Materials Advances最新文献

Conductive hydrogel-based soft devices are gaining increasing attention. Still, their dependence on water makes them susceptible to freezing and drying, which affects their long-term stability and durability and limits their applications under subzero temperatures. Developing hydrogels that combine exceptional strength, high strain sensitivity, anti-freezing properties, synchronous sensing, durability, and actuating capabilities remains a significant challenge. To overcome these issues, a universal solvent replacement strategy (USRS) was adopted to fabricate anti-freezing and anti-drying organohydrogels with ultra stretchability and high strain sensitivity in a wide temperature range. Ethylene glycol (Eg) and glycerol (Gl) were used as secondary solvents to replace water (primary solvent) from the hydrogel network. Due to the strong hydrogen bonding capabilities of Eg and Gl with water and the hydrogel network, the organohydrogels formed show resistance to freezing and drying. This allows the organohydrogels to maintain conductivity, sensitivity, stretchability, and durability under subzero temperatures. The developed organohydrogels display remarkable stretchability (850%), good electrical conductivity (0.45 S m⁻¹), exceptional anti-freezing performance below −90 °C and very high sensitivity (GF = 10.14). Additionally, the strain sensor demonstrates a notably wide strain range (1–600%) checked within the temperature range of −15 °C to 25 °C. It also effectively monitors various human movements with differing strain levels, maintaining good stability and repeatability from −15 to 25 °C. It is also believed that this strain sensor can work efficiently above and below the mentioned temperature range. This study introduced a straightforward approach to developing conductive organohydrogels with outstanding anti-freezing and mechanical properties, demonstrating significant potential for use in wearable strain sensors and soft robotics.

The present study introduces Trigonella foenum-graecum (TFG, fenugreek)-mediated Co₃O₄ nanoparticles (NPs) as an innovative solution for eliminating industrial azo dyes from contaminated water. The novelty lies in their rapid, cost-effective synthesis and excellent photocatalytic and antimicrobial performance, which mark a significant advancement in environmental remediation. The NPs are synthesized using a co-precipitation method and characterized through advanced techniques. UV-visible absorption spectroscopy revealed two prominent direct bandgap transitions, surpassing previous reports and enhancing light absorption for efficient photocatalysis. FTIR analysis confirmed the successful incorporation of TFG phytochemicals, while XRD and SAED patterns indicated high crystallinity, a small crystallite size (1.6 nm), and ultrafine average particle size (5.5 nm) as observed by HRTEM. XPS analysis validated the synthesis with controlled oxidation states and defect sites featuring Co²⁺ and Co³⁺ ions. The optimized synthesis process led to outstanding photocatalytic performance, achieving 100% degradation of Congo red dye in just 60 minutes at a concentration of 120 mg L⁻¹. This efficiency underscores their capability to treat CR-contaminated water under specific conditions. The synergy between TFG phytochemicals and Co₃O₄ NPs demonstrates significant potential for water pollution remediation. Additionally, these NPs exhibit strong antimicrobial activity against Gram-negative and Gram-positive bacteria, highlighting their broader environmental significance and potential applications in various ecological fields.

A novel red-emitting scintillator Li₂MnCl₄ is proposed as a candidate for thermal neutron detection. It features high Li content, low density, a low effective atomic number, and emission in the red-NIR region. These characteristics make it an interesting candidate for long-distance neutron detection in harsh environments e.g. decommissioning of nuclear power plants. The absorption is thoroughly investigated in the scope of the Tanabe–Sugano diagram. The luminescence mechanism in undoped Li₂MnCl₄ is studied in depth using steady-state and time-resolved photoluminescence. Doping with Eu²⁺ and Ce³⁺ is introduced as a trial to improve the scintillation efficiency. We show that in the Eu²⁺ and Ce³⁺ doped Li₂MnCl₄ the luminescence mechanism involves energy transfer from the dopants to Mn²⁺, and propose the local lattice distortion around the dopant and possible charge compensation mechanisms.

In spite of remarkable advancements in tissue engineering and regenerative medicine in recent years, a notable gap remains in the availability of economically feasible and efficient treatments to address the hypoxic conditions within wounds. This perspective delves into cutting-edge strategies leveraging autotrophic tissue engineering for regenerative medicine, and provides new pathways for wound healing and repair. Autotrophic tissue engineering harnesses the innate photosynthetic ability of algae to provide optimal oxygen levels within cell-seeded scaffolds. This innovative approach attempts to fabricate tissue constructs endowed with self-sustainability. It also reduces the dependence on external nutrient sources, and seeks to produce functional scaffolds suitable for 3D bioprinting applications. Similarly, we envision a creative design approach focused on devising a novel methodology to functionalize carbon quantum dots (CQDs) with fucoidan derived from algae through click chemistry.

The electrical conductivity of powdered carbon aerogels is one of the key factors required for electro-chemical applications. This study investigates the correlation between the structural, physical, mechanical and electrical properties of pure and activated carbon aerogels, as well as aerogel-composites. The thermal activation with carbon dioxide led to higher electrical conductivity and a decrease in density and particle size. Furthermore, the influence of applied force, compressibility of aerogels and aerogel composites on electrical conductivity was studied. A number of different carbonaceous powdered additives with various morphologies, from almost spherical to fiber- and flake-like shaped, were investigated. For two composites, theoretical values for conductivity were calculated showing the great contribution of particle shape to the conductivity. The results show that the conductive behavior of composites during compression is based on both the mechanical particle arrangement mechanism and increasing particle contact area.

Among promising new materials, π-conjugated organic molecules are considered an attractive platform for the design and development of a wide range of self-assembled superstructures with desirable optical and electrical properties necessary for use in organic optoelectronics applications. The optical and electrical properties of π-conjugated organic molecules and their possible applications are usually determined by their primary molecular structure and their intermolecular interactions in the self-assembled state. However, satisfying the structural requirements for achieving tuneable optical properties is a difficult task, which makes the design and development of novel high-performance π-conjugated organic systems for nano-optoelectronics a considerable challenge. In this paper, we report on the design and synthesis of a naphthalene–phenanthro[9,10-d] imidazole-based π-conjugated Schiff base molecule (L1) that exhibits aggregation-induced tunable luminescence properties facilitated by solvent polarity. Upon varying the medium polarity of the self-assembly medium, L1 self-assembles into various superstructures with distinct morphologies and generates multiple tunable emission colours (blue–green–yellow–white). In a highly polar THF : water = 1 : 9 medium, it displays aggregation-induced white light emission. These single component-based white-light emitters attract broad attention due to their potential applications in lighting devices and display media. Computational studies incorporating full geometry optimization, time-dependent density functional theory (TDDFT) calculations and molecular dynamics (MD) simulations were utilized to elucidate the enhanced π–π interaction influenced by increasing solvent polarity and orbitals involved in electronic transitions associated with different self-assembled states. More importantly, we constructed a highly efficient artificial light-harvesting system in a THF : water = 1 : 1 medium based on self-assembled L1 and rhodamine B (RhB), where L1 acts as an energy donor and RhB acts as an acceptor, exhibiting a strong antenna effect at a substantial donor/acceptor ratio. Our findings provide a novel versatile approach for developing efficient artificial light-harvesting systems based on the supramolecular self-assembly of suitably designed π-conjugated organic molecules with tuneable multiple emission properties.

MXenes, a class of two-dimensional (2D) materials derived from transition metal carbides, nitrides, and carbonitrides, have garnered significant attention due to their unique properties and potential applications in various fields, including energy storage, catalysis, and electronics. Mechanochemistry, the study of chemical reactions driven by mechanical forces, offers a novel approach to synthesize and manipulate MXenes, enhancing their properties and expanding their functional applications. This review explores the intersection of MXenes and mechanochemistry, highlighting recent advancements in the mechanochemical synthesis of MXenes and their derivatives. We discuss the mechanisms underlying the mechanochemical processes, including the role of shear forces, ball milling, and other mechanical techniques in facilitating the exfoliation and functionalization of MXenes. Furthermore, we examine the impact of mechanochemical methods on the structural integrity, surface chemistry, and electronic properties of MXenes, which are crucial for their performance in applications such as supercapacitors, batteries, and sensors. This review also addresses the challenges and limitations associated with mechanochemical approaches, including scalability and reproducibility, while proposing future directions for research in this promising field. By integrating mechanochemistry with MXene research, we aim to provide insights into innovative strategies for the development of advanced materials that can meet the demands of next-generation technologies. This synthesis of knowledge not only underscores the versatility of MXenes but also emphasizes the transformative potential of mechanochemistry in materials science.

Ag-doped LaMnO₃ perovskite oxides were synthesized as new cathode materials for solid oxide fuel cells (SOFCs), and their phase stability, reactivity with yttria-stabilized zirconia (YSZ), electronic state of Mn, electrical conductivity, and power generation properties were investigated. La_0.9Ag_0.1MnO_3±δ (LAM01) showed no evidence of Ag metal deposition, whereas La_0.9Ag_0.2MnO_3±δ (LAM02) showed Ag metal deposition, suggesting that Ag dissolved in a perovskite-type structure and its solid solution limit for the La-site was 10%. LAM01 did not react with the YSZ electrolyte at 975 °C for 100 h. The electronic state of Mn was between that of the trivalent and tetravalent states at room temperature, suggesting that the Ag acceptor dopant was charge-compensated by the oxidation of Mn. Electrical conductivity and Seebeck coefficient measurements indicated that the main charge carrier was electron–hole. Stable power generation properties were obtained using the LAM01 cathode and indicated that the Ag acceptor was stable and was compatible with the YSZ electrolyte. Therefore, Ag-doped LaMnO₃ is promising as a novel SOFC cathode.

The study involved the formulation of cabazitaxel loaded D-alpha-tocopheryl succinate/chitosan conjugate (CSVE) and hyaluronic acid (HA) based redox-responsive nanoparticles crosslinked using 3,3′-dithiodipropionic acid (DTPA). The nanoparticle surface was functionalized with cetuximab (Cmab) to give CSVE/HA/DTPA/Cmab NP for EGFR targeted delivery of the payload. The formulations were subjected to particle analysis, morphological assessment, solid-state characterization, and in vitro drug release studies. The results showed cationic, sub-200 nm sized spherical particles with the glutathione-responsive release of cabazitaxel. In vitro studies revealed a marked decrease in the IC₅₀ value, improved cellular uptake, and a superior apoptotic effect. To determine the in vivo efficacy of the formulation, pharmacokinetic assessment, tumor regression analysis, and survival analysis were performed. The nanoparticles showed improved pharmacokinetic and anti-tumor efficacy compared to free cabazitaxel. The prepared nanoparticles demonstrated immense potential in targeted delivery of the payload for enhanced breast cancer therapy.

Three bio-based propargyl ether thermosetting resins with trans-stilbene cores were synthesized from p-coumaric (CD), ferulic (FD), and sinapic (SD) acid, respectively. Differential scanning calorimetry (DSC) analysis of these materials indicated modest processability due to high melting points, short processing windows and large exotherms. To address this issue, a fourth resin with a more flexible bridging group (TD) was synthesized from p-coumaric acid and used as a blending agent. In parallel, CD was photochemically isomerized to the cis-isomer (PD) and blends of CD:PD were prepared. Cross-linked networks derived from the resins exhibited glass transition temperatures (T_gs) ranging from 285–330 °C (storage modulus) and char yields from 27–59% at 1000 °C under N₂. The processable resin blends exhibited exceptional thermal stability due to a higher degree of cross-linking enabled by the structural diversity of the blends. The fire resistance of the networks was evaluated through microscale combustion calorimetry. The networks exhibited heat release capacity (HRC) values ranging from 43–103 J g⁻¹ K⁻¹, which classified them as either non-ignitable or self-extinguishing materials. The results demonstrate that abundant, bio-based hydroxycinnamic acids can serve as platform chemicals for the preparation of thermally stable, fire-resistant networks for aerospace applications.