High-performance regenerated cellulose materials rely on the precise regulation of aggregate structures, particularly the long-range ordered alignment of molecular chains. However, conventional regeneration is generally hindered by cellulose chains' strong tendency toward disordered aggregation, making it difficult to achieve directional assembly of microstructures. The alkali/urea aqueous system provides an ideal precursor for alignment via dynamic inclusion complexes, enabling the low-temperature non-derivatizing dissolution of cellulose and thereby offering an ideal homogeneous precursor for the construction of ordered structures. Recently, an "oriented crosslinked network" strategy has been established based on this system under hydrogen-bond shielding. In this strategy, cellulose chains remain dissolved via dynamic inclusion complexes, while intra- and intermolecular hydrogen-bond interactions are temporarily screened. Chemical crosslinking is then used to construct a covalent topological network, transforming the deformation mechanism from the random motion of individual chains to the cooperative deformation of the network. Subsequently, external fields are employed to induce orientation, followed by the permanent locking of the aligned structure via hydrogen bond reconstruction triggered by the dissociation of inclusion complexes. This review summarizes the mechanisms by which crosslinked network topology regulates molecular-chain conformation and discusses orientation-induction methods, including flow fields, mechanical stretching, and microfluidic techniques. Particular emphasis is placed on how highly oriented structures can overcome the strength‒toughness trade-off and improve functional properties. In addition, recent advances in micro-Raman imaging for in situ characterization of multiscale orientation distribution and microscopic stress transfer are highlighted, underscoring its unique advantages in elucidating structure-property relationships. Finally, future prospects in this field are discussed.

Poly(lactic acid) (PLA) has attracted extensive attention owing to its renewable raw materials, biodegradability and many other advantages. However, its poor toughness severely limits its practical application. Traditional toughening methods suffer from problems such as the introduction of petroleum-based components, low toughening efficiency, or deteriorated biodegradability. In this study, a bio-based polyester l-BPE_LAn containing lactic acid units, with low glass transition temperature (T_g) and low molecular weight, was designed and synthesized. PLA/l-BPE_LAn blends were prepared via melt blending, and the struture, mechanical properties, processing properties and degradation behavior of the PLA blends were systematically investigated. The results showed that the blend with 15 phr l-BPE_LA20 exhibited an elongation at break of (609.5±23.5)% and a notched impact strength of (39.5±1.6) kJ/m², achieving super-tough modification of PLA. The toughening mechanism was attributed to the multiple microcracking mechanism induced by l-BPE_LA20. Meanwhile, the melt flow rate of the blend reached 12.8 g/10 min, enabling 3D printing into products with complex structures. Simulated composting degradation tests revealed that the blend was almost completely degraded within 30 days, while obvious residues remained for neat PLA. This study provides a novel strategy for developing fully bio-based, high-toughness and rapidly degradable PLA materials, which will promote the practical application of environmentally friendly PLA materials.

Employing functionalized initiators is a key strategy for the efficient synthesis of end-functionalized polymers. Initiators containing protonic functional groups are often incompatible with the harsh conditions of anionic polymerization, leading to uncontrollable product structures. In this work, amino-protected dipeptides were used as biomass initiators to achieve one-step controlled synthesis of end-functionalized poly(ethylene/propylene oxide) in multiprotonic systems. Experimental results and theoretical calculations jointly demonstrated that polymerization occured exclusively from the carboxyl site of the dipeptide. The two-component Lewis pair organocatalyst exerted an acidity reversal effect between the alcohol hydroxyl group at the growing polyether chain end and the peptide amide on the initiator moiety, ensuring that the polyethers had controllable molar mass, low dispersity, and fully retained end-group dipeptide structures. This work broadens the applicability of the acidity reversal mechanism and site-selective anionic ring-opening polymerization method, laying the foundation for further expansion of biomass initiators and the construction of diverse biomass-polyether functional materials.

To achieve green and efficient ring-opening copolymerization of cyclic monomers and prepare sustainable block copolyesters, this study developed a series of bifunctional ionic organocatalysts based on ureas and organic bases. These catalysts exhibited excellent catalytic activity and controllability in the ring-opening polymerization of lactides and lactones, achieving a turnover frequency (TOF) as high as 2.341×10⁵ h^-1 in the homopolymerization of lactide. Among the prepared bifunctional ionic urea-base organocatalysts, the catalyst U2BN, derived from the reaction of 1,3-diphenylurea (U2) and tetrabutylammonium hydroxide (BN), exhibited high catalytic activity toward both lactide and caprolactone simultaneously. Therefore, a triblock copolyester with poly(ε-caprolactone-co-δ-valerolactone) (PCVL) as the soft segment and polylactide (PLA) as the hard segment was successfully synthesized via a one-pot sequential feeding strategy using U2BN. Nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) analyses confirmed the ABA sequence structure. The PLA-PVCL-PLA block copolyester exhibited a microphase-separated morphology, as evidenced by the distinct melting peaks of PVCL and PLA in the differential scanning calorimetry (DSC) analysis. This structural feature endowed the polymer with thermoplastic elastomer characteristics, achieving a combination of high elongation at break and high elastic recovery. This study provides a new strategy for the catalytic and structural regulation of biodegradable copolyesters.

Diglycidyl ether of bisphenol-A (DGEBA) is widely used as a matrix material for wind turbine blades due to its excellent comprehensive properties. However, the highly cross-linked three-dimensional network formed after curing severely limits their degradability and recyclability. To address this issue, a biodegradable bio-based epoxy resin (VTEP) was synthesized using bio-derived vanillin as the raw material, introducing dynamic Schiff base linkages via a condensation reaction. The effects of different polyetheramine curing agents (D400, D230, and T403) on the mechanical and thermal properties of VTEP were systematically investigated. The results demonstrated that T403, which features higher functionality and shorter polyether chain segments, enabled the formation of a curing network with a higher crosslinking density, thereby significantly enhancing the overall mechanical performance. Compared with the conventional DGEBA/T403 system, VTEP/T403 exhibited markedly improved tensile, flexural, and impact strengths by 29.31%, 32.07%, and 47.10%, respectively, and the cured product could be completely degraded in a phosphoric acid solution at 25 ℃. Furthermore, VTEP was incorporated into DGEBA to construct VTEP/DGEBA composite systems. The composite with 20 wt% VTEP achieved optimal performance, showing increases of 26.40%, 30.66%, and 42.90% in the tensile, flexural, and impact strengths, respectively. Notably, the composite could be fully degraded within 15 h under mild conditions (85 ℃, phosphate/DMF/H₂O₂ system). This study demonstrates a feasible strategy for integrating dynamic Schiff base chemistry into epoxy networks, offering a promising pathway toward high-performance and recyclable bio-based thermosetting resins.

Achieving the simultaneous removal of gas-solid pollutants composed of respirable particulate matter (PM) and toxic gases under harsh high-flow operating conditions remains a key technical bottleneck in personal protection and environmental remediation. In confined occupational environments, PM frequently coexists with sulfur dioxide (SO₂). However, many reported materials suffer from insufficient structural stability, poor interfacial compatibility, and limited selectivity under high-throughput and high-humidity conditions, thereby necessitating the development of multifunctionally integrated separation materials. Herein, a layer-by-layer self-assembly strategy was employed to construct a biomimetic armor-functionalized poly(lactic acid) nanofibrous membrane (LbL-APLA). Specifically, the membrane featured a polydopamine interlayer and in situ coordination‑grown bimetallic metal‑organic framework (BMOF) nanocrystals successively assembled onto the fiber surfaces. This hierarchical architecture imparted the composite membrane with an exceptionally high nanocrystal loading (72.3%), a large specific surface area (547 m²·g^-1), and a high density of coordinatively unsaturated metal sites. To evaluate its performance under realistic conditions, tests were conducted under simulated high‑velocity airflow (85 L·min^-1). Exploiting the synergistic mechanisms of size exclusion, electrostatic attraction, and graded pore confinement, the membrane attained an ultrafine PM_0.3 removal efficiency of 96.7%, a high SO₂ uptake of 6.2 mmol·g^-1, and an outstanding SO₂/N₂ IAST selectivity of 6480 in a mixed gas stream. In addition, the high surface electroactivity and signal transduction capability of the multifunctional membrane provided a versatile material platform for self-powered health-monitoring systems, thereby addressing the long-standing trade-off among high dust tolerance, high gas permeability, and selective molecular recognition under complex operating conditions. This study offers a new structural design paradigm and reliable technical support for the development of next-generation integrated air-purification systems and intelligent environmental materials.

Using bovine serum albumin (BSA) and polyethyleneimine (PEI) as raw materials, an amyloid-like protein composite materials, PTB@PEI, was rapidly fabricated by employing tris(2-carboxyethyl) phosphine (TCEP) to break the intramolecular disulfide bonds of BSA, thereby inducing a conformational transition from α-helix to β-sheet and subsequent amyloid-like aggregation. Static adsorption experiments demonstrated that PTB@PEI exhibited excellent gold ions adsorption performance, with an adsorption efficiency of up to 93% and a maximum saturated adsorption capacity of 1270 mg/g. Mechanistic studies revealed that the gold ions recovery process proceeded through a synergistic mechanism involving electrostatic enrichment, coordination complexation, and in situ reduction. Under acidic conditions, the protonated amine groups in PEI efficiently captured [AuCl₄]^- through strong electrostatic interactions, while electron-rich sulfur-, nitrogen-, and oxygen-containing amino acid residues in BSA coordinated with Au(III). Subsequently, cysteine and tyrosine residues further reduced Au(III) to Au(0). Moreover, PTB@PEI displayed remarkable anti-interference capability and high selectivity in complex anionic systems, multi-metal coexisting systems, and aqua regia leachates of waste CPUs. This study provides a new strategy for the design and application of bio-based polymer materials for metal resource separation.

In view of the current issues of petroleum resource depletion, the greenhouse effect, and environmental pollution, the full development and high-value utilization of bio-based materials are in line with the current development concepts of the bio-economy and circular economy. At the same time, in response to the difficulty of balancing the high performance and recyclability of polyurethane materials, the development of high-performance and reusable polyurethane using bio-based polyols has attracted much attention. In this study, palm oil-based diethanolamide (POEA) was prepared by the ammonolysis of palm oil (PO) and used as a bio-based polyol to react with poly(tetramethylene ether glycol) (PTMEG-1000), isophorone diisocyanate (IPDI), and boric acid (BA). A series of palm oil-based polyurethane elastomers (POPU-BAs) with boron/nitrogen (B/N) internal catalytic dynamic covalent bonds were prepared. The results showed that the material exhibited excellent mechanical properties and thermal stability, with an initial thermal decomposition temperature higher than 200 ℃ and demonstrated good self-healing and repeatable processability. Among them, the POPU-BA2 sample achieved complete scratch repair after treatment at 120 ℃ for 2 h. The tensile strength and elongation at break after the first cycle of recycling reached 19.5 MPa and 299.1%, respectively, and the recovery efficiency reached 91.5% and 100.9%, respectively. Simultaneously, the polymer contains abundant polar groups and exhibits benign adhesion to various substrates underwater. This multifunctional polyurethane elastomer, which integrates bio-based sources, high mechanical strength, self-healing, and recyclability, provides a feasible technical strategy for the design and synthesis of polyurethane covalent networks derived from plant oil.

This study reports the preparation of novel degradable copolymers via ring-opening metathesis polymerization (ROMP) of bio-based oxanorbornene derivatives and 2,3-dihydropyrrole derivatives. First, oxanorbornene derivatives (OxaNBs) were obtained through a two-step process involving the reaction of bio-based furfuryl alcohol with itaconic anhydride followed by esterification. These derivatives successfully copolymerized with commercial N-benzyloxycarbonyl-2,3-dihydropyrrole (CBZDHP) using G3 as the initiator. The study revealed that CBZDHP cannot undergo homopolymerization by itself; instead, it was isolatedly distributed within the polymer chains after copolymerization. Importantly, the incorporation of CBZDHP via ROMP introduced cleavable enamide groups, providing potential sites for subsequent degradation. By varying the side-chain structures on the OxaNBs, the glass transition temperature and mechanical properties of the copolymers could be tuned. The copolymers exhibited significant degradation behavior under acidic conditions, with the degradation products confirmed as oligomeric fragments by NMR and SEC. This work offers a new route for constructing main-chain degradable functional polyolefin materials from renewable biomass resources via ROMP, holding potential application value in the fields of biomedical and environmentally friendly materials.

Developing novel bio-based flame retardants and exploring their application scope is of great significance for reducing environmental pressure. Carrageenan (CA), a sulfated galactan derived from marine red algae, possesses good potential for flame-retardant applications; however, the application as a flame retardant in flammable substrates is still very limited. This study proposed an adhesive using carrageenan as a flame-retardant additive and melamine-modified urea-formaldehyde (MUF) resin as the matrix for producing flame-retardant plywood. The polyhydroxy characteristics of carrageenan and its efficient catalytic dehydration and charring ability not only ensured good compatibility with the matrix but also enhanced flame retardancy in the condensed phase by promoting the formation of a dense intumescent carbon layer. Compared with plywood without carrageenan, the bonding strength of the plywood with 2.0% carrageenan addition was increased by 40.3%, with a glue line thickness of only 125 μm. During ignition, the after‑flame and after‑glow time were effectively shortened, heat release was reduced, the limiting oxygen index (LOI) was increased to 35.0%, and smoke suppression was also achieved, thus overall improving the fire safety rating of the plywood. This work provides new insights for the processing of flame‑retardant plywood and the application of carrageenan in the field of flame retardancy.

The influence of entanglement networks on polymer crystallization during uniaxial stretching was investigated using coarse-grained molecular dynamics simulations. Polymer systems with different entanglement densities were constructed based on the Kremer-Grest bead-spring model. After equilibration at a high temperature, the systems were stretched along the Z-axis under isothermal conditions to examine the evolution of the chain orientation, crystallinity, and entanglement distribution. The results showed that highly entangled systems exhibited a lower critical onset strain for crystallization and achieved higher crystallinity in the intermediate strain range. Although entanglements locally hinder chain alignment, they acted as stress transfer points during stretching, promoting the orientation of adjacent segments and facilitating the crystallization. Entanglements were gradually expelled from the crystalline regions as crystallization proceeds. Local stress analysis confirmed that the beads near the entanglements experienced higher stress and degree of segment orientation, supporting the proposed stress transfer mechanism. This study reveals the dual role of entanglements in strain-induced polymer crystallization and provides insights into the structural evolution during processing.

The secondary structure of proteins is tightly linked to their biological functions, and investigating polymer-protein interactions and their regulatory rules is of great significance. Linear poly(acrylic acid) (PAA) binds to amino groups on protein surfaces and triggers conformational transitions. However, systematic studies on how PAA with distinct topologies modulates protein conformation and function remain scarce. This work adopted the strategy of comparing molecular weights under identical topologies and contrasting topologies at comparable molecular weights. A series of linear and bottlebrush PAA samples were synthesized, and circular dichroism spectroscopy was employed to explore how polymer structures regulate proteins. The results revealed that linear PAA induced the transition from α-helix to β-sheet in low-molecular-weight proteins; longer equilibrium time for conformational conversion were observed at higher PAA molecular weights. At similar molecular weights, bottlebrush PAA accelerated this conformational transition. In contrast, the conformational changes of high-molecular-weight proteins showed weak correlation with PAA structures. PAA topologies exerted divergent effects on different proteins: bottlebrush PAA stabilizes β-galactosidase activity, whereas linear PAA impaired it. Mouse immunization assays verified that linear PAA acted as an adjuvant for ovalbumin (OVA) to elicit elevated levels of antigen-specific IgG and interferon-γ. Mechanistically, drastic antigen conformational remodeling induced by bottlebrush polymers tended to damage critical epitopes, while mild, gradual regulation by linear polymers better preserves functional epitopes. In summary, the molecular weight and topology of polymers serve as key parameters governing protein structure and function.

Recently, carbon monoxide (CO)-based gas therapy has emerged as a promising strategy to combat multidrug-resistant bacterial infections owing to its prominent antibacterial efficacy and anti-inflammatory capacity. However, the gaseous nature and high reactive of have hindered its stable loading and precise delivery. To overcome this, we developed a class of tripeptide-based delivery systems by appending the functionalized CO donor 3-hydroxyflavone (HF) to the N-terminus. Thus, the CO donor was precisely loaded, and the subsequent controlled release of CO could be modulated by irradiation with 405 nm light. Moreover, we revealed that when the side chain of the amino acid at the N-terminus changed, the resultant morphology varied, ultimately leading to distinct CO-releasing patterns. In vitro experiments further revealed that the HF-peptide conjugates exhibited light-triggered antibacterial and anti-inflammatory activities. We believe that our findings would be an important addition to the library of CO delivery platforms, which provides a way to achieve precise loading of CO donors and morphology-dependent controlled release of CO.

To address the issues of molecular chain aggregation and film thickness-dependent luminescence encountered by polyfluorenes in practical applications, a novel polyfluorene-based deep-blue semiconductor material PHDPF-DPA was designed and synthesized via a steric hindrance encapsulation strategy in this work. The results demonstrated that the steric hindrance effect of the diphenylamine side chains endowed the material with excellent thermal stability, which could effectively suppress interchain aggregation, reduce low-energy defect emission, and prevent erosion by water and oxygen, thereby significantly improving the stability of blue-light emission. The photophysical properties of this material showed no obvious dependence on film thickness. Transient absorption measurements further revealed that the steric groups can efficiently weaken exciton annihilation and enhance exciton utilization. Under optical pumping, the film exhibited deep-blue amplified spontaneous emission (ASE) with a threshold of 6.17 μJ/cm² and a full width at half maximum (FWHM) of only 1.4 nm. Polymer light-emitting diodes (PLED) fabricated with this material as the emitting layer achieved stable deep-blue electroluminescence. This work verifies the effectiveness of the steric hindrance encapsulation strategy for constructing high-performance and stable polyfluorene-based blue-light semiconductors, and provides an important foundation for the application of printing techniques in the preparation of organic optoelectronic devices.

This study investigated the mechanical properties of nylon 6 (PA6) films and fishing lines under multi-field conditions. The effects of salt concentration and temperature variations in aqueous solutions on their mechanical properties were systematically examined, revealing that PA6 materials exhibited enhanced mechanical strength in saline solutions compared to that in pure water. When PA6 films and fishing lines were immersed in water, their modulus and strength decreased compared to the dry state. With increasing temperature of aqueous solution, the mechanical strength of both films and fishing lines further declined. At 80 ℃ aqueous solution, the mechanical strength of the films dropped sharply. The breaking strength of fishing lines did not decrease abruptly due to their size and structural characteristics, but their mechanical curves displayed multi-stage yielding. Upon the addition of salt, in 1 mol/L NaCl solution at 80 ℃, both the strength and toughness of PA6 films were improved, and the multi-stage yielding in the mechanical curves of PA6 fishing lines disappeared. In saline solution, salt ions associated with water molecules through hydration shells, weakening the plasticizing effect of water on the material. This work presents the evolution of the mechanical properties of PA6 under various multi-field conditions, providing guidance for applications in different service environments.

A photonic crystal (PC) hydrogel film with a double-network structure and dual-responsive properties was prepared. Using acrylic acid (AA) and acrylamide (AM) as polymerizable monomers and quaternized chitosan (QCS) as the second-network component, the double network hydrogels composed of the first network of P(AA-co-AM) and the second network of QCS were prepared. Scanning electron microscopy (SEM) and a universal testing machine were used to characterize the surface morphology and mechanical properties of the hydrogel film. The results indicated that the double network structure can effectively prevent shrinkage and damage of the hydrogel in the drying process, thereby enabling it to retain a smooth and intact surface. Besides, the synergistic reinforcement effect between the two networks significantly improves the fracture toughness and tensile strength of the hydrogel film. Meanwhile, the introduction of QCS effectively inhibited excessive swelling and improved the water-retention capacity of the hydrogel. The Stöber method was used to synthesize SiO₂ nanoparticles, following by fabricating sequentially the SiO₂ PC template and double network PC hydrogel film via vertical deposition and sacrificial template methods. Due to the flexibility of the hydrogel and the photonic band gap of the PC, the prepared film exhibited distinct structural color changes under tensile strain. By introducing phenylboronic acid into the reaction system, the resulting PC hydrogel gained multi-stimulus responsive characteristics, allowing for the visual detection of sugar solutions via structural color changes. The prepared PC hydrogel film, with excellent mechanical properties and dual-stimuli-responsive behavior, exhibits great potential for applications in wearable devices and visual health monitoring.

The synthesis of bimodal functionalized polymers via cationic polymerization typically requires bimodal initiators such as p-dichlorobenzyl chloride (DCC), which are expensive, chemically unstable, and require low-temperature storage. Benzyl chloride can initiate cationic polymerization, but its initiation efficiency is generally low. In this study, the effect of the substituent structure of benzyl chloride on its apparent initiation efficiency (I_app) was systematically investigated within the SnCl₄ co-initiated 4-acetoxybenzene (STO) polymerization system. Experimental results demonstrated that the substituent of benzyl chloride determined its initiation efficiency, with higher methylation on the benzene ring leading to greater efficiency. When using bimethylbenzyl chloride initiators with multiple methyl substituents, such as 2,4-bis(methyl)chloro-1,3,5-trimethylbenzene (Ⅶ) and 3,6-bis(methyl)chlorodiene (Ⅷ), controllable initiation (I_app≈1) was achieved, resulting in a narrow molecular weight distribution (MWD,Ð=1.14-1.25). By adjusting the dosage of the bimethylbenzyl chloride initiator, the molecular weight (M_n) of the polymer could be effectively controlled. Further studies revealed that Ⅶ and Ⅷ could also achieve controllable initiation of the low-reactivity monomer styrene (St), synthesizing polystyrene with a narrow molecular weight distribution (Ð=1.22-1.24). However, p-methylstyrene (pMSt), which exhibited high monomer polymerization activity, demonstrated relatively low initiation efficiency. Mulliken charge calculations performed with Gaussian 16 software further confirmed that the negative charge value of benzyl carbon atoms in benzyl chloride initiators was closely correlated with their initiation capability. The novel bifunctional benzyl chloride initiator developed in this study exhibited stable chemical properties and could effectively replace DCC for the active cationic polymerization of low-reactivity styrene derivatives, such as STO and St, enabling the preparation of bifunctional polymers with broad application potential.

The composition and distribution of monomers have an important influence on the performance and application of the copolymers. In this study, the copolymerization of propylene and 4-methyl-1-pentene was catalyzed by non-metallocene pyridylamido hafnium catalyst with high stereoselectivity, and the effect of 4-methyl-1-pentene/propylene feed ratio on copolymerization was studied in detail. The pyridylamido hafnium catalyst showed high copolymerization activity, reaching 3.55×10⁷ g_polymer·mol_Hf^-1·h^-1. A series of propylene-4-methyl-1-pentene copolymers with different monomer compositions were successfully prepared. Carbon-13 nuclear magnetic resonance (¹³C-NMR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and tensile tests showed that 4-methyl-1-pentene modified polypropylene was prepared at a low 4-methyl-1-pentene incorporation (3.4 mol%-7.7 mol%), and propylene modified poly(4-methyl-1-pentene) was obtained at a high 4-methyl-1-pentene incorporation (94.6 mol%-96.8 mol%). The copolymers with intermediate incorporation (19.7 mol%-77.9 mol%) are random elastomers. By varying the monomer composition, the material's properties were successfully altered from plastic to elastomer and then back to plastic.

Due to its excellent electrical properties and processability, polyethylene is an important insulating material. Aromatic ketone compounds are widely used as voltage stabilizers to enhance the dielectric performance of polyethylene, yet their mechanism of action has not reached a consensus. This work investigated the effect of keto-enol isomerization on the electrical properties of low-density polyethylene when two structurally similar molecules, acetophenone and o-methylacetophenone, were employed as voltage stabilizers. Materials of acetophenone/polyethylene and o-methylacetophenone/polyethylene with different mass fractions of additives, as well as neat low-density polyethylene films, were prepared. These films underwent breakdown strength tests over a wide temperature range, conductivity tests, and surface potential decay tests. The results showed that both additives improved the breakdown and conductivity characteristics of polyethylene, with no significant difference in their effects on conductivity and traps. However, o-methylacetophenone outperformed acetophenone in enhancing breakdown performance. As the temperature decreases, the effectiveness of the two additives gradually converged; at the lower test temperature limit, their performance showed no clear gap, though both remain superior to the base material. Analysis indicates that the difference between the two types of additives stems from their distinct keto-enol tautomerization behaviors, and enolization is not the sole reason for the improvement in breakdown characteristics.

This study focuses on the preparation and property investigation of thermoplastic polyurethane/multi-walled carbon nanotube/ferroferric oxide (TPU/MWCNT/Fe₃O₄) composites. Aiming at the problems of uneven dispersion and easy agglomeration of MWCNTs in the traditional twin-screw melt blending process, TPU/MWCNT was synthesized by solution-based in situ polymerization, and then TPU/MWCNT/Fe₃O₄ composites with different Fe₃O₄ loadings (10 wt%, 20 wt%, 30 wt% and 40 wt%) were prepared via twin-screw melt blending. The effects of the filler content on the aggregate structure, micromorphology, thermal properties, and electromagnetic wave absorption performance of the composites were systematically studied. The results showed that Fe₃O₄ and MWCNTs were well dispersed in the TPU matrix without obvious agglomeration. The glass transition temperature (T_g) of the composites increased slightly with increasing Fe₃O₄ content. Specifically, the T_g of TPU-M6F40 reached -29.61 ℃, which is 4.66 ℃ higher than that of TPU/M6. In addition, the introduction of Fe₃O₄ effectively regulates the complex permittivity and complex permeability of the composites, thereby optimizing their impedance-matching characteristics and introducing a magnetic loss mechanism. The composites achieved full absorption in the X band, with a minimum reflection loss of -34.49 dB. This work provides a new design concept for flexible absorbing materials and has broad application prospects in fields such as wearable electromagnetic protection, shielding of flexible electronic devices, and stealth coatings.

Mucosal barriers severely limit the application of non-viral gene vectors in local therapy. Although conventional poly(ethylene glycol) (PEG) modification (PEGylation) can enhance the mucosal penetration of these vectors, it often encounters the "PEG dilemma" where charge shielding, leads to reduced cellular uptake and low transfection efficiency. To address this issue, the present study proposed a poly(β-amino ester)(PBAE)-based gene delivery system employing an oligomeric PEG shielding strategy. A series of modified PBAE-EG vectors with different PEG densities and chain lengths were synthesized by introducing oligomeric PEG into the PBAE backbone via Michael addition reaction. The results showed that these materials could efficiently complex with plasmids encoding green fluorescent protein (GFP) and condense the pDNA into spherical nanoparticles with diameters of 170-270 nm. Notably, PBAE-EG₄-5 and PBAE-EG₉-5 achieved complete DNA encapsulation at low material-to-DNA mass ratios and exhibited excellent transfection performance across multiple cell lines. The transfection efficiency of PBAE-EG₉-5 in 293T cells reached up to 99.3% while maintaining >80% cell viability at a concentration of 75 μg/mL, highlighting its high efficacy and low toxicity. In vivo vaginal imaging in mice further confirmed that oligomeric PEG modification significantly enhanced nanoparticle retention and diffusion within the vaginal mucosa. Therefore, this oligomeric PEG modification strategy enables simultaneously efficient mucosal penetration and high transfection activity, providing valuable insights and a promising non-viral delivery platform for mucosal local gene therapy and DNA vaccine development.

With the rapid development of fields such as artificial intelligence, the demand for chips has significantly increased. As a key material in the production process of advanced chip packaging, the thermal curing speed of bottom filling adhesive severely limits the improvement of production efficiency. This study employed two structurally distinct alicyclic epoxy resins—3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexylcarboxylate (ERL-4221) and bis(7-oxabicyclo[4.1.0]3-heptylmethyl)adipate (ERL-4299)—along with a thiolane curing agent, (4-hydroxyphenyl)(2-methylbenzyl)thiolane hexafluoroantimonate, to significantly reduce curing time through a thermal cationic curing system. Additionally, spherical silica modified with 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (KH-566) is incorporated as a filler, effectively lowering the thermal expansion coefficient (CTE) of the filling adhesive. All systems achieve curing within 20 min at 120 ℃, with Eq. (3) demonstrating outstanding thermal stability (glass transition temperature T_g=170 ℃, 5% thermal decomposition temperature T_d,5%=386 ℃) and excellent rheological properties (viscosity at a shear rate of 10 s^-1 was 8.4 Pa·s). In the glassy state (T < T_g), the CTE is 38.9 K^-1, and the storage modulus E'=3.46 GPa. This research presents a bottom filling adhesive solution that integrates rapid curing, high heat resistance, and superior rheological performance, showing promising applications in advanced electronic packaging.

Superamphiphobic surfaces that are both hydrophobic and oleophobic represent an important trend in the development and application of liquid-repellent surfaces. However, when subjected to external friction, the micro-nano rough structure of such surfaces causes a rapid decline or even loss of their superamphiphobic properties owing to wear. The addition of high-molecular-weight adhesives to superamphiphobic powders to construct composite coatings is the most commonly used method for enhancing the wear resistance of superamphiphobic surfaces. However, the effect is often not good because the superamphiphobic powder can be embedded in the adhesive. To address this issue, in this study, superamphiphobic nanopowders with superior performance were synthesized. Then, taking advantage of the property that high-molecular-weight adhesives dissolved in good solvents undergo phase transition and form spherical morphologies when added to poor solvents, an epoxy resin solution was dropped into a poor solvent in which superamphiphobic nanopowders were dispersed to trigger the phase transition. Subsequent ultrasonic treatment promoted the tight coating of superamphiphobic nanopowders on the surface of epoxy resin phase-transition droplets, forming fine and stable Pickering emulsion droplets. A superamphiphobic coating composed of multiple core-shell microspheres was obtained after spraying and curing. The superamphiphobic powder was located on the surface of the core-shell microspheres, ensuring that the superamphiphobic properties of the coating did not decline in the presence of the adhesive. The multi-layer self-similar structure also endowed the coating with good wear resistance characteristics. Tests showed that a coating with a thickness of approximately 60 µm could withstand 60 cycles of friction on a 400# sandpaper surface under a 200 g weight without significant loss of superhydrophobicity and retained a certain degree of oleophobicity. This method can be applied to any polymer adhesive that undergoes phase transformation in poor solvents, providing a reference for the preparation and application of wear-resistant superhydrophobic/superamphiphobic coatings.