Journal of Materials Chemistry C最新文献

Incorporating cellulose nanocrystals (CNCs) into eutectogels has emerged as a promising strategy to impart enhanced functional properties, such as improved ionic conductivity, optical responses to stimuli, and mechanical strength, to give rise to next-generation sustainable and biobased iontronics. These enhancements rely on interfacial engineering approaches, including the physical adsorption of hydrogen-bonding molecules (e.g., tannic acid, TA) onto CNC surfaces and their surface chemical modification (e.g., carboxylation) to optimize compatibility with both protein-based gelling agents and deep eutectic solvents (DESs). In this study, we integrate both strategies, i.e., CNC physical and chemical modifications, by first introducing carboxylic functional groups onto the CNC surface, followed by the improved adsorption of TA. This dual modification promotes favorable interactions among CNCs, the gelatin protein network (via triple-helix formation), and the nonaqueous choline chloride:ethylene glycol (ChCl–EG) DES. The resulting eutectogels demonstrate outstanding mechanical properties (elongation at break of 425% and compressive strain at break of 90%), enhanced thermal stability (T_m above 50 °C), and high ionic conductivity (1.73 mS cm⁻¹) compared with those prepared using either physical or chemical modification alone, while retaining the transient and reversible nature of gelatin-based eutectogels for strain-sensing applications. Moreover, the dynamic assembly of the eutectogel components allows the system to act as a reservoir of antibacterial agents, including the DES and TA-coated CNC, thereby imparting additional bioactivity in vitro against clinically relevant bacterial strains. This feature is particularly advantageous for iontronic applications such as multifunctional strain sensors, where gelatin-based eutectogels reinforced with TA-coated CNC complexes can combine mechanical and thermal resilience with antimicrobial functionalities.

Perovskite light-emitting diodes (PeLEDs) have achieved remarkable breakthroughs in efficiency; however, their insufficient operational stability remains a critical bottleneck hindering commercialization. This issue primarily stems from the inherent disorder during perovskite film formation, which leads to inhomogeneous grain growth and accumulation of interfacial defects, thereby accelerating device degradation. In this work, we innovatively introduce a two-dimensional MXene material (Ti₃C₂Cl₂) as a buried interfacial layer. The surface termination (Cl) functional groups of Ti₃C₂Cl₂ strongly interact electrostatically with Pb²⁺ ions in the perovskite precursor, providing abundant active nucleation sites. This interaction significantly enhances the crystal quality of the perovskite film and effectively suppresses defect density and ion migration. Moreover, the high electrical conductivity of MXene optimizes hole injection and carrier-transporting, promoting balanced charge distribution at the interface and thereby improving the electrochemical stability of the device. Experimental results demonstrate that this interfacial engineering strategy enables PeLEDs to achieve a maximum external quantum efficiency (EQE) of 13.58%, accompanied by a substantially extended T₅₀ operational lifetime. This study confirms the exceptional performance of MXene as an interfacial material and offers a novel pathway toward high-stability, long-lifetime perovskite optoelectronic devices by synergistically enhancing perovskite crystallinity, passivating interfacial defects, and weakening the ion migration effect.

Rare-earth orthochromites (RCrO₃) are multifunctional perovskites exhibiting coupled electronic and magnetic properties of significant interest. Spin reorientation is one such intriguing phenomenon arising from R–Cr (4f–3d) exchange interactions in these systems, mostly observed in bulk forms. In this work, we report the growth of epitaxial SmCrO₃ (SCO) thin films via a pulsed laser deposition technique and confirm the presence of a spin reorientation transition using AC/DC magnetometry. Using high-resolution X-ray diffraction, we also observe the presence of a strained lattice in the epitaxial films in comparison to the bulk SCO (−0.18% in-plane and +0.42% out of plane). Interestingly, relative to the bulk polycrystal, there is a concomitant reduction in both the Néel transition temperature (∼2%) and the optical band gap (∼3%). Our results highlight that the complex Cr–O–Cr pathways in these systems are susceptible to modest values of lattice strain, where distortions/tilts of the octahedra lead to variations in their electronic and magnetic properties. This work will thus encourage future investigations on the effects of lattice strain on strongly correlated electron phenomena in orthochromites.

Tunable lasers can change lasing wavelength within a certain range and have potential applications in the fields of optical communication, spectral analysis, and medical equipment. Multiple tunable lasers based on responsive photonic crystals (RPCs) are particularly important due to their tunable lasing action under diverse external stimuli. Herein, we demonstrate dually switchable lasing emission in the PRC cavity under the stimuli of temperature and solvent. When the RPC cavity is heated from room temperature to 80 °C, lasing emission is tuned from 645.8 nm to 637.6 nm, owing to the blueshift of the stopband of the RPC from 631 nm to 611 nm. Moreover, reversible switching of lasing wavelength could be achieved by exposing the RPC cavity to different solvents. When the RPC cavity is exposed to 40% acetaldehyde, the lasing wavelength is switched from 607 nm to 639 nm with the change of the stopband from 581 nm to 628 nm. Notably, the lasing wavelength could return from 639 nm to 607 nm under further exposure to tetrahydrofuran, owing to the recovery of the stopband from 628 nm to 581 nm. The dually switchable lasing action is attributed to the fact that the lasing wavelength is always located at the low-energy bandedge in the RPC cavity due to the bandedge effect. This study provides a robust strategy to tune the lasing wavelength in the RPC cavity by the stimuli of temperature and solvent, which will be a perspective in the construction of multiple switchable organic solid-state lasers.

Perovskite manganites exhibit unique phenomena such as phase diversity and colossal magnetoresistance (CMR), originating from the strong interplay between charge, spin, orbital, and lattice degrees of freedom. In this review, we discuss intrinsic mechanisms, including double exchange (DE), electron–phonon interactions, polaron formation, and Griffiths phases, as well as extrinsic factors such as grain boundaries, strain, and spin-polarized tunneling. By integrating experimental data from the literature, we demonstrate how these contributions collectively govern the metal–insulator transition and magnetotransport response. This review highlights the dual significance of bulk manganites as both large-scale synthesizable systems and rich platforms for fundamental physics, while also underscoring their relevance to modern applications in spintronics and magnetic sensors.

The morphology of the active layer has a significant impact on the performance of organic solar cells (OSCs). However, building a reliable and quantifiable relationship between the molecular structure design and the film morphology is hindered by the complex composition and interactions in the bulk-heterojunction blend. In this study, we designed and synthesized a series of non-fullerene acceptors, TTTPs, by precisely modulating the side chains at distinct positions to systematically investigate the influence of side-chain length on the blend morphology. To quantify the relation, we used fractal dimension (D_f) to assess the connectivity between the inter-acceptor domains and analyze the phase separation scale of the blend film. Among the TTTP series, TTTP2 with a butyl chain on the diphenylamine and a branched 2-butyloctyl chain on the thieno[3,2-b]pyrrole exhibited a D_f value of 2.08 and moderate domain sizes, leading to well-extended acceptor crystalline domains dispersed within a matrix of donor/acceptor intermixed amorphous domains, ensuring adequate donor/acceptor interfaces for charge separation and continuous channels for carrier transport. Other TTTP acceptors with varied side-chain lengths exhibited larger D_f values, characterized by more agglomerated crystalline domains. The optimal morphology in PBDB-T:TTTP2 is beneficial for balanced carrier transport, reduced charge recombination, and minimized voltage loss. As a result, OSCs based on PBDB-T:TTTP2 achieved a champion power conversion efficiency of 14.0%, which was much higher than those of its counterparts, ranging from 5.1% to 10.0%.

In this work, we address the challenge of designing versatile luminophores that maintain their emissive properties across various phases, including solutions and solid states (dual-state emission, DSE). We report the synthesis and detailed characterization of a series of Twisted Intramolecular Charge Transfer (TICT)-type luminophores with D–A–D molecular geometries composed of triphenylamine (TPA) or dimethylphenylamine fragments as donors (D) and aromatic ortho-substituted aldehydes as acceptors (A). In solutions, they exhibit polarity-dependent solvatochromism, with emissions spanning 500–600 nm. Importantly, their luminescence persists even in restrictive environments, such as crystalline, aggregated states, mechanically treated solids, and solid polymer matrices (PMMA). This durable condensed-phase luminescence results from their non-planar structure, particularly the ortho-substituted acceptor and propeller-shaped donor components, which effectively hinder stacking interactions linked to aggregation-induced quenching (AIQ), leaning more toward characteristics similar to aggregation-induced emission (AIE). Crystallographic data and theoretical calculations confirm the presence of twisted biaryl D–A fragments with D–A angles of 41–45°, a structural feature vital for preventing efficient solid-state stacking. Additionally, we find that these luminophores can undergo further twisting, showing a mechanochemically induced batochromic shift in luminescence (mechanochromism). The most sterically hindered compound consistently exhibits higher photoluminescent quantum yields under various conditions. Our results, supported by structural analysis, suggest that multi-state luminescence is a common trait among D–A–D-type twisted molecules and has significant potential for future development.

The development of high-performance microwave dielectric ceramics requires precise control of both intrinsic and extrinsic factors governing dielectric response. This work systematically investigates aliovalent ion doping (Na⁺, Ca²⁺, Al³⁺, Ge⁴⁺, Nb⁵⁺) in LiMg_0.5Ti_0.5O₂ ceramics to establish composition-structure–property relationships. First-principles calculations reveal enhanced electron density in [Li/Ti/MgO₆] octahedra across all doped systems, indicating improved polarization characteristics. Experimental results demonstrate that Al³⁺ doping achieves optimal performance by completely suppressing secondary phases, enhancing densification at reduced sintering temperature (1225 °C), and strengthening bond energy. The Al³⁺-modified ceramic exhibits superior properties: Q × f = 124 535 GHz, ε_r = 15.99, and τ_f = −20.5 ppm °C⁻¹. Comparative analysis identifies the critical role of bond energy in controlling τ_f, while lattice vibration damping governs dielectric loss. This study not only identifies Al³⁺ as the optimal dopant for LiMg_0.5Ti_0.5O₂ ceramics but also provides fundamental insights into designing thermally stable microwave materials through crystal chemistry engineering.