ACS Applied Polymer Materials最新文献

This work reports chemically cross-linked poly(vinyl alcohol) (PVA) hydrogels cofunctionalized with graphene oxide (GO ≤ 0.2 wt %) and vitamin A palmitate (VAP ≤ 0.2 wt %) as a single platform wound dressing that couples multiple functionalities: mechanical reinforcement, photoprotection, tunable swelling and retinoid delivery. The GO/VAP loading significantly enhances the mechanical properties of neat PVA (E_c = 15.8 ± 0.5 kPa; failure strain 0.51), transforming it into highly compressible networks with E_c up to 57.4 ± 1.0 kPa, compressive stresses up to 327 kPa and strains of 0.64–0.76 without fracture, and tensile strains up to 2.6 at 68 kPa, outperforming previously reported PVA/GO hydrogels. The equilibrium swelling ratio was tuned from 120 to 222% by varying GO and VAP contents, which correlates with a transition from mixed diffusion/relaxation to predominantly diffusion-controlled VAP release (as described by Peppas–Sahlin fits, R² = 0.998–0.999). A key finding of this system is the marked extension of VAP photostability upon incorporation into GO-containing PVA matrices: the characteristic UV–C photodegradation time increases from 3.6 × 10² min for free VAP to 1.2 × 10³ min in GO/VAP formulations (3.3-fold increase), while still retaining 71–86% of the initial absorbance at 330 nm after 1 week versus 59% for VAP alone. PVA-GO_0.1%/VAP_0.2% and PVA-GO_0.2%/VAP_0.2% release 55 and 44% of VAP within 150 min, and their cumulative release at 58 h reaches 89 and 72%, respectively. In contrast, the sample without GO (PVA-VAP_0.2%) release only 35%. All hydrogels are noncytotoxic to human dermal fibroblasts (HDF) (viability ≥ 86%, up to 122%), nonhemolytic (HR < 2%) and nonirritant in vivo (PII = 0). The PVA-GO_0.2%/VAP_0.2% formulation promotes near-complete closure (in a scratch test at 48 h) and organized collagen in a porcine full-thickness wound model, thus underscoring the originality of integrating GO and VAP within a single PVA matrix for multifunctional wound care.

This work outlines a flexible skeleton-rigid enhancement strategy to meet the needs for low thermal conductivity, sound absorption, noise reduction, and electromagnetic wave transmission in aerospace, electronic communications, and energy vehicles. It involves creating high-aspect-ratio thermotropic liquid crystalline polyarylate (PAR) nanofibers via melt spinning and wet ball milling to form a customizable 3D network. Rod-shaped SiC particles are then interlocked with these nanofibers through high-speed shear, resulting in a uniform preform. Directional freeze-drying and heat treatment follow, inducing molecular chain relaxation and viscous flow on the PAR surface, forming an in situ diffusion bonding layer at the SiC-PAR interface for efficient coupling and structural reinforcement. The SiC/PAR nanocomposite aerogels feature 72% porosity and an ultralow density of 0.0428 g/cm³. Increasing the SiC content from 70 to 80 wt % boosts its maximum stress by 32.3%. It offers excellent thermal stability at 250 °C, a low thermal conductivity of 0.035 W m^–1 K^–1, and a sound absorption coefficient of 0.34 in the 0–5500 Hz range. It also maintains strong electromagnetic wave transmission from 9 to 12 GHz. This makes it suitable for multifunctional uses in thermal insulation, sound absorption, and electromagnetic wave transmission.

Humanity has always been challenged by infectious diseases, which remain a major burden on global health. The discovery of antibiotics and the rise of modern medicine in the last century represented a major breakthrough in the fight against infections. However, the adaptive nature of pathogens, together with the widespread misuse of antibiotics, has led to the emergence of strains resistant to previously successful therapies. The increasing prevalence of antimicrobial resistance is now undermining our ability to treat infectious diseases, creating an urgent need for therapeutic approaches. The discovery of new treatments begins in the laboratory, where reliable infection models are essential. Conventional two-dimensional (2D) in vitro models often fail to reproduce the structural and functional complexity of human tissues, thereby limiting the translational relevance of their findings. In this context, three-dimensional (3D) in vitro infection models have emerged as powerful platforms to bridge this gap, offering more physiologically relevant systems that better recapitulate in vivo conditions. Among these, 3D (bio)printing technologies provide a reproducible and versatile approach for fabricating cellular models with controlled spatial architecture, enabling the design of complex tissue-like structures. These advances facilitate the creation of biomimetic in vitro environments that support more realistic host–pathogen interactions, offering valuable opportunities to accelerate the development of new therapeutics and to deepen our understanding of infectious mechanisms. This review summarizes recent progress in 3D (bio)printed in vitro infection models, with a particular focus on bacterial and viral infections, which remain the most extensively studied. Finally, we discuss current limitations, future perspectives, and regulatory considerations needed to translate these models into clinically relevant tools.

Polymethacrylimide (PMI) aerogels are promising lightweight thermal insulation materials; however, those prepared by freeze-drying often exhibit poor mechanical properties due to structural collapse and the formation of large macropores induced by ice crystal growth. In this study, robust PMI nanoporous structure aerogels featuring methylene-bridged and imide-cross-linked networks were successfully fabricated via a supercritical CO₂ drying process combined with the introduction of N,N′-methylenebis(acrylamide) (MBA) as a cross-linking agent. The effects of varying MBA contents on the shrinkage behavior, microstructure, thermal stability, mechanical strength, and thermal conductivity were systematically investigated. Increasing the cross-linker content effectively reduced shrinkage and thermal mass loss while enhancing density, structural integrity, and compressive strength. FTIR and TGA analyses confirmed the formation of methylene and imide cross-linked networks, contributing to improved thermal stability. SEM and BET characterizations revealed a highly porous mesostructure (pore size of ∼15–30 nm) with porosity exceeding 70% and specific surface areas up to 156.81 m²·g^–1. The optimized aerogel achieved an ultralow thermal conductivity of 0.0385 W·m^–1·K^–1 and a high compressive modulus of 112.73 ± 5.67 MPa. This work demonstrates a scalable dual-cross-linking strategy combined with supercritical CO₂ drying to fabricate mechanically robust and thermally insulating PMI aerogels, offering great potential for applications in aerospace, transportation, and advanced thermal protection systems.

The current study establishes the effect of surfactant (cetyltrimethylammonium bromide (CTAB)) and the directional agent (polyethylene glycol (PEG)) on the development of porous calcium carbonate (PCC) rhombohedral-like particles as a reservoir to load self-healing material for corrosion-prevention applications. The aspartic acid (AA)-doped polyaniline (PANI)–calcium carbonate reservoirs (CaCO₃) (PACCR) were prepared by precipitation, followed by thermal treatment and oxidative polymerization. The nitrogen sorption results for PCC showed an average BET surface area of 358 m²/g, with a pore size of 3.1 nm and a total pore volume of 0.363 cm³/g. The morphological study of PACCR exhibited a rhombohedral-like shape with a size of ∼0.8–1.5 μm. Further, the AA loading efficiency of 79 ± 2% in PACCR was confirmed by UV–vis spectroscopy. The electrochemical impedance spectroscopy (EIS) validated the improved corrosion resistance of this latest-designed active system comprising PACCR over the pure epoxy coating during 35 days of testing. The scanning vibrating electrode technique (SVET) analysis confirmed the healing process of the PACCR coating via inhibitor release in 180 min. These results authenticate that the developed self-healing systems are highly applicable for corrosion-resistant environments.

The development of high-performance nanocomposite barrier coatings hinges on the efficient exploitation of nanosheet geometry and dispersion. While Cussler’s model predicts extreme barrier improvement with increasing aspect ratio of nanosheets, experimental values frequently fall short. In this study, we identify and characterize smectic liquid crystalline domains─termed “accordions”─as critical structural defects within liquid crystalline suspensions of high aspect ratio synthetic hectorite. These vertically oriented structures represent defects penetrating otherwise lamellar, cofacially aligned nanosheet domains and thus act as gas diffusion pathways, significantly reducing barrier performance. We develop an ion-exchange strategy using NH₄⁺ to selectively eliminate these accordions via interstratification, yielding double stacks that can be subsequently redelaminated into monolayers. Despite a reduction in nanosheet diameter during this procedure that is expected to hamper the barrier improvement factor, in reality the resulting coatings demonstrate a 36-fold lower oxygen permeability, confirming the dominant role of accordion-type defects as permeation pinholes. These findings highlight a previously overlooked structural origin of limited barrier enhancement and provide a general route to suppress defect formation in 2D material-based barrier films.

Gelatin has long been considered the gold standard in tissue engineering (TE) due to its biocompatibility, cell-adhesive properties, and low cost. However, its application is constrained by inferior porosity and an upper critical solution temperature (UCST) around physiological temperature. The latter leads to a need for processing, including cell encapsulation, at low temperatures exerting stress on cells. Herein, an efficient pathway was developed for the grafting of polyesters and polycarbonates onto gelatin using thiol–ene coupling, creating a library of amphiphilic brush-type polymers. After in-depth analysis of the synthesized grafts, in terms of graft lengths, coupling efficiencies (>90%) and grafting densities (30–100% of amines in gelatin), the self-assembly, driven by hydrophobic interactions, into nanoparticles and physical gelation potential was investigated. The tunable grafting densities led to a wide range of mechanical properties (E′: 1–50 kPa), showing applicability for soft to medium-soft tissues. Dual cross-linking enabled rapid covalent gelation (1.7–2.3 s) after physical assembly. The hydrophobic associations yielded enhanced porosities (>200 μm), which correlated to graft identity and mechanical properties. Finally, the materials revealed high biocompatibility, as evidenced by the cell viabilities during cytotoxicity (>90%), without loss of cell interactivity.

This study explores the emulsion Forcespinning (FS) approach for fabricating nanofibers with a hydrophilic phase encapsulated within a hydrophobic polymer matrix. Key factors influencing fiber production and morphology, including the concentration of the internal water phase and the presence of ionic and nonionic surfactants, were systematically investigated. Additionally, the centrifugal spinnability of the emulsions was assessed using environmentally controlled dripping-onto-substrate (DoS) rheometry, correlating the observed extensional flow behavior and emulsion extensibility with fiber spinnability. The nanofibers were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. These findings offer critical insights for optimizing emulsion-based FS systems in fiber design, with significant potential for biomedical and food industry applications.

Polyester fiber possesses a high refractive index, making it difficult to achieve a deep color. To overcome this challenge, this study develops a bioinspired antireflective coating based on moth-eye structures. A stable emulsion was initially prepared using methyl methacrylate and ethylene glycol dimethacrylate as monomers and then applied to polyester fabrics via a dip-pad-cure process. The treated polyester exhibits a significantly enhanced color depth. The K/S value increases from 24.50 to 43.77, and the CIE L* value decreases from 15.61 to 10.55. Meanwhile, the comfort of the fabric remains well preserved. The air permeability of the fabric shows a negligible change from 2667 to 2511 mm/s. The softness score slightly changes from 87.08 to 86.35. Furthermore, the coating exhibits outstanding abrasion resistance. The K/S value of the treated fabric retains over 40% improvement after 400 abrasion cycles. These findings provide a promising, sustainable strategy for improving the visual depth of color in polyester textiles.

Directional permeation through dense laminated membranes is relevant for applications in various fields, including separation processes, wound care, and packaging. While theoretical models have been used to describe the asymmetric permeation in heterogeneous dense membranes, only a few systems have been experimentally explored. Here, we report dense asymmetric laminated membranes based on hydrophilic poly(vinyl alcohol) (PVA) and hydrophobic glycol-modified poly(ethylene terephtalate) (PETG). Modeling the system allowed us to optimize the thickness of the PVA and PETG layers. While bilayer membranes made from the two components suffered from poor interfacial adhesion and delamination, this problem is overcome by using a thin polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride (SEBS-MA) adhesive layer. The maleic anhydride groups (MA) react with the hydroxyl groups present in the two polymers, and this greatly improves the adhesion between the hydrophilic and the hydrophobic layers. Membranes with optimized geometry display an asymmetry factor of up to 6.7, one of the highest values ever reported. The directional water transport is caused by the moisture-induced plasticization of the PVA layer at high relative humidity (RH), which occurs only when the PVA side of the membrane is exposed to moisture.