Materials Horizons最新文献

Correction for 'Application of carbon-based nanomaterials in Alzheimer's disease' by Mengyao Bai et al., Mater. Horiz., 2024, https://doi.org/10.1039/D4MH01256A.

Functional catalytic materials play an important role in environmental, biological, energy, and other fields, wherein unique properties can be endowed through various synthesis strategies. However, conventional catalyst preparation methods suffer from mild conditions, prolonged treatment and low energy transfer efficiency, thus leading to limited inherent characterisation of catalysts (such as surface oxidation and agglomeration). Recently, the rapid Joule heating method, as a novel synthesis method, has attracted widespread attention owing to its controllable kinetic conditions and eco-friendly operation, while the mechanisms, advantages and recent progress of this method have been summarized in few reviews. Herein, we systematically summarize basic fundamentals and parameters of the Joule heating technique as well as recent processes in terms of effective modification strategies based on Joule heating. Meanwhile, perspective suggestions and challenges for Joule heating methods in terms of catalytic materials are put forward. This review provides an understanding for designing advanced catalytic materials.

The imperative advance towards achieving "carbon neutrality" necessitates the development of porous structures possessing dual acoustic and mechanical properties in order to mitigate energy consumption. Nevertheless, enhancing various functionalities often leads to an increase in the structural weight, which limits the feasibility of using such structures in weight-sensitive applications. In accordance with the outlined specifications, a novel structural design incorporating carbon fiber reinforced polymer (CFRP) composites alongside mechanical and acoustic metamaterials has been introduced for the first time. This innovative construction exhibits a lightweight composition with excellent mechanical and acoustic characteristics. Experimental findings demonstrate that with meticulous planning and fabrication, CFRP composite structures can achieve a balance of lightweight construction, high strength, exceptional energy absorption, and remarkable resilience. By introducing membrane and reasonable cavity design, the structure can produce low broadband noise reduction performance by a local resonance effect and impedance matching mechanism of metamaterials. The structural sound insulation capability breaks traditional mass law, resulting in an exceptionally broadband sound insulation peak (bandwidth of nearly 1000 Hz). Furthermore, the sound absorption characteristic of the structure surpasses that of the melamine sponge at frequencies below 300 Hz, demonstrating superior low-frequency sound absorption properties. The proposed structure provides new approaches for the design of multifunctional lightweight superstructures.

Improving the high-temperature performance of polymer dielectrics is critical for the development of advanced electrical systems. The deterioration of the capacitive performance of polymer dielectrics at high electric fields and elevated temperatures is attributable to the exponentially increased conduction loss. Herein, a synergistic strategy of molecular trap and aggregation structure optimization is developed to suppress the conduction loss of polymer dielectrics. A molecular semiconductor - HAT-CN with high electron-affinity (EA) and special distribution of electrostatic potential is designed in this work. The theoretical calculation and experimental results show that HAT-CN can introduce electron traps and simultaneously interrupt the conjugation between aromatic rings in molecular chains via electrostatic interaction with polyetherimide (PEI). Consequently, the collective effect of electron trap and aggregation structure optimization reduces the leakage current density of PEI by nearly an order of magnitude at 200 °C and improves the mechanical properties of films. Finally, the HAT-CN/PEI all-organic composite achieves a discharge energy density of 3.8 J cm^-3 with efficiencies above 90% (U_η>90%) and long-term reliability over 100 000 cycles at 200 °C, outperforming most current polymer dielectrics. This work provides a new idea for the design of high-temperature polymer dielectrics based on molecularly engineered organic semiconductors.

An unconventional yet facile low-energy method for uniquely synthesizing neat poly(vinylidene fluoride) (PVDF) films for energy harvesting applications by utilizing nanoelectromechanical vibration through a 'piezo-to-piezo' (P2P) mechanism is reported. In this concept, the nanoelectromechanical energy from a piezoelectric substrate is directly coupled into another polarizable material (i.e., PVDF) during its crystallization to produce an optically transparent micron-thick film that not only exhibits strong piezoelectricity, but is also freestanding-properties ideal for its use for energy harvesting, but which are difficult to achieve through conventional synthesis routes. We show, particularly through in situ characterization, that the unprecedented acceleration associated with the nanoelectromechanical vibration in the form of surface reflected bulk waves (SRBWs) facilitates preferentially-oriented nucleation of the ferroelectric PVDF β-phase, while simultaneously aligning its dipoles to pole the material through the SRBW's intense native evanescent electric field . The resultant neat (additive-free) homopolymer film synthesized through this low voltage method, which requires only -orders-of-magnitude lower than energy-intensive conventional poling methods utilizing high kV electric potentials, is shown to possess a 76% higher macroscale piezoelectric charge coefficient d₃₃, together with a similar improvement in its power generation output, when compared to gold-standard commercially-poled PVDF films of similar thicknesses.

Among type I photosensitizers, stable organic radicals are superior candidate molecules for hypoxia-overcoming photodynamic therapy. However, their wide applications are limited by complicated preparation processes and poor stabilities. Herein, a nitroxide radical was simply synthesized by introducing a commercially available "TEMPO" moiety. The radical exhibits efficient type-I ROS generation and appreciable photo-cytotoxicity under hypoxia, which open up a new avenue for the exploration of a novel and efficient type-I photosensitizer.

A variety of therapeutic strategies are available to treat glioblastoma (GBM), but the tumor remains one of the deadliest due to its aggressive invasiveness, restrictive blood-brain barrier (BBB), and exceptional resistance to drugs. In this study, we present a hydrogen sulfide (H₂S)-generating semiconducting polymer nanoparticle (PFeD@Ang) for amplified radiodynamic-ferroptosis therapy of orthotopic glioblastoma. Our results show that in an acidic tumor microenvironment (TME), H₂S donors produce large amounts of H₂S, which inhibits mitochondrial respiration and alleviates cellular hypoxia, thus enhancing the radiodynamic effect during X-ray irradiation; meanwhile, Fe³⁺ is reduced to Fe²⁺ by tannic acid in an acidic TME, which promotes an iron-dependent cell death process in tumors. H₂S facilitates the ferroptosis process by increasing the local H₂O₂ concentration via inhibiting catalase activity. This kind of amplified radiodynamic-ferroptosis therapeutic strategy could remarkably inhibit glioma progression in an orthotopic GBM mouse model. Our study demonstrates the potential of PFeD@Ang for GBM treatment via targeted delivery and combinational therapeutic actions of RDT and ferroptosis therapy.

Harnessing the potential of hydrogel-based localized drug delivery systems holds immense promise for mitigating the systemic side effects associated with conventional cancer therapies. However, the development of such systems demands the fulfillment of multiple stringent criteria, including injectability, biocompatibility, and controlled release. Herein, we present an ultra-small peptide-based hydrogel for the sustained and targeted delivery of doxorubicin in a murine model of breast cancer. The hydrogel evades dissolution and remains stable in biological fluids, serving as a reliable drug reservoir. However, it specifically reacts to the high levels of glutathione (GSH) in the tumor microenvironment and releases drugs in a controlled manner over time for consistent therapeutic benefits. Remarkably, administration of a single dose of doxorubicin-loaded hydrogel elicited superior tumor regression (approximately 75% within 18 days) compared to conventional doxorubicin treatment alone. Furthermore, the persistent presence of the drug-loaded hydrogel near the tumor site for up to 18 days after administration highlights its enduring effectiveness. There is great clinical potential for this localized delivery strategy because of the minimal off-target effects on healthy tissues. Our findings underscore the efficacy of this smart peptide-hydrogel platform and pave the way for developing next-generation localized drug delivery systems with enhanced therapeutic outcomes in cancer treatment.

Biodegradable alternatives to classic solid-state components are rapidly taking place in front-end photonic systems like metamaterials, meta-surfaces and photonic crystals. From this point of view, numerous solutions have been proposed involving eco-friendly compounds. Among them, the Luria Bertani agar (LBA) growth medium has been recently proposed as a functional option with the remarkable advantage of allowing the growth of fluorescent protein expressing bacteria. Such a possibility promises to lead to development of a new generation of biological and eco-sustainable optical sources based on meta-surfaces. There is, however, still a main drawback to address, related to the highly scattering nature of these compounds. To ensure adequate nutritive elements for cell growth, LBA hosts several compounds like NaCl, yeast extracts and tryptone. The presence of these components leads to very scattering LBA films, thus hindering its performance as an optical polymer. A trade-off arises between nutritive capacity and optical performance. In this paper, we successfully address this trade-off, demonstrating that a reduction of the basic nutrients (net Agar concentration) of LBA largely enhances the optical properties of the film as a photonic polymer without compromising its cell-viability. We considered two new LBA formulations with two- (LB₂A) and four-fold (LB₄A) reduction of the nutrients and replicated a square-lattice meta-surface used as a benchmark architecture. We demonstrated that both the replica molding performances and the optical properties (absorption, scattering and diffraction efficiency) of LBA formulations increase with decreasing nutrient concentration, without losing their cell-growth capability. To demonstrate this fundamental aspect, we inoculated the most critical case of LB₄A with green-fluorescent-protein-expressing E. coli bacteria, verifying both their vitality and good photoluminescence properties. These results overcome one of the main limitations of LBA as a functional biopolymer for optical applications, unlocking its use in a new generation of biological quantum optical frameworks for all-biological weak and strong light-matter interactions.

Polyolefins are the most widely used and produced petroleum-based plastics. Unfortunately, the enormous production and usage of traditional polyolefins, coupled with the lack of effective disposal or recycling options, have led to significant fossil fuel depletion and severe environmental pollution. To foster sustainable societal development, there is an urgent need to design high-performance and inherently recyclable polyolefin-like bio-derived materials by innovative structural and molecular designs. Here, inspired by a copolymerization molecular design approach that simultaneously confers recyclability and superior properties to materials, high-performance recyclable polyolefin-like bio-derived polyesters (PBC_xS) enabled by a novel judicious combination of building blocks are reported. PBC_xS display excellent mechanical (40.6 MPa, 498.4%) and gas barrier properties (O₂ 0.09 barrer, H₂O 1.70 × 10^-13 g cm cm^-2 s^-1 Pa^-1), even greater than those of bio-based materials and most aliphatic polyester. Meanwhile, PBC_xS also exhibit multifunctionality with excellent biocompatibility properties and ultra-high processability (thermoforming, extrusion spinning, and 3D printing processing). Notably, PBC_xS undergo depolymerization in the absence of any additional organic solvents, regenerating 92.0% of the high-purity (98.3%) original monomers, even with polyolefin blend plastics. Repolymerized polyesters still maintain their exceptional mechanical and thermal qualities. The successful application of this approach in polyesters opens up exciting possibilities for designing high-performance and recyclable bio-derived polyolefin-like materials.