最新刊期
卷 37 ， 期 10 ， 2024
- 摘要：Platinum (Pt) drugs are the most common chemotherapeutic agents in the clinic due to their unique anticancer mechanism, which endows them with high efficiency and broad-spectrum resistance to tumors. However, the toxicity and side effects induced by Pt drugs, also, the drug resistance limits the therapeutic effects of Pt drugs. With the development of nanotechnology, the use of nanocarriers to realize the targeted delivery of Pt drugs has become a hot research topic in recent years. Among the various kinds of nanocarriers, the development of stimuli-responsive polymeric nanocarriers has become a trend in the construction of Pt drug delivery systems at this stage. On the one hand, polymer-based nano-delivery system is capable of taking advantage of polymer segments to enhance loading capacity and achieve the conjugation of different drugs. On the other hand, it is capable of utilizing the tumor microenvironment to achieve the precise delivery and accumulation and penetration of Pt drugs through stimulation response.According to the classification of stimuli-responsive sources, this review overviews the recent progress of different stimuli-responsive polymeric nanocarriers to deliver Pt drugs efficiently, following the introduction of platinum drugs. The design strategy and the controlled-release mechanism of polymeric nanocarriers are analyzed with emphasis. This review aims to provide the research and development (R&D) idea and theoretical support for a clinically applicable polymer-based nano-delivery system for Pt drugs.关键词：Platinum drugs;Polymer;Nano-delivery systems;Stimulus response
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发布时间：2024-09-24 - 摘要：Natural polymers, such as polysaccharides and proteins, are abundant in nature, boasting abundent functional groups that lend themselves readily to modify. Some natural polymers also exhibit inherent antibacterial properties, alongside unique biological attributes. Hydrogels derived from natural polymers typically demonstrate excellent biocompatibility, degradability, and hydrophilicity, owing to their three-dimensional structure which provides an ideal reservoir for antibacterial agents. These attributes confer a distinct advantage upon natural polymers in the formulation of antibacterial hydrogel dressings. Beyond material selection, the choice of crosslinking strategy is pivotal. This work summarizes recent methodologies for the preparation of natural polymer antibacterial hydrogel dressings, encompassing chemical, physical, and hybrid crosslinking techniques. Based on their antibacterial attributes, hydrogels are categorized into two classes: those with inherent antibacterial properties and those laden with antibacterial agents. Detailed accounts are provided regarding the application and potential of these hydrogel dressings in medical, healthcare, and allied domains. Lastly, the extant research bottlenecks are analyzed and the future development for natural polymer antibacterial hydrogels is prospected.关键词：Natural polymer;Antibacterial hydrogel;Wound dressing
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发布时间：2024-09-24 - 摘要：Given the escalating energy consumption and environmental pollution, there is an urgent need to develop photoelectric conversion materials that are green, efficient, and eco-friendly. Dye-sensitized solar cells (DSSC), representing the third generation of novel photovoltaic cells, are characterized by low cost, simple manufacturing and superior photovoltaic conversion efficiency, which has enabled their application in diverse areas, including wearable devices, mobile batteries and photovoltaic buildings. The electrolyte plays an important decisive role in the photovoltaic performance of DSSCs. However, traditional liquid electrolytes, which contain volatile organic solvents, can lead to sealing and leakage issues in devices. These problems not only compromise the safety of the batteries but also limit their long-term stability, thereby restricting its application. Therefore, the development of gel polymer electrolytes (GPE) that combine stability and high ionic conductivity emerges as an effective strategy. This work provides a review of the structure and current development of DSSCs, with a particular emphasis on the research progress on various polymer-based gel electrolytes and their impact on DSSC performance. Additionally, it briefly outlines the role of ionic liquids in electrolyte modification research, taking into account the factors that influence the ionic conductivity of GPE. Concurrently, a strategy for improving the performance of GPE-based DSSCs is proposed.关键词：Dye-sensitized solar cells;Gel polymer electrolytes;Ionic liquids
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发布时间：2024-09-24 - 摘要：With the increasing global energy crisis and environmental pollution, the design and synthesis of bio-based flame retardants and epoxy monomers using biomass raw materials for flame retardant modification of epoxy resin have attracted widespread attention. This paper provides an overview of the research progress including additive, reactive and intrinsic flame retardant epoxy resins based on biomass. The synthesis of bio-based flame retardants and flame retardant epoxy monomers are described, and the performance and flame retardant mechanism of bio-based flame retardant epoxy resin using three flame retardant modes are analyzed. Furthermore, the development trend of bio-based flame retardant epoxy resin is prospected.关键词：Epoxy resin;Bio-based halogen-free flame retardant;Intrinsic flame retardant;Flame retardancy;Flame retardant mechanism
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发布时间：2024-09-24 - 摘要：In the current 5G and information society, intelligent wearable electronic devices are developing rapidly. However, limited by flexible sensing technology, they are still in the early stage of product development and are moving towards a second generation product with higher integration and flexibility. The research on flexible electronic sensors, as one of its core components, has attracted much attention. Starting from the basic composition of carbon nanotube based flexible sensors, this review introduces the flexible matrix and the active material carbon nanotubes, respectively. Subsequently, the preparation process, potential application areas, and latest progress of carbon nanotube based flexible sensors in recent years were summarized and analyzed, and the direction of their multifunctional application expansion was explored. Finally, a summary and outlook were made on the challenges and future development directions faced, providing reference for the development of carbon nanotube based flexible electronic sensors with excellent comprehensive performance in the future.关键词：Flexible sensor;Carbon nanotubes;Smart devices
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发布时间：2024-09-24 - 摘要：The performance requirements for high-performance organic fibers are increasing with the rapid development of military equipment, air and space exploration, optoelectronic transportation, and other fields. Although the existing high-performance aryl heterocyclic polymers have enough excellent performances to make it from the molecular structure design to practical production applications, there are still many defects, so there is an urgent need to develop a better overall performance of high-performance aryl heterocyclic polymer fibers. This paper briefly introduces the intrinsic correlation between the molecular structure and performance of three existing high-performance aryl heterocyclic polymer fibers, benzimidazole heterocyclic copolymerized aramid (aramid III) fibers, poly(p-phenylene benzobisoxazole) (PBO) fibers, and poly-pyridobisimidazole (PIPD/M5) fibers, summarizes the preparation process, application scope, and defects of the three kinds of fibers, and reviews the research progress of copolymerization modification for the preparation of new aryl heterocyclic polymer fibers and also looks ahead to the future research and development of high-performance aryl heterocyclic polymer production.关键词：Benzimidazole heterocyclic copolymerized aramid fibers;Poly(p-phenylene benzobisoxazole) fibers;Poly-pyridobisimidazole fibers;Chemical copolymerization modification;Molecular structure design
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发布时间：2024-09-24 - 摘要：The supported Ziegler-Natta catalyst utilizing MgCl2 as carrier holds paramount significance in the synthesis of polyolefins, notably polyethylene and polypropylene. The inherent characteristics of the carrier of Ziegler-Natta catalyst-activated MgCl2, such as particle structure and morphology, play an important role in regulating the spatial distribution and electronic effects of active species, which then determine the catalytic features of the final Ziegler-Natta catalyst (such as catalytic activity and stereoselectivity). This article provides a comprehensive review on the influences of activation methods of MgCl2 carrier on the morphology, structure, and composition of the carrier precursors and the prepared Ziegler-Natta pre-catalysts, and the olefin catalytic properties of the pre-catalysts. Based on the industrial applications of the various pre-catalysts, the high-performance polyolefin catalysts in the future are prospected.关键词：Ziegler-Natta catalyst;MgCl2;Activation;Catalytic feature;olefin
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发布时间：2024-09-24 - 摘要：Taking advantage of the different charges of k-carrageenan oligosaccharide (KOS) and chitosan (CS), using KOS as a cross-linking agent, a thermosensitive hydrogel which can release KOS and control degradation can be prepared by ionic cross-linking glue. The CS acid solution and the KOS aqueous solution are mixed at room temperature to prepare a series of gel systems with the mass ratio of KOS to CS ranging from 2.25:1.0 to 2.75:1.0. The gel time is determined by the test tube inversion method, the volume change of phase transition is measured by the difference method, the swelling degree and degradation rate are measured by the weighing method, the sustained release of KOS from the gel is measured by the phenol-sulfuric acid method, and gel surface structure is observed under a scanning electron microscope (SEM). The adhesion and proliferation of central nervous immune effector cells (N9) on the gel were detected by MTT method. The results show that a series of KOS/CS hydrogels are temperature-responsive, appearing in a liquid sol state at 4 °C, and can be phase-transformed into solid hydrogels at physiological temperature (37 °C), and the gel time is 300±50–17±5 min. After gelation, there is obvious phase transition volume change, the porosity is (78.7±2.5)% – (92.9±2.1)%, the swelling rate is (558.7±5.046)% – (853.9±6.143)%, the degradation rate is (77.46±3.520)% – (70.68±4.080)% and the KOS sustained release degree is (30.38±0.952 3)% – (24.24±3.988)%; the gel shows a fibrous porous structure under SEM, and supports the adhesion and proliferation of N9 cells. KOS/CS hydrogel has good temperature sensitivity, swelling property, controllable degradability, sustained release ability for KOS and cytocompatibility, which can provide a better biomaterial for the fields of drug delivery and tissue engineering.关键词：Chitosan;k-Carrageenan oligosaccharide;Hydrogel;Biocompatibility
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发布时间：2024-09-24 - 摘要：This study introduces a new peptide-polysaccharide hydrogel for drug carriers, exploring its physical properties and drug release capabilities. Three variations of hydrogel EPS33, EPS50 and EPS66 with exopolysaccharides (EPS) contents of 33%, 50% and 66%, respectively, were created using different ratios of 9-fluorenylmethoxycarbonyl-phenylalanine (Fmoc-F) to EPS. The influence of EPS on the structural, morphological, and mechanical characteristics of hydrogels was assessed using rheological, scanning electron microscopy, and textural analyses. The interaction between EPS and Fmoc-F within the hydrogels was examined by Fourier Transform Infrared (FTIR) spectroscopy. Furthermore, the effects of EPS on the biocompatibility, antioxidant properties, and drug delivery capabilities of the hydrogels were evaluated via hemolysis, free radical scavenging, drug loading, and in vitro release profiling using rhodamine B. The findings indicated that the Fmoc-F/EPS hydrogels with varying ratios of EPS displayed characteristics of gel-elastic solid behavior, with an observed increase in the network pore size with higher EPS content. The ―OH groups of EPS were found to establish hydrogen-bonding interactions within and between Fmoc-F molecules. Compared to Fmoc-F, the hardness of EPS66 decreased to 1.689 g, and the loading capacity of rhodamine B increased by 22.79% to 259.8 mg/mL. The penetration depth through pig skin increased by 20.15% within 24 h, reaching 1 576.5 μm. Therefore, it was demonstrated that Bifidobacterium EPS can create a stable hydrogel with a larger network pore size by engaging in hydrogen bonding interactions with Fmoc-F, resulting in an enhanced hydrophilic drug loading capacity. By manipulating the EPS ratio, novel peptide-polysaccharide hydrogels can be developed with superior drug-loading capacity, antioxidant properties, release capabilities, and biosafety, making them suitable for applications in skin hydrophilic drug delivery.关键词：Self-assembly;Peptide-polysaccharide hydrogels;Drug carriers;Exopolysaccharides;Sustained release of the drug
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发布时间：2024-09-24 - 摘要：A series of long-chain branching polybutene-based elastomers (PBEs) were successfully prepared by incorporating distinct comonomers of 1-dodecene (C12), 1-hexadecene (C16), and 1-icosaene (C20). The improved elongation at break of PBE could exceed 5 000%, and the best elastic recovery of PBE reached 88.9%. Moreover, PBEs were blended with isotactic polypropylene (iPP) to improve the material toughness. The effects of additional, side chain length, and comonomer incorporation of PBEs on the toughening effect were systematically studied. The results showed that for PBE-C16(52.3) incorporated 52.3 mol% 1-hexadecene comonomers, the addition of 5 wt% PBE increased the elongation at break of iPP blend by more than 8 times to 900% and its impact strength increased by 2 times to 15.3 kJ/m2. The high elastic recovery of PBE and its small dispersed phase size are beneficial to the improvement on toughness of the iPP blend material. This work provides a simple and effective method for obtaining iPP blend material with the improved toughness.关键词：Polybutene elastomers;Long-chain branching;Polypropylene toughening
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发布时间：2024-09-24 - 摘要：Walnut shell (WS) powder, a kind of industrial waste of forest products, was used as raw material to prepare WS-based supports WS-Gn-IM (n=1,2,3) functionalized with imidazole salt dendrimers by multi-step chemical modification, and then the WS-based heterogeneous catalysts WS-Gn-FeCl3 (n=1,2,3) were obtained by complexing WS-Gn-IM (n=1,2,3) with FeCl3. WS-Gn-FeCl3 (n=1,2,3) were characterized by various characterization methods, such as Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and elemental analysis. In addition, WS-Gn-FeCl3 (n=1,2,3) were used in the catalytic N-formylation reaction with CO2. The results showed that the generation of imidazole salt dendrimers had an important influence on the catalytic activity of the catalysts, and WS-G3-FeCl3 showed the highest catalytic activity. Using WS-G3-FeCl3 to catalyze the N-formylation reaction between organic amines and CO2 (1.0 MPa), formamide compounds can be efficiently synthesized at a temperature of 100 ℃ for 1 h. WS-G3-FeCl3 could be easily recovered and reused at least 10 times without a significant reduction in activity.关键词：Walnut shell powder;Dendrimers;CO2;N-formylation;Heterogeneous catalysis
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发布时间：2024-09-24 - 摘要：Boric acid functionalized polymer microspheres were prepared via suspension polymerization by using methacrylate (MMA) and 4-vinylphenylboronic acid (VPBA) as functional monomers, and ethyleneglycol dimethacrylate (EDMA) as crosslinkers, respectively. Naringin template was covalently anchored onto the surface of the microspheres by boronate affinity, and then a thin coating layer of dopamine and polyethyleneimine was formed onto the microspheres surface via oxidative self-copolymerization. After removal of the template with an acidic solution, the naringin surface molecularly imprinted microspheres (SMIMs) based on boronate affinity were obtained. The resulting materials were characterized by scanning electron microscopy, laser confocal microscopy, water contact angle experiment, nitrogen adsorption/desorption and infrared spectroscopy. The results show that the hydrophilic imprinted film has been successfully formed on the surface of boric acid functionalized polymer microspheres (BPMs). The adsorption experiments indicate that the SMIMs possess high adsorption capacity, excellent specific selectivity and fast adsorption kinetic rate toward template under water phase conditions. In addition, the extraction experiments reveal that the SMIMs as the adsorbed materials of solid phase extraction (SPE) can effectively separate naringin from Exocarpium Citri Grandis extract, and the total recovery of elution solution can reach 50.52%.关键词：Naringin;Boronate affinity;Surface imprinted microspheres;Dopamine co-coating;Extraction separation
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发布时间：2024-09-24 -
Calculation of Stereoselectivity and Alternating Probability for Chiral Cyclic Esters Polymerization
摘要：The stereostructure and monomer/unit sequence structure of chiral monomer homopolymers and copolymers are important parameters of the regularity of polymer. Improving the stereoselectivity of polymerization reactions and increasing the alternating level of two different chiral monomer copolymerization reactions are important means to obtain high regularity polymers. In order to demonstrate the performances of a new catalytic synthesis system, it is necessary to analyze the microstructure of the polymer through its nuclear magnetic resonance spectrum, and then derive the stereoselectivity and alternating level of the polymerization reaction. In recent years, there have been many publications on stereoselective polymerization and alternating polymerization of chiral cyclic ester monomers. However, there are few relevant literature, especially Chinese literature, on calculation methods. This article provides a systematic review of the identification of different chiral configurations in racemic chiral monomer homopolymers, and further demonstrates the stereoselectivity calculation methods based on two stereoselective mechanisms: chain end control mechanism and site control mechanism, as well as the alternating probability calculation method for polymers obtained from alternating polymerization reactions of different chiral monomers.关键词：Stereostructure;Sequence structure;Multiads;Stereoselectivity;Alternating probability- 0
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发布时间：2024-09-24 - 摘要：The glass transition temperature (Tg) is an important concept in polymer physics, marking the transition from the mobile state to the frozen state of polymer chain segments. It also serves as a crucial indicator for measuring the operating temperature of non-crystalline polymers. The dilatometry method for determining the Tg of polymers is helpful for students’ deepened understanding of the glass transition and the “free volume theory”. However, experimental failures are often encountered during the teaching process. Based on the experimental data, this article analyzed the two key issues that affect the experiment, both objectively and subjectively, and proposed different measures to improve the success rate of the experiment when using glycerol and ethylene glycol as filling reagents, respectively. This article aims to provide a reference for teachers and students in the major of the polymer materials and engineering.关键词：Polymer physics experiment;Dilatometry;Glass transition temperature
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发布时间：2024-09-24
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