This review focuses on the spark plasma sintering (SPS) of Ti-based MAX phases, particularly those with Al and Si at the A-site, emphasizing their role in composite materials. The general properties and detailed oxidation behavior of the MAX phases (especially Ti2AlC, Ti3AlC2 and Ti3SiC2) are investigated. The production review is structured under two main categories: first, binary composites using spark plasma sintered MAX phases as the matrix are examined, and an in-depth analysis of their microstructural and mechanical properties is presented. Secondly, composites in which MAX phases are used as additives to enhance the properties of other matrices via the SPS method are reviewed, paying consideration to the impact of the inclusion of the MAX phase on overall performance. Important aspects such as sintering kinetics, phase stability, and property optimization are also discussed for both MAX phases and composites, based on comparisons of findings reported in the literature. This review aims to provide a comprehensive understanding of the role of SPS in tailoring MAX phase-based composites for advanced applications by integrating findings from recent studies.

Embedding quantum dots (QDs) in a solid-state matrix represents a promising hybrid platform that offers great flexibility and tunability. However, the lack of clear underlying designing principle and presence of large design space make the design process heavily relies on trial-and-error methods. Here we present a new principle that can drastically tailor the light-matter interaction of matrix by matrix-mediated QD interactions. We show that conducting matrices like P3HT can mediate a non-perturbative inter-QD interactions that lead to qualitatively distinct properties, including the enhanced carrier lifetime and enhanced binding energies with increased QD densities, which cannot be explained by conventional perturbative scattering theories and in sharp contrast to independent embedded QDs in an insulating matrix like PMMA. An effective quantum-field-theory is developed, showing qualitative agreement with experiments. Our study serves as a foundation for the predictive design of advanced hybrid materials aimed at optimizing functionalities.

Ulcerative colitis (UC) is a serious global disease whose incidence has been increasing. Currently, its clinical therapies are mainly anti-inflammatory agents and still result in a remission rate of less than 60%. Therefore, developing novel oral delivery systems to achieve multitarget therapy for UC treatment remains crucial. This study develops a hierarchically assembled oral delivery formulation for targeted UC therapy through a three-pronged strategy, including anti-inflammatory effects, barrier restoration, and microbiota modulation. Specifically, berberine and dehydrocostus lactone (BD), which are compatible bioactive molecules derived from herbs, are embedded into nano/microscale protein aggregates (PA) for prolonged retention and sustained drug release. Subsequently, BD-embedded PA (BD/PA) is encapsulated by sodium alginate microspheres (@SA) to yield BD/PA@SA for colon-targeted delivery. The coordination of components in BD/PA@SA considerably extends the drugs’ bioavailability up to 1 week at approximately 1/20 original dosage and targets the three most important pathological features (inflammation, mucosal barrier damage, and gut microbiota disorders) of UC to achieve excellent three-pronged efficacy. Importantly, the delivery carriers (PA and @SA) can be converted into short-chain fatty acids through microbial metabolism to treat UC, as confirmed by the microbiome, metabolomics, and transcriptomics analyses. This work presents a hierarchically assembled oral formulation effective against UC, utilizing carriers that can achieve 1-week retention and sustained drug release, along with the drug-convertible capacity to maximize therapeutic efficacy.

The goal of intensive energy storage research is to find and create new electrode materials with improved potential windows. In this report, we develop a novel electrode material that combines a characteristic fusion morphology with an enlarged potential window. Using a two-step in-situ growing technique, multilayered nickel–chromium-enveloped cobalt oxide (NiCr@CoO) nanowire-fused microsheets were created on a nickel foam (NF) substrate. The procedure consists of a basic hydrothermal technique after a standard wet chemical method. It was examined and optimized how experimental duration affected the in-situ evolution of morphology. A unique combination of one-dimensional (1D) nanowires and 2D microsheets was demonstrated by the optimized CoO-3h/NF electrode. The NiCr@CoO-3h/NF electrode that resulted from applying an amorphous NiCr layer to the electrode surface showed an extended potential window. In comparison to its antecedent, the NiCr@CoO-3h/NF electrode that was produced by covering the electrode surface with an amorphous NiCr layer enhanced the potential window. For 10,000 charge/discharge cycles, this innovative NiCr@CoO-3h/NF working electrode retained 134.38% cycling retention and attained a remarkable areal capacity of 1019.59 µAh cm−2. The usefulness of the NiCr@CoO-3h/NF was further demonstrated when it was used as the positive electrode in a hybrid supercapacitor (HSC) device. With a maximum energy density of 480.76 µWh cm−2 and a peak power density of 21,600 µW cm−2, the HSC device produced an areal capacitance of 1601.87 mF cm−2. Furthermore, a smart biometric system with a transparent illuminative display mechanism was developed, and the fabricated HSC device was used to drive that system to practically prove its functionality.Graphical

Morphology control strategy is a critical factor in optimizing permittivity and impedance matching. Nevertheless, developing materials with tunable morphology enabling broadband electromagnetic wave (EMW) absorption is a challenging task. In this work, Y2O3/Ni@N-doped carbon (YNC) composites were prepared by solvothermal method and high-temperature carbonization using metal-organic frameworks (MOFs) as raw materials. By regulating the molar ratio of Y3+/Ni2+, the morphology evolved from microsphere to spiky microspheres, and eventually formed dumbbell-like structures. This controllable morphological transformation provides an effective approach for modulating the permittivity. Especially, the spiky microspheres exhibited stronger EMW absorption performance than other morphologies. When the molar ratio of Y3+/Ni2+ was 3:7, the minimum reflection loss of YNC reached −64.74 dB at a 25 wt% filling ratio. At a thickness of 2.02 mm, the effective absorption bandwidth value reached 6.56 GHz (11.44–18.00 GHz), covering the entire Ku band. Notably, the composites with the controllable matching thickness and porous structure achieved effective absorption in multiple bands (C, X, and Ku). The exceptional absorption capability was linked to the tunable morphology of the composites, achieving a balance of impedance matching and attenuation capacity. Furthermore, the presence of magnetic Ni nanoparticles provided magnetic loss capability for the composites. Density functional theory indicated that the formation of heterostructures boosted the carrier mobility, facilitating effective electron transfer across interfaces, and thus increasing interfacial polarization. Therefore, this study offered a new idea for designing rare-earth based MOFs derived absorbers with broadband absorption capability.

A green flexible film heater is integrated into fiber-reinforced panels to activate the anti/de-icing function through electrical power. The heater is composed of nanometric graphitic layers embedded into a polyvinyl-alcohol (PVA) thermoplastic matrix. The influence of PVA molecular weight (M.W.) on electrical conductivity and heating efficiency is investigated. For the same nanofiller percentage (50%), the electrical conductivity decreases as the M.W. of the hosting matrix increases, going from 926.0 (M.W. 30 ÷ 70 kDa) to 8.5 S/m (M.W. 146 ÷ 186 kDa). This different behavior, which also affects heating efficiency, is due to the peculiar arrangement of polymeric chains between the nanofiller layers. The M.W. of PVA sensibly affects this arrangement, even leading to the intercalation of polymer chains between graphitic layers that prevents them from arranging into a crystalline lattice, causing complete PVA amorphization. Due to the preservation of the nanometric electrical paths in the polymeric network, unlike metal wire heaters, the film heater retains its heating function after damage. A centimeter-sized perforation does not break all electrically conductive paths, leaving the heating function active. The energy required to heat the developed functional fiber-reinforced panels is significantly lower than that of traditional electrothermal systems, saving up to 88.5% of energy. A traditional repair method for accidental damage, such as the “hot bond repair”, is considered, and a modified methodology, allowing restoration of the heating function, is proposed.Graphical abstract

Following the primary injury of intracerebral hemorrhage (ICH), the accumulation of excessive iron leads to neuronal ferroptosis. At the same time, the pro-inflammatory cascade reaction in the perihematomal region composed of activated resident microglia can propagate neural cell death. The progressive secondary brain injury following ICH is driven by a persistent reactive oxygen species (ROS) accumulation in the cerebral microenvironment and dysregulation of the glutathione (GSH)/glutathione peroxidase 4 (GPX4) antioxidant system. Targeting ROS clearance and reactivating this antioxidant defense system represent promising therapeutic strategies for mitigating secondary damage in ICH management. Here, we have designed a selenium-enriched ultrafine nanoparticle (PtSe) with enzyme-like reactivity, simultaneously serving as a ROS scavenger and a selenium reservoir for GPX4 biosynthesis. By aggregating and encapsulating PtSe into platelet-derived microvesicles, PtSe@PMV was obtained. In vitro and in vivo studies showed that the engineered modification of platelet-derived microvesicles resulted in multivalent targeting characteristics of PtSe@PMV to the site of ICH, with a local drug concentration 11.9 times higher than the control group. In mice with ICH, PtSe@PMV was found to effectively inhibit neuronal ferroptosis, reshape the immune microenvironment of the lesion area, and inhibit the deterioration of ICH. This study provides a new method for treating secondary injury caused by ICH and demonstrates the potential of cell-derived drug carriers and enzyme-like drugs in biomedicine.

Polymer-derived ceramics (PDCs) have garnered significant attention as a very promising class of materials owing to their unique combination of ceramic-like properties and the inherent processability of polymers. Nanofillers with one- and two-dimensional structures have attracted considerable interest as functional additives in PDCs due to their remarkable electrical, mechanical, thermal, and electrochemical properties. The principal aim of their inclusion in PDC-based composites is to augment the adaptability of the material for a wider range of industrial applications. This review commences by providing a comprehensive analysis of the primary synthesis techniques employed for producing PDCs, emphasizing the significant influence of the pyrolysis conditions in modifying the microstructure and properties of the resulting ceramics. A detailed analysis of the fabrication of PDCs with integrated one-dimensional (1D) nanofillers, such as carbon nanotubes, boron nitride nanotubes, nanowires, and carbon nanofibers, is then provided. This review also focuses on the incorporation of two-dimensional (2D) nanofillers, including graphene, hexagonal boron nitride (h-BN), MXene, transition metal dichalcogenides (TMDs), as well as 2D metal organic frameworks, into PDC matrices. Moreover, the effects of 1D/2D nanofiller addition on the mechanical, thermal, and electrical characteristics of PDC nanocomposites are discussed in detail and related to their microstructural attributes and processing conditions. This review article provides insights for researchers, engineers, and material scientists who are actively engaged in the field of advanced ceramics and nanocomposites with the objective of facilitating the exploration of new horizons in material properties and applications.

Public health emergencies increasingly threaten human health and socio-economic stability, necessitating enhanced monitoring and early warning capabilities to effectively prevent and mitigate public health risks. Real-time detection devices, through precise detection and dynamic monitoring enabled, play a crucial role in preventing disease outbreaks and reduce the spread of harmful substances. Among these, paper-based optical detection devices have emerged as one of the most promising strategies in the field of point-of-care testing (POCT), owing to their advantages such as portability, low cost, foldability, and visual results. This article systematically reviews the research progress and key challenges of paper-based optical detection devices. Firstly, various types of paper-based detection devices are outlined. Then, the optical sensing methods, recognition elements, and their loading techniques involved in these devices are combed in detailed. Subsequently, specific applications of paper-based optical detection devices in detecting foodborne pathogens, viruses, and heavy metals are summarized. Finally, challenges faced by paper-based optical detection devices and their future prospects are also discussed. This perspective offers researchers a unique viewpoint for developing portable and cost-effective paper-based optical detection devices.Graphical

The electrical conductivity (σ) of composites varies significantly depending on matrix polymer even when identical conductive fillers are employed. Here we elucidate the governing parameter of the filler–polymer interaction and σ of composites. The σ of the AgPolymer composites, synthesized by dispersing silver flakes (AgFLs) in different elastomer, thermoplastic, or thermoset polymers, varies by more than an order of magnitude in spite of the identical filler concentration (35 vol%). Although elastic modulus (E, related to the bond stiffness) and fracture energy (G, corresponding to the energy absorbed during bond cleavage) offer some insights, they are insufficient to fully elucidate the filler–polymer interaction. The excessive interaction between the AgFLs and poly-vinyl alcohol leads to the deviation from the σ-E and σ-G relationships of other AgPolymer composites. Surprisingly, the surface energy (γ) of composites (20.4–41.7 mJ m−2), obtained by the van Oss-Good model, is found to govern the σ of composites (1,598.4–36,508.0 S cm−1) without an outlier. The dispersive and polar components of the γ of AgFLs and polymer determine the filler–polymer interaction, AgFL dispersion, and σ of composites. The σ can also be predicted using the intrinsic γ of AgFLs and polymers, before synthesizing composites, which is useful for the future composite design.