ACS Applied Polymer Materials最新文献

We introduce a structural strategy to develop amorphous hole-transporting materials for organic electronics. Utilizing a highly selective nickel-catalyzed cycloaddition oligomerization of 1,6-diyne monomers containing triphenylamine (TPA) or N,N-diphenylnaphthalen-1-amine (DPNA) moieties afforded cyclic polyene oligomers (2a and 2b) in high yields. These medium-sized oligomers are structurally defined, possessing narrow molecular weight polydispersities and adopting an unusual rigid, shrunken cyclic conformation. This feature enables dense accumulation of conductive TPA/DPNA moieties. The resulting materials exhibit excellent thermal stability and successfully maintain a desired amorphous-like morphology in the solid state. Hole-only devices constructed with these oligomers show effective electrical conductivity, achieving a high number of hole mobilities.

Epoxy resins are widely used in aerospace and defense composites owing to their excellent mechanical strength and thermal resistance, and the structural characteristics of curing agents are critical in determining final network properties. In this study, the high-functionality epoxy resin tetraglycidyl-4,4′-diaminodiphenylmethane (TGDDM) was cured with two positional isomers of diaminodiphenyl sulfone (3,3′-DDS and 4,4′-DDS), and the resulting networks were investigated by molecular dynamics (MD) simulations, while complementary density functional theory (DFT) calculations were conducted on the curing agents to elucidate their molecular structures. Under identical curing conditions, the 3,3′-DDS network exhibited a higher tensile modulus with denser packing, whereas the 4,4′-DDS network showed broader free volume distribution and stronger π-electron resonance interactions. Thermal characterization further revealed that the 4,4′-DDS system possessed a higher glass transition temperature (T_g) and lower coefficient of linear thermal expansion (CLTE), consistent with molecular dynamics results such as mean square displacement and ring-flip behavior. Overall, this study identifies positional isomerism in DDS as a key factor governing the balance between mechanical stiffness and thermal stability in TGDDM-based networks, thereby providing molecular-level insights for the rational design of high-performance epoxy materials.

Acylhydrazone-based Covalent Adaptable Networks (CANs) are attractive candidates for recyclable thermosets due to their strong hydrogen bonding and excellent creep resistance. However, their slow exchange kinetics under catalyst-free conditions severely restricts reprocessability and advanced manufacturing potential. Herein, a substituent-guided molecular design strategy is proposed to tune the acylhydrazone exchange dynamics through the electronic effects of aromatic substituents. This approach enables programmable control over viscoelastic behavior, achieving a unique balance between rapid stress relaxation (τ = 187 s at 100 °C) and high creep resistance (onset up to 130 °C). The nitro-functionalized network exhibits strong intrinsic UV absorption, enabling dye-free, high-resolution DLP 3D printing (600 μm features) with excellent printing fidelity. Moreover, the printed materials display efficient reprocessability at 180 °C and thermal self-healing at 130 °C with minimal loss of mechanical strength. This catalyst-free and generalizable design provides deeper insight into substituent-driven dynamic control and offers a practical pathway for recyclable, precision-manufacturable thermoset systems relevant to sustainable polymer engineering.

Improving the toughness, antibacterial properties, and flame retardancy of poly(l-lactic acid) (PLLA) is crucial for its use in plastic packaging. However, few studies have achieved simultaneous enhancement with a single additive due to poor interfacial compatibility and low efficiency. To overcome these challenges, a multifunctional additive poly(butylene succinate)-based polyurethane ionomer (PBSUI) was synthesized. Specifically, the flexible polyester segments in PBSUI enhance toughness, while its unique ionic units provide antibacterial performance and flame retardancy. Thanks to this unique structure, the long-standing challenge of achieving good compatibility between additives and PLLA has been effectively addressed. Notably, the PLLA/PBSUI₉ blend achieved an elongation at break of 212%, which is 20 times higher than that of pure PLLA, while maintaining a moderate tensile strength of 39.7 MPa. Moreover, the fire safety of PLLA is significantly enhanced even with a low addition of PBSUI. When the PBSUI content reaches 5 wt %, the limiting oxygen index (LOI) value increases to 25.8%, and the UL-94 rating achieves the highest level V-0. In addition, the PLLA/PBSUI blends exhibit excellent antibacterial properties. Even with only 3 wt % PBSUI, the antibacterial activity against both Escherichia coli and Staphylococcus aureus exceeds 99.9%, demonstrating strong potential for practical applications.

Integrating zero-energy cooling technology into personal thermal management (PTM) systems offers an effective approach to prevent heat-related illnesses and reduce energy consumption. Although materials designed for passive radiative cooling have been introduced, achieving an optimal balance between cooling efficiency and user comfort continues to pose a significant challenge. Here, we present a biomimetic personal thermal management (BPTM) fabric that couples passive radiative cooling with transpiration-like evaporative cooling through a hierarchical trilayer polymer architecture. The top layer consists of an electrospun cellulose acetate (CA) nanofibrous photonic coating loaded with Al₂O₃ nanoparticles, providing strong solar back scattering and (mid-infrared MIR) emission via the intrinsic vibrational bands of CA. A middle porous layer composed of polyurethane (PU)/CA establishes a wettability and pore-size gradient for self-driven, outward liquid transport. The bottom layer is a waterborne polyurethane (WPU) fabric substrate that imparts flexibility and wearer comfort. Owing to this trilayer design, the BTPM fabric exhibited favorable spectral selectivity, with around 92% sunlight reflection and 96% thermal emissivity in the atmospheric window. It also demonstrated Janus wettability (R = 340), achieved through electrospinning and hierarchical design, while maintaining superior moisture permeability. Temperature reductions of approximately 10 °C were observed in the BPTM fabric compared to that of commercial cotton. The fabric’s moisture-wicking properties (water evaporation rate of 0.21 g h^–1) facilitate rapid sweat evaporation, cooling the skin so as to minimize the possibility of excessive sweating when exercising. Moreover, the fabric’s cost-effectiveness and wearability offer a promising direction for sustainable energy solutions, smart textiles, and applications focused on thermal comfort.

Conjugated microporous polymers (CMPs) provide a versatile platform for incorporating various photoactive structures into porous frameworks through the strategic design of molecular building units. This molecular engineering approach allows for precise modulation of bandgap structures and electronic configurations at the atomic level. Current research predominantly focuses on two-motif molecular designs for CMP-based photocatalysts, whereas three-motif architectures remain significantly underexplored with respect to synthetic accessibility, structure–property relationships, and the mechanistic elucidation of photocatalytic processes. Herein, we report the synthesis of a thiazolo[5,4-d]thiazole (TZ)-incorporated three-motif molecular junction CMP (CMP-TZ-BTDT) through condensation polymerization of dithiooxamide with 4,4′,4″,4‴-((benzo[c][1,2,5]thiadiazole-4,7-diylbis(1,4-phenylene))bis(azanetriyl))tetrabenzaldehyde (BTDT). Strategic incorporation of benzothiadiazole as a photoactive component within the CMPs framework significantly enhances visible-light absorption capacity, resulting in improved photocatalytic performance through the efficient generation and separation of photogenerated charge carriers. Systematic characterization reveals that CMP-TZ-BTDT with a three-motif molecular junction architecture, as a heterogeneous photocatalyst, has a broad substrate scope and recyclability, enabling diverse visible-light-mediated organic transformation reactions. This molecular engineering approach provides significant insights into the rational design of advanced photocatalytic CMP systems with customized optoelectronic properties.

The continuous rise of atmospheric CO₂ and its associated impacts, including ocean acidification, demand innovative strategies for capture, detection, and monitoring. Here, we report a class of hybrid optical sensing platforms based on poly(N-isopropylacrylamide-co-methacrylic acid) (pNIPAm-co-MAA) microgels interlaced with MIL-53(Al)-NH₂ metal–organic framework (MOF) nanoparticles for in situ sensing of dissolved CO₂ (dCO₂). Using an in situ hybridization strategy, MIL-53(Al)-NH₂ is uniformly embedded within the polymeric matrix, yielding microgel–MOF (M&M) hybrids with tunable porosity, optical responsiveness to dCO₂, and structural integrity controlled by the cross-linker. N,N’-Methylene-bis-acrylamide (BIS)-cross-linked M&M hybrid beads display greater rigidity, while poly(ethylene glycol)diacrylate (PEGDA)-cross-linked beads exhibit higher swelling ratios. Gas adsorption studies reveal reduced CO₂ uptake compared to pristine MIL-53(Al)-NH₂ MOF due to partial pore blocking by the polymer, yet the hybrid beads consistently outperform MOF-free ones, confirming that MIL-53(Al)-NH₂ remains functionally active within the microgel network. Ultraviolet–visible (UV–Vis) absorbance experiments highlight distinct hybrid behavior with dCO₂, inducing clear decreases in absorbance linked to MOF-mediated swelling, in contrast to the negligible response of pristine microgels. Reflectance spectroscopy further demonstrates that M&M-based etalons respond to dCO₂ through characteristic red shifts driven by MOF-mediated CO₂ adsorption and pore expansion, while MOF-free microgels show purely pH-driven blue shifts in response to dCO₂ due to the acidic environment. M&M beads with three different mass ratios between the microgel and the MOF are synthesized, among which the 5:1 hybrids with the BIS cross-linker exhibit the highest CO₂ uptake and deliver the most stable optical performance, maintaining reproducible responses over three consecutive CO₂ cycling tests. Notably, even the relatively low MOF loadings retained within the polymer matrix are sufficient to impart measurable CO₂ adsorption capacity and distinct optical responsiveness, underscoring the efficiency of the hybrid design. Our study establishes M&M etalons as dynamic, tunable platforms for real-time dCO₂ monitoring with potential applications in environmental and carbon capture technologies.

Flexible sensors, as an emerging development in the field of sensors, have advantages that are incomparable to those of traditional rigid sensors. Although recognized as ideal materials for flexible sensors due to their intrinsic softness, biocompatibility, and stimuli-responsiveness, hydrogels face fabrication challenges in achieving complex structures and integrated functionalities. The advent of 3D printing technology has successfully addressed the limitations inherent in conventional fabrication approaches, thereby offering robust technical underpinnings for the advancement and innovation of flexible sensors. This paper first introduces the 3D printing techniques employed in the fabrication of hydrogel-based flexible sensors, followed by an analysis of their underlying sensing mechanisms and examines the application studies of 3D printed hydrogel-based flexible sensors across various domains, including strain, pressure, pH, temperature, and biosensing. Finally, the review summarizes the current achievements, discusses persistent challenges, and provides perspectives on future directions for material innovation, printing technology advancement, and broader application scenarios of 3D printed hydrogel flexible sensors.

Achieving efficient underwater adhesion has been a long-standing challenge, as the surface hydration layer impedes the adhesive contact with substrates. To address this issue, we have developed a supramolecular semi-interpenetrating polymer network (SsIPN) for pressure-sensitive adhesive (PSA) applications. The SsIPN combines poly(butyl acrylate)-based copolymers as both linear polymer chains and a cross-linked network. The linear polymer, acting as a fluid, effectively diffuses to repel the hydration layer, while the cross-linked network provides cohesion through chain entanglement and structural integrity. Both components feature hydrogen bonding, which not only enhances intermolecular interactions with substrates but also acts as sacrificial bonds within the gels. As a result, SsIPN tapes demonstrate outstanding water-repellent properties and underwater adhesion, achieving an adhesion strength of over 2000 N/m on glass substrates. Moreover, even after 72 h of underwater storage, the adhesive retains a peel strength of 1243 N/m due to its hydrophobic nature. This simple, robust method for producing SsIPN offers a promising approach to developing high-performance underwater adhesives.

Heavy metal contamination remains a major global problem. Because these ions are complex to remove and highly harmful to living organisms, efficient and practical remediation methods are urgently needed. Adsorption is one of the most attractive solutions due to its low cost, simplicity, and high removal efficiency. In this work, we developed a sulfur-rich pillararene polymer (Pol-P[5]-EDT) specifically designed to capture Hg²⁺ and Pb²⁺ from water. The polymer was synthesized through a straightforward thiol–ene click reaction between an alkenyl pillararene and ethanedithiol. Characterization showed that Pol-P[5]-EDT is amorphous, with a rough, loosely packed morphology and a well-developed hierarchical porous structure. It has a high surface area (391.20 m²/g) and pore sizes mainly around 4.72 and 12.12 nm. Compared with its monomer analogue (Pol-Mono-EDT), the polymer exhibited much better adsorption performance. Adsorption studies revealed monolayer behavior, with maximum capacities of 322.58 mg/g for Hg²⁺ and 271.23 mg/g for Pb²⁺. The uptake was extremely fast, removing both ions completely within 5 min. The polymer was also highly reusable, retaining about 99% Hg²⁺ removal efficiency after five cycles. In a practical test, Hg²⁺-contaminated water treated with the material allowed wheat seeds to grow normally, demonstrating its effectiveness for real environmental and agricultural applications. The Pol-P[5]-EDT@PES membrane further showed selective current–voltage responses for Hg²⁺ and Pb²⁺, indicating potential for sensing as well as removal.