The morphology modulation of graphene is essential for exploring its physical properties and enabling functional applications. However, the morphology of graphene is highly sensitive to various experimental factors during the chemical vapor deposition growth process. Here, we report the growth of single-crystal spiral graphene on a dynamic, non-equilibrium liquid Cu–Ni alloy substrate. The as-grown spiral graphene exhibits excellent uniformity and crystallinity with a Bernal stacking configuration, while the number and chirality of the spiral branches are randomly distributed. Spiral graphene featuring one to six spiral branches has been successfully synthesized. Moreover, experimental evidence confirms that the spiral branches follow a surface-mediated growth mechanism and are located beneath the first graphene layer. The spiral morphology arises from the heterogeneous distribution of active carbon species, driven by the synergistic interplay of substrate surface fluidity, dynamic Cu–Ni interdiffusion, the high catalytic activity of Ni, and high H2 partial pressure. This study not only provides new insights into the formation mechanism of unconventional graphene structures on liquid alloy substrates but also highlights the substantial potential of liquid alloys as growth platforms for two-dimensional materials, while the resulting broken-symmetry spiral structure may offer opportunities for future spintronic exploration.
Layered oxide cathodes are attractive for sodium-ion batteries because of their high capacity, yet their practical deployment is limited by voltage decay and capacity fading due to structural degradation and interfacial instability. Herein, using O3-NaNi1/3Fe1/3Mn1/3O2 (NFM) as a model cathode, we develop a penetrative Zr regulation strategy that integrates bulk lattice anchoring with interfacial Na+ conduction through spatially differentiated Zr chemistry. Structural and chemical analyses reveal spatial partitioning of Zr species between the bulk lattice and interfacial region of NFM. The incorporated Zr4+ preferentially occupies transition-metal (TM) sites, forming strong Zr–O bonding that reinforces local oxygen coordination and expands Na-layer spacing, thereby mitigating irreversible structural evolution and facilitating Na+ migration. Meanwhile, surface-enriched Zr species are converted in situ into an approximately 8 nm Na2ZrO3 ion-conductive interfacial layer during calcination, which enables rapid Na+ transport while shielding active cathode particles from direct electrolyte attack. The modified NFM cathode exhibits markedly enhanced electrochemical stability benefiting from this dual bulk-interface regulation, and enables stable operation in presodiation-free full cells, retaining 84.4
Endowed with flexible structure and excellent actuation performance, artificial muscles have emerged as core components in cutting-edge fields including bionic medicine, wearable exoskeletons, and humanoid robots, boasting immense development prospects. However, conventional electrochemical artificial muscles rely on liquid electrolytes, which have inherent drawbacks such as poor processability for encapsulation, high leakage risks, and inadequate biocompatibility, severely limiting their application in advanced domains. Therefore, solid-state electrolytes with high ionic conductivity and good biocompatibility are urgently required to advance the practical application of artificial muscles. Herein, a polyvinyl alcohol-polyacrylic acid hydrogel electrolyte was fabricated and integrated with twisted carbon nanotube yarns by ultraviolet curing, thus successfully constructing an all-solid-state artificial muscle unit with high actuation performance. Even after undergoing mechanical deformation treatments such as weaving and knotting, the unit maintained structural integrity without significant attenuation of actuation performance. Experimental results demonstrated that it achieved a maximum contractile stroke of 16
Balancing mechanical properties, corrosion resistance, and soft magnetic performance in soft magnetic materials (SMMs) remains a fundamental challenge. This study reports a novel face-centered cubic (FCC) Fe40Co35Ni15-Al3Ta2Cr5 (at.
Silk fibroin (SF) hydrogels hold great potential in regenerative medicine; however, their clinical application in scenarios requiring a long-term soft matrix, such as traumatic brain injury (TBI) repair, has been severely limited by their progressive stiffening due to excessive β-sheet assembly. To address this, we propose an innovative dopamine (DA)-mediated synergistic topological entanglement strategy. By constructing an SF-DA/gelatin-DA composite hydrogel (SG), we achieved long-term regulation of SF assembly dynamics at the molecular level. This system ingeniously integrates multiscale interactions, including covalent cross-linking, net cationic electrostatic repulsion, hydrogen bonding, and π–π stacking, which enables stable maintenance of brain-tissue-matched soft mechanical properties (∼1.7 kPa) over three weeks under physiological conditions. In vitro studies confirmed that this steady soft matrix specifically guides the neuronal differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and promotes the expression of synapse-associated markers through cellular mechanotransduction. In a rat TBI model, the SG hydrogel effectively enhanced endogenous neuroregeneration, axonal myelination, and structural integration of the lesion area, leading to significant recovery of motor and cognitive functions. By addressing the long-standing challenge of soft mechanical instability in silk-based biomaterials, this work enables broader application of SF materials in scenarios that demand a durably soft matrix or interface.
