Macromolecular Research最新文献

This study explores the effects of incorporating 2-hydroxypropanoic acid as a plasticizer, along with vacuum application, to enhance the properties of cellulose propanoate ester membranes, making them more suitable as porous materials. Scanning electron microscopy (SEM) revealed a substantial increase in pore formation within 2-hydroxypropanoic acid-modified membranes, which can be attributed to the plasticizer's role in enhancing polymer flexibility and reducing intermolecular forces. Fourier transform infrared spectroscopy (FT-IR) analysis indicated chemical shifts, including changes in carbonyl absorption peaks, signifying a decrease in intermolecular interactions. Thermogravimetric analysis (TGA) demonstrated that the inclusion of 2-hydroxypropanoic acid lowers the pyrolysis onset temperature, suggesting modified thermal degradation characteristics. Notably, porosity and air permeability testing showed a significant increase in performance, with porosity reaching 92.8%, confirming the plasticizer’s effectiveness in promoting pore development. This comprehensive evaluation highlights the potential of cellulose propanoate ester membranes modified with 2-hydroxypropanoic acid as high-performance materials. The study provides insights into the impact of plasticizers on polymer membrane properties, emphasizing applications in energy storage.

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The significant increase in porosity, reaching up to 92.8%

Composite fibers have attracted significant attention due to their distinctive structural properties and performance characteristics. Currently, the focus of research lies in innovating composite spinning technology and optimizing mechanism parameters. Among these techniques, rotary jet spinning has emerged as a notable method for cost-effective and high-speed production of composite fibers. Rotary jet spinning utilizes centrifugal force to stretch two polymer solutions from a composite droplet into a composite jet, with this morphological transformation occurring within the micro-triangle. The continuous and stable stretching motion within the micro-triangle directly influences the velocity distribution and flow stability of the composite solution, ultimately impacting the morphology and quality of the resulting composite fibers. This article presents the utilization of a rotary jet spinning device for fabricating composite fibers. It provides an in-depth analysis of the cone formation mechanism in composite spinning solutions and establishes a theoretical model for micro-triangle motion. The flow field of the micro-triangle is simulated using finite element simulation software, investigating how rotation speed and solution concentration impact PEO/PVP composite fiber morphology. Experimental results validate both theoretical modeling accuracy and numerical simulation, demonstrating that adjusting relevant parameters can control composite fiber morphology and structure.

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Formation process of micro-triangular zones in rotary jet spinning, numerical simulation, and experimental results

This study presents a low-cost thin-film fabrication technique for the synthesis of polymer-based composites. Various graphene/PLA composites were prepared at different concentrations. Comprehensive analysis using X-ray diffraction (XRD) and differential scanning calorimetry (DSC) confirmed that the graphene filler acted as a nucleating agent, increasing PLA’s crystallinity initially. Fourier transform infrared spectroscopy (FTIR) revealed the physical interaction between graphene and PLA, while UV–visible spectroscopy demonstrated a decline in transmittance with higher graphene content and enhanced UV blockage. The thermal stability showed an obvious improvement with an increase in the filler content. The optimal graphene content enhances the mechanical properties (elongation at break and tensile strength) of the composites. Moreover, the conductivity, absorption coefficient, refractive index, reflectivity, and dielectric response were modified by the desired filler loading. Moreover, using density functional theory (DFT), the energy bandgaps were observed to decrease with increasing graphene content. This study establishes clear structure–property relationships and identifies the optimal graphene loading for specific applications, particularly in packaging materials that require balanced mechanical and thermal properties. These findings will contribute to the development of sustainable high-performance materials that maintain PLA’s environmental benefits of PLA.

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Preparation procedure of graphite/PLA composite materials

Nature-inspired structures provide optimised designs that effectively balance significant energy absorption with lightweight features, making them highly suitable for crashworthiness applications. Their structured geometries facilitate controlled deformation and better impact resistance, thereby improving safety in automotive vehicles. The present study introduces novel nature-inspired hierarchical hexagonal tubes aimed at improving deformation behavior and energy absorption capabilities. The proposed thermoplastic composite tubes were fabricated using the 3D printing technique, which allows for precise control over both the design and the material properties. In order to determine the crashworthiness characteristics of the hierarchical hexagonal tube configurations, experimental testing was carried out subjected to quasi-static axial loads. The findings showed that the PG-HH6 tube exhibited superior crashworthiness characteristics highlighting stable, progressive folding with high mean crushing force of 8.31 kN, and the highest specific energy absorption capacity of 8.31 kJ/g. In this study, an extensive framework for the design of high-performance lightweight protective energy absorbers is presented. The framework utilize ideas inspired by nature and hierarchical designs in order to improve energy absorption capacities.

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We systematically investigated how contact geometry and channel length affect the gas-sensing performance of organic field-effect transistor (OFET)-based sensors employing poly (3-hexylthiophene) (P3HT) films without any molecular modification or additive doping. Devices with top-contact (TC) and bottom-contact (BC) architectures were fabricated with channel lengths ranging from 50 to 1000 μm. Gas sensing characteristics—including responsivity, sensitivity, and dynamic response behavior—were evaluated upon exposure to nitrogen dioxide. The results revealed that devices with intermediate channel lengths (~ 200 μm) exhibited the highest sensing performance, attributed to an optimal balance between the sensing area available for gas adsorption and the hole carrier diffusion length. Notably, BC gas sensors consistently outperformed their TC counterparts owing to the active layer’s improved gas accessibility. This study demonstrates that the gas-sensing area-specific optimization of channel length and device structure can substantially optimize gas-sensing performance, offering a facile and scalable strategy for developing high-performance organic gas sensors.

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We optimized the gas sensing performance of conjugated polymer-based devices by adjusting the device geometry—specifically channel length and contact structure—without chemical or physical modifications. Notably, the gas sensing area substantially optimizes the gas sensing performance, offering a facile and scalable strategy for developing high-performance organic gas sensors.

Emamectin benzoate (EMB) is a biological pesticide with high insecticidal activity and a broad spectrum of impact, highly effective against many worms, insects, larvae and even fungi. However, the activity of EMB is often rapidly reduced due to easy decomposition under UV radiations, sunlight, natural light, pH and high temperature. Therefore, encapsulating EMB with polymers is extremely necessary, both to protect it from environmental degradation agents and to control the release process, thereby prolonging its activity and improving its effectiveness. In this study, EMB was encapsulated with a mixture of microparticles from two biodegradable polymers, polylactic acid (PLA) and polybutylene succinate (PBS). The effect of the PLA/PBS ratios on the encapsulation and release performance of EMB was elucidated. Besides, the morphological structure, thermal properties, UV and thermal stabilities of EMB-encapsulated microparticles were also investigated. Especially, the toxicity of these pesticide microparticles was also evaluated through contacting test with superworm. The experimental results showed that the pesticide microparticles fabricated from the predominant PLA or PBS components had small diameter sizes, 4.96 and 3.73 μm, with EMB loading content above 29% and encapsulation efficiency higher than 87%. The microparticles still maintained their insecticidal efficacy up to 21 days of toxicity test showing the potential applications of these microparticles as smart pesticides against pests and storehouse weevils, to contribute to the sustainable development of agriculture.

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Structural morphology, release performance and toxic exposure test are the most important characteristics of slow-release pesticide formulations. For PLA/PBS microparticles loaded with EMB, the structural morphology of these microparticles depends on the variation of PLA/PBS ratio and strongly affects their other performances. LB20E corresponding to microparticles containing 20 wt% PBS exhibits a more perfect and finer particle structure, hence, they encapsulate EMB better and show more controlled EMB release with longer-lasting activity, as demonstrated by their ability to kill super worms for a longer period of time

Chitosan-based pluronic thermo-sensitive hydrogels represent a class of biomaterials characterized by their favorable biocompatibility and exceptional thermo-sensitive properties. The purpose of this study was to investigate their potential as carriers for embedding α-Mangostin (α-M), a bioactive compound derived from mangosteen peel, with the aim of inhibiting methicillin-resistant Staphylococcus aureus (MRSA). During the synthesis process, chitosan (CS), tannic acid (TA), pluronic F-127 (F127), and pluronic F-68 (F68) were combined to form the thermo-sensitive hydrogel, into which α-M was physically incorporated through crosslinking (designated as CTFF@α-M). We are very interested in the results obtained during the research process. The results of fluorescence imaging in small animals showed that CTFF extended the residence time of α-M in the body from 3 to 9 days, improved the bioavailability of α-M, and achieved the goal of sustained drug release. In vitro antibacterial experiments showed that CTFF@α-M (30 mg/mL) had an inhibition rate of 79.69% against MRSA, which was higher than CTFF@amoxicillin (AM) (5 mg/mL) increased by 71.68%. This study is expected to provide new insights into the integration of biomaterials and natural therapy, and emphasize the therapeutic potential of thermosensitive hydrogels and α-M in antibacterial treatment, especially in the fight against MRSA infection.

Graphic Abstract

In this study, a CTPP hydrogel was prepared using a physical cross-linking method, and α-M was encapsulated to create the CTPP@α-M drug-loaded hydrogel. Various characterization techniques, including SEM, FT-IR, and XRD, were employed to confirm its physicochemical properties. The hydrogel exhibited excellent water solubility, swelling capacity, sustained release characteristics, and biocompatibility, with the ability to transform into a semi-solid gel at 37 °C. In vitro experiments demonstrated that the CTPP@α-M hydrogel showed a powerful inhibitory effect on MRSA, exhibiting strong resistance to antibiotic resistance. Infection experiments using a mouse model confirmed that CTPP@α-M not only accelerated wound healing but also significantly reduced bacterial counts at the wound site. Moreover, the CTPP@α-M group significantly decreased the expression of pro-inflammatory cytokines while increasing the levels of anti-inflammatory factors, indicating its promising anti-inflammatory properties. Collectively, these data suggest that CTPP@α-M is a highly effective antibacterial thermo-sensitive hydrogel with excellent performance.

Diagram of the preparation of protocol CTFF@α-M and the treatment process of bacterial infection wounds

With the increasing demand for sustainable and non-toxic alternatives, bio-based plasticizers derived from renewable sources are being developed as environmentally friendly replacements for conventional synthetic plasticizers such as phthalate esters, adipates, trimellitates, benzoates, sebacates, etc. This study investigated the extraction of solid plasticizers from the leaves of the abundantly available Millettia pinnata plant (MPL). It was chemically treated through processes including phytoremediation, slow pyrolysis, alkylation, and filtration to extract the plasticizers. Scanning electron microscopy revealed a porous, smooth surface, while atomic force microscopy further supported the morphological suitability of these materials for biofilm and composite preparation. Fourier transform infrared spectroscopy identified functional groups such as alcohol, amine, amide, hydrocarbon, alkene, and aromatic compounds, while UV analysis confirmed the presence of alcoholic, amino, and carboxyl constituents. The primary phytoconstituents detected in the MPL were molecularly docked to determine binding affinity. Thermal analysis demonstrated that the extracted plasticizer can withstand temperatures up to 267 °C. Furthermore, X-ray Diffraction analysis yielded a high crystallinity index (47.5%) and a low crystalline size (11.3 nm), desirable characteristics in plasticizers. These findings suggest that plasticizers extracted from MPL leaves could serve as a viable, eco-friendly alternative to conventional synthetic plasticizers, offering a sustainable replacement with considerable functional benefits.

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Microencapsulation has a wide range of applications in many industries, and can be used to solve a variety of technical challenges, such as isolating reaction activities properties, encapsulating active substances, and improving the effective utilization of essential oils, etc. As the research on microcapsule applications advances, temperature-controlled release microcapsules have been proposed and emphasized. Microcapsules that achieve core-controlled release under temperature stimulation hold promising applications in agriculture, medicine, battery and other fields. The preparation methods and release types of temperature-controlled release microcapsules were reviewed in this paper, with a summary of the principles, advantages and disadvantages of common and novel preparation methods for slow-release, burst release, and burst release followed by slow-release microcapsules. Furthermore, the article also discusses the applications of temperature-controlled release microcapsules in agriculture, food, biomedicine, textiles, and batteries. It is expected to provide researchers with design inspiration and ideas for the development of temperature-controlled release microcapsules.

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Microencapsulation and temperature-responsive release: mechanisms and applications