RSC Applied Polymers最新文献

Research over the past four decades on polyaniline has matured, and consequently it has become one of the most popular conducting polymers. Also, several methods have been proposed by researchers for the synthesis and conversion of polyaniline (PANI) to various forms as well as its doping with chalcogens especially selenium (Se) and tellurium (Te). These composites have been explored using various chemical methods and their different properties have been extensively studied in terms of electrical, thermal, morphological and optical behaviour. This review summarizes the results from research experiments, including their synthesis and characterization, and the study of their various properties such as DC conductivity measurements, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, field emission studies, EMI shielding behaviour, and electrochemical, supercapacitive, optoelectronic and thermoelectric properties. The incorporation of chalcogens in PANI leads to a significant improvement in its electrical conductivity and field emission properties, making the resulting nanocomposites promising materials for various electronic applications. The global energy crisis underscores the need for innovative materials for the production of energy. In this case, solution-based polymer thermoelectric (TE) technologies offer an eco-friendly and cost-effective approach to convert heat into electricity. The successful electrodeposition of tellurium films onto phenolic foam with PANI coatings and the synthesis of novel PANI/Te nanocomposites with enhanced nonlinear optical properties open up new avenues. These nanocomposites were prepared using different methods including simultaneous electrochemical reactions, in situ polymerization, and interfacial polymerization.

Continuous glucose monitoring (CGM) is essential for managing diabetes, including closed-loop (artificial pancreas) technology. However, the current lifetime of commercial glucose sensors used in CGM based on the electrochemical method is limited to 3–15 days. The instability or failure of implanted electrochemical glucose sensors caused by tissue reactions, outer membrane degradation, calcification, and delamination can decrease in vivo sensor accuracy and lifetime. Durable outer membrane materials with good biocompatibility are crucial to improve the accuracy and durability of long-term implantable electrochemical glucose sensors in vivo and overcome these obstacles. This study used PDMS/HydroThane as the outer membrane of the glucose sensors to demonstrate long-term in vivo stability in non-diabetic dogs for 28 days. The good biocompatibility and stability of the outer membrane contributed to the extended sensor lifetime. Additionally, the study evaluated the effect of oxygen on the performance of glucose sensors coated with PDMS/HydroThane blending membranes containing different PDMS contents. The results showed that glucose sensors coated with blending membranes of PDMS/HydroThane with a weight ratio of 10 : 50 were essentially independent of environmental PO₂ while blending membranes of PDMS/HydroThane with a weight ratio of 5 : 50 coated glucose sensors were affected by oxygen fluctuation. This new membrane was developed to increase the in vivo lifetime of CGM sensors with quick response time and good in vivo stability and provide valuable insights into the design and development of new glucose sensors for long-term CGM applications.

We would like to take this opportunity to thank all RSC Applied Polymers reviewers for helping to preserve quality and integrity in chemical science literature. We would also like to highlight the Outstanding Reviewers for RSC Applied Polymers in 2023.

Hybrid organic–inorganic hybrid perovskite (OIP) nanocrystals have gained considerable excitement due to high photoluminescence (PL) quantum yields, bandgap tunability, and narrow band emission, which are essential for photovoltaic devices, light emitting diodes (LEDs), and optical displays. While researchers have designed numerous ways to synthesize OIP nanomaterials, there is still a need to explore faster, cheaper, and scalable methods of making stable, highly performing nanomaterials for device applications. Polymers are commonly used to encapsulate OIP nanomaterials, yielding enhancements in long-term stability as well as improved PL properties. However, the exact impact of polymer chemical composition on perovskite nanocrystal growth and material properties is still unknown. Here, we reveal how polymer chemical composition directly modulates the formation of perovskite composite materials with ∼75 wt% perovskite with respect to polymer and the optical properties during a one-step, co-precipitation synthesis procedure. Specifically, a series of polymers were explored, poly(styrene) (PS), poly(4-vinylpyridine) (P4VP), poly(ethyleneimine) (PEI), poly(ethylene oxide) (PEO), poly(vinylpyrrolidone) (PVP), and poly(methyl methacrylate) (PMMA), to compare the structure and optical properties of the resulting OIP materials. Polymers with nitrogen-containing functional groups, such as amides, pyridine, and amines, are shown to preferentially bind to and passivate perovskite surfaces, acting as polymer macroligands. Nitrogen atoms in the polymer coordinate with under-coordinated lead ions on the perovskite surface, passivating surface defects and leading to an enhancement in the optical properties. Polymer macroligands also promote nanocrystal formation in a similar method as prototypical surface-active ligands used in nanocrystal syntheses. This work uncovers design rules for creating composite materials exhibiting desired nanostructures and enhanced optical properties for future OIP devices through the use of polymer macroligands.

To systematically explore the influence of microscopic substituent structures on the macroscopic dielectric properties of polyethylene (PE), ten PE derivatives, incorporating 18 mol% of diverse functional groups such as halogens, azides, norbornene-based groups, and macrocyclic structures, were synthesized using post-functionalization reactions from the same poly(ethylene-co-vinyl acetate) precursors. Using linear low-density PE (LLDPE) as a reference, the experimental results reveal the effective modulation of the dielectric constants of PE derivatives by introducing various functional groups. The PE units in the molecular chain ensure excellent compatibility of PE derivatives with LLDPE to form homogeneous polymer blends in molten states. Blending with LLDPE effectively reduces the dielectric loss of PE derivatives and exhibits a higher dielectric constant than LLDPE at the frequencies below 10 Hz. Notably, these blends exhibited a more pronounced temperature dependence of the dielectric constants, indicating higher values at elevated temperatures. More importantly, the dielectric breakdown strength of the blends was effectively enhanced, reaching up to 1.4 times that of LLDPE. In addition, improvements in the mechanical properties of the blends were also observed with the strain-at-break exceeding 1000%. This research confirms that post-polymerization functionalization provides an excellent platform to systematically evaluate the influence of substituents on synthetic polymers, and it is expected to generate new insights into the mechanisms of enhancing polymer dielectric properties.

A novel non-chemically amplified resist (n-CAR) based on biphenyl iodonium perfluoro-1-butanesulfonate-modified polystyrene with a naphthalimide scaffold (PSNA_0.4) was synthesized and characterized. Through extensive exploration using dose-dependent resist thickness analysis, acetonitrile was identified as the optimal developer. Employing electron beam lithography (EBL), the n-CAR of PSNA_0.4 demonstrated its high-resolution patterning capability by resolving a dense line pattern of 18 nm L/S at an exposure dose of 1300 μC cm⁻², achieving a high contrast of 7.1. Further studies using extreme ultraviolet lithography (EUVL) demonstrated that the PSNA_0.4 resist can achieve 22 nm L/S patterns at a dose of 90.8 mJ cm⁻², underscoring its high sensitivity for n-CARs. Detailed studies to gain insights into the underlying patterning mechanisms using X-ray photoelectron spectroscopy (XPS) suggest that the cleavage of polar iodonium into nonpolar polystyrene (PS)-based iodobenzene species enables a solubility switch, resulting in negative lithographic patterns. These findings highlight the innovative potential of the PSNA_0.4 resist in advancing the capabilities of n-CAR technologies, particularly in the realms of EBL and EUVL, for high-resolution lithographic applications.

In this study, we aim for the fabrication of precise multi-color 3D microstructures utilizing organic emitters. We have carefully selected dyes with red, green, and blue (RGB) emission characteristics and incorporated them into printable formulations suitable for two-photon laser printing (2PLP). Specifically, we have chosen an OAPPDO derivative, a boron dipyrromethene difluoride (BODIPY), and a coumarin derivative as red, green, and blue emitters, respectively, each functionalized with acrylate groups. The photopolymerizable groups allow for covalent linking to the polymer network formed in the subsequent step, enabling precise control over the incorporation of the desired emitter. The formulations including these three photopolymerizable dyes have been employed to print emissive 3D microstructures via 2PLP. Furthermore, we have studied and optimized their printability, resolution, and emission properties for each case. In a last step, we have fabricated complex multi-material 3D microstructures, demonstrating the versatility and potential application of our method in displays or anti-counterfeiting systems.

The evolution of a non-spherical shape of microorganisms helped them survive by evading capture and digestion, which is crucial for their biological functioning. Synthetic imitation of the non-spherical shapes of various microorganisms and cells can enhance the ability of synthetic particulates to deliver therapeutics inside the body. Herein, we synthesized non-spherical polymer hydrogel microcapsules with bacteria-mimicking shapes, including prolate ellipsoid, peanut, and hourglass shapes similar to some pathogen microorganisms like Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Corynebacterium diphtheriae. The hydrogel shells were synthesized through a multilayer assembly of hydrogen-bonded poly(methacrylic acid) (PMAA) and non-ionic poly(N-vinylpyrrolidone) (PVPON) homopolymers on the surfaces of non-porous iron oxide microparticles of 2 μm in length. After covalent cross-linking of PMAA layers, followed by the release of PVPON at pH = 8 and the dissolution of the particle templates, curved rod-shaped (PMAA) multilayer hydrogel microcapsules with a pH-responsive shell were obtained. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) analysis confirmed the covalent cross-linking of the shell and the release of PVPON from the capsule shell networks. The (PMAA) hydrogel capsules demonstrated excellent retention of their ellipsoid, peanut, and hourglass shapes after core dissolution in acidic solutions despite a nanothin (∼40 nm) hydrogel membrane. Remarkably, all systems retained bacteria-like shapes in solutions at pH = 8, increasing in size by 20–30%, as confirmed by confocal fluorescence microscopy. All bacteria-like shaped microcapsules demonstrated homogeneous swelling in all directions regardless of the coating location at the initial particle perimeter, indicating similar cross-linking for all shapes and no effect of the iron oxide particle surfaces on the formation of the hydrogel shell. This work can help develop polymeric non-spherical particulates that are adaptable and on-demand for biomedical applications, including advanced targeting of pathological tissues and developing artificial cells with intelligent responses to environmental cues. Synthetic imitation of bacteria-like shapes and morphological flexibility demonstrated in this work using a multilayer assembly of polymer hydrogel capsules can bring new insights into the understanding and synthetic reproduction of properties essential for the synthetic particulates to evade the immune system and increase tissue targeting. These properties can be critical for developing unconventional particulates for controlled delivery and advanced imaging.

In the realm of deep-tissue imaging, fluorescence imaging in the second near-infrared window (NIR-II, 1000–1700 nm) has proved to be an emerging tool, allowing scientists to probe biological processes with unprecedented depth. Within the NIR-II window, the NIR-IIa region (1300–1400 nm) has proved to have excellent imaging quality in the NIR-II window. Among the diverse types of NIR-II fluorophores, polymer dots (Pdots) have surfaced as a unique category of probes due to their exceptional properties including exorbitant brightness, excellent photostability, outstanding water dispersibility, and facile structural modification compared to traditional fluorescent molecules. The utilization of NIR-IIa Pdots has also addressed critical limitations in imaging by utilizing the advantages of reduced light scattering, diminished autofluorescence, and decreased light absorption by biospecies. Realizing such remarkable characteristics, this review offers insights into the design of high-performance NIR-IIa Pdots through a comprehensive interplay between chemical structures, photophysical properties, and their application in deep-tissue imaging.

The feasibility of utilizing salicylhydroxamic acid (SHAM) as a new adhesive molecule for designing structural adhesives is investigated in this study. SHAM-containing polymers were prepared with a hydroxyethyl methacrylate (HEMA) or methoxyethyl acrylate (MEA) backbone and mixed with polyvinylidene fluoride (PVDF). PVDF was included to increase the cohesive property of the adhesive through hydrogen bond (H-bond) formation with the adhesive polymers. SHAM-containing adhesive demonstrated lap shear adhesion strength (S_adh) greater than 0.9 MPa to glass, metal, and polymeric surfaces. Adhesive formulations with elevated SHAM-content also demonstrated increased adhesive properties with S_adh values reaching as high as 4.8 MPa. Due to the physically crosslinked nature of these adhesives, formulations with extensive H-bonding resulted in strong adhesion and stability. HEMA consists of a terminal hydroxyl group with both H-bond donor and acceptor, which enabled HEMA-containing adhesives to demonstrate strong adhesion even without PVDF. On the other hand, MEA contains a methoxy group that lacks H-bond donors for forming H-bonding and MEA-containing adhesives required PVDF to provide H-bond acceptors to increase its cohesive property. An aging study was performed on the bonded joints. While the adhesive joints did not demonstrate any reduction in S_adh values over 25 days when incubated in a dry condition, S_adh values decreased by 80% over 48 h when incubated in water. This is potentially due to the hydrophilic and physically crosslinked nature of the adhesive. Nevertheless, the SHAM-containing adhesive outperformed a catechol-containing adhesive and epoxy glue and is a promising new adhesive molecule for designing structural adhesives.