-added recycling. Based on our experiences, this feature article reviewed our work on the selection of bio-based platform compounds, integrative design of resin with high-performance and multi-functionality, and high value-added recycling. In the end, the prospect and future of sustainable thermosetting resins were forecasted.关键词：Sustainable thermosetting resins;Bio-based;Functionalization;Recycling
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发布时间：2024-10-08
Feature Article
- 摘要：In recent years, soft robots have attracted great attention with the continuous development of artificial intelligence. Flexible actuators and artificial muscles, which are the key components of soft robots, have attracted extensive studies in order to meet the requirements of human-machine interaction and environmental adaptability of soft robots. Soft actuators can overcome the drawbacks of traditional actuators, such as complex structure, bulk volume, and rigidity, which also expand new ideas for the development of future intelligent equipment. Artificial muscles, as one of the most common flexible actuators, has aroused extensive research interest. Artificial muscles respond quickly to external stimuli, producing movements such as rotation, contraction, and elongation. Artificial muscles are expected to be widely used in artificial intelligence, intelligent manufacturing, biomedicine, robotics and other fields. Among different kinds of artificial muscles, fiber-based artificial muscles have attracted more and more scholars' interest due to its excellent driving performance and broad application prospect. This review paper mainly introduces the preparation mechanism of fiber artificial muscles, and summarizes the fiber artificial muscles with different driving modes, including electro-driven, thermally driven, electrochemical driven, humidity driven, and light driven. In addition, the research progresses and application of fiber-based artificial muscles are introduced in detail. We also discussed the perspective development of fiber artificial muscle in the future.关键词：artificial muscles;Fiber;Actuators;twisted structure
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发布时间：2024-10-08
Review
- 摘要：Bacteria are one of the oldest life forms on the earth. They have strong adaptability to various environments and can be seen almost everywhere on the earth. Bacteria will adhere to different surfaces and then reproduce to form dense aggregates or biofilms with a thickness of several microns to tens of centimeters, which will seriously affect the properties of materials, especially for medical devices. Bacterial adhesion and biofilm formation on these devices are an important reason for the failure of medical implantation and the formation of large-area medical infection. Therefore, researchers are focusing on developing antibacterial surface coatings to eliminate or prevent the initial adhesion of bacteria and biofilm formation on the surface of materials. Alternating layered self-assembly (LBL) film, as the most popular coating technology, is applicable to the surface of various materials. Due to its advantages of simple operation, high controllability and easy functionalization, LBL film is widely used in separation technology, sensor, controlled drug release, surface modification of biomaterials and so on. However, its inherent shortcomings, such as poor stability, easy decomposition, etc., greatly limit their applications. To solve the above problems, a kind of photo crosslinking antibacterial LBL membrane was designed and prepared by alternating deposition of photosensitive o-nitrobenzyl alcohol modified hyaluronic acid (HANB) and quaternized chitosan (ACS) on the glass substrate through electrostatic interaction. The photoligation reaction of o-nitrobenzyl alcohol to amine of chitosan enables the crosslinking of the assembled polyelectrolyte membrane, which stabilizes and maintains the integrity of the membrane for a long time in salt solutions with different pH values. The antibacterial property of chitosan endows LBL membrane with good antibacterial property and strong electrostatic supramolecular interactions with HANB. Cytotoxicity analysis confirms the cytocompatibility of the LBL membranes. Antibacterial experiments show that the non-photocrosslinked LBL membrane shows higher release-sterilization due to the release of quaternized chitosan to the solution. However, the photocrosslinked LBL membrane shows better contact-sterilization due to the membrane stability, which is more friendly to the environment. Compared with other chemical crosslinking methods, o-nitrobenzyl alcohol photocrosslinking strategy has better biocompatibility without the introduction of any initiator or additive, which provides a new idea for the construction of antibacterial coating on the surface of medical implants.关键词：Alternating Layered self-assembly film;Antibacterial coating;Photocrosslink;Cytocompatibility
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发布时间：2024-10-08 - 摘要：Electrodeposition of biopolymer shows attractive development on fabricating novel functional materials and devices. ZnO quantum dots (QDs) have drawn increasing attention due to their environmentally friendly and non-toxic features, and good fluorescence properties. This work develops a method based on the coordination electrodeposition of sodium alginate to prepare ZnO QDs and ZnO QDs/sodium alginate nanocomposite films on electrodes. The method has many advantages such as the simple operation, the mild condition, the good controllability and the environmentally friendly process. Moreover, it allows a facile post-treatment for products to directly obtain the nanocomposite films of QDs and biopolymer on electrodes. In the method, sodium alginate was not only used as the electrodeposition biopolymer, but also served as the stabilizing agent for preparing ZnO QDs as well as the main ingredient in the resulting nanocomposite film. TEM observation shows that there are nanoparticles with a relatively uniform size in the nanocomposite film, and that the average size of these nanoparticles is 6.0 nm. The ZnO QDs/sodium alginate nanocomposite film shows a clear orange fluorescence under 365 nm UV light. The UV-Vis spectrum of the nanocomposite film has a clear absorption peak at 340 nm, which is attributed to the typical absorption peak of ZnO QDs. The photoluminescence spectrum of the nanocomposite film shows a clear emission peak at 550 nm, which agrees with the emission peak of ZnO QDs. The above spectral data both prove that there are ZnO QDs in the nanocomposite film. Furthermore, the ZnO QDs/sodium alginate nanocomposite film on the electrode can be applied to conduct electrochemical detection of K3[Fe(CN)6] with a detection limit of 2.64 μmol/L. By taking advantage of the fluorescence properties, the ZnO QDs/sodium alginate nanocomposite film can be used for fluorescence detection of Cu2+ ions. Therefore, this work provides a novel method for the preparation of ZnO QDs and construction of QDs/biopolymer nanocomposite films. The resulting ZnO QDs/sodium alginate nanocomposite film has promising applications in the fields of electrochemical detection and fluorescence detection.关键词：Electrodeposition;Sodium alginate;ZnO QDs;Nanocomposite film;Detection
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发布时间：2024-10-08 - 摘要：In order to develop anion exchange membranes (AEMs) with simutaneously good anion conductivity, low vanadium ion permeability, excellent mechanical property, and high chemical stability, a fluorinated poly-(arylene ether) (FPAE) containing tertiary amine groups was condensation polymerized and then cross-linked with decabromopropyl pillar[5]arene (P5Br) via the nucleophilic substitution reaction. After that, iodomethane was introduced to convert the remaining tertiary amine groups into quaternary ammonium groups. A series of densely cross-linked FPAE AEMs, namely QAFPAE-P5Br-x, were prepared with high gel contents in polar aprotic solvents. As the loading amount of P5Br is increased from 0.5% to 5%, the water uptake, swelling ratio, anion conductivity and VO2+ permeability of the membranes are decreased, but the ion selectivity, tensile strength, area resistance and oxidative stability of the membranes are increased. The QAFPAE-P5Br-1% with only 1% of P5Br loaded has both low area resistance and low VO2+ permeability, which are promising for VRFB applications. At a current density of 80 mA·cm-2, the VRFB assembled with QAFPAE-P5Br-1% shows an energy efficiency of 86.5%, which is 7.7% higher than that of the VRFB assembled with Nafion 212. Besides, the VRFB assembled with QAFPAE-P5Br-1% has excellent cycling stability, high discharge capacity retention and good anti-self-discharge performance. Therefore, the dense cross-linking is an effective protocol to enhance the overall performance of AEMs.关键词：Vanadium redox flow battery;Anion exchange membrane;Poly(arylene ether);Dense cross-linking;Oxidative stability
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发布时间：2024-10-08 - 摘要：Personal thermal management is a strategy to energy management of human body and its local environment, which can significantly improve human body thermal comfort and reduce energy consumption on building cooling and heating. Traditional approaches could either self-cooling or thermal insulation, but could hardly fulfill both thermal insulation and cooling in one structure. Thus, it’s still a challenge to design and synthesize materials with dual functions. In this work, phase-change-material aerogels (PCMAs) were designed and synthesized via a sol-gel and freeze drying process, in which PVA and microencapsulating PCM acted as stable skeleton for the porous structures. The PCMAs showed excellent mechanical properties and could be compressed up to 55% or be tensile stressed up to 25%, making them outstanding for traditional aerogels and PCMs. The specific surface areas of the aerogel reached 14.4 m2/g, and extremely low density (0.11 g/cm3) and low thermal conductivity (0.040 W/(m·K)) were also achieved. Impressively, the PCMAs exhibited high latent heat up to 46.1 J/g. When the outer temperature was 78 ℃, the inner temperature protected by PCMA was ca. 60 ℃, which was 18 ℃ lower. On the other hand, when the environment temperature was reduced, the temperature reservation ability of the PCMA was 2.6 times of that of pure PVA aerogel (which possessed lower thermal conductivity of 0.028 W/(m·K) but zero latent heat). The results indicated that the PCMAs had excellent thermal insulation and temperature reservation capacities, suggesting that the PCMAs could be ideal candidates for personal thermal management.关键词：Aerogel;phase change materials;Porous materials;Poly(vinyl alcohol)
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发布时间：2024-10-08 - 摘要：In this study, we design and synthesize a second near-infrared window (NIR-Ⅱ) fluorescence molecule (TTQ-F-PAMAM) by modifying polyamidoamine dendrimers on donor-acceptor-donor (D-A-D) NIR-Ⅱ fluorescence core TTQ-F. TTQ-F-PAMAM can realize fluorescence image during 900-1200 nm excited by 808 nm laser, and shows outstanding photostability. According to the dynamic light scattering (DLS) and transmission electron microscopy (TEM) results, the hydrodynamic size of TTQ-F-PAMAM was approximately 45 nm. As shown in the NIR-Ⅱ images of TTQ-F-PAMAM at different depths, the tissue penetration of NIR-Ⅱ fluorescence signal from TTQ-F-PAMAM can reach up to 4 mm. Owing to the polyamidoamine dendrimers, TTQ-F-PAMAM showed great antigen-loading capacity. And the MTT assay showed that TTQ-F-PAMAM exerted lower cell toxicity on cells. Ovalbumin (OVA), a model antigen in immune research, could be adsorbed onto TTQ-F-PAMAM by electrostatic binding. The loading capacity of TTQ-F-PAMAM was 16.43%. TTQ-F-PAMAM@OVA, the nanoparticles loaded with antigen can easier transported to antigen presenting cells than free OVA. Dendritic cell (DC) is the major antigen presenting cell in innate immunity and plays an important role in cancer suppression. After cell uptake of TTQ-F-PAMAM@OVA, the antigen induces the maturation of DC and promotes specific anti-tumor immunity. Compared with other groups, the percentage of both CD80 and CD86 significantly increased after cultured with TTQ-F-PAMAM@OVA. These cells activated by TTQ-F-PAMAM can release tumor necrosis factor-α (TNF-α) and interleukin-12p70 (IL-12p70). The secretion of TNF-α and IL-12p70 from DCs incubated with TTQ-F-PAMAM@OVA was much higher than that incubated with free TTQ-F-PAMAM or OVA. TTQ-F-PAMAM was used not only as a NIR-Ⅱ fluorescence probe, but also as the delivery of proteins to antigen presenting cells. This treatment strategy may greatly improve the efficiency of cancer therapy and provides a new method for immunotherapy research.关键词：Polyamidoamine dendrimers;NIR-Ⅱ fluorescence imaging;Immune therapy
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发布时间：2024-10-08 - 摘要：The epoxidation of rubber is an effective way to improve the oil resistance, gas permeability and other properties of the modified product. Although extensive research has been carried out on the epoxidation of natural rubber and other unsaturated rubber, few studies focused on the epoxidation of butyl rubber (IIR) and the possible side reaction of the epoxy group in the epoxidized IIR (EIIR). In this study, the epoxidation of IIR was invesitigated in detail for the first time, and the basic properties of the obtained epoxidized IIR were characterized. The epoxidation of IIR was carried out in n-hexane employing m-chloroperoxybenzoic acid (mCPBA) as the epoxidation reagent. The effects of the ratio of raw materials, reaction temperature, and the concentration of IIR solution, on the epoxidation reaction were investigated systematically. The structure of EIIR was characterized and the degree of epoxidation was calculated quantitatively by 1H-NMR spectra. The optimal conditions for the synthesis of EIIR with complete epoxidation and without side-reaction were determined: 15% IIR solution with 1.1 times of mCPBA relative to double bond reacted at 40-45 oC for 45 min, and then the solution was washed with NaOH aqueous solution to remove the formed acid. Furthermore, the side reaction that occurred during the epoxidation reaction and post-treament procedure was affirmed through the comparison with model compound reaction and the side reaction in the epoxidation of IIR by hydrogen peroxide/formic acid. The ring-opening reaction of the epoxy group via hydrolysis is the main form in EIIR, which is different from those in ENR. The epoxidation of IIR lead to slight increase of Tg and thermal decomposition temperature, as evaluated by the results of DSC and TGA. Finally, the solubility and epoxy-group content analysis showed that EIIR possesses excellent strorage stability.关键词：Butyl rubber;Epoxidation;m-Chloroperoxybenzoic acid;Ring-opening reaction
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发布时间：2024-10-08
Research Article
- 摘要：Thermogravimetric analysis (TGA) is an efficient research tool that characterizes the weight of materials with temperature or time under a program controlled temperature and a certain atmosphere. One of its advantages is that the TGA results can be well repeated with high sensitivity. In addition, its heating process is accurately and flexibly controlled according to real thermal environment of samples. In recent years, TGA is popularly used in the field of polymer materials, which promotes the detailed analyses on their thermal stability, composition analysis and thermal decomposition mechanism et al. This review covers many aspects of TGA, including basic principles, calibration, scheme design, curve analysis, as well as those common errors during sample preparation and experiments, abnormal data figuring and the solution to them. Additionally, the typical application cases of TGA in polymer science, as well as their opportunity and challenges in future, are also presented. In the applications of TGA technology, more information about the thermal-response behavior of polymers under different atmosphere and heating conditions could be revealed by TGA coupled with FTIR, DSC, GC/MS technologies. In this case, not only the weight information of sample during a specific heating condition, but also the endothermic and exothermic behaviors, released gas components at the same time can be analyzed together. They are helpful for new polymer design, thermal decomposition mechanism and flame spread models development.关键词：Thermogravimetric analysis;Curve analysis;Thermal stability;Thermal decomposition mechanism;Case analysis
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发布时间：2024-10-08
Review (Special Topic: Techniques of Polymer Characterization)
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