RSC Applied Polymers最新文献

Flexible supercapacitors (FSCs) based on hydrogel electrolytes have the advantages of high ionic conductivity, no liquid leakage, flexibility and versatility, making them the most promising power sources for wearable devices. Herein, a flexible and stretchable, ultrathin polyvinyl alcohol/carboxymethyl chitosan incorporated with a redox active ionic liquid (PVA/CMCS-[ViEtIm][Br]) hydrogel electrolyte is prepared by a facile coating and freezing/thawing method, which is used to improve the practical performance of supercapacitors. The PVA/CMCS-[ViEtIm][Br] hydrogel film has good mechanical properties. More importantly, the redox reaction caused by [ViEtIm][Br] in the hydrogel electrolyte provides a crucial pseudocapacitive contribution to supercapacitors. Thus, the flexible supercapacitor assembled with the PVA/CMCS-[ViEtIm][Br] hydrogel at a thickness of 0.1 mm has an areal specific capacitance of 314.4 mF cm⁻² and an energy density of 78.6 μWh cm⁻² at 540 μW cm⁻², with a capacitance retention of 87.5% after 10 000 charge/discharge cycles. Moreover, the flexible supercapacitor can also exhibit stable performance at different bending angles. This work provides a simple and feasible method for realizing ultra-thin flexible capacitors with high energy density.

Microplastics have been found in our food, water, and air, raising concerns about their potential health impacts. While environmental remediation may be intractable, we should prioritize minimizing our exposure. In this context, an adhesive-coated stainless-steel filter was developed herein to remove microplastics from water.

Antimicrobial resistance is a threat to public health for which new treatments are urgently required. The capability of bacteria to form biofilms is of particular concern as it enables high bacterial tolerance to conventional therapies by reducing drug diffusion through the dense, exopolymeric biofilm matrix and the upregulation of antimicrobial resistance machinery. Quorum sensing (QS), a process where bacteria use diffusible chemical signals to coordinate group behaviour, has been shown to be closely interconnected with biofilm formation and bacterial virulence in many top priority pathogens including Pseudomonas aeruginosa. Inhibition of QS pathways therefore pose an attractive target for new therapeutics. We have recently reported a new series of pqs quorum sensing inhibitors (QSIs) that serve as potentiators for antibiotics in P. aeruginosa infections. The impact on biofilms of some reported QSIs was however hindered by their poor penetration through the bacterial biofilm, limiting the potential for clinical translation. In this study we developed a series of poly(β-amino ester) (PBAE) triblock copolymers and evaluated their ability to form micelles, encapsulate a QSI and enhance subsequent delivery to P. aeruginosa biofilms. We observed that the QSI could be released from polymer micelles, perturbing the pqs pathway in planktonic P. aeruginosa. In addition, one of the prepared polymer variants increased the QSIs efficacy, leading to an enhanced potentiation of ciprofloxacin (CIP) action and therefore improved reduction in biofilm viability, compared to the non-encapsulated QSI. Thus, we demonstrate QSI encapsulation in polymeric particles can enhance its efficacy through improved biofilm penetration.

The problem of antibiotic resistance has raised serious concerns globally and hence the development of new materials which can combat these drug-resistant strains has gained a great deal of attention. Herein, we report the use of a biocompatible material, chitosan, as a scaffold to graft saccharides which can specifically target Pseudomonas aeruginosa. We realized this by synthesizing N-functionalized chitosan conjugates by coupling chitosan to fucose and galactose moieties which intercept Pseudomonas aeruginosa lectins and target the bacterial biofilms. A series of six conjugates containing similar proportions of cationic and sugar moieties were synthesized by direct modification of the chitosan backbone using a method that is highly efficient and reproducible. The conjugates showed a bactericidal effect against both Gram positive and Gram negative bacterial strains. An investigation into the antibiofilm activity of the conjugates revealed the optimum combination of the type and positioning of the functionalities that were highly effective in eradicating Pseudomonas aeruginosa biofilms. 2D and 3D imaging of the conjugate-treated biofilms using confocal laser scanning microscopy (CLSM) allowed us to determine that the conjugates not only acted on the surface but also dispersed into deep layers of the biofilm. Interaction between the conjugates and individual bacterial cells in the biofilm was further confirmed by fluorescence labelling of the conjugates and imaging by CLSM.

Flexible and lightweight sensors can assess their environment for a broad range of applications that include wearables for health monitoring and soft robotics. While 2D and 3D printing enables control over sensor design in multiple dimensions, customizability of a sensor toward different individual use cases is still limited because each sensor requires a new design and manufacturing process. Thus, there is a need for methodologies that produce modular sensor components that can be assembled and customized by an individual user. Herein, we demonstrate 3D printed, elastomeric ionogels comprising covalent adaptable networks (CANs) for modular sensor assemblies. Reversible Diels–Alder connections incorporated into the network can occur at the interface between two 3D printed objects in physical contact with each other. As a result, modular components can be combined and assembled on-demand into customized piezoionic sensors. Thermal curing of these modular blocks triggered the dynamic remodeling of the polymer networks that caused them to become fused together. Three different configurations (linear, cyclic, and box assemblies) were demonstrated to afford piezoionic sensors from the same set of 3D printed building blocks. This study highlights the benefits of dynamic covalent networks toward decentralized manufacturing, wherein a modular approach enables customization of 3D printed parts without the need for modifying the original design.

Counterfeiting is a significant threat in the intricate realm of global commerce, casting shadows over industries, economies, and unsuspecting consumers. Fluorescent anti-counterfeiting labels have been widely used in the past, but their level of security is still relatively inadequate. Therefore, the ongoing research is aimed at improving security through the encapsulation of information within predefined geometric structures. Herein, fluorescent organohydrogels with a hydrophilic polymer network of poly(N,N-dimethylacrylamide-acrylic acid) (P(DMA-AAc)), containing blue fluorescent monomers (PyMA), and a hydrophobic polymer network, polystearyl methylacrylate (PSMA), are fabricated by two-step interpenetrating polymerization. Upon treatment with Fe³⁺, the blue fluorescence of organohydrogels is quenched owing to the intramolecular charge transfer (ICT) effect, which can be reinstated by adding H⁺. Furthermore, coupled with the shape memory function induced by the crystallization of PSMA, the organohydrogels enable the concealment of encoded fluorescent information in specific three-dimensional shapes. This work presents innovative possibilities for designing and constructing advanced anti-counterfeiting systems.

Carbonic anhydrase is an enzyme which can convert dissolved carbon dioxide into carbonate and is commonly investigated in carbon capture applications as a green alternative to sequester carbon. It is common to immobilize the enzyme within a scaffold or polymer matrix for these applications to improve the efficiency and lifetime of the enzyme. A potential manufacturing route to generate protein–polymer composite materials at scale is melt processing: a technique capable of processing large amounts of material into pre-defined geometries. Intuitively, for such applications, the carbonic anhydrase would need to retain its activity under the harsh temperature and shear conditions associated with polymer melt processing, which had yet to be demonstrated. This manuscript demonstrates the recovery of active bovine carbonic anhydrase following high temperature and low- to moderate-shear exposure in a polyethylene oxide melt using both rheometry and twin-screw extrusion. Following processing, kinetic assays demonstrate that the enzyme can retain measurable amounts of activity, even following treatment up to 190 °C. Activity assays are supported by spectroscopic measurements suggesting that no significant structural change in the enzyme occurs until roughly 160 °C. Retaining more protein activity at higher temperatures appears to be related to the molecular weight of the polyethylene oxide in the melt. In sum, we demonstrate that carbonic anhydrase can retain appreciable activity following the rigors of melt processing in model systems and under real-world twin-screw extrusion.

Over the past few decades, thermosetting plastics have emerged as indispensable materials in both industrial applications and our daily lives, primarily due to their exceptional thermal and mechanical properties resulting from their covalently crosslinked structures. Nevertheless, conventional thermosets face a significant environmental challenge due to their inability to be recycled and reliance on the petroleum resources. Consequently, there is an urgent need to develop innovative, biobased thermosetting materials that are smartly designed to enable efficient chemical recycling, thus contributing to the realization of a circular plastic economy. Here, we present synthesis of a biobased di-furfural monomer and its polymerization with mixtures of various biobased multi-functional amines to construct a library of polyimines. These polyimine thermosets displayed tailor-made thermal and mechanical properties, featuring a wide range of glass transition temperatures from 8 °C to 60 °C and tensile strength spanning from 6.5 to 77.8 MPa. They also demonstrated high char yields, reaching 57% at 800 °C. Notably, these novel polyimines exhibit high bio-content (in the range of 78% to 90%) and closed-loop recyclability under mildly acidic and energy-efficient conditions. This unique property enables the recovery of monomers on demand with high yields and purity. The findings presented in this work represent a valuable contribution in the field of biobased thermosetting polymers with circular economy potential, offering new possibilities for sustainable material design.

Bioapplication of 3D printing in the fabrication of scaffolding, implants of organ replacements/recovery, etc. has been drawing increasing interest due to its capability to replicate complex structures present in organs, etc. Alongside the structure and physical properties, the functionality of printed parts is equally important to deliver appropriate materials for this type of application. Herein, complex structures integrated with a reversibly covalently linked peptide have been fabricated with high resolution via digital light processing (DLP) type VAT photopolymerization. Bisacryloyl cystamine was synthesized and incorporated into the printer resin to include disulfide functionality in some of the crosslinks. The printed objects were subsequently treated with tris(2-carboxyethyl) phosphine (TCEP) and loaded with covalently bound lanreotide, as an example of a disulfide bearing peptide, via a thiol–disulfide exchange. The uptake of lanreotide and subsequent release by a second reductive treatment of TCEP were monitored. This current method was successful in producing objects different structures capable of reversiblly binding functional peptides with the potential for a controlled release profile by adjusting the crosslink density and disulfide content in the objects has been investigated.

Biodegradable polyesters with interconnected macroporosity, such as poly(L-lactide) (PLLA) and poly(ε-caprolactone) (PCL), have gained significant importance in the fields of tissue engineering and separation. This study introduces functional macroinitiators, specifically polycaprolactone triol (PCL_T) and polyethylene glycol (PEG), both OH-terminated, in the solventless ring-opening polymerization (ROP) of a liquid deep eutectic system monomer (DESm) composed of LLA and CL at a 30 : 70 molar ratio, respectively. The macroinitiators selectively initiate the organocatalyzed ROP of LLA in the DESm during the first polymerization stage, thereby modifying the PLLA architecture. This results in the formation of either branched or linear PLLA copolymers depending on the macroinitiator, PCL_T and PEG, respectively. In the second stage, the ROP of the CL, which is a counterpart of the DESm, produces PCL that blends with the previously formed PLLA. The insights gained into the PLLA architectures during the first stage of the DESm ROP, along with the overall molecular weight and hydrophobicity of the resulting PLLA/PCL blend in bulk, were advantageously used to design polymerizable high internal phase emulsions (HIPEs) oil-in-DESm. By incorporating a liquid mixture of DESm and macroinitiators (PCL_T or PEG), stable HIPE formulations were achieved. These emulsions sustained the efficient organocatalyzed ROP of the continuous phase at 37 °C with high conversions. The resulting polymer replicas of the HIPEs, characterized by macroporous and interconnected structures, were subjected to a degradation assay in PBS at pH 7.4 and 37 °C and remained mechanically stable for at least 30 days. Notably, they exhibited the capability to sorb crude oil in a proof-of-concept test, with a rate of 2 g g⁻¹. The macroporous and interconnected features of the polyHIPEs, combined with their inherent degradation properties, position them as promising degradable polymeric sorbents for efficient separation of hydrophobic fluids from water.