Materials Advances最新文献

We present a simple method for bonding an elastomer substrate using a stretchable, low-molecular-weight adhesive. By mixing 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (EDC) and gallic acid on an aminated surface, EDC is converted into a urea derivative. This derivative features both hydrogen bond donor and acceptor functionalities, combined with bio-inspired adhesive gallol groups, which collectively enhance adhesiveness through extensive hydrogen bonding. Importantly, the adhesive preserves the stretchability of the elastomer.

Defect-induced alkali-metal cerium double tungstate compounds, ACe(WO₄)₂ (where A = Li, Na, K), have been synthesized through a trisodium citrate-based hydrothermal process. The influence of alkali-metal ions on the local structure of ACe(WO₄)₂ has been explored using various methods, including the Rietveld technique for powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Although the ACe(WO₄)₂ compounds exhibit similar transitions, they differ in luminescent intensity. Notably, in the case of the alkali metal Na, the material displays a larger crystal compactness due to its comparable ionic radii with Ce³⁺. This proximity indicates lower distortion. Conversely, Li and K possess significantly different ionic radii from Ce³⁺, leading to pronounced crystal distortion. The ACe(WO₄)₂ materials show emissions in blue and green spectra, including blue I (439 nm), blue II (462 nm), blue III (487 nm), and green (531 nm). The blue I emission is attributed to the 5d → 4f transition within the CeO₈ polyhedra, whereas the blue III emission arises from the same transition within CeO₇ polyhedra. The blue II and green emissions result from the formation of CeO₆ polyhedra. Additionally, ab initio calculations employing density functional theory reveal that the valence and conduction bands are composed of O 2p and O 2p–Ce 5d hybridization, respectively. Notably, the 5d_xy, 5d_xz, 5d_yz, 5d_x²−y², and 5d_xz, 5d_x²−y² orbitals significantly contribute to the 5d–4f transition within CeO₇ and CeO₆ polyhedra, respectively. The resulting Commission Internationale de l'Éclairage (CIE) coordinates in the blue region, coupled with a correlated color temperature (CCT) of approximately 7800 K, suggest that ACe(WO₄)₂ materials hold promise for applications in cold solid-state lighting.

The pursuit of effective drug delivery systems is critical in advancing cancer therapies, particularly in the realms of chemotherapy, radiotherapy and immunotherapy. This review focuses on plant-based extracellular vesicles (PBEs) as innovative nanoplatforms for encapsulating and delivering genetic materials, including microRNAs (miRNAs), small interfering RNAs (siRNAs), and mitochondrial DNA (mtDNA). We explore the unique properties of PBEs that enhance the stability and bioavailability of these therapeutic molecules, particularly their resistance to degradation by ribonucleases (RNases) and their ability to withstand gastrointestinal digestion. By improving the stability and facilitating cellular uptake of these genetic particles, PBEs offer a significant enhancement of their therapeutic efficacy through nuclear gene modulation. This review highlights the transformative potential of PBEs in developing novel drug delivery systems for cancer treatment, paving the way for future research and clinical advancements in RNA-based therapies and beyond.

The soot oxidation activity of manganese-doped ceria-praseodymium catalysts, synthesized via solution combustion synthesis, was evaluated. The analyses performed with XRD and Raman spectroscopy indicated that the Mn-doped CP catalysts displayed the typical fluorite structure of CeO₂. The addition of Mn to CP led to a reduction in crystallite size from 14 nm to below 10 nm. The F_2g Raman active mode of fluorite-structured Ce and the oxygen vacancies resulting from the addition of Mn and Pr (bands ∼ 560 cm⁻¹ to 580 cm⁻¹) were consistently observed across all Mn-doped CP catalysts. 15 and 20 Mn-CP exhibited an additional secondary phase identified as Mn₂O₃. The analysis of BET surface area and BJH pore size revealed that the Mn-doped CP catalysts exhibited both micro and mesoporous characteristics. The H₂-TPR and O₂-TPD profiles indicated enhanced reducibility resulting from the incorporation of Mn and Pr into CeO₂-doped catalysts. The improved T₅₀ (365 ± 1 °C) for the 5 Mn-CP catalytic system is primarily due to its increased specific surface area of 45 m² g⁻¹ and the presence of active surface adsorbed oxygen species identified in the XPS and O₂-TPD studies. 5 Mn-CP exhibited the lowest activation energy value compared to all other Mn-doped catalysts.

The reaction between volatile platinum and rhodium gas species and bulk materials (alloys or oxides) is of high practical importance in the chemical process industry. Herein, an X-ray photoelectron spectroscopy (XPS) study has been conducted to understand how PtO₂(g) and RhO₂(g) react with LaNiO₃ (LNO) thin films grown via atomic layer deposition (ALD) at elevated temperatures (900 °C). In this study, XPS data for reference powders of La₂NiPtO₆, LaNi_0.95Pt_0.05O₃, LaNi_0.88Rh_0.12O₃ and LaRhO₃ provide a library for the interpretation of oxidation states of platinum and rhodium after reaction with LNO thin films. Upon short exposure to PtO₂(g) and RhO₂(g), platinum appear as Pt(III) in the LNO surface, but after prolonged exposure, Pt(IV) appears. Complementary diffraction analysis shows that LaNi_1−xM_xO₃ solid solution forms initially where Ni, Pt and Rh are predominantly +III, however, quickly accompanied by the formation of a La₂Ni_2−2xM_2xO₆ (M = Pt, Rh) double perovskite phase with its characteristic (004) peak. Rhodium appears as Rh(III) and Rh(IV) in both the Rc and the double perovskite like phases. Furthermore, platinum and rhodium depth profiles were generated by the combination of XPS and Ar⁺ sputtering. Platinum depth profiles reveal major differences between as-grown ALD films and post-annealed films when exposed to PtO₂(g). Pt penetrates faster into the LNO material for films without post annealing, probably due to its smaller grain size and larger surface area and grain boundaries. When exposed to a mixture of PtO₂(g) and RhO₂(g), the Rh : Pt ratio in LNO increases upon prolonged reaction time. These results may have implications on the use of LNO as platinum and rhodium capture material in the Ostwald process.

The ability to convert light to higher energies through triplet–triplet annihilation upconversion (TTA-UC) is attractive for a range of applications including solar energy harvesting, bioimaging and anti-counterfeiting. Practical applications require integration of the TTA-UC chromophores within a suitable host, which leads to a compromise between the high upconversion efficiencies achievable in liquids and the durability of solids. Herein, we present a series of methacrylate copolymers as TTA-UC hosts, in which the glass transition temperature (T_g), and hence upconversion efficiency can be tuned by varying the co-monomer ratios (n-hexyl methacrylate (HMA) and 2,2,2-trifluoroethyl methacrylate (TFEMA)). Using the model sensitiser/emitter pair of palladium(II) octaethylporphyrin (PdOEP) and diphenylanthracene (DPA), the upconversion quantum yield was found to increase with decreasing glass transition temperature, reaching a maximum of 1.6 ± 0.2% in air at room temperature. Kinetic analysis of the upconversion and phosphorescence decays reveal that increased PdOEP aggregation in the glassy polymers leads to a competitive non-radiative relaxation pathway that quenches the triplet state. Notably, the threshold intensity is highly sensitive to the glass transition temperature, ranging from 1250 mW cm⁻² for PHMA₉₀TFEMA₁₀ (T_g = −9.4 °C) to ∼200 mW cm⁻² for more ‘glassy’ hosts, e.g. PHMA₃₃TFEMA₆₇ (T_g = 20.1 °C), suggesting the TTA-UC mechanism switches from diffusion-based collisions to triplet exciton migration at localised sensitiser–emitter pairs.

In geometrically frustrated (GF) magnets, conventional long-range order is suppressed due to the presence of primitive triangular structural units, and the nature of the ensuing ground state remains elusive. One class of candidate states, extensively sought in experiments and vigorously studied theoretically, is the quantum spin liquid (QSL), a magnetically-disordered state in which all spins participate in a quantum-coherent many-body state. Randomly located impurities, present in all materials, may prevent QSL formation and instead lead to the formation of a spin-glass state. In this article, we review available data on the specific heat, magnetic susceptibility, and neutron scattering in GF materials. Such data show that a pure GF magnet possesses a characteristic “hidden energy scale” significantly exceeded by the other microscopic energy scales in the material. When cooled down to a temperature below the hidden energy scale, a GF material develops significant short-range order that dominates its properties and, in particular, dictates the spin-glass transition temperature for experimentally accessible impurity densities. We review the manifestations of short-range order in the commonly observed thermodynamics quantities in GF materials, possible scenarios for the hidden energy scale, and related open questions.

In this study, we developed novel Gd₂O₃/Fe₃O₄ composite nanoparticles (GFO CNPs) via a simple one-step thermal decomposition of Fe(III) actylacetonate and Gd(III) acetate in octadecene solvent, with oleic acid (OA) and oleylamine (OM) serving as surfactants. The effects of the Gd/Fe molar ratio on the formation, size, and T₁, T₂ relaxation efficiency of the NPs were investigated. The as-synthesised GFO CNPs were characterised using various analytical techniques such as TEM, HRTEM, XRD, UV-Vis, VSM, EDX and XPS. The results showed that GFO CNPs synthesised at a Gd/Fe ratio of 7/3 (GFO-7/3 CNPs) had an average size of about 10 nm, exhibited monodispersity with a narrow size distribution, and demonstrated superparamagnetic properties at room temperature. Additionally, surface modification of the NPs with PMAO improved their dispersibility and stability in aqueous media. Cytotoxicity tests confirmed the biocompatibility of the PMAO encapsulated GFO CNPs. In vitro relaxivity studies showed high r₁ and r₂ values of 18.20 and 94.75 mM⁻¹ s⁻¹, respectively, with an r₂/r₁ ratio of 5.21, outperforming commercial products such as Feraheme, Resovist, Feridex, and Dotarem. These findings suggest that GFO CNPs provide a promising nanoplatform for non-invasive T₁–T₂ dual-modality MRI diagnosis.

Highly active and stable cathodes play a crucial role in aqueous Zn-organic batteries, enabling them to achieve high capacity, rapid redox kinetics, and an extended lifespan. However, currently reported electrode materials for Zn-organic batteries face challenges such as low capacity and inadequate cycling stability. In this contribution, aiming to overcome the challenges above, we develop a new Zn-organic battery. In this battery, saturated ZnSO₄ served as an electrolyte and its cathode is based on dipyrido [3,2-a:2′,3′-c] phenazine (DPPZ). Theoretical calculations and ex situ analyses demonstrate that the Zn//DPPZ batteries mainly undergo an H⁺ uptake/removal process with a highly reversible structural evolution of DPPZ. As a result, the aqueous Zn//DPPZ full cell exhibits a remarkable capacity of 94 mA h g⁻¹ at a mass-loading of 2 mg cm⁻² (achieved at 0.5 A g⁻¹), and rapid kinetics. Moreover, the cell possesses remarkable cycling durability such that at a mass-loading of 2 mg cm⁻², the cell owns a long lifespan of 8000 cycles with a current density of 5 A g⁻¹, and even at a high mass-loading of 8 mg cm⁻², it can still endure 600 cycles with a current density of 0.5 A g⁻¹. These findings pave the way for the development of advanced organic electrodes.

Calcium ions play a vital role in skeletal growth, muscle action and neural signalling. Thus, the level of calcium in the body is a crucial parameter in the diagnosis of muscle weakness and osteoporosis. Fluorescence conductive hydrogels are widely employed in electronic devices as they are able to monitor single or multiple parameters in synergistic optical and electrical modes. However, integrating optical and conductive modalities and synergizing their various functions to develop a wearable sensor is challenging. In this regard, a PVA–agar hydrogel (PAGH) cross-linked with copper-doped carbon dot (MCD) was fabricated. The developed MCD@PAGH addressed Ca²⁺ recognition through a change in ionic conductance and fluorescence. The hydrogel patch sensor was not cytotoxic, exhibited bactericidal activity, and monitored Ca²⁺ level in sweat in both the fluorescence and electrical modes. This work provides a strategy to design multifunctional materials to address prospective applications in wearable biosensors.