Chinese Journal of Polymer Science最新文献

Janus vesicles, unique nanostructures, have attracted significant attention for their diverse applications in biomedical and microfluidic systems. In practical micro-nano systems, flow and electric fields often coexist, and the perforation dynamics of Janus vesicles exhibit complex motion due to their synergistic effects. Studying Janus vesicle perforation dynamics under the combined influence of fluid flow and electric fields provides valuable insights into their applications in drug delivery, catalyst delivery, and controlled release. This study focuses on the perforation dynamics and directional motion of Janus vesicles in microchannels, emphasizing how electric field strength and charge distribution on the membrane influence vesicle migration, deformation, and trajectories. Results show that when electromagnetic forces and flow-driven forces align, increasing electric field strength promotes vesicle migration and perforation. Vesicle migration is correlated with charge distribution on the membrane, with broader distributions resulting in more pronounced migration. When electric field strength remains constant, charge distribution has little effect on vesicle deformation. Conversely, when electromagnetic forces and flow-driven forces oppose, increasing electric field strength inhibits vesicle migration. At a specific potential difference, charged vesicles cease movement before reaching the perforation site, indicating the critical potential for perforation. The study also reveals that the direction of the electric field significantly affects vesicle migration direction. Adjusting potential values at microchannel boundaries can control the directional movement of Janus vesicles. This research provides new insights into Janus vesicle behavior in complex environments and deepens understanding of their potential as drug carriers for delivery and targeted therapy.

The [2+2] photopolymerization of bisolefinic monomers is an important method for the synthesis of polymeric materials. However, these processes are usually carried out in solid states under the irradiation of high-energy UV light, while the corresponding [2+2] polymerization in solution has proved to be inefficient due to the lack of preassembly of the monomers. Herein, we demonstrate that the [2+2] polymerization of p-phenylenediacrylate monomers can be achieved in solution under visible light by employing energy transfer catalysis with 2,2′-methoxythioxanthone as a photocatalyst. Because no preassembly is required, this solution polymerization is applicable to p-phenylenediacrylate monomers with different ester groups, affording a series of cyclobutane-imbedded full-carbon chain polymers with high thermal stability, good solubility, and processibility. In addition, by virtue of the reversibility of the photo [2+2] cycloaddition, this [2+2] photopolymerization product can also undergo depolymerization to lower molecular weight polymers, suggesting the potential of this class of photopolymerization in the development of closed-loop chemical recyclable polymers.

The development of organic afterglow materials with high environmental stability and multi-mode luminescence remains a significant challenge in luminescent anti-counterfeiting. In this work, an organic luminescent molecule was encapsulated within polyacrylamide microspheres and embedded in a gold nanorod-doped, ferric ion-crosslinked hydrogel exhibiting upper critical solution temperature behavior. The obtained composites exhibited fluorescence, thermally activated delayed fluorescence, and phosphorescence. Through the application of extrusion or uniaxial stretching, the orientation of the gold nanorods was modulated, enabling polarization-dependent luminescence through transverse surface plasmon resonance absorption. At 300% uniaxial strain, the polarized fluorescence intensity difference at 520 nm reached 0.29. Furthermore, ultraviolet irradiation was employed to locally disrupt the orientation of the gold nanorods, resulting in depolarization within the irradiated regions. These areas displayed non-polarized fluorescence, while the non-irradiated regions retained both emission and fluorescence polarization characteristics. Localized imprinting was employed to modulate material thickness, thereby controlling the density of gold nanorods. Thinner regions exhibited weaker transverse localized surface plasmon resonance absorption, while thicker regions showed stronger absorption, enabling the coexistence of blue–green fluorescence and polarization patterns. Local humidification effectively reduced phosphorescence intensity, enhancing the material’s environmental responsiveness. The composite demonstrated excellent reversibility over multiple stretching–self-healing cycles and pattern-switching processes, highlighting its strong potential for multidimensional optical encryption and intelligent anti-counterfeiting applications.

The most widely used bisphenol A-type epoxy resin (DGEBA) in electrical engineering demonstrates excellent mechanical and electrical properties. However, the insoluble and infusible characteristics of cured DGEBA make it difficult to efficiently degrade and recycle decommissioned electrical equipment. In this study, a degradable itaconic acid-based epoxy resin incorporating dynamic covalent bonds was prepared through the integration of ester bonds and disulfide bonds, with itaconic acid as the precursor. The covalent bonding effects on the mechanical, thermal, electrical, and degradation characteristics were systematically evaluated. The experimental results revealed that the introduction of dynamic ester bonds enhanced the mechanical properties and thermal stability of the resin system, achieving a flexural strength of 141.57 MPa and an initial decomposition temperature T_5% of up to 344.9 °C. The resin system containing dynamic disulfide bonds exhibited a dielectric breakdown strength of 41.11 kV/mm. Simultaneously, the incorporation of disulfide bonds endowed the epoxy resin with remarkable degradability, enabling complete dissolution within 1.5 h at 90 °C in a mixed solution of dithiothreitol (DTT) and N-methylpyrrolidone (NMP). This research provides a valuable reference for the application of itaconic acid-based vitrimer with dynamic covalent bonds in electrical materials, contributing to the development and utilization of environmentally friendly electrical equipment.

The use of biomass feedstocks for the manufacture of high-performance polymers can help expand their range of applications and reduce their dependence on finite fossil resources. However, improving the heat resistance and hydrophilicity of bio-based polyesters remains a significant challenge. Herein, we introduce N,N′-trans-1,4-cyclohexane-bis(pyrrolidone-4-methylcarboxylate) (CBPC), a novel bio-based tricyclic dibasic ester synthesized from renewable dimethyl itaconic acid and trans-1,4-cyclohexane diamine via an aza-Michael addition reaction. As a unique comonomer, CBPC features a rigid tricyclic backbone that significantly enhances chain packing and thermal stability, whereas its pyrrolidone side groups impart tunable polarity and improved hydrophilicity. Using CBPC, diphenyl carbonate, and 1,4-butylene glycol, a series of PBCC copolymers with 10 mol%–30 mol% CBPC was synthesized via ester-exchange and melt polycondensation methods. Incorporation of CBPC raised the melting temperature (T_m) from 56.8 °C to 225.8 °C and the initial decomposition temperature (T_d5%) from 258.0 °C to 306.7 °C, positioning PBCC among the most heat-resistant bio-based polyesters reported. Additionally, the pyrrolidone units enabled transformation from hydrophobic to hydrophilic. This study demonstrates that CBPC is an effective and innovative building block for the design of bio-based polymers with enhanced thermal and surface properties, offering a promising strategy for the development of high-performance sustainable materials.

The preparation of polypeptide materials in continuous flow reactors shows great potential with improved reproducibility and scalability. However, conventional polypeptide synthesis from the polymerization of N-carboxyanhydride (NCA) is conducted at relatively slow rates, requiring long tubing or ending up with low-molecular-weight polymers. Inspired by recent advances in accelerated NCA polymerization, we report the crown-ether-catalyzed, rapid synthesis of polypeptide materials in cosolvents in flow reactors. The incorporation of low-polarity dichloromethane and the use of catalysts enabled fast conversion of monomers in 30 min, yielding well-defined polypeptides (up to 30 kDa) through a 20-cm tubing reactor. Additionally, random or block copolypeptides were efficiently prepared by incorporating a second NCA monomer. We believe that this work highlights the accelerated polymerization design in flow polymerization processes, offering the continuous production of polypeptide materials.

In this study, a novel linear polyimide chain (PTCDA-DCH) was used as an electrochemiluminescence (ECL) emitter, employing a chiral metal-organic framework (MOF) (Zn-Dcam-dabco) as the chiral selector and ferrocene (Fc) as a quencher to construct a chiral sensor for detecting histidine (His) enantiomers. Competitive interactions between Fc and His induce partial Fc desorption from the sensor surface, leading to ECL signal recovery. Differential Fc release due to the distinct binding affinities of Zn-Dcam-dabco for His enantiomers enabled precise chiral discrimination. Notably, the sensor achieved the quantitative detection of His enantiomers with an limits of detection (LOD) of 8 µmol/L. Furthermore, the sensor demonstrated excellent recovery rates of 98.0%–104% for l-histidine (L-His) and 92.0%–95.9% for D-His in spiked milk samples, validating its reliability for real-sample analysis. This study provides a promising platform for ECL-based chiral recognition, bioanalysis, and the rapid assessment of amino acids in food products.

Single-step ethylene polymerization over a binary catalyst, including zirconocene precatalysts of various designs, has been studied to obtain polymer compositions based on ultrahigh-molecular-weight polyethylene (UHMWPE) and low-molecular-weight HDPE (LMWPE) directly in synthesis. Zirconocenes rac-(CH₃)₂SiInd₂ ZrCl₂ (Zr-1) and rac-(C₆H₁₀)CpIndZrCl₂ (Zr-2) activated with methylaluminoxane (MAO) were used as the components of the binary catalyst. It has been shown that the use of Zr-1/MAO and Zr-2/MAO in ethylene polymerization at 30 °C leads to the production of UHMWPE with M_w=1000 kg·mol^-1 and LMWPE with M_w=18 kg·mol^-1, respectively. Reactor polymer compositions (RPC) with LMWPE fraction contents ranging from 9 wt% to 42 wt% were obtained when a molar fraction of Zr-2 in the binary catalyst (Zr-1+Zr-2)/MAO varied in the range from 0.3 to 0.85. A study of the molecular weight characteristics of RPC showed that it has a wide bimodal molecular weight distribution (MWD) and includes UHMWPE (M_w=1000 kg·mol^-1) and LMWPE (M_w=18 kg·mol^-1) fractions. The degree of crystallinity of the polymer products was determined using the DSC method. The tensile properties and melt indices of the materials were studied depending on the LMWPE fraction content in the polymer composition. UHMWPE/LMWPE compositions with high tensile properties and fluidity at a load of 5 kg were obtained.

Conductive hydrogels derived from natural polymers have attracted increasing attention in wearable electronics due to their inherent biocompatibility and sustainability. However, their poor mechanical strength, limited conductivity and unsatisfactory environmental adaptability remain significant challenges for practical applications. In this study, we report a high-performance gelatin-based conductive hydrogel (GPC) reinforced with polypyrrole-decorated cellulose nanofibers (PPy@CNF) and enhanced by a zwitterionic betaine/(NH₄)₂SO₄ solution. The PPy@CNF hybrid nanofillers were synthesized via in situ oxidative polymerization, enabling homogeneous dispersion of PPy along the CNF surface. The incorporation of PPy@CNF significantly improved both mechanical strength and conductivity of the gelatin hydrogel. Meanwhile, the Hofmeister effect induced by (NH₄)₂SO₄ strengthened the hydrogel network, and the introduction of betaine further enhanced its anti-freezing and moisture-retention properties. The optimized GPC hydrogel exhibited a high tensile strength of 1.02 MPa, conductivity of 1.5 S·m^-1, and stable performance at temperatures down to -50 °C. Furthermore, it was successfully assembled into a wearable strain sensor for real-time human motion monitoring, and as an electrode layer in a flexible triboelectric nanogenerator (TENG), enabling biomechanical energy harvesting and self-powered sensing. This work provides a promising strategy for developing sustainable, multifunctional hydrogels for next-generation wearable electronics.

Silibinin, a natural flavanone extracted from the milk thistle plant (Silybum marianum), has been shown to have various therapeutic applications, including liver protection, antioxidant, anticancer, anti-inflammatory, and many other effects. However, silibinin exhibits poor oral absorbance and low bioavailability owing to its limited water solubility, which limits its therapeutic efficiency and further clinical translation. To address these issues, we propose an antioxidant glycopolypeptide micelle strategy to target the delivery of silibinin to enhance its solubility, bioavailability, and antioxidant activity. This versatile micelle self-assembled from a glycopolypeptide, N-acetylgalactosamine-grafted poly(glutamic acid)-block-poly(tyrosine). N-acetylgalactosamine (GalNAc) is incorporated to enable liver targeting by selectively binding to the asialoglycoprotein receptor, which is overexpressed on hepatocellular carcinoma cells. The antioxidant polypeptide polytyrosine, as well as encapsulated silibinin, exhibits a synergistic reactive oxygen species (ROS) scavenging effect. The obtained results confirmed that silibinin can be effectively encapsulated into the glycopolypeptide micelles through self-assembly, achieving a loading efficiency and loading content of 96.6% and 42.9%, respectively. The silibinin-loaded glycopolypeptide micelles exhibited enhanced cellular uptake and a synergistic ROS scavenging effect in hepatocellular carcinoma cells. Overall, these antioxidant glycopolypeptide micelles hold promise as safe and efficient drug delivery systems for targeting hepatocellular carcinoma cells, potentially providing an effective strategy to enhance the bioavailability and antioxidant activity of silibinin.