ACS Applied Polymer Materials最新文献

In this study, a durable fire-resistant and self-healing dual-network gel polymer electrolyte (GPE) comprising poly(vinyl alcohol) (PVA), sodium alginate (SA), NaCl, and a water-in-deep eutectic solvent (DES) system was prepared using a one-step freezing-thawing technique for flexible supercapacitors (FSCs). Various GPEs were synthesized to investigate the influences of choline chloride (ChCl) and ethylene glycol (EG) molar ratios, the comprising components of the DES, and the impact of NaCl. The developed DES-based GPEs were formed through noncovalent interactions, offering several advantages, including the absence of chemical initiators and binders, environmental compatibility, and a simple preparation process. The dual-network GPEs exhibited extraordinary ionic conductivity, mechanical strength, stretchability, and self-healing properties as a result of the synergistic interaction between DES and NaCl and the creation of physically entangled networks. The optimized GPE, which showed an impressive ionic conductivity of 104.27 mS cm^–1 at room temperature, was utilized in the fabrication of carbon-based FSC by sandwiching it between two same-size carbon cloth electrodes. The resulting device exhibited an energy density of 181.47 mWh cm^–2 at a power density of 350 mW cm^–2, and exceptional durability with a cycle life exceeding 10,000 cycles while providing approximately 93.32% capacitance retention throughout the testing period. Moreover, the prepared FSC maintained its electrochemical performance characteristics to an acceptable extent even under 90 and 180° bending deformation. Furthermore, the device prepared based on the self-healed GPE maintained 93.85 and 91.35% of its initial capacitance after the fifth and seventh cycles of cutting/healing, respectively, due to the remarkable self-repairing ability of the developed GPE. Our findings provide valuable insight into the development of flexible and leakproof GPEs for FSCs with potential applications in wearable electronic devices.

Epoxy (EP) vitrimers with excellent mechanical properties that could be efficiently healed under mild temperatures (<150 °C) are of great importance to practical applications but are difficult to accomplish yet up to now. In this work, we used l-cystine dimethyl ester (CDE), a disulfide-containing diamine, as the hardener to synthesize a type of EP vitrimer, EPV-CDE. The tensile strength of EPV-CDE reached 81.5 MPa mainly due to the relatively short chains of the CDE hardener and resulting high cross-linking density, and at the same time, EPV-CDE was able to be recycled under a mild temperature at 120 °C, with a 93.4% recovery ratio after the first recycling cycle, enabled by the relatively flexible chains and low steric hindrance of the CDE hardener. Compared to most of disulfide-containing EP vitrimers reported in the literature, EPV-CDE demonstrated higher tensile strength and lower activation energy and topology freezing transition temperature. Moreover, the liquid nature of CDE allows the incorporation of up to 25 wt % carbon fiber powder into the EPV-CDE matrix to prepare the EPV-CDE/CF composite, which achieved the tensile strength of 112.5 MPa and maintained excellent recyclability. Even though our EP vitrimer exhibited strong resistance performance to most solvents, it could also be chemically degraded by thiol-containing solvents such as dithiothreitol, offering environmental-friendly substitutes for unsustainable thermoset resins.

Donor–acceptor (D-A) type linear conjugated polymer is considered as a promising photocatalyst due to its facile adjustment of energy bands and spectral range. Herein, we designed a series of D-A linear conjugated polymers based on terthienyl-diphenylstyrene. The comparative effect was investigated via ultraviolet–visible (UV–vis), X-ray powder diffraction (XRD), transient photocurrent response (TPR), cyclic voltammetry (CV), etc. The results demonstrated that incorporating styryl building blocks into the acceptor moiety can efficaciously enhance the photocatalysis hydrogen production (PHP) activities, surpassing the effect of incorporating cyano substituents into the acceptor moiety. Among them, BTT-PPAN (BTT is 2,2′:5′,2″-terthiophene, PPAN is (2Z,2′Z)-3,3′-(1,4-phenylene)bis(2-phenylacrylonitrile)) exhibited an outstanding PHP rate (35.54 mmol g^–1 h^–1). The terpolymers (PPAN_xPFN_y; PPAN is (2Z,2′Z)-3,3′-(1,4-phenylene)bis(2-phenylacrylonitrile), PFN is 2,3-diphenylfumaronitrile) were subsequently constructed by changing the feed ratio of 2,3-bis(4-bromophenyl)fumaronitrile (M3) and (2Z,2′Z)-2,2′-(1,4-phenylene)bis(3-(4-bromophenyl)acrylonitrile) (M4) and polymerization with BTT. The investigation of terpolymers also demonstrates that the conjugation length plays a more critical role in the performance of PHP than the cyano substituent effect. The comparative impact result obtained in this investigation will provide an invaluable theoretical guideline for the future rational design of high PHP performance materials.

Hyper-cross-linked polymers (HCPs) represent a promising type of adsorbent for volatile organic compounds (VOCs), exhibiting ultrahigh porosity, excellent physicochemical stability, and superior cost-effectiveness. HCPs are typically prepared using solvothermal methods, which require at least 18 h at 80 °C, resulting in significant energy and time consumption, thus limiting large-scale production. Herein, we propose a rapid self-cross-linking synthesis strategy to prepare HCPs in one-pot within 5 min at room temperature (25 °C) by predispersing the catalyst and predissolving the monomers. The specific surface area of the prepared HCP, synthesized using 4,4′-bis(hydroxymethyl)biphenyl as monomer is as high as 1784 m²/g, which is comparable to those synthesized by solvothermal methods. This strategy makes the self-cross-linking reaction more homogeneous, playing a crucial role in accelerating the reaction and reducing the reaction temperature. In addition, it is observed that the HCPs exhibited excellent adsorption properties for benzene and methanol with adsorption amounts of up to 30.3 and 53.2 mmol/g, respectively. This work presents a simple strategy for the rapid and large-scale synthesis of HCPs as efficient adsorbents for VOCs.

The increasing proliferation of electronic devices has led to significant electromagnetic pollution, posing risks to communication systems and human health. Moreover, the trend toward miniaturizing electronic components complicates effective heat dissipation, leading to overheating and degraded performance. To address these issues, a microcellular nanocomposite foam composed of ethylene–octene copolymer (EOC) and multiwall carbon nanotubes (MWCNTs) was developed by using a blend of melt and solution mixing techniques. A chemical blowing agent was employed to introduce porous structures into the nanocomposite, resulting in a foam with a density range of 0.4–0.53 g/cm³ and a low percolation threshold at 4 wt %. This porous composite demonstrated an outstanding electromagnetic interference (EMI) shielding effectiveness of 25.5 dB in a 2 mm thick, 10 wt % MWCNT-loaded nanocomposite within the X-band frequency. Additionally, the composite foam exhibited a thermal conductivity of 0.25 Wm^–1K^–1, facilitating heat absorption. These properties make the EOC/MWCNT nanocomposite foam highly suitable for EMI shielding in sealing and packaging applications. The material’s attributes suggest substantial potential for diverse applications in aerospace technology, military operations, smart-wearable technology, and portable electronic devices.

Poly(zwitterionic ionic liquid) (PZIL) refers to a polymeric architecture with an ionic liquid moiety also capable of being zwitterionic in each repeating unit, which has not been explored so far in the literature. Owing to their versatile structures and interesting properties, nowadays they are attracting much interest in industrial and biomedical applications. Thus, this work demonstrates the design and synthesis of two styryl-based homopolymers containing repeating units comprising carboxyalkylbenzimidazolium bromide functionalities, employing RAFT polymerization in water. These PZILs exist as poly(zwitterion)s and form pH-tunable aggregated nanostructures, appearing as turbid suspensions in water at pH 4.1. The transformation of a turbid suspension to a transparent solution on heating and vice versa on cooling suggests a clear upper critical solution temperature (UCST)-type phase behavior of the PZILs in water, and the derived cloud points (T_cps) are found to be tunable with pH and PZIL concentrations, as well. Below the isoelectric point (pI), at any pH, the PZILs also exhibit a reversible UCST-type transition from one-phase to two-phase in the presence of different Hofmeister anions in water, with T_cps tunable with anion and PZIL concentrations. In this pH range, these PZILs behave as cationic poly(ionic liquid)s and are found to be very effective in dispersing multiwalled carbon nanotubes (MWCNTs) in water. The aqueous dispersions of MWCNT-PZIL composites are responsive toward different stimuli such as temperature, pH, and anions. Both PZILs exhibit antiprotein-fouling activities by preventing nonspecific aggregation of bovine serum albumin in water at pH 7 (beyond the pI). The zwitterionic hydrogel derived from zwitterionic ionic liquid monomers shows multistimuli-responsive behavior and exhibits excellent water-uptake ability in water and aqueous NaCl solutions, with % equilibrium swelling of ∼123 and ∼320, respectively.

This work presents a synthesis strategy to yield DQPVB-EVOH anion-exchange membranes (AEMs) by grafting hydroxyl-containing bis-cationic side chains onto a rigid poly(4-vinylbenzyl chloride) (PVB) backbone (DQPVB) and blending it with a flexible ethylene vinyl alcohol copolymer (EVOH). The intermolecular hydrogen bonding between the hydroxyl groups on DQPVB side chains and those on flexible EVOH delivers good tensile strength (TS = 8.3–22.9 MPa), high elongation at break (EB = 94.9–218.5%), restricted swelling degree (SD = 12.0–42.7%), and high water uptake (WU = 106.8–311.2%) of the AEMs. The bis-cationic properties promote a high ion-exchange capacity (IEC = 2.77–4.01 mmol g^–1) for DQPVB-EVOH AEMs, contributing to their improved ionic conductivity (IC = 51.3–89.3 mS cm^–1 at 80 °C). Additionally, the absence of polar groups on the PVB backbone, coupled with high water uptake, diminishes the nucleophilic attack ability of hydroxyl groups, resulting in good alkali stability for DQPVB-EVOH AEMs. (After soaking in 1 M KOH at 80 °C for 360 h, IEC retentions = 86.2–93.5% and IC retentions = 85.5–95.6%.) A H₂/O₂ fuel cell based on the DQPVB-EVOH-0.5 AEM exhibits a maximum power density of 303.6 mW cm^–2. In comparison, QPVB-EVOH-0.5, which is formulated by blending singly cationic-grafted quaternized PVB (QPVB) with EVOH, exhibits excessive swelling at 30 °C due to the lack of hydrogen bond cross-linking. It has a SD of up to 95.8% with an IEC of 2.36 mmol g^–1, making it not feasible.

Due to the high cross-linking density of cured epoxy resins resulting in the inherent brittleness of adhesives, epoxy adhesives are less resistant to crack initiation and growth and often fail in a brittle manner. Thus, promoting maximum elongation and ductility without sacrificing mechanical strength remains challenging. In this study, according to molecular structure design, through using amide bonds to combine flexible aliphatic amines and furan structures by a simple transesterification method, a polyamide curing agent, N,N-bis(6-aminohexyl)furan-2,5-dicarboxamide oligomer (FDAH), was obtained. This curing agent was used to prepare a series of high-performance epoxy adhesives based on noncovalent interactions. Noncovalent bond interactions could provide additional aid in energy dissipation and dynamic behavior, while flexible aliphatic chains ensure enough flexibility in the network. On the one hand, the adhesion strength of the adhesive was improved by introducing noncovalent interactions into and between molecular chains. On the other hand, the structure of furan-amide and the characteristics of flexible aliphatic amines were combined to adjust the cross-linking density of structural adhesives, thereby improving their mechanical properties. By adjusting the content of the modified curing agent in the epoxy network, the molecular structure, curing behavior, and properties of the cured epoxy adhesive were systematically characterized, and it was found that the prepared adhesive had high tensile strength (62.4 MPa), large elongation at break (14%), excellent adhesion performance, suitable sizing, and curing window. The strengthening mechanism of reversible dynamic bonds on adhesives was also preliminarily elucidated. Overall, this work provides more possibilities for tuning the physical properties of cross-linked networks, and using similar strategies to enhance rigid polymers can achieve a good combination of high strength and scalability.

This study investigates the mechanical and biological properties of hydrophobically associated poly(sulfobetaine methacrylate-co-2-hydroxyethyl methacrylate) (poly(SBMA/HEMA)) hydrogels synthesized via micellar copolymerization. These hydrogels exhibit remarkable toughness and self-healing capabilities due to their reversible cross-linked networks. Experimental results indicate that increasing the HEMA content enhances the tensile modulus but reduces elongation and toughness. By optimizing the ratio of SBMA to HEMA, the hydrogels can maintain tensile strength, self-healing properties, adhesiveness, and biocompatibility. Additionally, these hydrogels can encapsulate hydrophobic curcumin, promoting controlled drug release and demonstrating effective antibacterial properties, highlighting their potential for biomedical applications. This research pioneers the preparation of hydrogels using hydrophobic association mechanisms, differing from chemically cross-linked poly(SBMA/HEMA) hydrogels, not only improving mechanical properties but also providing an effective approach for encapsulating hydrophobic drugs within hydrogels.

Supercapacitors (SCs), with their exceptional properties, present a promising solution to the ongoing energy crisis by meeting the increasing demand for high-energy storage devices. Conjugated microporous polymers (CMPs) offer a range of sizes, precisely controlled porosities, impressive intrinsic porosity, remarkable stability, and customizable structures and functionalities. These attributes collectively make CMPs cost-effective materials for energy storage applications. In this research, we effectively created three organic electrodes based on CMPs for energy storage via the Suzuki coupling reaction of 1,3,6,8-tetrakis(4-bromophenyl)pyrene (PyPh-Br₄) and benzene-1,4-diboronic acid (BZ-2B(OH)₂) with 2,8-dibromothianthrene (Th-Br₂) or 3,7-dibromodibenzothiophene S, S-dioxide (SU-Br₂) or 2,8-dibromothianthrene-5,5′,10,10′-tetraoxide (DSU-Br₂) to produce PyPh-BZ-Th, PyPh-BZ-SU, and PyPh-BZ-DSU CMP, respectively. Their thermal stability was examined using TGA measurements, and both PyPh-BZ-Th CMP and PyPh-BZ-SU CMP displayed T_d10 of 540 and 467 °C with high carbon reside up to 70 wt % at 800 °C. Electrochemical performance for these materials was evaluated using cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD). Within a three-electrode setup, specific capacitances of 617, 538, and 596 F g^–1 for PyPh-BZ-Th, PyPh-BZ-SU, and PyPh-BZ-DSU CMPs were recorded by GCD at 0.5 A g^–1. To obtain a more practical and accurate evaluation, we further constructed symmetric devices for each CMP. Using GCD curves, the specific capacitances were found to be 187, 63, and 105 F g^–1, respectively, for PyPh-BZ-Th, PyPh-BZ-SU, and PyPh-BZ-DSU CMPs. The high capacitances of the synthesized CMPs in this study, comparable to those of other reported porous CMPs, can be attributed to electronegative moieties, such as sulfur (S) and sulfone (SO₂) groups. These groups enhance electrostatic interactions and improve the wettability of the electrodes. This study demonstrates that using the Suzuki coupling reaction technique, CMPs incorporating Py, Th, and DSU moieties can be effectively produced for energy storage applications.