Macromolecular Research最新文献

Traditional lignin-silver nanoparticle hydrogels are often limited by slow gelation (> 3 h), weak mechanical properties, and limited antibacterial efficacy. In this study, we introduce a novel approach by incorporating metal ions (Fe³⁺ and Al³⁺) into lignin-silver nanoparticle (AgNP) composites embedded in an acrylic acid (AA) matrix. This modification significantly enhances the hydrogel's multifunctionality. The presence of metal ions accelerates gelation, enabling rapid formation of highly crosslinked structures within seconds, a notable improvement over conventional lignin-based hydrogels, which typically exhibit slower gelation. Detailed characterization using SEM, FTIR, and XPS analyses reveals that metal ions interact with lignin moieties, inducing redox reactions and coordinating with functional groups, such as phenolic hydroxyl and carboxyl groups. The Fe³⁺-based hydrogel demonstrates potent antibacterial activity, driven by reactive oxygen species (ROS) generation (MIC = 1 mg/mL and MBC = 2 mg/mL against Escherichia coli and Staphylococcus aureus, respectively), while the Al³⁺-based hydrogel shows enhanced mechanical resilience, maintaining 95% recovery after compression. Compared to conventional lignin@AgNPs-AA hydrogels, both hydrogels exhibit remarkable multifunctional properties, including 2.5 × higher compressive strength, 90% DPPH radical scavenging activity, and improved stability. Mechanistic studies highlight distinct antibacterial pathways: Fe³⁺ promotes oxidative stress through Fenton reactions, while Al³⁺ disrupts bacterial membranes. This work establishes a rapid, metal-ion-catalyzed approach for the development of lignin-based hydrogels, addressing previous limitations and offering promising applications in wound healing, sensors, and environmental remediation.

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The rapid growth of the electronics industry has exacerbated the issue of heavy metal–contaminated wastewater, leading to significant environmental challenges. In recent years, various methods have been developed for heavy metal removal, among which membrane technology offers a practical and efficient approach to water purification. Chitosan, an abundant, biodegradable, and non-toxic biopolymer, serves as an excellent heavy metal adsorbent due to its high adsorption capacity and its versatility in film formation. As a result, chitosan-based membranes are regarded as superior alternatives to conventional membranes for heavy metal removal due to their active functional groups. In this study, porous chitosan membranes were prepared using silica particles as pore-forming agents. The fabrication process involved: (1) ozone treatment of a thin chitosan film, (2) casting a mixture of chitosan and silica particles onto the treated film, (3) drying the composite film and immersing it in a NaOH solution to remove the silica particles and create a porous structure, and (4) crosslinking the porous membrane by immersion in an epichlorohydrin solution. To optimize membrane properties, we adjusted the silica particle stirring time during the mixing process and monitored its effect on pore size, ultimately identifying conditions that yielded a membrane with improved heavy metal adsorption efficiency.

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TiO₂ with iron–porphyrin complex functionalization is proposed to act as hemoglobin accommodation matrix via multiple mutual interactions between elements of nano-complex and integrated heme protein including the competitive ligation. The spectrometric and electrochemical techniques are used to explore the influences of the mutual interactions on the electron transferring mechanism, electro-catalytic kinetics and the photo-electrocatalytic performance of nano-complex with protein immobilization. The electrochemical reaction occurred on hemoglobin based electrode consists of two concurrent redox processes and it is dominated by cofactors of hemoglobin in coordination with porphyrin derivative. Such redox processes indicate one electro-chemical reaction for heme sites of hemoglobin ligation with porphyrin ring with favorable electron shuttle efficiency (0.54 s⁻¹) and another one for electro-active sites onto TiO₂ with inferior activity. The redox process of such electrode could be classified into a typical quasi-reversible surface-controlling reaction with four electrons and two protons participation involvement. Such competitive ligation would debase H₂O₂ transformation with inferior dynamics (0.38 s⁻¹). The emulous complexation would increase the photo-electrical conversion efficiency remarkably. However, such competitive coordination could not be regarded as the decisive factor in restricting the electro-catalytic performance because the substrate diffusion is supposed to be the rate-determining step (6.7 × 10^–2 s⁻¹).

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The competitive coordination between porphyrin-like chemical: TCPP and heme site in hemoglobin molecule would produce the intermediate species with the unique spectroscopic and electrochemical features.

Multicompartment polymer nanoparticles, such as two-faced Janus and patchy particles composed of distinct chemical features, have received increasing attention because of their utility for interfacial and self-assembly applications originating from the asymmetric particulate structure. This review discusses such nanoparticles in several tens of nanometers produced by controlled polymerizations, which enable scalable synthesis with control of molecular characteristics. We focus on miktoarm core cross-linked star polymers and Janus core–shell bottlebrush polymers as 0D and 1D anisotropic nano-objects containing a discrete core and a compartmentalized shell. We discuss how controlled polymerizations can covalently build such complex architectures with spatial control of the constituting segments to achieve intramolecular segregation. Then, we collectively view their distinct interfacial and self-assembling behaviors reported in the literature from experimental and simulation perspectives.

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In this review, we discuss synthetic approaches to compartmentalized core cross-linked star and bottlebrush copolymers composed of chemically distinct segments and their self-assembly/interfacial behavior as Janus and patchy soft nanoparticles with spherical and elongated geometries.

Polyether Ether Ketone (PEEK) is gaining recognition as a promising polymer for various biomedical applications. This study investigates PEEK's mechanical, wear, and in vivo cytotoxicity behavior and its composites. The composites were reinforced with graphene oxide at 0.5, 1, and 1.5 wt% and hydroxyapatite at 10, 20, and 30 wt%. The tensile results reveal that 30 wt% HA infusion enhances tensile strength by 74.03% compared to bare PEEK (BP). Hybrid GO and HA-infused PEEK composites show further improvements by 134%, despite their impact resistance being unremarkable and hardness slightly enhanced. Wear properties were examined under varying loading conditions by pin-on-plate tribometer. The coefficient of friction and wear rate increase with load and are 0.5 wt% of GO–10 wt% of HA-PEEK, demonstrating superior wear resistance. MG-63 cell line was used to assess the biological behaviour of theprepared composites, including MTT assay and alkaline phosphatase assay. The higher cell viability was noted after 72 h of incubation, with ALP activity reaching 48.52 ± 0.99 U/L in 30 wt% HA-PEEK and cell viability in 95.41% at 0.5 wt% GO–10 wt% of HA-PEEK composite. The examination concludes the GO and HA-infused PEEK system will be a potential candidate for various orthopedic applications.

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Mechanical, Tribological and Cytotoxic Properties of GO-HA-PEEK Composites

Two Cardo-based diamine derivatives containing ester and amide groups were synthesized and polymerized with BPDA to prepare polyimides. In the ester-containing polyimide, both oxygen atoms carry negative charges, effectively suppressing intramolecular charge transfer to reduce molecular polarization and dipole moments, resulting in a low-dielectric constant (2.85) and excellent optical properties (86% transmittance at 450 nm). Conversely, the amide-containing polyimide forms intramolecular hydrogen bonds, exhibiting stronger intermolecular interactions that influence aggregation structures, delivering superior thermal stability with an ultralow coefficient of linear expansion (5.2 ppm·K⁻¹). However, the hydrogen and oxygen atoms in its structural units create complementary positive and negative charge centers, amplifying unit dipole moments and elevating the dielectric constant to 2.96. In addition, the hygroscopic nature of amide bonds increases water absorption to 3.7% due to interactions with polar water molecules. Both polyimides demonstrate robust mechanical performance, with tensile strengths exceeding 250 MPa and elongation at break surpassing 20%. The ester-containing polyimide achieves an optimal balance of dielectric properties, thermal stability, and mechanical performance, positioning it as a promising candidate for high-frequency electronic applications.

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Molecular simulation of PIs

Nanotechnology is a promising tool to enhance the therapeutic efficacy of chemotherapy by improving drug solubility, stability, and bioavailability. Among various nano-based drug delivery systems, nanogels exhibit a high drug-loading capacity, stimuli-responsive release mechanisms, and the ability to penetrate tumor tissues effectively, therefore offering precise and sustained delivery with minimal off-target effects. In this study, a self-assembled gelatin-polyoxyethylene stearyl ether (GB) nanogel was developed as a potential nanoformulation to improve the poor solubility, rapid degradation, and instability of bare curcumin. Gelatin was used as a functional agent to increase both the drug loading efficiency and biocompatibility of polyoxyethylene stearyl ether (Brij S100) based nanogels. By chemically binding amine groups of gelatin and p-nitrophenyl chloroformate-Brij derivative, different self-assembled amphiphilic GB nanostructures are achieved by varying the grafting ratio of gelatin and Brij. The GB loading cucurmin nanogels (GB/Cur) were successfully synthesized and evaluated through ¹H-NMR, FT–IR, and DLS measurements. It was found that the grafting ratio of 1:6 (gelatin:Brij mass ratio) results to the optimal particles with small size (127 nm), high stability (over 96 h), and drug loading efficacy (70%). In addition, the GB (1:6)/Cur system had the lowest Cur release at both pH 7.4 and pH 5.5 levels, in which the Cur was triggeredly released at the tumor microenvironment (pH 5.5). The in vitro results demonstrated that GB nanogels exhibited excellent biocompatibility on healthy cells (HDF), while the GB/Cur nanogel showed superior anti-cancer activity against MCF-7 cells. Therefore, this GB nanogel system has great potential in cancer treatment, through significantly improving the therapeutic efficacy and reducing the side effects of chemotherapy.

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pH-responsive gelatin-Brij nanogel to improve the bioavailability and stability of curcumin for targeted cancer therapy

Polymer nanocomposites with enhanced optical and electrical properties are highly sought after for various technological applications, including optoelectronic devices, energy storage systems, and sensors. This study focuses on the development and characterization of PMMA/PVDF nanocomposites incorporating LiCl/ZnO nanofillers, aiming to improve their optical and electrical properties. These nanocomposites were synthesized using a solution casting method, where varying concentrations of LiCl/ZnO nanoparticles were dispersed within a PMMA/PVDF blend. XRD analysis was employed to examine the crystalline structure of the nanocomposites, revealing a reduction in crystallinity with increasing LiCl/ZnO concentration. This suggests that the nanoparticles disrupt the polymer chain packing, leading to a more amorphous structure. FTIR spectroscopy confirmed the presence of both PMMA and PVDF in the nanocomposites and provided insights into the interactions between the polymers and the nanoparticles. In addition, UV–Vis–NIR spectrophotometry was used to study the optical properties of the nanocomposites, and the results showed a decrease in the optical band gap with increasing nanofiller concentration. This indicates that the nanocomposites can absorb light more efficiently, making them potentially suitable for solar energy harvesting applications. Electrical measurements were conducted to evaluate the conductivity and dielectric properties of the nanocomposites. The experimental results suggest that PMMA/PVDF-LiCl/ZnO nanocomposites have the potential to be used in a wide range of advanced technologies. Their properties make them suitable for optoelectronic applications such as optical coatings and bandgap tuners, as well as energy storage solutions like thin-film capacitors and solid polymer electrolytes. Furthermore, they could be used in electronic devices as conductivity regulators and high-permittivity tunable nanodielectrics.

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Preparation of polymer nanocomposite films.

In this study, we investigated the application of polyurethane (PU) coating on poly(ethylene terephthalate) (PET) films for optical film applications using pyrazole-blocked waterborne PU dispersion (PUD) (PUDpy) and PET-recycled polyol. Real-time Fourier transform infrared spectroscopy, dynamic mechanical analysis, ultra-micro hardness tests, ellipsometry and ultraviolet–visible spectroscopy were used to analyse the deblocking process for PUDpy, the reaction between PUDpy and polyol and the optical properties of the PU-coated PET film. The PU-coated PET films prepared in this study were clear, smooth and transparent enough for optical film applications. The deblocking of pyrazole and activation of isocyanate (NCO) groups started at 100 °C and ended at 180 °C, and the PU reaction between the activated NCO and polyol started immediately after NCO activation and lasted up to a maximum operation temperature of 240 °C. Notably, the PU reaction continued even after cooling to room temperature (25 °C), thereby necessitating a post-curing process to achieve complete curing. As the polyol content in the coating layer increased, the refractive index increased, whereas the coating layer hardness decreased. The evaluation of the compositional effects of the PUDpy:polyol precursor solution indicated that the optimal optical and mechanical properties of the PU-coated PET film were achieved when equal amounts of PUDpy and polyol were used in the precursor solution.

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The polyurethane (PU)-coated PET optical films were prepared using pyrazole-blocked waterborne PU dispersion (PUD) (PUDpy) and PET-recycled polyol.

To improve nitrate ion removal from water, we focused on synthesizing and evaluating a new polymer composite adsorbent based on gum tragacanth (GT) grafted with polyimidazolium (PIL-MGT). For this purpose, 1-butyl-3-vinylimidazolium chloride was synthesized to be grafted on the polymer surface. In the next step, GT was modified using maleic anhydride which led to the formation of the final adsorbent derived from the reaction between the ionic liquid and the modified GT. The FT-IR, FE-SEM, and TGA analyses were used to characterize synthesized compounds. The PIL-MGT adsorbent achieved a maximum removal efficiency of 95.66% and an adsorption capacity of 14.35 mg/g at pH 5, with a 20-min contact time and an initial nitrate concentration of 30 mg/L using 40 mg of adsorbent. To investigate the selectivity coefficient for nitrate ions removal, other ions such as bicarbonate, phosphate, chloride, and sulfate were also added to the nitrate solution. The results showed that nitrate ion removal was decreased the most due to the presence of chloride and the least by phosphate ions. The reusability of PIL-MGT was assessed through an adsorption/desorption experiment, and the results demonstrated consistent loading efficiency after six reuse cycles. Several models of isotherms and kinetics were undertaken, a second-order model best described the adsorption kinetics and the equilibrium data conformed to the Langmuir isotherm model. Finally, with the disk diffusion method, the antimicrobial properties of the adsorbent were investigated.

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Polyionic liquid based on modified gum tragacanth for the removal of nitrates