Macromolecular Research最新文献

Nerve agents, toxic organophosphorus compounds used in chemical warfare, present significant threats to security and public health. These agents disrupt physiological processes by covalently binding to acetylcholinesterase and blocking its ability to break down the neurotransmitter acetylcholine. Despite international efforts to eliminate such weapons, nerve agents continue to be employed due to their ease of production and stability. Their colorless, odorless nature, combined with their rapid action, underscores the importance of developing efficient detection techniques. Traditional detection methods, such as mass spectrometry, rely on the use of bulky, complex equipment and sample preparation procedures. Recent progress in the development of colorimetric and fluorescent probes has enabled direct visual confirmation of nerve agents without the need for such instrumentation. Building on these advancements, we present a turbidity-based approach to detect nerve agent mimics in water. Our method employs a polymer that, upon reacting with a nerve agent mimic, transforms from a water-insoluble polymer to a water-soluble polymer. This change causes a turbid polymer dispersion in water to become clear when exposed to a nerve agent mimic, offering a clear visual signal and a turn-on response in terms of light transmission. The method, which forgoes the need for spectroscopy, represents a platform for the future integration of the transparency-based detection scheme into sensor devices.

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A schematic illustration of the turbidity-based sensing used in this study and the corresponding digital photographs of the opaque dispersion of P1 in water along with photographs taken after the injection of DCNP

The interface is one of the most important factors affecting the macroscopic properties of polymer nanocomposite dielectrics. However, the study of the interface still faces many challenges, such as the evolution mechanism of the interface microstructure, interface compatibility, interface polarization, and the internal mechanism of crystallization. Due to the lack of direct observation and characterization of the interface, the theoretical research is seriously hindered. The influence of the nanoparticles embedded in the nanodielectric and the interfacial region on charge transport and accumulation is still unclear. Since the nanoscale interface is beyond the spatial resolution of traditional analytical techniques, the understanding of the interfacial charge behavior of polymer nanocomposites is largely dependent on speculation and indirect experimental results. Atomic force microscopy (AFM), as a nanometer high-resolution measuring instrument, has become an important means to study the interfacial microregions of polymer nanocomposite dielectrics. In this paper, the latest research progress of various interface models and functional AFM in interface structure, charge transport, and interface polarization are reviewed. The existing problems and possible development directions in the future are also discussed.

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Nanodielectrics show excellent dielectric properties, and many scholars try to explain this phenomenon from different angles, among which, the interface effect between nanoparticles and polymer matrix has aroused great interest of researchers. However, due to the complexity of the interface region, it is impossible to intuitively obtain the microstructure and interaction mechanism between the polymer chain and the nanoparticles in the interface region, so researchers have proposed different interface models to speculate and explain the macroscopic properties of the nanocomposites. Such as diffusion electric double layer model, multi-core model, interphase volume model, double layer model, water shell model, multi-zone structure model, penetration theory model, three-dimensional electrostatic model, deep trap model, etc.

The present work reports formulation of nanohybrids of CuFe₂O₄ using polypyrrole (PPy) in the weight ratios of 1%, 3% and 5%. The synthesized nanohybrids were characterized using FTIR, UV–Vis, XRD and SEM–EDS. The optical band gaps were calculated to be 2.31 eV, 2.11 eV and 1.74 eV for 1-PPy/CuFe₂O₄, 3-PPy/CuFe₂O₄, and 5-PPy/CuFe₂O₄, respectively. The photocatalytic degradation of urea and polyethene (PE) was carried out under visible light irradiation to study the effect of degradation of pollutants in presence of an organic–inorganic hybrid photocatalyst. The nanohybrids showed superior photocatalytic performance when compared with pure CuFe₂O₄. The maximum photocatalytic degradation was found to be 62% within 120 min using 5-Ppy/CuFe₂O₄ as photocatalyst and 40% degradation of PE films was achieved under microwave irradiation. The catalysts showed promising results for the highly efficient degradation of polymers.

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Photocatalytic activity of polypyrrole/copper ferrite nanohybrids

Almost all fabricated polymers need high stabilization to prevent harmful effects. Adding specialized chemicals that rule as light stabilizers (or UV stabilizers) and tailor to the resin's characteristics might accomplish the desired stability. In this work, five antipyrine derivatives were synthesized by the Schiff bases using five benzaldehyde substituents (benzaldehyde, 4-bromobenzaldehyde, 4-nitrobenzaldehyde, 4-dimethylaminobenzaldehyde, and 4-hydroxybenzaldehyde) with 4-aminoantipyrene. The produced complexes are characterized using hydrogen-1 and carbon-13 nuclear magnetic resonance (¹H-NMR and ¹³C-NMR, respectively) and Fourier-transform infrared (FTIR) spectroscopy; then they are filled with polyvinyl chloride (PVC) films. Further techniques are used to study the effects of long-term radiation exposure on these films. The IR spectra of PVC films showed side products containing polyene and carbonyl groups before, during, and after irradiation. The presence of antipyrine derivatives led to a decrease in the intensity of their associated functional groups. Furthermore, it is shown that films with antipyrine compounds performed lower weight loss when exposed to radiation compared with the virgin film.

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As effective treatments for sarcopenia other than exercise have not yet been established, research is needed on treatment methods using drugs that can control muscle atrophy. Therefore, in this study, we aimed to assess the use of intramuscular sustained-release drug delivery systems and direct intramuscular injection for the control of muscle atrophy. First, we evaluated the inhibitory effects of camphor on skeletal muscle atrophy in vitro. L6 skeletal muscle cells were analyzed by WST-1 cell viability, 3D tomographic lipid accumulation, and mitochondrial length. These results indicated that camphor significantly regulates L6 cell atrophy. Next, we established poly(lactic-co-glycolic acid) (PLGA)-based microspheres loaded with camphor (PLGA-camphor), with each PLGA-camphor microsphere have a size of ~ 66–75 μm. Camphor was released ~ 93.29% over 10 days. Finally, we administered the PLGA-camphor by intramuscular injection in the starved fed mice model and performed immunohistological and histological analyses. The results indicate that PLGA-camphor is able to significantly regulate skeletal muscle atrophy in vivo. Our results suggest that PLGA-camphor may affect skeletal muscle atrophy.

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In the present study, our research findings indicate that camphor significantly reduces muscle atrophy in vitro. It used gravity to load camphor into PLGA-based microspheres, which were 66–75 μm in size. The sustained release properties of PLGA-camphor microsphere were shown to release 93.29% of camphor over ten days. When directly injected into the muscle of mice with muscular dystrophy, the PLGA-camphor microsphere resulted in a noteworthy reduction in muscle atrophy, particularly in the starved-induced muscle atrophy model mice. Our results suggest that PLGA-camphor microsphere could be a promising method for addressing skeletal muscle atrophy.

Zinc gallate (ZnGa₂O₄) has been introduced in various studies as a good host phosphorescent material, and the change of its optical properties by ion doping has received much attention. However, ZnGa₂O₄ is mostly synthesized through solid-state reactions, the reaction conditions of high temperature and pressure were required, and its low dispersibility often limited its applications. In this study, we synthesized normal spinel structured ZnGa₂O₄ nanocrystals through a colloidal method. Lanthanide doping specifically with europium and terbium resulted in red (614 nm, photoluminescence quantum yield (PLQY): 2.2%) and green (545 nm, PLQY: 13.6%) emissions under 254 nm UV excitation. By applying the novel co-doping system of europium and terbium to the synthesis of colloidal ZnGa₂O₄ for the first time, we were able to achieve various color conversions including green, red, and white by adjusting amount and ratio of lanthanide ions.

Graphic Abstract

PL emission spectra by adjusting the ratios of Eu³⁺ and Tb³⁺ doping and the CIE 1931 chromatography diagram of Eu³⁺ and Tb³⁺ co-doping system of ZnGa₂O₄ nanocrystals

Global warming and environmental pollution from fossil fuels have spurred the need for clean energy technologies, among which thermoelectric (TE) devices are promising due to their ability to convert waste heat into electricity. Conducting polymers, particularly poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), have emerged as notable organic TE materials owing to their inherent low thermal conductivity, non-toxicity, and mechanical flexibility. PEDOT:PSS exhibits good stability under high doping level, yielding high electrical conductivity over 1000 S cm⁻¹. This review focuses on the enhancement of the TE performance of PEDOT:PSS through strategies such as post-solvent treatments to selectively remove excess PSS, thereby improving charge carrier mobility and electrical conductivity. Additionally, modifying the interaction between PEDOT and PSS can optimize the macro- and microstructure, leading to improved charge transport properties. The formation of PEDOT:PSS nanocomposites further enhances the Seebeck coefficient and electrical conductivity by enabling effective energy-filtering and improved charge transport pathways. These advancements underscore the potential of PEDOT:PSS in developing efficient, flexible, and stable TE generators for various applications.

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Strategies to improve thermoelectric performance of PEDOT:PSS

Waste (polyethylene terephthalate) (PET) water bottles are among the most common plastic wastes in nature. These plastic wastes disappear within hundreds of years after they are released into nature. Therefore, it causes serious environmental pollution. Therefore, it is important to make these wastes reusable. This study aims to bring a new perspective to the reuse literature. It is aimed to produce smart polymer blend from waste PET, which is highly demanded and important in practical applications. Therefore, in this study, waste polymer PET was blended with smart polymer PLA into filament blends. The thermal properties of the blends were analysed by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), chemical bond structures were determined by Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR spectroscopy) and shape memory tests were performed to determine whether the blends exhibit smart material properties. As a result of this study, it was observed that the thermal stability of the blended filaments varied according to the polymer ratio and the blend was characterized as an immiscible polymer blend. It was also found that the polymer blends exhibit shape memory properties.

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The novel injectable hydrogel (IH) is developed at 37 ℃ using the dynamic imine bond between mesquite gum with multi-aldehyde groups (MG-CHO) and carboxymethyl chitosan (CMCh). The investigation consists of determining the ideal concentration of an oxidizing agent to maximize the amount of aldehydes in mesquite gum. Then, the oxidized mesquite gum with the optimized aldehyde content (47.6%) determines the minimum gelation time (7 to 2 min.). Structural characterization is conducted through Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (¹H-NMR). The scanning electron microscopy (pore size = 14 to 34 µm) and rheometer examine surface morphology and rheological properties. The swelling ratio in phosphate buffer saline (PBS) at varying pH levels (5.5, 7.4, and 8.5) is measured for both dry and gel forms, revealing a decrease in the swelling ratio with increasing pH (5.5 to 7.4), followed by an increase at pH 8.5. Ciprofloxacin HCl is employed as a model drug for release experiments, and drug release behavior is compared in PBS at pH 5.5, 7.4, and 8.5, using the Korsemeyer–Peppas model to determine the release mechanism. Biocompatibility of injectable hydrogels is assessed regarding in vitro cytotoxicity using L-929 fibroblast cell lines and hemolysis assay. Additionally, the antibacterial study is analyzed using gram-positive and gram-negative bacteria. Furthermore, the hydrolytic biodegradability of IHs in phosphate buffer saline at pH 7.4 is evaluated.

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Synthesis of self-healing, biocompatible, and biodegradable injectable hydrogel using mesquite gum and carboxymethyl chitosan crosslinked through Schiff base mechanism utilized for drug delivery application

In this work, we proposed and synthesized sustainable nanocomposite polyurethane foam (PUF) derived from waste poly(ethylene terephthalate) (PET), reinforced with nano ZnO and incorporating aluminum hydroxide (ATH) as a flame retardant. Chemical structure of oligodiol obtained from the glycolysis of waste PET by diethylene glycol and ZnSO4.7H2O catalyst under microwave irradiation was confirmed by FTIR and 1H-NMR and continuously product of that was used to prepare PUF nanocomposite material. The density of the PUF decreased from 58 to 35 g/cm3 by the addition of ZnO nanoparticles, which are suitable for lightweight and insulation applications. In addition, the incorporation of ATH is indispensable to enhancing the flame retardancy of the PUF nanocomposites with UL-94 (HB) at 100 php ATH loading and UL-94 (VB) V-0 at 150 php ATH loading, simultaneously enhancing the mechanical properties of PUF/ZnO/ATH nanocomposites. The outcomes not only met the fire safety requisites, light-weight, and high mechanical properties for polymer nanocomposite material applications in construction but also incorporated a substantial proportion of discarded PET bottles sourced from associated industries.

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The PUF nanocomposite foam derived from waste PET has high mechanical property and excellent flame-retardant performance to create a sustainable recycling polymer material and improve waste management.