Polymers最新文献

The development of multifunctional smart packaging materials capable of simultaneously monitoring temperature and suppressing microbial contamination is critical for next-generation food and pharmaceutical safety systems. In this study, we report the design and characterization of a polymeric film integrating a spin crossover (SCO)-based thermochromic sensor with zinc oxide (ZnO) nanoparticles serving as an antimicrobial agent. Beyond the individual functionalities, we demonstrate a synergistic effect between SCO and ZnO components. Notably, the SCO transition of the pristine SCO complex is broadened, and the hysteresis width of the transition is decreased (i.e., from 6 K to 1.5 K, 2 K, and 1.5 K for ZnO loading of 0.5%, 1%, and 2%, respectively), in the polysulfone-SCO-ZnO composites. Migration studies reveal that the co-existence of SCO and ZnO does not disrupt the low release profile of active agents, which remains low across ZnO loadings. The polymeric film exhibited dose-dependent antiproliferative activity against MCF-7 breast cancer cells, with a significant reduction in cell viability observed only at the highest tested concentration, indicating cytotoxic potential. This multifunctional platform represents a promising advancement in smart packaging design, enabling real-time thermal indication combined with the integration of ZnO as a literature-established antimicrobial component, within a non-toxic, and visually transparent system. Collectively, the material's properties offer promising scalability for both food and pharmaceutical packaging applications where visual clarity, antimicrobial integrity, and temperature monitoring are imperative.

Additive manufacturing (AM) has reshaped production methodologies by enabling the fabrication of complex geometries for high-performance applications. As a leading AM technique, Fused Deposition Modeling (FDM) is widely used for its versatility. However, the structural reliability of FDM-printed parts is fundamentally dictated by their mechanical performance, where impact toughness functions as a critical benchmark across demanding industrial environments. Polylactic acid (PLA) has distinguished itself as a premier biodegradable polymer, favored for its superior stiffness and processability. Nevertheless, the inherent brittleness and anisotropic behavior of FDM-printed PLA pose significant challenges, necessitating investigation of their fracture mechanics. This study firstly evaluates the impact toughness of FDM-processed PLA Izod specimens using impact tests, structured within a Taguchi design of experiments (DoE) methodology. An L27 orthogonal array was employed to investigate the influence of manufacturing parameters on impact behavior and fracture energy. Then, to achieve high-fidelity predictions from experimental data, the parametric effects were systematically investigated through an advanced machine learning framework. In the first stage, optimal prediction models were identified by evaluating five mathematical formulations hybridized with five nature-inspired optimization algorithms (GWO, SMA, GSA, FPA, and KH) across nine dataset combinations. In the second stage, these best-performing models were integrated into a metaheuristic ensemble using the GWO to perform a weighted aggregation. This hybrid ensemble methodology significantly enhanced predictive accuracy, achieving a Mean Absolute Percentage Error (MAPE) of 5.0847%, which represents a 37.3% relative improvement over the best individual base model.

Polyolefin materials are widely used due to their excellent properties and low cost. However, in high-temperature oxygen environments, they are susceptible to thermo-oxidative aging, which reduces mechanical properties and durability. This study systematically analyzed the aging behavior and mechanisms of polyolefins at varying temperatures and exposure durations through accelerated thermal oxidation experiments. The results indicate that the thermo-oxidative aging behavior of polyolefins can be divided into three stages. In Stage I, elevated temperature promotes segmental mobility and chain rearrangement, which increases crystallinity and temporarily improves mechanical properties. In Stage II, antioxidants are progressively consumed and oxygen-containing groups begin to accumulate, resulting in reduced crystallinity, a decline in mechanical performance, and the onset of slight surface yellowing. In Stage III, the antioxidant system is largely depleted and oxidative reactions are intensified, leading to mainchain scission and molecular weight reduction. This causes a further decrease in crystallinity, a significant deterioration in both strength and toughness, accompanied by aggravated yellowing. This study elucidates the thermo-oxidative aging mechanism of polyolefins, providing a theoretical basis for assessing their service life and evaluating the stability of waste plastics.

Glibenclamide (Gli), widely used in the management of type 2 diabetes mellitus (T2DM), shows low oral bioavailability, while curcumin (Cur) is limited by poor aqueous solubility and instability. This study reports the development of a niosomal co-delivery system combining hypoglycemic and antioxidant agents to improve formulation performance for T2DM. Gli and Cur were co-encapsulated into niosomal vesicles (NIOs) using the thin-film hydration method, followed by surface coating with chitosan (CS). The formulations were characterized by dynamic light scattering, scanning transmission electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy, complemented by in vitro release studies under simulated gastrointestinal conditions. The prepared NIOs exhibited particle sizes between 413.5 and 576.9 nm, with encapsulation efficiency strongly dependent on formulation composition. The optimized system showed high encapsulation efficiency for both Gli (98.95 ± 0.87%) and Cur (91.09 ± 2.00%). In vitro release studies demonstrated enhanced release compared with the physical mixture, providing gastric protection and sustained intestinal delivery. Release kinetics indicated controlled drug release governed by diffusion- and erosion-based mechanisms. Both uncoated and CS-coated NIOs displayed good physical and osmotic stability, with CS coating further reducing drug leakage. These results highlight the potential of niosomal systems for efficient Gli and Cur administration in T2DM.

The prediction of fatigue life is critical in the design process, and current models offer a viable alternative to costly and time-consuming experimental fatigue testing. The constitutive fatigue model used integrates low-cycle and high-cycle fatigue behavior. This model is grounded on the concept of fatigue damage evolution and incorporates a moving endurance surface within the stress space, eliminating the need for ambiguous cycle-counting methods. An interesting observation is that many polymers exhibit macroscopic fatigue characteristics, specifically, the form of the S-N curve similar to those observed in metals. Consequently, all fatigue model parameters were expressed in terms of the well-established Coffin-Manson-Basquin model parameters. However, the constitutive mathematical modeling itself is computationally time-consuming, particularly when applied to predict high-cycle fatigue across large design spaces. Therefore, the proposed model was utilized exclusively to generate high-quality data for training machine learning models that offer significantly improved computational efficiency. The high-cycle fatigue design of polymers and other ductile materials, traditionally dependent on expensive and time-consuming experimental methods, is now expedited through an advanced modeling framework that combines constitutive mathematical modeling with AI-based approaches.

In this study, ultrasound-assisted extraction (UAE) of Adenophora triphylla root polysaccharides (ATRPs) was optimized using response surface methodology (RSM), and the physicochemical and functional properties of the resulting polysaccharides were investigated. A Box-Behnken Design (BBD) was applied to optimize the UAE conditions for ATRPs. The optimal UAE conditions for ATRPs with the maximum extraction yield were an extraction temperature of 34 °C, an extraction time of 41 min, and a solvent-to-solid ratio of 34 (mL/g). Under these conditions, the maximum extraction yield of UAE-ATRPs (12.46%) was significantly higher than that obtained by water extraction without sonication (WE-ATRPs, 9.76%). The results of monosaccharide composition showed that WE-ATRPs and UAE-ATRPs were heteropolysaccharides, mainly composed of glucose. In addition, FT-IR and ¹H-NMR analyses indicated that both ATRPs had α-pyranose-type glycosidic structures. The optimal UAE process reduced the glucose content from 57.70% to 53.87% relative to WE-ATRPs. Moreover, UAE-ATRPs exhibited lower solution viscosity and improved the emulsifying properties relative to WE-ATRPs. Both ATRPs also exhibited anti-inflammatory activity by inhibiting nitric oxide synthesis. In summary, our findings suggest that UAE is an effective approach for improving the extraction yield and functional properties of ATRPs, highlighting their potential applications in the food industry.

This study investigated the effect of a polyurethane-modified polycarboxylate superplasticizer (P-PCE) on the volume deformation of hydraulic concrete. Macroscopically, the autogenous and drying shrinkage of concrete incorporating different types and dosages of PCEs were measured to analyze their influence. Microscopically, scanning electron microscopy (SEM) was employed to observe the hydration product morphology at 7 and 28 days. Low-field nuclear magnetic resonance (NMR) was utilized to quantify the pore structure, and a fractal dimension model was applied to correlate the microstructural characteristics with the macroscopic deformation. The results demonstrated that, compared to conventional PCEs, the laboratory-synthesized P-PCE (40% solid content) significantly reduced shrinkage and improved pore structure, thereby enhancing the volumetric stability of hydraulic concrete. The experimental results showed that, compared to ordinary PCE, P-PCE reduced the 60-day autogenous-shrinkage strain by 8.8% and the drying-shrinkage strain by 8.4%. Additionally, it decreased the total porosity by 19.46%, while also optimizing the pore structure distribution, thereby significantly improving the volume stability of hydraulic concrete.

Effective treatment of coal slime water is essential for sustainable coal preparation plant operation but hindered by the stable suspension of fine, negatively charged particles. To address this, a novel star-shaped inorganic-organic hybrid polymer (aluminum hydroxide-polyacrylamide, Al-PAM) was synthesized via in situ polymerization. Its performance was systematically compared with well-established coagulants/flocculants-polyaluminum chloride (PAC), non-ionic polyacrylamide (NPAM), and their binary combination through settling tests and quartz crystal microbalance with dissipation monitoring (QCM-D). The results showed a positive correlation between the molecular weight of Al-PAM and its flocculation efficiency. The optimal variant, Al-PAM-442, achieved an exceptionally high initial settling rate (50.4 m/h) and low supernatant turbidity (45.77 NTU) at an ultralow dosage of 6 mg/L. QCM-D analysis elucidated the mechanism: Al-PAM forms a thick, soft, and irreversibly adsorbed hydrated layer on silica, enabling strong electrostatic anchoring and effective polymer bridging. In contrast, PAC adsorption was reversible, while NPAM formed a thin, compact film with poor bridging capacity. Although the combined PAC/NPAM system showed synergistic performance, it required a significantly higher dosage (70 mg/L). This study demonstrates that the star-shaped Al-PAM architecture successfully integrates charge neutralization and bridging into a single molecule, offering a highly efficient and practical solution for industrial coal slurry dewatering.

The surface properties and electrical behavior of carbon-based materials can be effectively modified by energetic ion irradiation. In the present study, graphene oxide (GO) and cyclic olefin copolymer foils (COC, Topas 112 and 011, respectively) were irradiated with 1 MeV Au ions using a 3 MV Tandetron accelerator at fluences of 1 × 10¹⁴, 1 × 10¹⁵, and 2.5 × 10¹⁵ cm^-2. The irradiation induced systematic modifications in surface chemistry, morphology, wettability, and electrical properties. Composition changes were investigated using Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA), while surface morphology and roughness were characterized by atomic force microscopy (AFM). This revealed a clear fluence-dependent evolution of nanoscale topography. The vibrational characteristics were assessed through Raman spectroscopy, and the chemical composition of the surface layers was analyzed by X-ray photoelectron spectroscopy (XPS). The surface wettability was evaluated by static contact angle measurements, and surface free energy was determined using the Owens-Wendt-Rabel-Kaelble (OWRK) method. These measurements showed a consistent decrease in water contact angle and an increase in surface free energy with increasing ion fluence in the COC substrates, whereas GO exhibited a distinct response. Electrical characterization demonstrated a pronounced fluence-dependent decrease in sheet resistivity in polymers. The results show that 1 MeV Au ion irradiation enables systematic and fluence-dependent modification of both surface and electrical properties.

The development of smart coatings with active protection is a promising approach to prolonging the service life in extreme environments. Herein, the corrosion inhibitors 2-mercaptobenzimidazole (MBI) and CeO₂ were in situ loaded onto the surface of graphene oxide (GO) by dopamine (DA) polymerization, and we ultimately obtained the multifunctional composite MBI@CeO₂@PDA@GO (MCPG). The electrochemical impedance spectroscopy (EIS) results revealed that after 30 days of immersion in the corrosive media, the |Z|_0.01 Hz value of MCPG/WEP coating remained at 3.7 × 10⁹ Ω/cm², which displayed four orders of magnitude higher than that of pure WEP coating (1.4 × 10⁵ Ω/cm²). In a 200 h salt spray test, the MCPG/WEP coating also demonstrated minimal corrosion products and bubbles, affirming the exceptional corrosion-inhibiting effect and excellent self-healing performance. Consequently, the synergistic combination of pH-sensitive properties and outstanding barrier effect imparted dual active/passive anti-corrosion capabilities to the coating, resulting in long-lasting metal protection.